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Diagnosis, Pathophysiology and Treatment of Photophobia
Abstract
Photophobia, an abnormal intolerance to light, is associated with a number of ophthalmic and neurologic conditions. In the presence of normal neurologic and ophthalmologic examinations, the most common conditions associated with photophobia are migraine, blepharospasm, and traumatic brain injury. Recent evidence indicates that the intrinsically photosensitive retinal ganglion cells play a key role in the pathophysiology of photophobia. Although pharmacologic manipulation of intrinsically photosensitive retinal ganglion cells and the neural pathways that mediate photophobia may be possible in the future, current therapies are directed at the underlying cause of the photophobia and optical modulation of these cells and pathways.
... Photophobia is defined as an abnormal intolerance to normal light levels. [16][17][18] Photophobia is probably a response to protect the retina from the light stimulus, as the threshold is lowered from baseline after concussion. [18,19] Photophobia is one the most common symptoms in both acute and chronic phases of concussion. ...
... [16][17][18] Photophobia is probably a response to protect the retina from the light stimulus, as the threshold is lowered from baseline after concussion. [18,19] Photophobia is one the most common symptoms in both acute and chronic phases of concussion. It has gained more attention in recent years, partly because of the number of veterans returning from Iraq and Afghanistan with TBI and the increased awareness of sports-related TBI. ...
... [23] A large contribution to prolonged post-traumatic photophobia may be related to the comorbidity of migraine-like headache after TBI. [18] Furthermore, patients tend to be particularly sensitive to artificial indoor light and all kinds of electronic screens. [18] Patients often need to dim the light intensity or modify the hue settings. ...
Purpose of Review
Concussion frequently results in visual symptoms, necessitating careful neuro-ophthalmic examination. Both afferent and efferent visual systems are sensitive to brain injury. The present review focuses on the pathophysiology, clinical presentations, examinations, management, and future directions regarding visual disturbances after concussion.
Recent Findings
Photophobia is common in both acute and chronic concussion. Abnormalities of accommodation, convergence, saccades, and smooth pursuits can result in blurred vision, double vision, and difficulty with near work. Vision-based testing is crucial in the detection of concussion. Retinal nerve fiber layer thickness measurement may elucidate the risk of structural and functional sequelae. Patients presented with visual field loss or cranial neuropathies require evaluation for structural lesions.
Summary
Proper neuro-ophthalmic examination is instrumental in clinical decision-making for the diagnosis and management of concussion, as well as directing future investigations on preventing long-term complications.
... Through the pterygopalatine ganglion, this causes ocular vasodilation and activation of ocular trigeminal afferents through the trigemino-autonomic reflex [85]. These afferents then project to the trigeminal nucleus caudalis, the thalamus, and to the cortex [85,86]. The trigeminal system is key in the pathophysiology of photophobia as it is very closely linked to pain sensation [85]. ...
... These cells, also through the optic nerve, project directly to the thalamus which is also receiving intracranial nociceptive input. The thalamus receives light and pain information, which is then projected to sensory and association cortices [85,86]. The pathway involving the thalamus is particularly interesting because of the role of the thalamus for multiple sensory integration [85,86]. ...
... The thalamus receives light and pain information, which is then projected to sensory and association cortices [85,86]. The pathway involving the thalamus is particularly interesting because of the role of the thalamus for multiple sensory integration [85,86]. This pathway could explain the photophobia seen in patients with meningitis or sub-arachnoid hemorrhage [85]; -The third pathway also involves intrinsically photosensitive regular ganglion cells, but through projections that do not involve the optic nerve. ...
Photosensitivity or “visual sensitivity” is in the literature used in different ways: (1) the focal or generalized epileptiform EEG reaction to Intermittent Photic Stimulation (IPS) or other visual stimuli, so called photoparoxysmal response or PPR; (2) visual stimuli that provoke seizures in everyday life, such as flickering sunlight, TV, videogames or striped patterns; and (3) sensitivity to lights in terms of ocular discomfort or photophobia. The variability in photic driving as physiological visual evoked responses has intrigued scientists since the use of IPS in EEG clinical research and gave insight into pathophysiological mechanisms.
... Although occasionally reported in isolation, photosensitivity is commonly seen in patients with PTH and is frequently associated with migraine-type headaches. 23 The primary difference between PTH and migraine is that the PTH is initiated from an mTBI, whereas the migraine is possibly initiated by chemical imbalances, nerve communication errors, and blood vessel damage and can be triggered by hormonal, emotional, or physical causes. 24 Similarities, however, between the classic migraine and PTH include headache, nausea, dizziness, insomnia, and many more diverse symptoms. ...
... 54 Of interest, certain features are shared between TBI and DES, including predilection to light sensitivity. 17,23,54,59 Therefore, when patients with TBI present with eye pain in the absence of ocular surface damage or tear film disruption, clinicians should consider the possibility of NOP. ...
... Such ipRGC axons project to the OPN, which then lead downstream to the SSN causing ocular vasodilation and activation of ocular trigeminal afferents, which are heavily expressed in blood vessels (figure, D). 60,61 These afferents further project to the trigeminal nucleus and function in the relaying of sensory information to the face that in response to light and pain stimuli. 23,60 Sleep disturbance in subjects with mTBI ...
The majority of traumatic brain injury (TBI) patients are classified as having a mild traumatic brain injury (mTBI). Despite being categorized as mild, these individuals report ongoing and complex symptoms, which negatively affects their ability to complete activities of daily living and overall quality of life. Some of the major symptoms include anxiety, depression, sleep problems, headaches, light sensitivity, and difficulty reading. The root cause for these symptoms is under investigation by many in the field. Interestingly, several of these symptoms such as headaches, ocular pain, light-sensitivity, and sleep disturbances may overlap and share underlying circuitry influenced by the intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells are light-sensing, but non-image forming, and they influence corneal function, pupillary constriction, and circadian rhythm. In this review, we discuss these symptoms and propose a role of the ipRGCs as at least one underlying and unifying cause for such symptomology.
... Photophobia is defined broadly as a sensory state in which light causes discomfort or pain in the eye or head, or that light causes an avoidance reaction (e.g., seeking to be or remain in darkness), even without the presence of overt pain (Digre & Brennan, 2012;Katz & Digre, 2016). If protective blinking evolved with the first terrestrial vertebrates 375 M years ago (Aiello et al., 2023), if ipRGCs are the most ancient of our five photoreceptors (Davies, Hankins, & Foster, 2010), and if light-induced pain evolved to discourage looking at the sun (Fishman, 2017), then the connection between the PBR and photophobia could be a very old one. ...
... It is important to note that photophobia is not a disease; rather it is a symptom in association with a disorder. The disorders and conditions associated with photophobia fall into four general categories (Albilali & Dilli, 2018;Digre & Brennan, 2012;Katz & Digre, 2016;Kooij & Bijlenga, 2014;Wu & Hallett, 2017): ...
... Dry eye is a multifactorial ocular surface disease [8]. Montes et al. indicted that patients with dry eye have unstable tear films and irregular corneal surfaces, which significantly increase optical aberration [9] and reduce the retinal imaging quality, further inducing glare disabilities, photophobia [10][11][12][13], and contrast sensitivity(CS) degeneration [14]. Rolando et al. found that the CS of dry eye patients is 35% to 70% lower than that of subjects with normal eyes [15,16]. ...
... Activated stimulation of intrinsically photosensitive retinal ganglion cells has been shown to reduce the uncomfortable symptoms of anti-glare and also improve contrast quality [18]. Filtering out 480 nm or 620 nm light beams showed initial anecdotal efficacy in patients with dry eye or any syndromes which were similar to dry eye patients, such as photosensitive epilepsy, post-traumatic photosensitivity, or eye strain [10]. However, the FL-41 lens that also filters out the 480 nm band does not achieve the same effect, indicating that the manufacturing process of the lens still affects the results of the dependent term. ...
Purpose
Glare visual acuity and contrast sensitivity are important indicators of visual quality. Studies have shown that the glare visual acuity and contrast sensitivity in dry eye patients tend to degenerate, further affecting their quality of life. The objective of this study was to investigate the effect of notch filters on glare VA and contrast sensitivity in patients with dry eye or with dry eye syndrome.
Method
36 subjects in the 20‒65 age group were diagnosed as having dry eye disease or perceived dry eye syndromes themselves who were included after the initial screening with the OSDI questionnaire, and one was subsequently excluded as they had undergone retinal detachment surgery. Finally, 35 subjects (14 male and 21 female) with a mean age of 40.66 ± 15.62 years participated in this study. All subjects wore their habitual prescriptions and four different filter lenses (namely 480, 620, dual 480 & 620 notch filter, and FL-41 tinted lens), and measured the parameters of glare visual acuity and contrast sensitivity using CSV-1000 and sine wave contrast test (SWCT), respectively. Student t-test and Repeated measurement analysis (R-ANOVA) were utilized by using SPSS 26.0 software.
Results
A dual-wavelength 480 & 620 nm optical notch filter had a significant anti-glare effect decreasing glare disabilities or discomfort, and leading to better visual quality, the same effect was also shown on a 480 nm notch filter lens. All participants showed a significant difference among the baseline, three notch filters (480 nm, 620 nm, dual-wavelength 480 & 620 nm), and FL-41 tinted lens were used on SWCT_A (1.5 cpd, F = 3.054, p = 0.019) and SWCT_E (18 cpd, F = 2.840, p = 0.049); but did not show statistical different on SWCT_B (3 cpd, F = 0.333, p = 0.771), SWCT_C (6 cpd, F = 1.779, p = 0.159), and SWCT_D (12 cpd, F = 1.447, p = 0.228).
The baseline showed the best visual performance on CS at a low spatial frequency (SWCT_A, 1.5 cpd), any filter might reduce the contrast sensitivity at low spatial frequencies in the clinical trial, whereas 480 nm notch filter showed the best effectiveness on CS at a high spatial frequency (SWCT_E, 18 cpd), the FL-41 lens that also filters out the 480 nm band does not achieve the same effect. Moreover, patients with dry eye or those older than 40 years old preferred optical multilayer notch filters to FL-41 tinted lenses.
Conclusion
The 480- & 620-nm dual-wavelength and 480-nm single-wavelength notch filters have the best effect on the glare visual acuity and contrast sensitivity (CS) at high spatial frequencies in dry eye patients. The 620-nm notch filter performs better in CS at low and mid-low spatial frequencies; the FL-41 tinted lens performs poorly for glare VA and CS spatial frequencies examination. Patients with glare disabilities or CS disturbance at high spatial frequencies may choose a 480-nm notch filter lens, and patients who have CS disturbance at low spatial frequencies may consider a 620-nm notch filter for the prescription.
... Photophobia is the abnormal sensitivity to light and majorly affect patients with more cone cells [2]. The symptom of photophobia presents in two forms, that is the ocular and the central type which is majorly associated with blepharospasm and migraines [3]. However, for ocular presentation, the patients will always complain of intolerance to light both the artificial and the natural light. ...
... The threshold for light sensitivity varies among patients and those with migraines do experience a lower threshold as opposed to those with dry eye and corneal neuropathy [3]. At the same time, the state of retinal adaptation will dictate an individual sensitivity to light. ...
Aim: To assess the implication of tinted Plano lenses in photophobia management.
Methods: This was a cross-sectional study among eye care providers in Kenya in which data was collected through online surveys. Three main themes were derived from the study;
management of the underlying cause, impact of dispensing tinted Plano lenses and addressing astigmatism. Data was analyzed thematically.
Results: The response rate was (100%) with almost three quarter of the respondents (70%) working in private setups. Majority of the respondents (80%) agreed that uveitis,
cyclitis, iritis, and blepharitis are strongly associated with photophobia (p=0.001). Although most respondents (78%) were dispensing tinted Plano lenses for patients with visual acuity
of 6/6, the patients would still come back with similar complains. Only 24% of the respondents agreed that astigmatism was strongly associated with photophobia (p=0.002). Most
respondents agreed that if a patient astigmatic status is corrected even with clear lenses then patients will rarely complain of photophobia. This is more cost effective as tinted Plano
lenses remain expensive for majority who presents with photophobia.
Conclusion: Photophobia is mismanaged and there is a dire need for eye care providers to properly evaluate the cause of photophobia before deciding on a cost effective
management plan. Notwithstanding, eye care professionals should correct any slight astigmatism as it is a major problem that is rarely factored in by most eye care professionals
but majorly contributes to photophobia.
... The tints may vary depending upon the effect of dystrophy on visual function and the comfort of the patient. [25,26] A study has reported improvement of visual acuity with red-tinted glasses in a patient with cone dystrophy. [26] Michaelides et al. [22] also suggested that tints were more commonly preferred by patients with cone-rod dystrophies. ...
... [25,26] A study has reported improvement of visual acuity with red-tinted glasses in a patient with cone dystrophy. [26] Michaelides et al. [22] also suggested that tints were more commonly preferred by patients with cone-rod dystrophies. In our study, the patients with cone-related dystrophies predominantly benefited from ET-40 dark gray tint, followed by ET-28 brown tint and clip-on filters. ...
Purpose:
The aim of this study was to elucidate the type of low vision devices (LVDs) prescribed for patients with cone dystrophy, cone-rod dystrophy, and rod-cone dystrophy and to analyze the visual improvement with the devices.
Methods:
A retrospective review of 300 electronic medical records of patients with cone dystrophy, cone-rod dystrophy, and rod-cone dystrophy referred to the low vision care (LVC) clinic for the first time between 2014 and 2016 at a tertiary eye care center was done. Collected data included the demographic profile of patients, details of LVDs, and best-corrected vision.
Results:
Out of 300 patients, 62.6% (n = 188) were male and 37.3% (n = 112) were female. Of the cases, 50% (n = 150) had cone-rod dystrophy, 45% (n = 135) had cone dystrophy, and 5% (n = 15) had rod-cone dystrophy. The most commonly prescribed LVD was SEE-TV binocular telescope (n = 6, 2.0%) for distance and dome magnifier (n = 60, 20%) for near. ET-40 dark grey tint (20.6%) was preferred for managing photophobia. There was a statistically significant difference in both distance and near visual acuities with LVDs (P < 0.05) in all categories, except rod-cone dystrophy.
Conclusion:
Early diagnosis with appropriate prescription of LVDs including tints helps in achieving good quality of vision in patients with cone-related dystrophies.
... Post-concussion syndrome can develop after head trauma, even after mTBI, due to neurophysiological influences and psychological factors that may exaggerate or increase the persistence of chronic symptoms due to stressful life situations or depression. 1 Head trauma that induces a concussion or postconcussion syndrome is associated with various visual symptoms in 69-82% of patients. 11 Researchers suggest that trauma can lead to structural changes, irritation or injury to specific painsensitive areas in the brain that could be involved in increased light sensitivity and photophobia. Thus, the brain's ability to adjust to numerous different lights is diminished, which results in symptoms such as eye strain, headaches, and a lack of concentration. 1 Although photophobia is caused mainly by light, some blind patients have been documented to have photophobia. ...
... This is another explanation why these patients find the light brighter and more painful than non-injured individuals. 11 Optical filters have been utilised in the treatment of photophobia. Rose-coloured tinted lenses, referred to as FL-41 tinted lenses, were found to successfully reduce migraine frequency in over 50% of children. 1 These glasses effectively filter out the noxious blue-green light emitted by fluorescent lighting in the visible light spectrum. ...
Photophobia is considered the second most common symptom of both concussion and post-concussion syndrome. Soldiers on duty experience photophobia after blast-related concussions or mild traumatic brain injury in 60–75% of instances. In addition, soldiers report other symptoms, such as asthenopia, squinting, dry eyes and headaches, for which they are considered to be at high risk. According to the International Brain Injury Association, some concussed patients report indirect symptoms such as multi-tasking difficulties, dizziness, vertigo, and fatigue. Moreover, some concussed individuals experience photophobia for approximately 6 months or indefinitely. We present the case of a 23-year-old soldier who presented with severe photophobia after a mild traumatic head injury. His photophobia was alleviated after the administration of topical anaesthetic drops in the eyes in the absence of any ocular surface pathology. He was diagnosed with post-concussion syndrome light sensitivity and was managed successfully with rose-coloured special photophobia glasses tinted with FL-41. Photophobia is a common neurological symptom in military personnel that needs more attention as it affects body and mind. We have reported an uncommon pathway of photophobia, which may unveil an unrecognised mechanism that may play a role in post-concussion photophobia.
... In migraine, mechanisms likely involve hypersensitivity of the intrinsically photosensitive retinal ganglion cells that may project to pain processing regions of the thalamus, and hypersensitivity, structural remodeling, and altered functional connectivity of visual processing regions in the brain. [26][27][28][29] Functional and structural brain imaging studies in PPTH are required to determine if there are similar findings in PPTH. Furthermore, photosensitivity is considered a relatively common symptom of mTBI, even in the absence of PTH. 30 However, in a study of 447 soldiers with mTBI, those with PTH (n ¼ 198) were more likely to have photophobia compared with soldiers who had mTBI but no PTH (62.7% vs. 49.3%, ...
... 19 Further research is needed to determine the extent to which photosensitivity following mTBI is due to the TBI itself versus being associated with PTH. 28 Hyperacusis symptoms were more severe in those with PPTH compared to migraine in this study. Although it is quite likely that hyperacusis symptom severity in PPTH is at least similar to that found in migraine, further studies are needed to determine if in fact they are more severe in PPTH. ...
Background and Objective
Symptoms of persistent post-traumatic headache (PPTH) most often resemble those of migraine, including the presence of photo-, phono-, and cutaneous hypersensitivities. The severity of these hypersensitivity symptoms in those with PPTH compared to those with migraine has yet to be fully elucidated. The objective of this study was to compare symptoms of sensory hypersensitivities between PPTH, migraine, and healthy controls (HCs). Further defining characteristics of PPTH and its similarities to migraine might assist with developing future diagnostic criteria for PPTH and provide insights into PPTH mechanisms.
Methods
This analysis included 56 individuals with PPTH attributed to mild traumatic brain injury, 30 with migraine, and 36 HCs. To assess sensory hypersensitivities, all subjects completed the Allodynia Symptom Checklist-12, the Photosensitivity Assessment Questionnaire, and the Hyperacusis Questionnaire. Differences among groups were assessed using Fisher’s exact test, Kruskal–Wallis, or Mann–Whitney U test.
Results
PPTH and migraine groups had greater severity of cutaneous, photo-, and phono-hypersensitivity symptoms compared to HCs. There were no statistically significant differences between the PPTH and migraine groups for cutaneous allodynia (median [first quartile, third quartile]; PPTH: 4.0 [2.0, 7.0]; migraine: 5.0 [3.0, 8.0]; p = 0.54) or photosensitivity severity (PPTH: 5.0 [2.0, 7.0]; migraine: 5.0 [2.0, 6.0]; p = 0.53). Those with PPTH had higher hyperacusis scores compared to those with migraine (PPTH: 23.0 [17.0, 31.0]; migraine: 13.5 [9.0, 24.0]; p = 0.001).
Conclusion
Sensory hypersensitivity symptoms among individuals with PPTH are at least as severe as those experienced by people with migraine. Results further confirm symptom similarities between PPTH and migraine and could suggest that PPTH and migraine have a partially shared underlying pathophysiology.
... The headache sensation can vary from sharp throbbing to dull. The onset of headaches can be gradual or sudden, and the duration can range from one hour to a day (Katz & Digre, 2016). ...
Good quality sleep is an important element in maintaining individual health and well-being. Even so, some individuals often experience sleep disorders which can have a negative impact on health. One of the health problems that is often associated with sleep disorders is primary headaches, including migraine headaches and tension headaches. This study aims to determine the relationship between sleep quality and primary headache classification. Data collected in this research used a survey method. This research applies an analytical approach with a cross-sectional design, where data collection is only carried out once. Data were collected through questionnaires evaluating sleep quality using the Pittsburgh Sleep Quality Index and Headache Screening Questionnaire, and data were analyzed using the Chi-square test. The population in this study was 189 students using the Simple Random Findings Technique with 100 samples. This study shows a significant correlation between poor sleep quality and the incidence of migraines and tension headaches, with test results showing a P value of 0.001<0.005. There is a correlation between sleep quality and the incidence of migraines and tension headaches.
... Dry eye patients commonly complain of tactile symptoms pertaining to pain and discomfort of the eyes; visual symptoms like light sensitivity, glare, and blurry vision are also prominent in dry eye condition. (7)(8)(9)(10)(11)(12)(13) However, it is unclear to what extent various visual symptoms differentiate dry eye from other eye conditions. Previous studies have shown that dry eye commonly co-exists with cataracts (40-80% of patients scheduled to have cataract surgery) (14) , (15) and glaucoma (20-59% of glaucoma patients). ...
Background: The diagnosis of dry eye and other common ophthalmological conditions can be supported using patient reported symptoms, which is increasingly useful in contexts such as telemedicine. We aim to ascertain visual symptoms that differentiate dry eye from cataract, glaucoma, or glaucoma suspects.
Methods: Adults with dry eye, glaucoma, cataract, and suspected glaucoma (controls) completed a questionnaire to rate the frequency and severity of 28 visual symptoms. Univariate, followed by multivariable logistic regression with backward stepwise selection (p<0.05), determined the individual symptoms and set of symptoms best distinguishing dry eye from each of the other conditions.
Results: Mean age of 353 patients (94 glaucoma suspect controls, 79 glaucoma, 84 cataract, and 96 dry eye) was 64.1 years (SD=14.1); 67% were female and 68% White. Dry eye patients reported more frequent light sensitivity (OR=15.0, 95% CI=6.3-35.7) and spots in vision (OR=2.8, 95% CI=1.2-6.3) compared to glaucoma suspect controls. Compared to glaucoma patients, dry eye patients experienced more frequent light sensitivity (OR=9.2, 95% CI=2.0-41.7), but less frequent poor peripheral vision (OR=0.2, 95% CI=0.06-0.7), difference in vision between eyes (OR=0.09, 95% CI=0.01-0.7), and missing patches of vision (OR=0.06, 95% CI=0.009-0.3). Compared to cataract patients, dry eye patients reported more frequent spots in vision (OR=4.5, 95% CI=1.5-13.4) and vision variability across the week (OR=4.7, 95% CI=1.2-17.7) and were less likely to report worsening vision (OR=0.1, 95% CI=0.03-0.4) and blindness (OR=0.1, 95% CI=0.02-0.8).
Conclusion: Dry eye can be distinguished from various ocular conditions using visual symptoms, though the symptoms that best distinguish dry eye differ across comparisons. Differentiating how patients visually perceive common eye diseases may be used in a variety of clinical settings to rule out specific conditions.
... In particular, we would like to propose the concept of "keratoneuropathy" which can be further differentiated into neurotrophic and neuralgic corneal diseases [5,6]. In Table 1, we have provided a list of (chronic) keratoneuropathies along with the hypothetical mechanisms and clinical pictures. ...
Ocular comfort is maintained by tear film adequacy, stability, and flow. Sjögren's syndrome, meibomian gland dysfunction, and conjunctivochalasis are the respective ocular surface disease prototypes, respectively; and the umbrella expression, dry eye diseases cover them. We introduced an otherwise primary keratoneuropathy as the fourth independent mechanism for ocular discomfort and pain. We differentiated keratoneuropathy into keratoneuralgic and keratoneurotrophic states, as well.
... [29][30][31] A suggested approach to the diagnosis of light sensitivity and photophobia comprises the assessment of ocular and neurologic causes. 32 Treatment options to relieve symptoms include intense treatment of dry eye, coloured tints, and sunglasses outdoors. 32 ...
Clinical relevance:
Vision-related problems can be part of longstanding sequelae after COVID-19 and hamper the return to work and daily activities. Knowledge about symptoms, visual, and oculomotor dysfunctions is however scarce, particularly for non-hospitalised patients. Clinically applicable tools are needed as support in the assessment and determination of intervention needs.
Background:
The purpose of this study was to evaluate vision-related symptoms, assess visual and oculomotor function, and to test the clinical assessment of saccadic eye movements and sensitivity to visual motion in non-hospitalised post-COVID-19 outpatients. The patients (n = 38) in this observational cohort study were recruited from a post-COVID-19 clinic and had been referred for neurocognitive assessment.
Methods:
Patients who reported vision-related symptoms reading problems and intolerance to movement in the environment were examined. A structured symptom assessment and a comprehensive vision examination were undertaken, and saccadic eye movements and visual motion sensitivity were assessed.
Results:
High symptom scores (26-60%) and prevalence of visual function impairments were observed. An increased symptom score when reading was associated with less efficient saccadic eye movement behaviour (p < 0.001) and binocular dysfunction (p = 0.029). Patients with severe symptoms in visually busy places scored significantly higher on the Visual Motion Sensitivity Clinical Test Protocol (p = 0.029).
Conclusion:
Vision-related symptoms and impairments were prevalent in the study group. The Developmental Eye Movement Test and the Visual Motion Sensitivity Clinical Test Protocol showed promise for clinical assessment of saccadic performance and sensitivity to movement in the environment. Further study will be required to explore the utility of these tools.
... Photophobia, a high sensitivity to light (photosensitivity), is a common sensory disturbance seen in several neurological conditions, especially migraine which is the third most prevalent disease worldwide (1,2). There are ∼70-80% of migraineurs experiencing photophobia (3). ...
Background:
Hypersensitivity to light is a common symptom associated with dysfunction of the occipital region. Earlier studies also suggested that clinically significant right-to-left shunt (RLS) could increase occipital cortical excitability associated with the occurrence of migraine. The aim of this study was to investigate the relationship between RLS and photosensitivity.
Methods:
This cross-sectional observational study included the residents aged 18-55 years living in the Mianzhu community between November 2021 and October 2022. Photosensitivity was evaluated using the Photosensitivity Assessment Questionnaire along with baseline clinical data through face-to-face interviews. After the interviews, contrast-transthoracic echocardiography (cTTE) was performed to detect RLS. Inverse probability weighting (IPW) was used to reduce selection bias. Photosensitivity score was compared between individuals with and without significant RLS using multivariable linear regression based on IPW.
Results:
A total of 829 participants containing 759 healthy controls and 70 migraineurs were finally included in the analysis. Multivariable linear regression analysis showed that migraine (β = 0.422; 95% CI: 0.086-0.759; p = 0.014) and clinically significant RLS (β = 1.115; 95% CI: 0.760-1.470; p < 0.001) were related to higher photosensitivity score. Subgroup analysis revealed that clinically significant RLS had a positive effect on hypersensitivity to light in the healthy population (β = 0.763; 95% CI: 0.332-1.195; p < 0.001) or migraineurs (β = 1.459; 95% CI: 0.271-2.647; p = 0.010). There was also a significant interaction between RLS and migraine for the association with photophobia (pinteraction = 0.009).
Conclusion:
RLS is associated with photosensitivity independently and might exacerbate photophobia in migraineurs. Future studies with RLS closure are needed to validate the findings.
Trial registration:
This study was registered at the Chinese Clinical Trial Register, Natural Population Cohort Study of West China Hospital of Sichuan University, ID: ChiCTR1900024623, URL: https://www.chictr.org.cn/showproj.html?proj=40590.
... Colored glasses, on the other hand, add the color of the lenses to all things in the field of view, causing still another level of annoyance. Meanwhile, because patients tend to be dark-adapted and increase their sensitivity to light, wearing dark or colored glasses indoors is strongly discouraged from a therapy standpoint [18]. ...
We propose a smart dimming sunglasses system for individuals with photophobia, especially those who are easily irritated by light intensity. The system uses a spatial light modulator (SLM) to selectively filter light entering the eye based on the scene detection of a camera. By controlling the transmittance of each pixel on the SLM using a modulation function, the proposed sunglasses enable an automated non-linear field of view dimming and also flexible light modulation that meets the photophobic user's visual requirements. Meanwhile, an occlusion mask created on the SLM, which possesses low transmittance to block the incoming light rays, appears blurred from the eye since the focal plane is not on the SLM and blocks the light stimulation insufficiently. To solve this problem, the aperture-based expanded mask has been used in past studies, however, the excessive large expansion ratio used in this approach leads to over-blocking (occlusion leak). In this work, we build an optimization model by simulating the defocused occlusion mask and determining the effective contribution of the degraded pixels based on the occlusion efficiency of the pixel transmittance. While the non-processed mask cannot provide sufficient occlusion and the aperture-based expanded mask causes occlusion leak, our optimized mask attenuates the intensely bright areas to a proper brightness without incorrectly attenuating surrounding areas that no need to modulation.
... Individuals have different thresholds for light sensitivity, and it has been found that migraine patients tend to have lower thresholds compared to the general population (28), not only during headaches but also between attacks (29). A "light-pain matrix" (30) has been hypothesized bridging together retinal structures and various brain area found to be involved in the painful sensation of light processing reported as photophobia, such as thalamus, trigeminal nucleus, superior colliculus and the visual cortex (31). Recently, a class of retinal ganglion cells has been discovered and named intrinsically photosensitive retinal ganglion cell (IPRGC), also known as melanopsin cells (32). ...
Background
Calcitonin gene-related peptide (CGRP) plays a pivotal role in migraine physiology, not only regarding migraine pain but also associated symptoms such as photophobia. The aim of the present study was to assess monoclonal antibodies targeting CGRP efficacy not only in terms of headache and migraine frequency and disability but also in reducing ictal photophobia.
Material and methods
This is a retrospective observational study, conducted at the Headache Center–ASST Spedali Civili Brescia. All patients in monthly treatment with galcanezumab with at least a 6-month follow-up in September 2022 with reported severe photophobia during migraine attacks were included. Data regarding headache frequency, analgesics consumption, and migraine disability were collected quarterly. Moreover, patients were asked the following information regarding photophobia: (1) whether they noticed an improvement in photophobia during migraine attacks since galcanezumab introduction; (2) the degree of photophobia improvement (low, moderate, and high); and (3) timing photophobia improvement.
Results
Forty-seven patients were enrolled in the present study as they met the inclusion criteria. Seventeen patients had a diagnosis of high-frequency episodic migraine and 30 of chronic migraine. From baseline to T3 and T6, a significant improvement in terms of headache days (19.2 ± 7.6 vs. 8.6 ± 6.8 vs. 7.7 ± 5.7; p < 0.0001), migraine days (10.4 ± 6.7 vs. 2.9 ± 4.3 vs. 3.6 ± 2.8; p < 0.0001), analgesics consumption (25.1 ± 28.2 vs. 7.6 ± 7.5 vs. 7.6 ± 8.1; p < 0.0001), MIDAS score (82.1 ± 48.4 vs. 21.6 ± 17.6 vs. 18.1 ± 20.5; p < 0.0001), and HIT-6 score (66.2 ± 6.2 vs. 57.2 ± 8.6 vs. 56.6 ± 7.6; p < 0.0001) was found. Thirty-two patients (68.1%) reported a significant improvement in ictal photophobia, with over half of the patients reporting it within the first month of treatment. Photophobia improvement was more frequent in patients with episodic migraine ( p = 0.02) and triptans responders ( p = 0.03).
Conclusions
The present study confirms previous reports regarding galcanezumab efficacy beyond migraine frequency. In particular, over 60% of patients, in our cohort, documented a significant improvement also in reducing ictal photophobia. This improvement was, in most patients, moderate to high, and within the first 6 months of treatment, regardless of the clinical response on migraine frequency.
... There is evidence that FL-41 tinted lenses can improve photophobia in patients with migraine headache, but prospective data on the effect in patients with TBI-associated photosensitivity do not exist. 43 A prospective study would be needed to address this concern, with controls to avoid a confounding effect from the anticipated benefit from concurrent headache treatment. ...
Optometric visual rehabilitation therapy has been employed for a variety of visual disorders. Descriptively-named entities such as post trauma visual syndrome (PTVS), visual midline shift syndrome (VMSS), and vertical heterophoria syndrome (VHS) are frequently diagnosed by neuro-optometrists and/or behavioral optometrist in patients after stroke or head injury or in the setting of dizziness and/or headache. The scientific underpinnings of these diagnoses and treatments are weak, and published clinical studies comprise case reports and case series without comparison to control populations. Neuro-ophthalmologists are frequently questioned by patients about the utility of such treatment strategies. Many ophthalmologists and neurologists also are involved in the care of patients who carry these diagnoses and undergo these visual therapies. Involved physicians may benefit from guidance about the rationale, evidence, and level of evidence for the efficacy of these therapeutic approaches.
... Photophobia has been associated with different conditions. 39 In 2019, Ueno et al studied photophobia through electroretinography in patients with paraneoplastic retinopathy; they found a relation between autoantibody transient receptor potential cation channel, subfamily M, member 1 (Anti-TRPM1), and photophobia. 40 Due to the limited number of studies reporting this association, we present the first study describing a statistically significant association between inflammatory biomarkers with photophobia. ...
Purpose:
Ocular involvement is frequent in autoimmune diseases and even can be the first manifestation. There are multiple descriptions in the literature around the world regarding this topic. However, we evidenced a lack of studies analyzing the relationship between the ocular manifestations and systemic biomarkers, especially in Latinamerica. Therefore, this study aimed to examine the relationship between the positivity of inflammatory biomarkers and the ocular manifestations in a Colombian cohort of rheumatological patients.
Patients and methods:
We conducted an observational, descriptive, non-comparative cross-sectional study in a rheumatology center, in Bogotá, Colombia, from 2013 to 2019. We calculated a sample size of 797 patients to assess the prevalence of ocular manifestations and inflammatory biomarkers. We performed univariate analyses for categorical and continuous variables and bivariate analyses using the Chi-square and Fisher's exact test for categorical variables.
Results:
Women represented 84% of the population, and the mean age was 54.61± 15.64 years. Of 797 patients, 21.45% reported one or more ophthalmological diagnoses, being keratoconjunctivitis sicca (KCS) the most common (15.93%), followed by uveitis, and cataract (1.38%, each one). Regarding ophthalmological symptoms, 35% presented at least one, being dry eye sensation (DE) the most common (30.86%), followed by ocular pain (2.76%), red eye, and decreased visual acuity (2.63%, each one). The antibodies or inflammatory biomarkers most frequently found were antinuclear antibodies (ANAs) (35.3%), C-reactive protein (28.7%), and rheumatoid factor (27.9%). We found statistical associations between consumption of complement 3, anti-CCP, anti-RO, and anti-LA antibodies with ocular manifestations such as photophobia, DE, conjunctivitis, KCS, uveitis, retinal vasculitis, and maculopathy.
Conclusion:
Ocular manifestations are frequently found in patients with positive antibodies and inflammatory biomarkers. Our results suggest antibodies and inflammatory molecules could be biomarkers for ocular manifestations in patients with rheumatological diseases. This study provides the basis for future longitudinal studies.
... Treatment of photophobia often involves polarized lenses, tinted lenses, filters, or visors [48] in addition to migraine treatment (when present). FL-41 tinted lenses have specifically been studied and demonstrated reduction in patient sensitivity to light [49]. Currently a computerized rehabilitation program has shown promise in improving a variety of ocular motor deficits in the setting of mTBI; however, these results are pending a randomized controlled trial [50]. ...
Purpose of Review
Mild traumatic brain injury, or concussion, is a major cause of disability. Vestibular and visual dysfunction following concussion is common and can negatively affect patients’ well-being and prolong recovery. Etiologies of visual and vestibular symptoms are numerous, including ocular, neuro-ophthalmic, otologic, and neuro-vestibular conditions. Some etiologies are benign and may be treatable, while others are potentially vision or life-threatening, making a focused history and examination essential. This review offers an approach to the evaluation and treatment of the most common neuro-visual and vestibular impairments that may result from concussion.
Recent Findings
Treatment of concussion including exercise, computerized programs, transcranial magnetic stimulation, gene therapy, stem cell therapy, and nanoparticles has shown promise.
Summary
Many novel therapies are in the pipework for visual and vestibular recovery after concussion; however, the treatment mainstay remains therapy and evaluation for co-existing diseases.
... Several peripheral sensors in the anterior of the eye contain melanopsin, a photopigment that offers a light transduction mechanism that may lead to pain perception. With a peak wavelength sensitivity of 480 nm, melanopsin-based photoreception can occur in intrinsically photosensitive retinal ganglion cells (ipRGCs) and is increasingly implicated as a source for light-induced pain (28)(29)(30)(31)(32). These ipRGCs can generate their own signal independent of rod and cone involvement in response to light absorption yet can additionally receive or relay input from classical RGCs and support cells (33)(34)(35)(36). ...
Supraspinal mechanisms of pain are increasingly understood to underlie neuropathic ocular conditions previously thought to be exclusively peripheral in nature. Isolating individual causes of centralized chronic conditions and differentiating them is critical to understanding the mechanisms underlying neuropathic eye pain and ultimately its treatment. Though few functional imaging studies have focused on the eye as an end-organ for the transduction of noxious stimuli, the brain networks related to pain processing have been extensively studied with functional neuroimaging over the past 20 years. This article will review the supraspinal mechanisms that underlie pain as they relate to the eye.
... • Patients with cone and rod dystrophies have intense photophobia and dyschromatopsia -affecting their day to day activities. [1][2][3][4]9 • Tinted glasses and filters -Management of photophobia. [5][6][7][8] • No recent advancements are available to stop the progression. ...
This poster explains a study on prescribing patterns of low vision devices in patients with cone dystrophy, cone rod dystrophy and rod cone dystrophy.
... Photic blink reflex can function as an accessory pupil, further controlling retinal luminance in addition to pupil size [11]. Since this reflex has a shorter latency than the pupil light reflex, it may play a more significant role in modulating retinal luminance under both a light stimulus and a steady-state light [11,12]. Even though the TEC is such a common feature in IXT, little is known about the association between TEC and IXT, and, thus, we should explore the phenomenon more thoroughly. ...
Abstract Background This study aimed to present a simple method for evaluating transient eye closure (TEC) evoked by bright light and find the agreement between TEC and photosensitivity. We also assessed the associated factors with TEC in the patients with intermittent exotropia (IXT). Methods In this retrospective study, IXT patients were exposed to different brightness: darkness, low-intensity white light, and high-intensity white light using a near-infrared camera vision monitor system (Mon CV3, Metrovision, France). TEC was considered to be present if the subject closed his or her eyes immediately, and for more than half of the scotopic lid fissure distance in response to the high-intensity or low-intensity photopic stimulus of light, compared with lid fissure distance in the scotopic phase. We assessed the presence of photosensitivity using a questionnaire and evaluated the agreement between TEC and photosensitivity. We also investigated the sensory fusion, motor fusion, and pupil dynamic components for the existence of TEC in IXT patients. Results Sixty-one patients with IXT were included. With the new method to evaluate TEC under different light intensities, 27 (44.3%) of the 61 IXT patients showed TEC, and 34 (55.7%) did not demonstrate TEC. TEC under high-intensity white light had a strong correlation with self-reporting photosensitivity (r = 0.77). The smaller angle of deviation at near was associated with the presence of TEC, with statistical significance (p = 0.04). Normal sensory status at a distance was significantly associated with TEC (p
... [87] In individuals with co-morbid headache and light sensitivity, migraine treatments can be initiated, such as botulinum toxin A (BoNT-A) or transcutaneous electrical nerve stimulation (TENS). [ [93] Tinted lens spectacles that block out specific wavelengths of light (~480 nm) are also helpful in managing individuals with photophobia [94], including those with co-morbid migraine. [95] Importantly, individuals with ocular pain are often found to have an emotional component to their symptoms. ...
Purpose of Review
Confocal microscopy and aethesiometry have allowed clinicians to assess the structural and functional integrity of corneal nerves in health and disease. This review summarizes literature on nerves in dry eye disease (DED) and discusses how this data can be applied to DED diagnosis and treatment.
Recent Findings
Subjects with DED have a heterogeneous symptom and sign profile along with variability in nerve structure and function. Most studies have reported lower nerve density and sensitivity in aqueous tear deficiency, while findings are more inconsistent for other DED subtypes. Examining nerve status, along with profiling symptoms and signs of disease, can help categorize subjects into disease phenotypes (structural and functional patterns) that exist under the umbrella of DED. This, in turn, can guide therapeutic decision-making.
Summary
Due to the heterogeneity in symptoms and signs of DED, corneal nerve evaluations can be valuable for categorizing individuals into disease sub-types and for guiding clinical decision-making.
... Психогенный БФС считается относительно редким состоянием. В серии наблюдений пациентов с психогенными расстройствами движения (n=131) БФС или другие гиперкинезы лица составляли только 0,3% [45]. Среди прочих конверсионных гиперкинезов психогенный БФС встречался у 2-7% пациентов [46]. ...
Blepharospasm (BPS) is a variant of focal dystonia manifested by involuntary eyelid spasms with eye closure and/or increased spontaneous blinking. Along with motor symptoms, this condition is characterized by sensory, affective, and cognitive disorders. Patients with BPS are found to have changes in the basal ganglia, cerebellum, primary/secondary sensorimotor and visual areas according to functional magnetic resonance imaging. This may reflect the involvement of above regions in suppressing defective movement and sensorimotor disintegration. Botulinum toxin therapy is the most effective treatment for BPS. The advantage of Xeomin® that does not contain complexing proteins, is characterized by a low probability of antibody production, is the ability to vary between-injection intervals. Probably, botulinum toxin therapy has a pathogenetic and modifying impact on BPS.
... Aniridia is known to cause photophobia and glare due to the absence of the iris protection. [6,16] In conclusion, we report the case of a traumatic total iridectomy due to iris extrusion through a 2.75 mm cataract incision after blunt trauma, with the distinct feature of an intact IOL and capsular bag, plus peripheral remnants of cortical material in the capsular bag and anterior capsule opacity that resemble a "pseudoiris" in a dilated pupil. There have been previous publications of traumatic expulsive iridodialysis with sparing of the IOL and capsular bag, but, to the best of our knowledge, our case seems to be the first to report a "pseudoiris". ...
Blunt trauma may cause a wound in the site of the cataract incision in patients that have received this surgery, even decades after the procedure. The opening of the incision seems to avoid globe rupture, acting as a "liberating valve" We report a case of a 92-year-old woman with advanced dry macular degeneration who is referred to our department after suffering a blunt trauma in her left eye with a nightstand. She was diagnosed of a traumatic total iridectomy due to iris extrusion through a 2.75 mm cataract incision after injury and vitreous hemorrhage, sparing an intact intraocular lens and capsular bag, as well as peripheral remnants of cortical material in the capsular bag and anterior capsule opacity resembling "pseudoiris". After the vitreous hemorrhage was completely resolved she referred no photophobia. Consequently, although a bad visual acuity of the patient could mitigate patient's photophobia, we believed that her "pseudoiris" plays an important role in diminishing the possible symptoms of photophobia.
... Photophobia is a common and debilitating sensory disturbance characterized by light-induced ocular or cranial discomfort that can be accompanied by a subsequent increase in tear production and squinting responses [1,2]. The most common neurologic condition associated with photophobia is migraine, with 80%-90% of patients experiencing photophobia [3,4] both during (ictally) and in between (inter-ictally) migraine attacks [5][6][7]. ...
The purpose of this pilot study was to investigate the light-induced pupillary and lacrimation responses mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) in migraine. Ten participants with episodic migraine and normal tear production, as well as eleven visually normal controls participated in this study. Following an initial baseline trial (no light flash), participants received seven incremental and alternating red and blue light flashes. Pupillometry recording of the left eye and a 1-min anesthetized Schirmer's test of the right eye (using 0.5% proparacaine) were performed simultaneously. Intrinsic and extrin-sic ipRGC photoactivities did not differ between migraine participants and controls across all intensities and wavelengths. Migraine participants, however, had significantly lower lacrima-tion than controls following the highest blue intensity. A positive correlation was found between melanopsin-driven post-illumination pupillary responses and lacrimation following blue stimulation in both groups. Our results show that participants with self-reported photo-phobia have normal ipRGC-driven responses, suggesting that photophobia and pupillary function may be mediated by distinct ipRGC circuits. The positive correlation between mela-nopsin-driven pupillary responses and light-induced lacrimation suggests the afferent arm of the light-induced lacrimation reflex is melanopsin-mediated and functions normally in migraine. Lastly, the reduced melanopsin-mediated lacrimation at the highest stimulus suggests the efferent arm of the lacrimation reflex is attenuated under certain conditions, which may be a harbinger of dry eye in migraine.
The Visual Snow Syndrome is a neurological condition that causes flickering dots to appear across a person’s entire field of vision. Those who suffer from this syndrome report seeing an unending stream of flickering dots throughout their visual field. Although patients often experience concurrent migraines, Visual Snow Syndrome appears to be a distinct phenomenon from prolonged migraine aura. The cause of this syndrome is not yet fully understood, but it has been linked to various eye and brain dysfunctions. The aim of this work is to make improvements to the environment in which exercises affected by this condition are developed. Currently, the Visual Snow Initiative provides an online platform where it is possible to carry out a 30-day exercise cycle during which patients are shown videos with noise that simulates Visual Snow and only affects certain areas of the visual field. This video noise moves and shifts along the screen occupying different areas of the screen. The video stream is sent from the servers to the users and requires a modern and efficient internet connection. A single video file occupies about 2GB of disk space. Modern codecs that deal with compressing video and encoding it into browser-supported formats have great difficulty encoding a stream where the pixel matrix of the video is in constant motion. The purpose of this work is to reconstruct the noise that is displayed within the video files for the exercises by means of JavaScript algorithms in such a way as to reduce the download required from users to a few kilobytes and to generate client-side the video that will then be used for the exercise.KeywordsAugmented RealityEyes diseaseVisual Snow SyndromeWeb Programming
Approximately 80% of patients with migraine report light sensitivity during attacks and almost half report that following headache, light sensitivity is the most bothersome symptom. Light wavelengths stimulating intrinsically photosensitive retinal ganglion cells (IPRGCs) exacerbate headache-associated light sensitivity; green light is most comfortable. We developed optical tints that block wavelengths exacerbating migraine pain and transmit wavelengths that are most comfortable. We studied patients with migraine to determine if spectacles with these tints ameliorate headache pain and light sensitivity. Randomized participants wore control lenses or lenses blocking light wavelengths that stimulate IPRGCs. Participants applied the lenses at migraine onset and recorded baseline, two- and four-hour headache pain on an 11-point scale. Primary endpoint was pain reduction at two hours following the first severe or very severe headache. Statistical tests used included mixed-effects model analysis, Mann-Whitney test, Cochran-Mantel-Haenszel test, Shapiro-Wilk test, Welch t-test. In 78 subjects, two- and four-hour pain reduction was not significantly different between groups. In post-hoc analyses of headaches with baseline pain scores ≥ 2, a mixed-effects model suggested that IPRGC lenses were associated with clinically and statistically significant reductions in two- and four-hour headache pain. In post-hoc analyses, fewer subjects wearing IPRGC lenses reported two-hour light sensitivity. Preliminary evidence suggests that optical tints engineered to reduce stimulation of IPRGCs may reduce migraine-associated pain and light sensitivity. Trial Registration: This study was registered at ClinicalTrials.gov (NCT04341298).
Significance:
Visual snow syndrome is a relatively new medical condition, with presence of visual snow as the primary visual-perceptual symptom. Information from the present study will improve future clinical diagnostic and treatment aspects in this population.
Purpose:
To determine the historical, diagnostic, and treatment aspects in patients with documented Visual Snow Syndrome /Visual Snow in an academic, optometric setting.
Methods:
A retrospective analysis was performed in patients (n = 40, ages 12-55 years) with documented Visual Snow Syndrome /Visual Snow examined over a four-year period. Information was collected by a detailed case history and the Visual Snow Syndrome Symptom Survey. Treatment assessment was performed using the Intuitive Colorimeter and a wide selection of chromatic tints assessed under the most provocative/exacerbating and other conditions.
Results:
Visual snow was typically constant and monochromatic, with it being present on average 6.43 years. Bright and dark surfaces were the most provocative/exacerbating/revealing conditions, along with the viewing of computer screens. The most common etiology was mild traumatic brain injury. The most common primary and secondary symptoms were photosensitivity and tinnitus, respectively. There was a high frequency of occurrence of oculomotor deficits, especially accommodative and vergence insufficiency (~40-50%). Eighty percent of the patients were prescribed a chromatic tint with subjective visual reduction of VS ranging from 15-100% (mean of 45%).
Conclusions:
The present information will help in understanding this unusual medico-perceptual condition, especially with respect to simple treatment frequently using readily available chromatic tints.
Introduction:
Light induced amaurosis refers to a transient monocular or binocular vision loss triggered by bright lights. Like amaurosis fugax, light induced amaurosis is associated with carotid artery stenosis but they differ from each other in presentation and pathophysiology. It is thought to be an impairment in the regeneration of retinal visual pigments caused by the inability of carotid circulation to sustain the increased metabolic activity occurring when the retina is exposed to bright lights. With this report we aim to present a case of light induced amaurosis and its management.
Case report:
We describe a 74-year-old man with the isolated complaint of monocular visual loss from his left eye when exposed to bright lights. These episodes were self-limited and lasted for several minutes. His vision was reportedly good between episodes. He also complained of headache and dizziness. There were no other focal neurological deficits present. The patient had a history of peripheral artery disease, chronic heart failure, hypertension, dyslipidaemia, permanent atrial fibrillation and had a history of heavy smoking in the past. Chronic medical therapy included anticoagulation with rivaroxaban, antiplatelet therapy with acetylsalicylic acid and atorvastatin. Imaging studies (doppler ultrasonography and Computed tomography angiography) revealed a significant morphologic stenosis of the left common carotid artery, left internal carotid artery with sub occlusive disease and right internal carotid artery with 70-75% stenosis (North American Symptomatic Carotid Endarterectomy Trial - NASCET). The vertebral arteries study did not reveal significant morphologic disease. The patient was submitted to left common and internal carotid artery endarterectomy and Dacron patch angioplasty. The visual symptoms progressively improved after surgical treatment. The dizziness and headache were completely gone.
Conclusion:
Light induced amaurosis is a rare and less known symptom associated with severe carotid artery stenosis. Its timely recognition is important to not deprive patients of timely treatment.
Çağımızın modern insanı, alışveriş merkezlerinden sinema salonlarına; araç farlarından bilgisayar ekranlarına kadar yaşamın farklı alanında ışığa maruz kalmaktadır. Ayrıca su, kum, kar, asfalt yol ve diğer yansıtıcı yüzeylerden yansıyan ışık, gözleri yormakta ve ışık hassasiyeti (fotofobi) olan kişilerin yaşam kalitesini düşürmektedir. Işığa duyarlılıkla ilgili yapılan küresel bir ankette, Türkiye’de yanıt verenlerin %91’ i ışıktan rahatsız olduğunu belirtmiştir. Pandemi sürecinin hayatımızda meydana getirdiği değişikliklerin bu çalışmaya ilham olduğu söylenebilir. Günümüzde herhangi bir sağlık sebebi ya da çevresel faktörlerden dolayı ışık hassasiyeti olan kişiler için 450 nanometreye(nm) kadar koruma sağlayabilen güneş gözlükleri, 500 nm’ye kadar koruma sağlayabilen sarı kromoforlu yani mavi filtreli lensler bulunmaktadır. Çalışmanın amacı, bu tür ürünlerin ışık blokajının 400-700 nm görünür ışığın üst sınırı olan 700 nm dalga boyuna kadar çıkarılarak geliştirilmesi hakkında alanyazın taraması yaparak kişiler üzerindeki faydasına dikkat çekmektir. Ayrıca mevcut ürünlerin ışık hassasiyeti olan kişilerde tek başına ve 400-700 nm dalga boyundaki görünür ışığa karşı maksimum koruma sağlayamadığından bu konuda ne tür sorunlar yaşanabileceği nitel yöntemin yarı yapılandırılmış görüşme tekniği kullanılarak tespit edilmeye çalışılmıştır. Bu bağlamda yedi soru hazırlanmış hem göz doktorlarıyla hem de optik çalışanlarıyla iletişime geçilerek veriler toplanmıştır. Araştırma verilerinden, mevcut ürünlerin geliştirilmesinin mümkün olduğu, 700 nm’ye kadar tüm zararlı ışıkları bloke edebilecek tek bir optik lens, kozmetik amaçlı renkli lens veya blokajı sağlayacak lens malzemesi üretiminin yapılabileceği bulgulanmıştır. Söz konusu araştırma ile bu tarz ürünlerin geliştirilebilmesine katkı sağlayacak bir alt yapı çalışması oluşturmak ve günümüz insanlarının yeni normalde yaşadığı örtük soruna dikkat çekmek amaçlanmıştır .
Traumatic brain injury disrupts the complex anatomy of the afferent and efferent visual pathways. Injury to the afferent pathway can result in vision loss, visual field deficits, and photophobia. Injury to the efferent pathway primarily causes eye movement abnormalities resulting in ocular misalignment and double vision. Injury to both the afferent and efferent systems can result in significant visual disability.
Photophobia (fear of light) occurs in a wide range of ophthalmic, neurological and behavioural conditions, the most common of which is migraine. The visual discomfort associated with migraine can occur not only in response to bright light but also flicker, spatial pattern and colour. The principles that underlie the discomfort are explored and methods to reduce it are proposed.
Objectives/background:
Treatment of migraine in the setting of either renal or hepatic disease can be daunting for clinicians. Not only does the method of metabolism have to be considered, but also the method of elimination/excretion of the parent drug and any active or toxic metabolites. Furthermore, it is difficult to think about liver or kidney disease in isolation, as liver disease can sometimes contribute to impaired renal function and renal disease can sometimes impair hepatic metabolism, through the cytochrome P450 system.
Methods:
A detailed search for terms related to liver disease, renal disease, and migraine management was performed in PubMed, Ovid Medline, Embase, and the Cochrane Library.For each medication, product labels were retrieved and reviewed using the US FDA website, with additional review of IBM Micromedex, LiverTox, and the Renal Drug Handbook.
Results:
This manuscript provides an overview of migraine drug metabolism and how it can be affected by liver and renal impairment. It reviews the standard terminology recommended by the US Food and Drug Administration for the different stages of hepatic and renal failure. The available evidence regarding the use of abortive and preventative medicines in the setting of organ failure is discussed in detail, including more recent therapies such as lasmiditan, gepants, and calcitonin gene-related peptide antibodies.
Conclusions:
For acute therapy, the use of NSAIDS should be limited, as these carry risk for both severe hepatic and renal disease. Triptans can be selectively used, often with dose guideline adjustments. Ubrogepant may be used in severe hepatic disease with dose adjustment and lasmiditan can be used in end stage renal disease. Though non-medicine strategies may be the most reasonable initial approach, many preventative medications can be used in the setting of hepatic and renal disease, often with dose adjustment. This review provides tables of guidelines, including reduced dosing recommendations, for the use of abortive and preventative migraine medications in hepatic and renal failure.
Background:
Although patients with abnormal light sensitivity may present to an ophthalmologist or optometrist for the evaluation of photophobia, there are no previous reviews of the most common causes of this symptom.
Methods:
We conducted a retrospective chart review of patients who presented to our eye center between 2001 and 2009 primarily for the evaluation of photophobia. We recorded demographics, ocular examination findings, and diagnoses of these patients.
Results:
Our population included 58 women and 53 men. The mean age at presentation to the clinic was 37 years (range 6 months-94 years). The most frequent cause of photophobia was migraine headache (53.7%), followed by dry eye syndrome (36.1), ocular trauma (8.2%), progressive supranuclear palsy (6.8%), and traumatic brain injury (4.1%). A significant proportion of patients (25.9%) left the clinic without a cause for their photophobia documented by the examining physician (11.7% of adults and 69.4% of children).
Conclusions:
Photophobia affects patients of all ages, and many patients are left without a specific diagnosis, indicating a significant knowledge gap among ophthalmologists and optometrists evaluating these patients.
Background:
Tinted lenses have been used to manage visual discomfort and photosensitivity in patients with migraines, benign essential blepharospasm (BEB) and epilepsy.
Objectives:
The purpose of this review is to examine the existing clinical research regarding the use of colored filters among patients recovering from traumatic brain injuries.
Methods:
A review of English articles from PubMed, Embase from embase.com, Web of Science, APA PsycINFO (OVID), Scopus, and Cochrane Central Register of Controlled Trials with publication years from date of inception to June 10, 2021 was performed. Articles were first screened by title and abstract, followed by full-text review. The search strategy resulted in 7819 results. The final analysis included seven articles which discussed the use of tinted lenses in patients post-traumatic brain injury.
Results:
While there is a paucity of information related to the therapeutic use of tinted lenses to mitigate post-traumatic light sensitivity and migraines, patients will subjectively report improved symptoms, specifically with precision tints or FL-41.
Conclusion:
Further studies are needed to understand the mechanism of action as well as objective and subjective benefits of tinted lenses in patient post-traumatic brain injury.
Background:
Photophobia is a common sensory symptom after traumatic brain injury (TBI) that may have a grave impact on a patient's functional independence, neurorehabilitation, and activities of daily living. Post-TBI photophobia can be difficult to treat and the majority of patients can suffer chronically up to and beyond one year after their injury.
Objectives:
This review evaluates the current theories of the pathophysiology of photophobia and the most-common co-morbid etiologies of light sensitivity in TBI to help guide the differential diagnosis and individualized management of post-TBI photophobia.
Methods:
Primary articles were found via PubMed and Google Scholar search of key terms including "photophobia" "light sensitivity" "photosensitivity" "photo-oculodynia" "intrinsically photosensitive retinal ganglion cells" "ipRGC" and "concussion" "brain injury" "dry eye". Due to paucity of literature papers were reviewed from 1900 to present in English.
Results:
Recent advances in understanding the pathophysiology of photophobia in dry eye and migraine and their connection to intrinsically photosensitive retinal ganglion cells (ipRGC) have revealed complex and multifaceted trigeminovascular and trigeminoautonomic pathways underlying photophobia. Patients who suffer a TBI often have co-morbidities like dry eye and migraine that may influence the patient's photophobia.
Conclusion:
Post-traumatic photophobia is a complex multi-disciplinary complaint that can severely impact a patient's quality of life. Exploration of underlying etiology may allow for improved treatment and symptomatic relief for these patients beyond tinted lenses alone.
Résumé
Objectif
Analyse des larmes de patients atteints de blépharospasme essentiel (BSE) afin d’explorer des mécanismes cornéo-conjonctivaux pouvant expliquer la photophobie, l’insuffisance lacrymale et les douleurs oculaires.
Méthodes
Sur une cohorte observationnelle de 42 patients atteints de blépharospasme essentiel, nous avons réalisé un test de Schirmer, une mesure du pH lacrymal, une électrophorèse des protéines lacrymales et une empreinte conjonctivale.
Résultats
Le test de Schirmer des patients objective une sécheresse lacrymale (8,4 ± 9,7 mm) avec 71,3 % des yeux ayant un Schirmer < 10 mm. Le pH lacrymal moyen de la cohorte est basique (8,4 ± 0,4) et est amélioré par le traitement de référence consistant en des injections trimestrielles de toxine botulique dans les paupières (8,32 ± 0,36 pour les patients traités vs 8,74 ± 0,53 pour les patients non traités ; p = 0,045). Ensemble, les électrophorèses des protéines lacrymales et les empreintes conjonctivales révèlent une inflammation conjonctivale associée au BSE.
Conclusion
Pour la première fois, cette étude apporte des arguments conjonctivaux objectifs pouvant en partie expliquer la photophobie, la sécheresse et les douleurs oculaires des patients atteints de BSE. Bien que ces résultats soient nouveaux et intéressants, des études complémentaires restent nécessaires pour évaluer l’efficacité de mesures correctives du pH et de l’inflammation lacrymale sur les symptômes oculaires et la qualité de vie des patients atteints de blépharospasme.
Dry eye disease (DED) is a diagnosis given to individuals with a heterogeneous combination of symptoms and/or signs, including spontaneous and evoked ocular pain. Our current study evaluated whether and which ocular pain assessments could serve as screening tools for central sensitization in individuals with DED. A cohort of individuals with DED symptoms (n = 235) were evaluated for ocular pain, DED signs (tear production, evaporation), evoked sensitivity to mechanical stimulation at the cornea, and evidence of central sensitization. Central sensitization was defined for this study as the presence of pain 30 seconds after termination of a thermal noxious temporal summation protocol (ie, aftersensations) presented at a site remote from the eye (ventral forearm). We found that combining ratings of average intensity of ocular pain, ratings of average intensity of pain due to light, response to topical anesthetic eye drops, and corneal mechanical pain thresholds produced the best predictive model for central sensitization (area under the curve of .73). When examining ratings of intensity of ocular pain due to light alone (0–10 numerical rating), a cutoff score of 2 maximized sensitivity (85%) and specificity (48%) for the presence of painful aftersensations at the forearm. Self-reported rating of pain sensitivity to light may serve as a quick screening tool indicating the involvement of central nociceptive system dysfunction in individuals with DED.
Perspective
This study reveals that clinically-relevant variables, including a simple 0 to 10 rating of ocular pain due to light, can be used to predict the contribution of central sensitization mechanisms in a subgroup of individuals with DED symptoms. These findings can potentially improve patient stratification and management for this complex and painful disease.
Purpose
To evaluate the visual photosensitivity threshold and objective photosensitivity luminance in healthy eyes, thereby providing a normative dataset that will lead to a better understanding of diseases causing photophobia.
Methods
This was a prospective cross-sectional study. Emmetropes whose visual acuity was better than 0.18 logMAR (6/9) with no other ocular abnormality were included. Headache Impact Test-6 and visual light sensitivity questionnaires were administered. Visual photosensitivity threshold was measured subjectively using the ocular photosensitivity analyser. Objective photosensitivity luminance was assessed manually by evaluating videos recorded using an infrared camera and noting the intensity of light at the first squeezing reflex.
Results
Seventy five normal subjects (age range, 7–71 years) were included. Median age was 32.7 years (inter-quartile range, 20.3–47.9 years). Forty (53.3%) were males. Median Headache Impact Test score was 38 (inter-quartile range, 36–42) and visual light sensitivity questionnaire score was 11 (inter-quartile range, 8–15). Mean (standard deviation) right eye, left eye and binocular visual photosensitivity threshold was 3.34 (0.78), 3.33 (0.81) and 3.37 (0.78) loglux, respectively. There was a significant negative correlation of visual light sensitivity questionnaire scores with right eye, left eye and binocular visual photosensitivity thresholds, and positive correlation of age with binocular visual photosensitivity thresholds. Mean (standard deviation) right eye, left eye and binocular objective photosensitivity luminance was 3.25 (0.55), 3.35 (0.47) and 3.15 (0.52) loglux, respectively. Age was only positively correlated with binocular objective photosensitivity luminance, and there was no correlation between age and right eye or left eye objective photosensitivity luminance.
Conclusions
The study characterised, for the first time, objective photosensitivity luminance and established normative data for both visual photosensitivity threshold and objective photosensitivity luminance. The data will help in understanding the pathophysiology of diseases causing photophobia, monitoring the disease progression and evaluating treatment modalities.
The case concerns a 54-year-old woman, with a history of fibromyalgia and normal preoperative ocular and systemic study, who presented with a long-lasting disabling photophobia, after sequential bilateral cataract surgery without complications. Photophobia was accompanied by good uncorrected VA, with no pain or subjective eye discomfort, without migraine or indicators of psychic conflict. It was refractory to any prescribed treatment of the ocular surface, finally responding to oral anticonvulsants (carbamazepine) that are frequently used in neuropathic pain. To the best of our knowledge this is the first reported case of a long-lasting disabling photophobia without pain and good VA after cataract surgery.
Photophobia is one of the most common visual complaints stemming from mild traumatic brain injury (mTBI) and causes significant distress. Despite extensive research, the etiology of photophobia is poorly understood, and symptoms are difficult to treat. No randomized controlled trials of treatment of photophobia in patients with mTBI exist; however, tinted glasses have been tried with some success. Targeted therapies involving infusion of calcium gene-related peptide antibody may hold promise.
Background: To present a simple method to evaluate transient eye closure (TEC) under bright light using binocular pupillometry in children with intermittent exotropia (IXT).
Methods: Sixty-one children with IXT were studied using binocular pupillometry. Each patient was exposed to each phase as follows: scotopic phase (darkness) for 3,300 ms, mesopic phase for 200 ms, scotopic phase for 3,300 ms, low-intensity white light phase (10 cd/m²) for 200 ms, scotopic phase for 3,300 ms, and high-intensity white light phase (100 cd/m²) for 200 ms. TEC was present if the subject closed eyes immediately more than half in response to light, compared with the one in the scotopic phase. We assessed the agreement between TEC and self-reporting photosensitivity, and also evaluated the associated factors for the presence of TEC in IXT patients.
Results: With the new method to evaluate TEC under different light intensities, 27 (44.3%) of the 61 IXT patients showed TEC, and 34 (55.7%) did not demonstrate TEC. TEC under high-intensity white light had a strong correlation with photosensitivity (r = 0.77). The smaller angle of deviation at near was associated with the presence of TEC, with statistical significance (p = 0.04). Normal sensory status at distance was significantly associated with TEC (p < 0.01). Multivariate analysis using multiple logistic regression analysis showed that normal sensory status was significantly associated with TEC (p = 0.02).
Conclusions: The test using binocular pupillometry is useful in identifying TEC related to bright light, and the presence of TEC was strongly correlated with photosensitivity in patients with IXT.
In our modern highly-illuminated world, symptoms of greater sensitivity to blue light increasingly appear. The impact of blue illumination on the ocular surface, the first barrier between the visual system and the external environment, is of particular interest. Since the crucial involvement of neurologic processes in ocular surface diseases such as dry eye is now widely recognized, the role of phototoxicity in neuro-ocular disorders is of great significance. The aim of this work was to investigate the potential harmful role of blue light in the context of dry eye and in relation to ocular nociception and light aversion. We demonstrated in vitro the phototoxic impact of blue light in human epithelial cells of the cornea and conjunctiva, and in neural and neuroglial cells from mouse trigeminal ganglia. In vivo, we reported that the significant aversion to blue light in mouse was accompanied by inflammation in the ocular surface and trigeminal pathways. We gave some insights into the ocular nociceptive pathways involved in photophobic mechanisms, together with the role of specific non-visual photoreceptors, melanopsin and neuropsin. This work sought to explain and corroborate frequent complaints about daily living increased photosensitivity in front of displays or under lightings rich in blue spectrum. Obtained results may therefore open new avenues for prevention and treatment of light-related ocular disorders and light aversion.
Photophobia can affect a person’s quality of life. We present a case of idiopathic photophobia that was successfully managed with smart light bulbs that allowed the patient to participate in daily activities. Smart light can complement other treatment options including tinted lenses. In conclusion, smart light is a novel way of treating photophobia and should be considered by clinicians.
Resumen
Paciente mujer, de 54 años, con antecedente de fibromialgia y estudio preoperatorio ocular y sistémico normal, que presenta fotofobia invalidante de larga duración, tras cirugía bilateral secuencial de cataratas sin complicaciones. La fotofobia se acompañaba de buena AV no corregida, sin dolor ni molestias subjetivas oculares y sin migraña ni indicadores de conflictos psíquicos. Fue refractaria a cualquier tratamiento de la superficie ocular pautado, respondiendo finalmente a anticonvulsivantes orales (carbamazepina) frecuentemente utilizados en dolor de tipo neuropático. Según nuestro conocimiento es el único caso descrito de fotofobia invalidante de larga duración sin dolor y buena AV tras cirugía de cataratas.
As the biological alarm of impending or actual tissue damage, pain is essential for our survival. However, when it is initiated and/or sustained by dysfunctional elements in the nociceptive system, it is itself a disease known as neuropathic pain. While the critical nociceptive system provides a number of protective functions, it is unique in its central role of monitoring, preserving and restoring the optical tear film in the face of evaporative attrition without which our vision would be non-functional. Meeting this existential need resulted in the evolution of the highly complex, powerful and sensitive dry eye alarm system integrated in the peripheral and central trigeminal sensory network. The clinical consequences of corneal damage to these nociceptive pathways are determined by the type and location of its pathological elements and can range from the spectrum known as dry eye disease to the centalised oculofacial neuropathic pain syndrome characterised by a striking disparity between the high intensity of symptoms and paucity of external signs. These changes parallel those observed in somatic neuropathic pain. When seen through the neuroscience lens, diseases responsible for inadequately explained chronic eye pain (including those described as dry eye) can take on new meanings that may clarify long-standing enigmas and point to new approaches for developing preventive, symptomatic and disease-modifying interventions for these currently refractory disorders.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
To analyze the density and morphology of corneal epithelial cells and keratocytes by in vivo confocal microscopy (IVCM) in patients with herpes zoster ophthalmicus (HZO) as associated with corneal innervation.
Prospective, controlled and masked cross-sectional study.
Setting: Single center study. Patients: Thirty eyes with the diagnosis HZO and their contralateral clinically unaffected eyes, fifteen eyes of 15 normal controls. Intervention procedures: In vivo confocal microscopy and corneal esthesiometry of the central cornea. Main Outcome Measures: Changes in morphology and density of the superficial and basal epithelial cells, stromal keratocytes and correlation with corneal sensation, number of nerves, and total length of nerves.
The density of superficial epithelial cells in HZO eyes with severe sensation loss (766.5±25.2 cells/mm(2)) was significantly lower than both healthy control eyes (1450.23±150.83 cells/mm(2)) and contralateral unaffected eyes (1974±298.24 cells/mm(2)). (p=0.003). Superficial epithelial cell size (1162.5 μm(2)) was significantly larger in HZO eyes with severe loss of sensation, as compared to contralateral (441.46 ± 298.14) or healthy eyes (407.4 μm(2); all p<0.05). The density of basal epithelial cells, anterior keratocytes, and posterior keratocytes did not show statistical significance between patients, controls and contralateral unaffected eyes. Changes in superficial epithelial cell density and morphology correlated strongly with corneal sensation.
In vivo confocal microscopy reveals profound HZO-induced changes in the superficial epithelium, as demonstrated by increase in cell size, decrease in cell density, and squamous metaplasia. We demonstrate that these changes strongly correlate with changes in corneal innervation in eyes affected by HZO.
Copyright © 2015 Elsevier Inc. All rights reserved.
Many adult outpatients with attention-deficit/hyperactivity disorder (ADHD) report an oversensitivity to light. We explored the link between ADHD and photophobia in an online survey (N = 494). Self-reported photophobia was prevalent in 69% of respondents with, and in 28% of respondents without, ADHD (symptoms). The ADHD (symptoms) group wore sunglasses longer during daytime in all seasons. Photophobia may be related to the functioning of the eyes, which mediate dopamine and melatonin production systems in the eye. In the brain, dopamine and melatonin are involved in both ADHD and circadian rhythm disturbances. Possibly, the regulation of the dopamine and melatonin systems in the eyes and in the brain are related. Despite the study’s limitations, the results are encouraging for further study on the pathophysiology of ADHD, eye functioning, and circadian rhythm disturbances.
Neurons in the mammalian retina expressing the photopigment melanopsin have been identified as a class of intrinsically photosensitive retinal ganglion cells (ipRGCs). This discovery more than a decade ago has opened up an exciting new field of retinal research, and following the initial identification of photosensitive ganglion cells, several subtypes have been described. A number of studies have shown that ipRGCs subserve photoentrainment of circadian rhythms. They also influence other non-image forming functions of the visual system, such as the pupillary light reflex, sleep, cognition, mood, light aversion and development of the retina. These novel photosensitive neurons also influence form vision by contributing to contrast detection. Furthermore, studies have shown that ipRGCs are more injury-resistant following optic nerve injury, in animal models of glaucoma, and in patients with mitochondrial optic neuropathies, i.e., Leber's hereditary optic neuropathy and dominant optic atrophy. There is also an indication that these cells may be resistant to glutamate-induced excitotoxicity. Herein we provide an overview of ipRGCs and discuss the injury-resistant character of these neurons under certain pathological and experimental conditions.
Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
This is to our knowledge the first systematic review regarding the efficacy of manual therapy randomized clinical trials (RCT) for primary chronic headaches. A comprehensive English literature search on CINHAL, Cochrane, Medline, Ovid and PubMed identified 6 RCTs all investigating chronic tension-type headache (CTTH). One study applied massage therapy and five studies applied physiotherapy. Four studies were considered to be of good methodological quality by the PEDro scale. All studies were pragmatic or used no treatment as a control group, and only two studies avoided co-intervention, which may lead to possible bias and makes interpretation of the results more difficult. The RCTs suggest that massage and physiotherapy are effective treatment options in the management of CTTH. One of the RCTs showed that physiotherapy reduced headache frequency and intensity statistical significant better than usual care by the general practitioner. The efficacy of physiotherapy at post-treatment and at 6 months follow-up equals the efficacy of tricyclic antidepressants. Effect size of physiotherapy was up to 0.62. Future manual therapy RCTs are requested addressing the efficacy in chronic migraine with and without medication overuse. Future RCTs on headache should adhere to the International Headache Society's guidelines for clinical trials, i.e. frequency as primary end-point, while duration and intensity should be secondary end-point, avoid co-intervention, includes sufficient sample size and follow-up period for at least 6 months.
Significance
Light is a powerful stimulant for human alertness and cognition that can be easily administered to improve performance or counteract the negative impact of sleepiness, even during the day. Here, we show that prior exposure to longer wavelength light (orange), relative to shorter wavelength (blue), enhances the subsequent impact of light on executive brain responses. These findings emphasize the importance of light for human cognitive brain function and constitute compelling evidence in favor of a cognitive role for melanopsin. This recently discovered photopigment may therefore provide a unique form of “photic memory” for human cognition and play a broader role than previously apprehended. Ultimately, these findings support the idea that the integration of light exposure over long periods of time can help optimize cognitive brain function.
The weekly incidence of headaches among office workers was compared when the offices were lit by fluorescent lighting where the fluorescent tubes were operated by (a) a conventional switch-start circuit with choke ballast providing illumination that pulsated with a modulation depth of 43-49% and a principal frequency component at 100 Hz; (b) an electronic start circuit with choke ballast giving illumination with similar characteristics; (c) an electronic ballast driving the lamps at about 32 kHz and reducing the 100 Hz modulation to less than 7%. In a double-blind cross-over design, the average incidence of headaches and eyestrain was more than halved under high-frequency lighting. The incidence was unaffected by the speed with which the tubes ignited. Headaches tended to decrease with the height of the office above the ground and thus with increasing natural light. Office occupants chose to switch on the high-frequency lighting for 30% longer on average.
Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) are the only functional photoreceptive cells in the eye of newborn mice. Through postnatal day 9, in the absence of functional rods and cones, these ipRGCs mediate a robust avoidance behavior to a light source, termed negative phototaxis. To determine whether this behavior is associated with an aversive experience in neonatal mice, we characterized light-induced vocalizations and patterns of neuronal activation in regions of the brain involved in the processing of aversive and painful stimuli. Light evoked distinct melanopsin-dependent ultrasonic vocalizations identical to those emitted under stressful conditions, such as isolation from the litter. In contrast, light did not evoke the broad-spectrum calls elicited by acute mechanical pain. Using markers of neuronal activation, we found that light induced the immediate-early gene product Fos in the posterior thalamus, a brain region associated with the enhancement of responses to mechanical stimulation of the dura by light, and thought to be the basis for migrainous photophobia. Additionally, light induced the phosphorylation of extracellular-related kinase (pERK) in neurons of the central amygdala, an intracellular signal associated with the processing of the aversive aspects of pain. However, light did not activate Fos expression in the spinal trigeminal nucleus caudalis, the primary receptive field for painful stimulation to the head. We conclude that these light-evoked vocalizations and the distinct pattern of brain activation in neonatal mice are consistent with a melanopsin-dependent neural pathway involved in processing light as an aversive but not acutely painful stimulus.
SYNOPSIS
In a questionnaire survey we determined the prevalence of visual symptoms and eye strain factors in a group of chronic headache sufferers as compared with age- and sex-matched controls. The visual symptoms studied were those not pecific for headache, i.e., sensitivity to light and blurred vision. Sensitivity to light in the absence of headache was reported by 27.8% of controls and 44.7% of headache sufferers (p<0.05). The latter figure increased to 71.3% when headache was actually present (p<0.001). Blurred vision occurred in 13.5% of controls and 7.4% of headache sufferers (not significant). In the presence of headache, the latter figure increased to 44.7% (p< 0.01).
Of the eye strain factors studied, bright light was reported to precipitate headache in 29.3% and to aggravate it in 73.4%. For reading, these figures were 16.0% and 55.3%, respectively; for working at the computer screen, 14.5% and 31.3%; and for watching television, 6.4% and 27.7%. We conclude that visual symptoms are more common in chronic headache and eye strain factors more important than is generally recognized.
A variety of animal species utilize the ultraviolet (UV) component of sunlight as their environmental cues, whereas physiological roles of UV photoreception in mammals, especially in human beings, remain open questions. Here we report that mouse neuropsin (OPN5) encoded by the Opn5 gene exhibited an absorption maximum (λmax) at 380 nm when reconstituted with 11-cis-retinal. Upon UV-light illumination, OPN5 was converted to a blue-absorbing photoproduct (λmax 470 nm), which was stable in the dark and reverted to the UV-absorbing state by the subsequent orange light illumination, indicating its bistable nature. Human OPN5 also had an absorption maximum at 380 nm with spectral properties similar to mouse OPN5, revealing that OPN5 is the first and hitherto unknown human opsin with peak sensitivity in the UV region. OPN5 was capable of activating heterotrimeric G protein Gi in a UV-dependent manner. Immuno-blotting analyses of mouse tissue extracts identified the retina, the brain and, unexpectedly, the outer ears as the major sites of OPN5 expression. In the tissue sections of mice, OPN5 immuno-reactivities were detected in a subset of non-rod/non-cone retinal neurons as well as in the epidermal and muscle cells of the outer ears. Most of these OPN5-immuno-reactivities in mice were co-localized with positive signals for the alpha-subunit of Gi. These results demonstrate the first example of UV photoreceptor in human beings and strongly suggest that OPN5 triggers a UV-sensitive Gi-mediated signaling pathway in the mammalian tissues.
Certain patterns can induce perceptual illusions/distortions and visual discomfort in most people, headaches in patients with migraine, and seizures in patients with photosensitive epilepsy. Visual stimuli are common triggers for migraine attacks, possibly because of a hyperexcitability of the visual cortex shown in patients with migraine. Precision ophthalmic tints (POTs) are claimed to reduce perceptual distortions and visual discomfort and to prevent migraine headaches in some patients. We report an fMRI visual cortical activation study designed to investigate neurological mechanisms for the beneficial effects of POTs in migraine.
Eleven migraineurs and 11 age- and sex-matched non-headache controls participated in the study using non-stressful and stressful striped patterns viewed through gray, POT, and control coloured lenses.
For all lenses, controls and migraineurs did not differ in their response to the non-stressful patterns. When the migraineurs wore gray lenses or control coloured lenses, the stressful pattern resulted in activation that was greater than in the controls. There was also an absence of the characteristic low-pass spatial frequency (SF) tuning in extrastriate visual areas. When POTs were worn, however, both cortical activation and SF tuning were normalized. Both when observing the stressful pattern and under more typical viewing conditions, the POTs reduced visual discomfort more than either of the other two lenses.
The normalization of cortical activation and SF tuning in the migraineurs by POTs suggests a neurological basis for the therapeutic effect of these lenses in reducing visual cortical hyperactivation in migraine.
Corneal confocal microscopy is a growing technique for the study of the cornea at the cellular level, providing images comparable to ex vivo histochemical methods. In vivo confocal microscopy (IVCM) has an enormous potential, being a noninvasive procedure that images the living cornea, to study both its physiological and pathological states. Corneal nerves are of great interest to clinicians and scientists due to their important roles in regulating corneal sensation, epithelial integrity, proliferation, wound healing, and for their protective functions. IVCM enables the noninvasive examination of corneal nerves, allowing the study of nerve alterations in different ocular diseases, after corneal surgery, and in systemic diseases. To date, the correlation of sub-basal corneal nerves and their function has been studied in normal eyes, keratoconus, dry eye, contact lens wearers, and in neurotrophic keratopathy, among others. Further, the effect of corneal surgery on nerves has been studied, demonstrating the regenerative capacity of corneal nerves and the recovery of sensation. Moreover, IVCM has been applied in the diagnosis of peripheral diabetic neuropathy and the assessment of progression in this systemic disease. The purpose of this review is to describe the principles, applications, and clinical correlation of IVCM in the study of corneal nerves in different ocular and systemic diseases.
Alterations in cortical excitability are implicated in the pathophysiology of migraine. However, the relationship between cortical spreading depression (CSD) and headache has not been fully elucidated. We aimed to identify the corticofugal networks that directly influence meningeal nociception in the brainstem trigeminocervical complex (Sp5C) of the rat. Cortical areas projecting to the brainstem were first identified by retrograde tracing from Sp5C areas that receive direct meningeal inputs. Anterograde tracers were then injected into these cortical areas to determine the precise pattern of descending axonal terminal fields in the Sp5C. Descending cortical projections to brainstem areas innervated by the ophthalmic branch of the trigeminal nerve originate contralaterally from insular (Ins) and primary somatosensory (S1) cortices and terminate in laminae I-II and III-V of the Sp5C, respectively. In another set of experiments, electrophysiological recordings were simultaneously performed in Ins, S1 or primary visual cortex (V1), and Sp5C neurons. KCl was microinjected into such cortical areas to test the effects of CSD on meningeal nociception. CSD initiated in Ins and S1 induced facilitation and inhibition of meningeal-evoked responses, respectively. CSD triggered in V1 affects differently Ins and S1 cortices, enhancing or inhibiting meningeal-evoked responses of Sp5C, without affecting cutaneous-evoked nociceptive responses. Our data suggest that "top-down" influences from lateralized areas within Ins and S1 selectively affect interoceptive (meningeal) over exteroceptive (cutaneous) nociceptive inputs onto Sp5C. Such corticofugal influences could contribute to the development of migraine pain in terms of both topographic localization and pain tuning during an attack.
Photophobia is an abnormal sensitivity to light experienced by migraineurs and is perhaps caused by cortical hyperexcitability. In clinical studies, an inter-relation between light perception and trigeminal nociception has been demonstrated in migraineurs but not in controls. The purpose of the study was to verify this interaction by functional imaging.
The authors used H(2)O(15) positron emitting tomography (PET) to study the cortical responses of seven migraineurs between attacks and the responses of seven matched control subjects to luminous stimulations at three luminance intensities: 0, 600 and 1800 Cd/m(2). All three intensities were both with and without concomitant trigeminal pain stimulation. In order to facilitate habituation, the stimulations were started 30 s before PET acquisitions.
When no concomitant pain stimulation was applied, luminous stimulations activated the visual cortex bilaterally in migraineurs (specifically in the cuneus, lingual gyrus and posterior cingulate cortex) but not in controls. Concomitant pain stimulation allowed visual cortex activation in control subjects and potentiated its activation in migraineurs. These activations by luminous stimulations were luminance-intensity-dependent in both groups. Concomitant stimulation by pain was associated with activation of the posterior parietal cortex (BA7) in migraineurs and controls.
The study shows the lack of habituation and/or cortical hyperexcitability to light in migraineurs. Moreover, the activation by light of several visual cortex areas (including the primary visual cortex) was potentiated by trigeminal pain, demonstrating multisensory integration in these areas.
The perception of migraine headache, which is mediated by nociceptive signals transmitted from the cranial dura mater to the brain, is uniquely exacerbated by exposure to light. We found that exacerbation of migraine headache by light is prevalent among blind individuals who maintain non-image-forming photoregulation in the face of massive rod/cone degeneration. Using single-unit recording and neural tract tracing in the rat, we identified dura-sensitive neurons in the posterior thalamus whose activity was distinctly modulated by light and whose axons projected extensively across layers I-V of somatosensory, visual and associative cortices. The cell bodies and dendrites of such dura/light-sensitive neurons were apposed by axons originating from retinal ganglion cells (RGCs), predominantly from intrinsically photosensitive RGCs, the principle conduit of non-image-forming photoregulation. We propose that photoregulation of migraine headache is exerted by a non-image-forming retinal pathway that modulates the activity of dura-sensitive thalamocortical neurons.
Light therapy is increasingly applied in a variety of sleep medicine and psychiatric conditions including circadian rhythm sleep disorders, seasonal affective disorder, and dementia. This article reviews the neural underpinnings of circadian neurobiology crucial for understanding the influence of light therapy on brain function, common mood and sleep disorders in which light therapy may be effectively used, and applications of light therapy in clinical practice.
In addition to rods and cones, the human retina contains light-sensitive ganglion cells that express melanopsin, a photopigment with signal transduction mechanisms similar to that of invertebrate rhabdomeric photopigments (IRP). Like fly rhodopsins, melanopsin acts as a dual-state photosensitive flip-flop in which light drives both phototransduction responses and chromophore photoregeneration that bestows independence from the retinoid cycle required by rods and cones to regenerate photoresponsiveness following bleaching by light. To explore the hypothesis that melanopsin in humans expresses the properties of a bistable photopigment in vivo we used the pupillary light reflex (PLR) as a tool but with methods designed to study invertebrate photoreceptors. We show that the pupil only attains a fully stabilized state of constriction after several minutes of light exposure, a feature that is consistent with typical IRP photoequilibrium spectra. We further demonstrate that previous exposure to long wavelength light increases, while short wavelength light decreases the amplitude of pupil constriction, a fundamental property of IRP difference spectra. Modelling these responses to invertebrate photopigment templates yields two putative spectra for the underlying R and M photopigment states with peaks at 481 nm and 587 nm respectively. Furthermore, this bistable mechanism may confer a novel form of "photic memory" since information of prior light conditions is retained and shapes subsequent responses to light. These results suggest that the human retina exploits fly-like photoreceptive mechanisms that are potentially important for the modulation of non-visual responses to light and highlights the ubiquitous nature of photoswitchable photosensors across living organisms.
To describe the magnitude and distribution of the public health problem posed by migraine in the United States by examining migraine prevalence, attack frequency, and attack-related disability by gender, age, race, household income, geographic region, and urban vs rural residence.
In 1989, a self-administered questionnaire was sent to a sample of 15,000 households. A designated member of each household initially responded to the questionnaire. Each household member with severe headache was asked to respond to detailed questions about symptoms, frequency, and severity of headaches.
A sample of households selected from a panel to be representative of the US population in terms of age, gender, household size, and geographic area.
After a single mailing, 20,468 subjects (63.4% response rate) between 12 and 80 years of age responded to the survey. Respondents and non-respondents did not differ by gender, household income, region of the country, or urban vs rural status. Whites and the elderly were more likely to respond. Migraine headache cases were identified on the basis of reported symptoms using established diagnostic criteria.
17.6% of females and 5.7% of males were found to have one or more migraine headaches per year. The prevalence of migraine varied considerably by age and was highest in both men and women between the ages of 35 to 45 years. Migraine prevalence was strongly associated with household income; prevalence in the lowest income group (less than $10,000) was more than 60% higher than in the two highest income groups (greater than or equal to $30,000). The proportion of migraine sufferers who experienced moderate to severe disability was not related to gender, age, income, urban vs rural residence, or region of the country. In contrast, the frequency of headaches was lower in higher-income groups. Attack frequency was inversely related to disability.
A projection to the US population suggests that 8.7 million females and 2.6 million males suffer from migraine headache with moderate to severe disability. Of these, 3.4 million females and 1.1 million males experience one or more attacks per month. Females between ages 30 to 49 years from lower-income households are at especially high risk of having migraines and are more likely than other groups to use emergency care services for their acute condition.
Previous evidence suggests optical treatments hold promise for treating migraine and photophobia. We designed an optical notch filter, centered at 480nm to reduce direct stimulation of intrinsically photosensitive retinal ganglion cells. We used thin-film technology to integrate the filter into spectacle lenses. Our objective was to determine if an optical notch filter, designed to attenuate activity of intrinsically photosensitive retinal ganglion cells, could reduce headache impact in chronic migraine subjects. For this randomized, double-masked study, our primary endpoint was the Headache Impact Test (HIT-6; GlaxoSmithKline, Brentford, Middlesex, UK). We developed two filters: the therapeutic filter blocked visible light at 480nm; a 620nm filter was designed as a sham. Participants were asked to wear lenses with one of the filters for 2weeks; after 2weeks when no lenses were worn, they wore lenses with the other filter for 2weeks. Of 48 subjects, 37 completed the study. Wearing either the 480 or 620nm lenses resulted in clinically and statistically significant HIT-6 reductions. However, there was no significant difference when comparing overall effect of the 480 and 620nm lenses. Although the 620nm filter was designed as a sham intervention, research published following the trial indicated that melanopsin, the photopigment in intrinsically photosensitive retinal ganglion cells, is bi-stable. This molecular property may explain the unexpected efficacy of the 620nm filter. These preliminary findings indicate that lenses outfitted with a thin-film optical notch filter may be useful in treating chronic migraine.
Background
We used in vivo corneal confocal microscopy to investigate structural differences in the sub‐basal corneal nerve plexus in chronic migraine patients and a normal population. We used a validated questionnaire and tests of lacrimal function to determine the prevalence of dry eye in the same group of chronic migraine patients. Activation of the trigeminal system is involved in migraine. Corneal nociceptive sensation is mediated by trigeminal axons that synapse in the gasserian ganglion and the brainstem, and serve nociceptive, protective, and trophic functions. Noninvasive imaging of the corneal sub‐basal nerve plexus is possible with in vivo corneal confocal microscopy.
Methods
For this case–control study, we recruited chronic migraine patients and compared them with a sex‐ and age‐similar group of control subjects. Patients with peripheral neuropathy, a disease known to be associated with a peripheral neuropathy, or prior corneal or intraocular surgery were excluded. Participants underwent in vivo corneal confocal microscopy using a H eidelberg R etinal T omography III confocal microscope with a R ostock C ornea M odule. Nerve fiber length, nerve branch density, nerve fiber density, and tortuosity coefficient were measured using established methodologies. Migraine participants underwent testing of basal tear production with proparacaine, corneal sensitivity assessment with a cotton‐tip applicator, measurement of tear break‐up time, and completion of a validated dry eye questionnaire.
Results
A total of 19 chronic migraine patients and 30 control participants completed the study. There were no significant differences in age or sex. Nerve fiber density was significantly lower in migraine patients compared with controls (48.4 ± 23.5 vs 71.0 ± 15.0 fibers/mm ² , P < .001). Nerve fiber length was decreased in the chronic migraine group compared with the control group, but this difference was not statistically significant (21.5 ± 11.8 vs 26.8 ± 5.9 mm/mm ² , P < .084). Nerve branch density was similar in the two groups (114.0 ± 92.4 vs 118.1 ± 55.9 branches/mm ² , P < .864). Tortuosity coefficient and log tortuosity coefficient also were similar in the chronic migraine and control groups. All migraine subjects had symptoms consistent with a diagnosis of dry eye syndrome.
Conclusions
We found that in the sample used in this study, the presence of structural changes in nociceptive corneal axons lends further support to the hypothesis that the trigeminal system plays a critical role in the pathogenesis of migraine. In vivo corneal confocal microscopy holds promise as a biomarker for future migraine research as well as for studies examining alterations of corneal innervation. Dry eye symptoms appear to be extremely prevalent in this population. The interrelationships between migraine, corneal nerve architecture, and dry eye will be the subject of future investigations.
Migraine is a complex and multifactorial brain disorder affecting approximately 18% of women and 5% of men in the United States, costing billions of dollars annually in direct and indirect healthcare costs and school and work absenteeism and presenteeism. Until this date, there have been no medications that were designed with the specific purpose to decrease the number of migraine attacks, which prompts a search for alternative interventions that could be valuable, such as acupuncture.
Acupuncture origins from ancient China and encompasses procedures that basically involve stimulation of anatomical points of the body.
This manuscript reviews large and well-designed trials of acupuncture for migraine prevention and also the effectiveness of acupuncture when tried against proven migraine preventative medications.
Acupuncture seems to be at least as effective as conventional drug preventative therapy for migraine and is safe, long lasting, and cost-effective. It is a complex intervention that may prompt lifestyle changes that could be valuable in patients' recovery.
© 2015 American Headache Society.
Background
Over the past 4000 years, acupuncture has survived the test of time. Recent scientific studies posit acupuncture is an effective intervention for back and joint pain and headache, including migraine.Methods
The process of acupuncture is explained, including the role of Qi, the integration of Yang and Yin, the 5 elements, the 8 trigrams, and the metaphors that help the acupuncturist understand the patient, interpret symptoms, and determine acupuncture points in the meridians used to prevent or treat disease. A case study is presented from 3 perspectives: allopathic, traditional acupuncture, and Western acupuncture.ResultsSelected acupuncture studies in headache are reviewed. The safety of acupuncture is discussed as well as the challenges in conducting clinical studies of acupuncture.
Objective.
—To describe the magnitude and distribution of the public health problem posed by migraine in the United States by examining migraine prevalence, attack frequency, and attack-related disability by gender, age, race, household income, geographic region, and urban vs rural residence.Design.
—In 1989, a self-administered questionnaire was sent to a sample of 15000 households. A designated member of each household initially responded to the questionnaire. Each household member with severe headache was asked to respond to detailed questions about symptoms, frequency, and severity of headaches.Setting.
—A sample of households selected from a panel to be representative of the US population in terms of age, gender, household size, and geographic area.Participants.
—After a single mailing, 20468 subjects (63.4% response rate) between 12 and 80 years of age responded to the survey. Respondents and non-respondents did not differ by gender, household income, region of the country, or urban vs rural status. Whites and the elderly were more likely to respond. Migraine headache cases were identified on the basis of reported symptoms using established diagnostic criteria.Results.
—17.6% of females and 5.7% of males were found to have one or more migraine headaches per year. The prevalence of migraine varied considerably by age and was highest in both men and women between the ages of 35 to 45 years. Migraine prevalence was strongly associated with household income; prevalence in the lowest income group (<$10 000) was more than 60% higher than in the two highest income groups (≥$30 000). The proportion of migraine sufferers who experienced moderate to severe disability was not related to gender, age, income, urban vs rural residence, or region of the country. In contrast, the frequency of headaches was lower in higher-income groups. Attack frequency was inversely related to disability.Conclusions.
—A projection to the US population suggests that 8.7 million females and 2.6 million males suffer from migraine headache with moderate to severe disability. Of these, 3.4 million females and 1.1 million males experience one or more attacks per month. Females between ages 30 to 49 years from lower-income households are at especially high risk of having migraines and are more likely than other groups to use emergency care services for their acute condition.(JAMA. 1992;267:64-69)
Objective
Post-traumatic headache (PTH) of the migraine type is a common complication of mild traumatic brain injury (including blast injuries) in active duty service members. Persistent and near-daily headache occur. Usual preventive medications may have unacceptable side effects. Anecdotal reports suggest that onabotulinum toxin A (OBA) might be an effective treatment in these patients.Methods
This study is a real-time retrospective consecutive case series of all patients treated with OBA at the Concussion Care Clinic of Womack Army Medical Center, Ft. Bragg, NC, between August 2008 and August 2012. Clinical treatment and pharmacy records were corroborated with the electronic medical records in the Armed Forces Health Longitudinal Technology Application to determine demographics, current headache and treatment characteristics, and clinical and occupational outcomes.ResultsSixty-four subjects (63 male) with mean age of 31.3 + 7.5 (range 20-59) years were evaluated and treated. Blast injuries were most common (n = 36; 56.3%) and 7 patients (11%) reported a prior history of headache. Most patients (36; 56.3%) described more than 1 headache type and 48 (75%) patients had continuous pain. The most prevalent treating diagnosis was mixed continuous headache with migraine features on more than 15 days per month (n = 26; 40.6%). The mean time from injury to the first injections was 10.8 + 21.9 (1-96) months. Forty (62.5%) patients received the Food and Drug Administration-approved chronic migraine injection protocol. Forty-one (64%) patients reported being better. Two patients discontinued for side effects. Twenty-seven (41%) remained on active duty.Conclusions
We demonstrate that active duty military patients with headaches related to concussions may benefit from treatment with OBA. Further studies are indicated.
To investigate causes, associations, and results of treatment with blepharospasm, 1,653 patients were evaluated by extensive questionnaires to study blepharospasm and long-term results of treatment with the full myectomy operation, botulinum-A toxin, drug therapy, and help from the Benign Essential Blepharospasm Research Foundation (BEBRF). The percent of patients improved by the BEBRF was 90%, full myectomy 88%, botulinum-A toxin 86%, and drug therapy 43%. The patient acceptance rate for the BEBRF was 96%, full myectomy 82%, botulinum-A toxin 95%, and drug therapy 57%. Blepharospasm is multifactorial in origin and manifestation. A vicious cycle and defective circuit theory to explain origin and direct treatment rather than a defective specific locus is presented. All four forms of therapy evaluated are useful and must be tailored to the patient's needs. Mattie Lou Koster and the BEBRF have helped blepharospasm sufferers more than any other modality, and all patients should be informed of this support group. The full myectomy is reserved for botulinum-A toxin failures, and the limited myectomy is an excellent adjunct to botulinum-A toxin. (C)1998The American Society of Opthalmic Plastic and Reconstructive Surgery, Inc.
Background
Migraine equivalents are common clinical conditions without headache component, occurring as repeated attacks with complete remission between episodes. They include abdominal migraine, cyclical vomiting, benign paroxysmal vertigo, and benign paroxysmal torticollis. Other clinical entities, such as motion sickness and limb pain have been associated with migraine. We aimed to investigate the migraine equivalents prevalence in a large population of children referred to a pediatric headache centre and to reveal a possible relationship between migraine equivalents and headache features.
Methods
A total of 1.134 of children/adolescents (73.2% with migraine and 26.8% with tension-type headache) was included. Patients were divided into two groups according to the attack frequency (high and low). Pain intensity was rated on a 3-levels graduate scale (mild, moderate and severe pain).
Results
Migraine equivalents were reported in 70.3% of patients. Abdominal migraine (48.9%), limb pain (43.9%), and motion sickness (40.5%) were the most common migraine equivalents. While headache type (migraine or tension-type headache) did not correlate with migraine equivalents presence (χ2=33.2; P=0.27), high frequency of headache attacks correlated with migraine equivalents presence. Moreover, migraine equivalents showed a protective role for some accompanying symptom of the headache attack.
Conclusions
Our results suggest that migraine equivalents should not be considered merely as headache precursors, but they are part of the migrainous syndrome. Thus, their inclusion among the diagnostic criteria for pediatric migraine/tension-type headache is hopeful.
The purpose of this study was to investigate the long-term visual dysfunction in patients after blast-induced mild traumatic brain injury (mbTBI) using a retrospective case series of 31 patients with mbTBI (>12 mo prior) without eye injuries. Time since mbTBI was 50.5 +/- 19.8 mo. Age at the time of injury was 30.0 +/- 8.3 yr. Mean corrected visual acuity was 20/20. Of the patients, 71% (n = 22) experienced loss of consciousness; 68% (n = 15) of patients in this subgroup were dismounted during the blast injury. Overall, 68% (n = 21) of patients had visual complaints. The most common complaints were photophobia (55%) and difficulty with reading (32%). Of all patients, 25% were diagnosed with convergence insufficiency and 23% had accommodative insufficiency. Patients with more than one mbTBI had a higher rate of visual complaints (87.5%). Asymptomatic patients had a significantly longer time (62.5 +/- 6.2 mo) since the mbTBI than symptomatic patients (42.0 +/- 16.4 mo, p < 0.004). Long-term visual dysfunction after mbTBI is common even years after injury despite excellent distance visual acuity and is more frequent if more than one incidence of mbTBI occurred. We recommend obtaining a careful medical history, evaluation of symptoms, and binocular vision assessment during routine eye examinations in this prepresbyopic patient population.
Photophobia refers to a sensory disturbance provoked by light. However, because it arises distinctly in a broad range of clinical conditions, its definition remains elusive. Many underscore the painful sensory aspects of photophobia, while others emphasize its unpleasant, affective qualities. To add further complexity, recent discoveries in photophobia research have raised disparate and potentially conflicting results. In this installment of an occasional series, we asked clinicians and scientists to give their interpretation of what these discoveries tell us about photophobia in the clinic, and vice versa.
The cornea receives the densest sensory innervation of the body, which is exclusively from small-fiber nociceptive (pain-sensing) neurons. These are similar to those in the skin of the legs, the standard location for neurodiagnostic skin biopsies used to diagnose small-fiber peripheral polyneuropathies. Many cancer chemotherapy agents cause dose-related, therapy-limiting, sensory-predominant polyneuropathy. Because corneal innervation can be detected noninvasively, it is a potential surrogate biomarker for skin biopsy measurements. Therefore, we compared hindpaw-skin and cornea innervation in mice treated with neurotoxic chemotherapy. Paclitaxel (0, 5, 10, or 20mg/kg) was administered to C57/Bl6 mice and peri-mortem cornea and skin biopsies were immunolabeled to reveal and permit quantitation of innervation. Both tissues demonstrated dose-dependent, highly correlated (r = 0.66) nerve fiber damage. These findings suggest that the quantification of corneal nerves may provide a useful surrogate marker for skin peripheral innervation.
Although a universally accepted definition is lacking, mild traumatic brain injury and concussion are classified by transient loss of consciousness, amnesia, altered mental status, a Glasgow Coma Score of 13 to 15, and focal neurologic deficits following an acute closed head injury. Most patients recover quickly, with a predictable clinical course of recovery within the first one to two weeks following traumatic brain injury. Persistent physical, cognitive, or behavioral postconcussive symptoms may be noted in 5 to 20 percent of persons who have mild traumatic brain injury. Physical symptoms include headaches, dizziness, and nausea, and changes in coordination, balance, appetite, sleep, vision, and hearing. Cognitive and behavioral symptoms include fatigue, anxiety, depression, and irritability, and problems with memory, concentration and decision making. Women, older adults, less educated persons, and those with a previous mental health diagnosis are more likely to have persistent symptoms. The diagnostic workup for subacute to chronic mild traumatic brain injury focuses on the history and physical examination, with continuing observation for the development of red flags such as the progression of physical, cognitive, and behavioral symptoms, seizure, progressive vomiting, and altered mental status. Early patient and family education should include information on diagnosis and prognosis, symptoms, and further injury prevention. Symptom-specific treatment, gradual return to activity, and multidisciplinary coordination of care lead to the best outcomes. Psychiatric and medical comorbidities, psychosocial issues, and legal or compensatory incentives should be explored in patients resistant to treatment.
Photoallodynia (photophobia) occurs when normal levels of light cause pain ranging from uncomfortable to debilitating. The only current treatment for photoallodynia is light avoidance. The first step to understanding the mechanisms of photoallodynia is to develop reliable animal behavioral tests of light aversion and identify the photoreceptors required to initiate this response. A reliable light/dark box behavioral assay was developed that measures light aversion independently from anxiety, allowing direct testing of one endophenotype of photoallodynia in mice. Mice lacking intrinsically photosensitive retinal ganglion cells (ipRGCs) exhibit reduced aversion to bright light, suggesting these cells are the primary circuit for light aversion. Mice treated with exogenous μ opiate receptor agonists exhibited dramatically enhanced light aversion, which was not dependent on ipRGCs, suggesting an alternative pathway for light is engaged. Morphine enhances retinal electrophysiological responses to light but only at low levels. This suggests that for the dramatic light aversion observed, opiates also sensitize central brain regions of photoallodynia. Taken together, our results suggest that light aversion has at least two dissociable mechanisms by which light causes specific allodynia behaviors: a primary ipRGC-based circuit, and a secondary ipRGC-independent circuit that is unmasked by morphine sensitization. These models will be useful in delineating upstream light sensory pathways and downstream avoidance pathways that apply to photoallodynia.
SYNOPSIS
20 children with clinically diagnosed migraine were asked to wear either a rose coloured tint or density matched blue tint for a period of 4 months. The frequency, duration and intensity of migraine attacks were recorded, together with the amount of visually provoked beta activity in the EEG. After one month's wear all the children in the study revealed an initial improvement in headache frequency. However, only those children wearing rose tints sustained this improvement up to 4 months, when the mean headache frequency had improved from 6.2 per month to 1.6 per month. The headache frequency of those children wearing blue tints revealed no overall improvement after 4 months. The improvements in headache frequency in children wearing rose tints correlated with a reduction in visually provoked bets activity. Key words: children, migraine, photophobia, tint, visual evoked responses
