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Ocular surface temperature of meibomia gland dysfunction patients and the melting point of meibomian gland secretions
Abstract
Since meibomian gland dysfunction (MGD) is thought to be caused by raising of the melting point and degeneration of lipid secretions, the melting point of secretions and the temperature of the ocular surface were investigated.
Twenty-three patients with MGD [mean age 69.3 +/- 7.2 (mean standard deviation) years) were examined. Seven subjects without MGD (mean age 32.5 +/- 5.8 years) were also observed as controls.
Solid secretions obtained from MGD patients were heated and the melting point was measured. The weight ratio of lipids and cell components was also determined.
Corneal temperature was 32.3 +/- 0.5 (mean +/- standard deviation) degrees C and eyelid temperature was 33.1 +/- 0.5 degrees C in the control subjects. Corneal temperature was 31.1 +/- 0.8 degrees C and eyelid temperature was 32.7 +/- 0.6 degrees C in MGD patients. However, the melting point of the secretions was 34.0 +/- 1.3 degrees C, which was higher than the temperature of the ocular surface and eyelid in both patients and controls. The cell components constituted about 60% of the secretions and the lipid composition, about 40%.
The cause of MGD is thought to be solid ification of lipids because of elevation of the melting point and the increase in the cell components of the secretions.
... 6 The application of a warm compress to the eyelids is a standard treatment for obstructive MGD. 7 The surface temperature of the eyelids ranges between 33 and 37 C, whereas the melting range of expressed meibum is between 19.5 and 33.8 C in normal individuals [8][9][10][11] and between 32.2 and 35.3 C in patients with MGD. 9,[11][12][13][14] In individuals with MGD, meibum consists of a mixture of melted lipid and desquamated, keratinized epithelial cells, which probably explains the difference in melting range between normal individuals and MGD patients. ...
... 7 The surface temperature of the eyelids ranges between 33 and 37 C, whereas the melting range of expressed meibum is between 19.5 and 33.8 C in normal individuals [8][9][10][11] and between 32.2 and 35.3 C in patients with MGD. 9,[11][12][13][14] In individuals with MGD, meibum consists of a mixture of melted lipid and desquamated, keratinized epithelial cells, which probably explains the difference in melting range between normal individuals and MGD patients. 9,15 Nuclear magnetic resonance analysis has revealed that lipid phase-transition temperatures of meibum are substantially higher (þ4 C) in patients with MGD than in age-matched normal controls. ...
... 9,[11][12][13][14] In individuals with MGD, meibum consists of a mixture of melted lipid and desquamated, keratinized epithelial cells, which probably explains the difference in melting range between normal individuals and MGD patients. 9,15 Nuclear magnetic resonance analysis has revealed that lipid phase-transition temperatures of meibum are substantially higher (þ4 C) in patients with MGD than in age-matched normal controls. 16 Eyelid temperature influences not only the secretion but also the delivery of meibum to the ocular surface. ...
... Over 90 proteins have been identified in human meibum (Tsai et al., 2006). Meibum from donors with MGD was found to contain cellular debris (Korb and Henriquez, 1980;Terada et al., 2004). The cellular debris, presumably containing proteins, composed 60% of the meibum (Terada et al., 2004). ...
... Meibum from donors with MGD was found to contain cellular debris (Korb and Henriquez, 1980;Terada et al., 2004). The cellular debris, presumably containing proteins, composed 60% of the meibum (Terada et al., 2004). The protein keratin was found to be 10% higher in meibum from donors with MGD compared to meibum from normal donors and, over 30 years ago, it was suggested that the increase in keratinization leads to the occlusion of the meibomian gland orifice and intiates MGD (Ong et al., 1991). ...
... Lipid-protein interactions may be important not only for the structure and function of meibum on the surface of the tear film but also for meibum in the meibomian glands. It has been proposed that keratinization could be responsible for blocking the orifice of the meibomian glands (Korb and Henriquez, 1980;Ong et al., 1991;Terada et al., 2004). The present study indicates that keratin has no major direct effect on the fluidity (viscosity) of wax, the most abundant lipid component in meibum. ...
Protein-meibum and terpenoids-meibum lipid interactions could be important in the etiology of meibomian gland dysfunction (MGD) and dry eye symptoms. In the current model studies, attenuated total reflectance (ATR) infrared (IR) spectroscopy was used to determine if the terpenoid β-carotene and the major proteins in tears and meibum affect the hydrocarbon chain conformation and carbonyl environment of wax, an abundant component of meibum. The main finding of these studies is that mucin binding to wax disordered slightly the conformation of the hydrocarbon chains of wax and caused the wax carbonyls to become hydrogen bonded or experience a more hydrophilic environment. Lysozyme and lactoglobulin, two proteins shown to bind to monolayers of meibum, did not have such an effect. Keratin and β-carotene did not affect the fluidity (viscosity) or environment of the carbonyl moieties of wax. Based on these results, tetraterpenoids are not likely to influence the structure of meibum in the meibomian glands. In addition, these findings suggest that it is unlikely that keratin blocks meibomian glands by causing the meibum to become more viscous. Among the tear fluid proteins studied, mucin is the most likely to influence the conformation and carbonyl environment of meibum at the tear film surface.
... The Tt measured by FTIR spectroscopy of meibum from donors without dry eye (Mn) is 30.3°C, similar to that measured by microscopy [ [46], and 34 ± 1.3 45 for meibum from patients with MGD (M MGD ). The Tt for meibum was slightly lower than that of the surface temperature of the eye, 33.4°C, and eye lid, 36°C [47]. ...
... Heating the meibum another 4°C above the temperatures listed above only results in 5% more disorder. Given that there is a 5°C difference in temperature between heat applied on the external eyelid surfaces and that which reaches the inner surface of the lids where the meibum is located [48], to obtain 90% disorder, the optimal applied heat must be [45][46].5°C at the surface of the eye lid for Mn and M MGD , respectively. At temperatures above 45°C, discomfort and safety are a factor to consider [22][23][24][25]. ...
Purpose:
Numerous devices have been developed to warm the eyelid as a therapy for Meibomian gland dysfunction. The optimum temperature for such therapy was determined.
Methods:
Meibum lipid disorder versus temperature was calculated from previously published phase transition parameters measured using infrared spectroscopy. Phase transitions parameters were calculated from meibum obtained from donors with Meibomian gland dysfunction (MMGD), donors who were susceptible to dry eye after hematopoietic stem cell transplantations (MHSCT) and meibum from donors without dry eye (Mn).
Results:
Heating Mn to 40 °C increases the lipid disorder by 20.4%-90%. Heating the meibum another 4° increases the disorder to 95%. MMGD is 73.2% disordered with no heating. Heating MMGD to 41.5 °C increases the disorder by 26.8%-90% disordered. Heating MMGD another 5.1 °C increases the disorder to 95%. As MHSCT is much more ordered, 56.9% disordered compared with Mn and MMGD, a higher temperature above safety limits, 52 and 59 °C is need to disorder MHSCT to 90 and 95% disorder.
Conclusions:
Heating the eye lid above the phase transition temperature of meibum increases the disorder of meibum lipid which could ameliorate dry eye symptoms. The optimum temperature for disordering Mn and MMGD to 90% maximum disorder is 40 and 41.5 °C, respectively. Safety issues and discomfort should be considered in obtaining an optimal level of disorder, especially for severe cases of dry eye.
... In patients with MGD, the melting point of meibum oil is increased; meibum from normal subjects melts at 32°C, whereas the melting point is Ͼ35°C in patients with MGD. 29,30 A constant warming of the meibomian glands to Ն38°C is vital to liquefy the meibum oil before eyelid massage. 30 The melting of meibum oil after warming is expected to lead to increased secretion of meibum oil 14 and consequently to have positive effects on the tear film lipid layer. ...
... 29,30 A constant warming of the meibomian glands to Ն38°C is vital to liquefy the meibum oil before eyelid massage. 30 The melting of meibum oil after warming is expected to lead to increased secretion of meibum oil 14 and consequently to have positive effects on the tear film lipid layer. At least 4 min of treatment with warm compresses is required to achieve an eyelid temperature of 40°C. ...
To assess the warming and humidifying effect and ocular safety of the Blephasteam® eyelid-warming device vs. warm and moist compresses in healthy volunteers.
Twenty subjects (8 females, 12 males; mean age 39.2 years) were included in the study. Temperature and relative humidity were measured over a period of 10 min at the lower eyelid margin of one randomly selected eye during application of the Blephasteam device and, 1 h later, during application of warm compresses (in a randomized order). Ocular signs and visual acuity were assessed before and after each application.
The mean duration of warming (temperature ≥38°C) was significantly longer with Blephasteam than with compresses (7.5 vs. 1.0 min; p < 0.01). There was no significant difference between treatments in the duration of 100% relative humidity. Compared with pretreatment values, visual acuity significantly improved after Blephasteam treatment (p < 0.05) but significantly decreased after treatment with compresses (p < 0.05). Limbal redness, eyelid redness, and corneal staining scores all improved significantly after Blephasteam treatment (p < 0.05 for all). Ocular signs did not change after compress treatment except conjunctival redness, which was significantly increased (p = 0.01 vs. pretreatment).
The Blephasteam eyelid-warming device appeared to provide more effective warming than warm and moist compresses in a group of healthy volunteers. Visual acuity, limbal redness, and eyelid redness were improved after Blephasteam use but not after treatment with compresses.
... The average phase-transition temperature for Md was approximately 4°C higher than that for age-matched Mn. Terada et al. 64 reported the only study that evaluated Md "melting" at 34.0 Ϯ 1.3°C, but this melting temperature was assessed visually. "Melting" of Mn from age-matched controls ranged from 32°C to 37°C in Terada et al. 64 and the SE was too large to be significantly different from the melting of Md. ...
... Terada et al. 64 reported the only study that evaluated Md "melting" at 34.0 Ϯ 1.3°C, but this melting temperature was assessed visually. "Melting" of Mn from age-matched controls ranged from 32°C to 37°C in Terada et al. 64 and the SE was too large to be significantly different from the melting of Md. The phasetransition temperature of Mn, 28.5°C (Table 4), was below the 59.47, 55.45, 52.14, 51.91, 51.37, 50.93, 50.57, 50.01, 49.41, 49.35, 48.78, 48.02, 42.74, 35.5, and 24.17 temperature of the eyelid, 33.1°C to 33.4°C, 65,66 ensuring that the Mn is predominantly disordered at lid temperature. ...
Instability of the tear film with rapid tear break-up time is a common feature of aqueous-deficient and evaporative dry eye diseases, suggesting that there may be a shared structural abnormality of the tear film that is responsible for the instability. It may be that a change in the normal meibum lipid composition and conformation causes this abnormality. Principle component analyses of infrared spectra of human meibum indicate that human meibum collected from normal donors (Mn) is less ordered than meibum from donors with meibomian gland dysfunction (Md). In this study the conformation of Md was quantified to test this finding.
Changes in lipid conformation with temperature were measured by infrared spectroscopy. There were two phases to our study. In phase 1, the phase transitions of human samples, Mn and Md, were measured. In phase 2, the phase transitions of model lipid standards composed of different waxes and cholesterol esters were measured.
The phase-transition temperature was significantly higher (4°C) for the Md compared with the Mn of age-matched donors with no history of dry-eye symptoms. Most (82%) of the phase-transition temperatures measured for Md were above the values for Mn. The small change in the transition temperature was amplified in the average lipid order (stiffness) at 33.4°C. The average lipid order at 33.4°C for Md was significantly higher (30%, P = 0.004) than for Mn. The strength of lipid-lipid interactions was 72% higher for Md than for Mn. The ability of one lipid to influence the melting of adjacent lipids is termed cooperativity. There were no significant differences between Mn and Md in phase-transition cooperativity, nor was there a difference between Mn and Md in the minimum order or maximum order that Mn and Md achieved at very low and very high temperatures, respectively. The model wax studies showed that the phase transition of complex mixtures of natural lipids was set by the level of unsaturation. A double bond decreased the phase-transition temperature by approximately 40°C. The addition of a second CH CH moiety decreased the phase-transition temperature by approximately 19°C. Unsaturated waxes were miscible with saturated waxes. When a saturated wax was mixed with an unsaturated one, the saturated wax disproportionately increased the phase transition of the mixture by approximately 30°C compared with the saturated wax alone. Cholesterol ester had little effect on the phase-transition temperature of the waxes. Model studies indicated that changes in the amount of lipid saturation, rather than the amount of cholesterol esters, could be a factor in the observed conformational changes.
Meibum lipid compositional changes with meibomian gland dysfunction reflect changes in hydrocarbon chain conformation and lipid-lipid interaction strength. Spectroscopic techniques are useful in studying the lipid-lipid interactions and conformation of lipid from individual patients. (ClinicalTrials.gov number, NCT00803452.).
... Thermoregulation of the eyelid has a significant impact on the release of Meibomian gland secretion. For example, the secretion of the Meibomian glands is only liquid in a certain temperature range (Nagymihályi et al., 2004;Rosenfeld et al., 2013;Terada et al., 2004); it is possible that a similar thermoregulatory mechanism applies to the Zeis glands, which are located adjacent to the Moll glands, although there is currently no available data to confirm this. If the Moll glands are thermoregulatory, their mechanism of action would likely differ from that of the eccrine sweat glands, which are well-known for their involvement in temperature regulation through sweat production. ...
Over the last 20 years, research into the Meibomian glands of the eyelids has increased exponentially and is now widely recognized as a field of research. It is all the more astonishing that knowledge about another type of gland in the eyelids, the Moll glands or ciliary glands, has almost stagnated and there has been little to almost no progress, even though this type of gland as a whole takes up a relatively large volume in the upper and lower eyelids. There is not much information about the namesake Moll or the function of the glands although these are listed in nearly every textbook of anatomy, histology and ophthalmology. For this reason, we set out to compile the existing knowledge about the Moll glands of the eyelids in order to create a basis for follow-up studies and to stimulate research into this type of gland. In our literature research, we went back to the middle of the 19th century and made contact with a descendant of the Moll family and illustrate their relevance for the present. The structure of the secretory part of the Moll glands is very well described, a number of secretory products are known, but the current state of research allows only very rough speculations about their function. The overview provides numerous interesting insights, which, however, raise more questions than they provide answers.
... These findings may be potentially explained by the thermal and selective photothermolysis effects of IPL treatment [33]. The production of heat during IPL liquefies pathological meibum with raised melting point found in MGD [34], alleviating ductal obstruction and improving meibum flow. Furthermore, IPL devices emits light of wavelengths ranging 500 nm to 1200 nm that is posited to reduce the release of inflammatory agents through coagulation of diseased vessels [35], providing relief to MGD symptoms. ...
... Although the major pathophysiology of hyposecretion in MGD is hyperkeratinisation of the acini, lipolysis by bacterial enzymes, such as lipases, may be related to the alterations in meibum quality. The melting point and viscosity of the abnormal meibum increase, resulting in plugging of the MG orifices [31]. Free fatty acids are also produced via lipolysis, and their decomposition products may induce tissue inflammation and tear film instability [6,32]. ...
Purpose
To assess the effects of 1% azithromycin ophthalmic solution (AZM) in patients with bacterial blepharitis accompanied by meibomian gland dysfunction (MGD).
Study design
A multicenter, single arm, prospective interventional study.
Methods
AZM was administered to the affected eyes twice daily for the first 2 days and once daily for the subsequent 12 days. Lid margin hyperaemia/redness, collarette at the root of the eyelashes, conjunctival hyperaemia, foreign body sensation, and epiphora were assessed on Days 1, 14, and 28. The Dry Eye-related Quality of Life Score (DEQS) and objectives related to MGD, including lid vascularity, lid margin irregularity, foaming, lid plugging, keratoconjunctival disorders, Marx line, meibum grade, and tear breakup time, were also assessed. Bacterial culture of the conjunctival sac and meibum was performed on Days 1 and 14.
Results
Twenty-four eyes of 24 patients (10 men/14 women, mean age 72.3 ± 13.2) were included. On Days 14 and 28, the total score, lid vascularity, lid plugging, and meibum grade showed significant improvement ( p < 0.05). On Day 1, 71 strains were isolated from 22 of the 24 eyes (91.7%). Cutibacterium acnes , Corynebacterium spp., and Staphylococci were detected at high frequencies. The overall disappearance rates of the bacteria in the conjunctival sac and meibum at the end of treatment were 65.7% and 58.3%, respectively. No serious ocular or systemic adverse events were observed.
Conclusion
Fourteen-day treatment with AZM was effective in patients with blepharitis accompanied by MGD, and the efficacy of AZM persisted for a period after the treatment.
... The ideal meibum-melting temperature is 41°C, which can be achieved with 45°C external heat. 3,15,16,22 After heat application, the patient underwent physician-facilitated expression of the glands using a slit-lamp biomicroscope and a handheld expressor functioning as the Clearance Assistant Plus (the third part of the system). The devices were used according to the manufacturer's approved indications. ...
Significance:
Meibomian gland dysfunction (MGD) can produce a myriad of symptoms. The effective treatment of MGD can reduce the burden of this condition. Although several studies have indicated that TearCare is an effective treatment for MGD, no studies currently provide information regarding the duration of efficacy.
Purpose:
The purpose of this analysis was to determine the duration of efficacy of symptom relief and improvement of signs (as measured by gland function) for a treatment consisting of controlled heating of the meibomian glands using SmartLids combined with manual expression of the liquified meibum by a physician.
Methods:
This study involved retrospective analysis of data gathered from a single-center ophthalmology/optometry practice. Symptoms were assessed using the Standard Patient Evaluation of Eye Dryness Questionnaire (SPEED), and the signs were assessed using the meibomian gland expression (MGE) scores before and at several time points (8 weeks, 6 months, 12 months, and 18 months). Further analysis evaluating the efficacy in subgroups based on age, race, and sex was performed.
Results:
There were 78 patients included in this study. The mean baseline SPEED score decreased from 14 to 7.9 at eight weeks. The mean SPEED scores at 6 and 12 months were maintained at 7.7 and 7.9, respectfully and at 18 months went to 8.9. At baseline, the mean MGE was 4.9 in the right eye and 4.8 in the left eye. In both eyes, the mean MGE increased to 9.0 in both eyes at 8 weeks. At 6 months the mean MGE score was maintained at 8.6 in the right and 8.2 in the left and remained consistent at 12 months with 7.8 in the right and 7.8 in the left. At 18 months the MGE score went to 6.8 in the right eye and 7.0 in the left eye.
Conclusions:
A Single TearCare treatment effectively reduced both the symptoms and signs of MGD and maintained its effects for 12 months.
... The device delivers constant 42℃ heat directly over the meibomian glands of the upper and lower inner eyelids while varying degree of pulsatile pressure simultaneously evacuates the obstruction meibum. This temperature is the optimal temperature intended to effectively melting of obstructed meibum, while posing no risk to ocular surface at the same time [18]. Considering that the meibomian glands are located on the inner eyelid, to achieve and maintain a therapeutic heat temperature on inner eyelid is an important prerequisite for subsequent meibomian gland dredging and treatment. ...
Objectives: To investigate the effect of thermal pulsation treatment on meibomian gland function, ocular parameters and tear inflammatory cytokines compared with the warm compress group.
Methods: Twenty-five participants with MGD underwent a 12-minute thermal pulsation treatment, while 25 participants with MGD underwent manual warm compress treatment. MGD related parameters, including meibomian gland function (MGE, MQ and lid margin), tear stability (NIKBUT, FBUT and LLT), tear secretion (SIT, and TMH), were examined and OSDI questionnaire was also obtained. Tear chemokines (MIG, IFN-γ, IL-8, IP-10 and MCP-1) were examined and analyzed the correlations with MGD related parameters and OSDI.
Results: Compared with warm compress subjects, OSDI, lid margin and tear stability were found improved more in thermal pulsation treatment at 3 months (OSDI: *p = 0.014, lid margin: *p = 0.021, LLT: **p = 0.008, CFS: *p = 0.028). The level of IP-10 and MIG decreased more in thermal pulsation group than in warm compress group (IP-10: *p = 0.021, MIG: *p = 0.039). IP-10 was positively correlated with MQ (r = 0.522, *p = 0.037) and negatively correlated with tear stability (r = -0.613, **p = 0.002), and OSDI was only positively correlated with IL-8 (r = 0.679, ***p < 0.001). The decrease of MIG was positively correlated with less corneal epithelium injury (r = 0.557, **p = 0.006) and meibograde (r = 0.49, *p = 0.019).
Conclusions: Thermal pulsation treatment obviously improved MGD probably by attenuating tear CXCL chemokines in ocular surface of MGD patients, which demonstrated an efficacy and well-tolerated therapy in clinical.
... This may explain the poor meibum secretion observed in this patient group [12][13][14]. This abnormal secretion in turn leads to glandular atrophy, dropout, and decreased gland function [15]. ...
Background
Meibomian gland dysfunction (MGD) reduces quality-of-life and hinders work productivity of millions of patients, with high direct and indirect societal costs. Thickened meibum obstructs the glands and disrupts ocular surface health. Heating the eyelids to soften and express meibum from the glands can be beneficial. The most accessible method for eyelid warming uses heated, wet towels. However, the efficacy of this treatment is reliant on the methodology, and evidence-based best-practice recommendations are needed.
Purpose
To evaluate the literature on hot towels in MGD treatment and recommend a best-practice protocol for future research and patient treatment.
Methods
Studies were identified through PubMed on the May 28, 2021, with the search terms: (warm* OR heat* OR thermal* OR towel OR wet towel) AND (meibomian OR MGD OR eyelid OR “dry eye” OR DED). All relevant original articles with English full-text were included.
Results
The search yielded 903 results, of which 22 met the inclusion criteria. Across studies, hot towels were found to be effective at reducing ocular symptoms. However, without reheating, the temperature quickly fell below the therapeutic range, which was deemed to be between 40 °C and 47 °C. Towels heated to around 45 °C and reheated every-two minutes were most effective at increasing eyelid temperature, comparable or better than several commercially available eyelid warming devices. No adverse effects were reported in the studies.
Conclusion
Hot towel treatment effectively warms the eyelids and reduces ocular symptoms, but must be standardized, and towels reheated to achieve maximum benefit. Future research should assess patient satisfaction with different hot towel treatment methods that reheat or replace the towel at least every-two minutes, to establish which methods yield the greatest compliance. Guidelines or clinical recommendations that do not mention the need for regular reheating during hot towel compress treatment should be updated to include this.
... The melting range of expressed meibum is between 19.5 and 33.8 • C in normal individuals, while it is between 32.2 and 35.3 • C in patients with MGD [9][10][11]. Although there were some studies related to TFLLT changes after warm compression, these have involved single-group participants who were either normal or had MGD [12,13]. ...
Meibomian gland dysfunction (MGD), a chronic abnormality of meibomian glands, causes various dry eye symptoms. Principal treatments for MGD are warm compression and mechanical squeezing of the eyelids. In this study, the immediate impact of this treatment on tear film lipid layer thickness (TFLLT) and the meibomian gland (MG) structure in MGD and normal groups was investigated to establish its efficacy and potential side effects. Nineteen MGD patients and seven normal subjects were enrolled. TFLLT and blinking parameters were evaluated before and after warm compression. Morphological changes of MG structures after mechanical squeezing were analyzed using Image J and Fiji. Differential analysis of the MGD and the normal groups of TFLLT changes after warm compression showed a significant increase in the normal group. In normal eyes, the average, maximum, and minimum TFLLT were significantly increased, and in the MGD group, only the minimum TFLLT was improved. Blinking parameters showed no significant change in either group. Morphometric analysis showed no damages of the MG after MG squeezing. A significant increase in MG length was observed in normal eyes. Warm compression immediately increased TFLLT more significantly in the normal group than in the MGD patients. Mechanical expression is a safe therapeutic option without remarkable structural MG damages.
... 7,8 The temperature required to soften or liquify pathological meibum is >40°C, 7 whereas the melting point for normal meibum is approximately 34.0°C. 9 While face cloths and towels are frequent recommendations for treating MGD in clinical care, Blackie et al (n = 32) showed that towels or cloths rapidly lose heat 10 and took approximately 6 minutes for the inner eyelid to reach a therapeutic temperature of 40.4 ± 0.3°C. This finding was corroborated by Bitton et al 11 and Lacroix et al,12 who also demonstrated the rapid cooling of towel compresses. ...
Meibomian gland dysfunction (MGD) is characterized by the obstruction and/or inflammation of the meibomian glands that result in decreased and altered meibum secretion. This results in deficiencies in the tear film lipid layer which contributes to increased evaporation and destabilization of the tear film. One of the mainstay therapies for MGD is medical devices that apply heat and/or pressure to the eyelids and promote the liquification and outflow of meibum into the tear film. Over the past two decades, there have been a surge of interest in diagnosing and managing MGD. As a result, numerous medical devices have been developed and each have their own unique approach to treating MGD. This narrative review was conducted to summarize the current state of knowledge on eyelid warming devices, specifically warm eye coverings, devices that direct heat and/or pressure to the eyelids, moisture chamber goggles, and light-based therapy. This review summarized 58 human clinical studies and found that most eyelid warming devices were efficacious in improving signs and symptoms in a wide range of MGD severities and were generally safe to use.
... Thus, raised temperature facilitates the secretion and delivery of meibum to the ocular surface. [21] Our study has a few limitations. The sample size in each group was small, resulting in an insignificant change in breakup time and tear osmolarity after intervention for MGD. ...
Purpose:
To compare the efficacy of physiological, non-detergent eyelid wipes with conventional lid hygiene in patients with meibomian gland dysfunction (MGD).
Methods:
Fifty participants with MGD were recruited and randomized into two groups. Participants in group I used Evolve Pure™ Eyewipes twice a day to clean the eyelid debris along with standard therapy (antibiotic and lubricants) and participants in group II followed lid hygiene with warm compresses along with standard therapy. Symptoms, ocular surface assessment (lipid layer thickness, tear meniscus height, non-invasive tear film breakup time, and meibography), slit-lamp biomicroscopy (eyelash contamination, meibomian gland blockage, meibomian gland secretion, and meibomian gland telangiectasia) and tear film osmolarity were noted at baseline and 90 days after therapy.
Results:
Significant improvement in symptoms and signs of MGD was observed in both groups after treatment (P < 0.001); however, the clinical improvement was better with the use of eyelid wipes. Lipid layer thickness increased significantly in group I (P = 0.0006) and group II (P = 0.0002), which was maintained even after adjusting for sociodemographic variables such as age, sex, and severity score of symptoms and signs.
Conclusion:
Lipid layer thickness of the tear film is a sensitive marker in monitoring response to treatment in patients with MGD. The use of physiological detergent-free eyelid wipes is non-inferior to lid hygiene and warm compresses, which remains the mainstay for treatment of MGD; the clinical improvement with eyelid wipes was noted to be better.
... The positive correlation observed between body temperature and ocular temperature (Purslow and Wolffsohn 2005) and between ocular temperature difference values (TDVs) and dry eye parameters suggest that OST monitoring is important to obtain POC ocular diagnostics. OST increase observed in patients with meibomian gland dysfunction (MGD) (Terada et al. 2004), phakic and pseudophakic (Sniegowski et al. 2015) psychiatric disorders (Monge-Roffarello et al. 2014, Tan et al. 2009) in post-corneal transplant undergoing inflammation (Sniegowski et al. 2018), and dogs with keratoconjunctivitis sicca (Biondi et al. 2015) further evidences for the necessity for the measurement of OST to monitor disease progression in personalized diagnostics . Thermochromic liquid crystals (TLCs) show reversible color change to temperature and this principle was adopted to fabricate a CL-based temperature sensor. ...
... The positive correlation observed between body temperature and ocular temperature (Purslow and Wolffsohn 2005) and between ocular temperature difference values (TDVs) and dry eye parameters suggest that OST monitoring is important to obtain POC ocular diagnostics. OST increase observed in patients with meibomian gland dysfunction (MGD) (Terada et al. 2004), phakic and pseudophakic (Sniegowski et al. 2015) psychiatric disorders (Monge-Roffarello et al. 2014, Tan et al. 2009) in post-corneal transplant undergoing inflammation (Sniegowski et al. 2018), and dogs with keratoconjunctivitis sicca (Biondi et al. 2015) further evidences for the necessity for the measurement of OST to monitor disease progression in personalized diagnostics . Thermochromic liquid crystals (TLCs) show reversible color change to temperature and this principle was adopted to fabricate a CL-based temperature sensor. ...
... In healthy subjects, the phase-transition of meibum is about 28 °C (when meibum transitions from an ordered and gel-like phase to a disordered fluid-like phase) 5 . MGD patients have a phase-transition at a higher temperature of about 35 °C [6][7][8][9] . This explains the rationale behind applying heat to the eyelids of MGD patients as it brings the meibum in the eyelids above its phase-transition temperature, enabling it to freely flow out of the meibomian glands to comprise the outermost layer of the tear film, thereby reducing evaporation of the aqueous layer 3 . ...
Meibomian gland dysfunction (MGD) is the most common cause of dry eye disease (DED). In this study, we aimed to compare the effects of eyelid warming treatment using either TheraPearl Eye Mask (Bausch & Lomb Inc., New York, USA) or Blephasteam (Spectrum Thea Pharmaceuticals LTD, Macclesfield, UK) in a Norwegian population with mild to moderate MGD-related DED. An open label, randomized comparative trial with seventy patients (49 females, 21 males; mean age 53.6 years). Patients were randomly assigned to treatment with Blephasteam (n = 37) or TheraPearl (n = 33). All received a hyaluronic acid based artificial tear substitute (Hylo-Comod, Ursapharm, Saarbrücken, Germany). Patients were examined at baseline, and at three and six months initiation of treatment. Treatment efficacy was primarily evaluated by fluorescein breakup time (FBUT) and Ocular Surface Disease Index (OSDI) scores. Other outcome measures included ocular surface staining (OSS), Schirmer’s test, and meibomian quality and expressibility. Baseline parameter values did not differ between the groups. After six months of treatment, Blephasteam improved FBUT by 3.9 s (p < 0.01) and OSDI by 13.7 (p < 0.01), TheraPearl improved FBUT by 2.6 s (p < 0.01) and OSDI by 12.6 (p < 0.01). No difference between treatments was detected at 6 months (p = 0.11 for FBUT and p = 0.71 for OSDI), nor were there differences in the other tested parameters between the treatment groups. Blephasteam and TheraPearl are equally effective in treating mild to moderate MGD in a Norwegian population after 6-months of treatment.
Clinicaltrials.gov ID: NCT03318874; Protocol ID: 2014/1983; First registration: 24/10/2017.
... Thus, it is possible that in defining the area of interest on the thermographic images for these 2 subjects a region of nasal conjunctiva was included in the demarcated area used to estimate the cornea-averaged temperature, leading to a measurement of ocular surface warming. Terada et al. measured corneal and eyelid temperatures in both control subjects and subjects with Meibomian gland dysfunction, and recorded eyelid temperatures 1-2 °C warmer than corneal temperatures 63 . It is also possible that frames demarcating the area of interest included a small section of the warmer upper eyelid, contributing to a measurement of apparent OST warming. ...
The surface of the human eye is covered with a protective tear film that refreshes with each blink. Natural blinking occurs involuntarily, but one can also voluntarily blink or refrain from blinking. The maximum time one can refrain from blinking until the onset of discomfort is the maximum interblink period (MIBP). During the interblink period the tear film evaporates and thins from the ocular surface. Infrared thermography provides a non-invasive measure of the ocular surface temperature (OST). Due to evaporation, ocular surface cooling (OSC) generally occurs when the eyes are open and exposed to the environment. The purpose of our study was to investigate the effect of OSC rate on the MIBP, and to investigate the association of the MIBP with tear film characteristics in subjects who do and do not exhibit OSC. The MIBP was measured simultaneously with OST over time. Non-invasive tear breakup time, tear meniscus height, tear lipid layer thickness, and Schirmer I test strip wetted lengths were measured on a day prior to the thermography visit. Subjects were divided into cooling and non-cooling groups based on OSC rate, and demographic and tear film characteristics were tested for inter-group differences. A faster OSC rate was associated with an exponentially shorter duration of the MIBP overall and within the cooling group alone. Faster non-invasive tear breakup time was significantly associated with a shorter MIBP in both groups. These results suggest that tear film evaporation initiates a pathway that results in the onset of ocular discomfort and the stimulus to blinking. The presence of a subset of subjects with no or minimal OSC who nevertheless have a short MIBP indicates that evaporative cooling is not the only mechanism responsible for the onset of ocular discomfort.
... Other key points include reducing epithelial turnover and reducing the risk of gland obstruction, activating fibroblasts, and improving collagen synthesis, minimizing demodex mite infestation, modulating the secretion of pro-and anti-inflammatory molecules, and reducing the concentration of MMPs by downregulating at the mRNA level and influencing reactive oxidative species (ROS) [19,20]. showing resolution with two treatments. ...
... The melting point of meibomian gland secretions ranges from 32°C to 40°C, 12 with melting points elevated in patients with meibomian gland dysfunction, allowing secretions to stagnate. 12,13 Warm compresses rapidly lose heat and fall below the therapeutic temperature of 40°C within the first minute of application. 14 Even commercially available eyelid masks microwaved for 10-20 s do not remain consistently above 38°C for the entire 10-min treatment. ...
Purpose
To compare the effects of eyelid treatment with the iLUX MGD Treatment System and the LipiFlow Thermal Pulsation System on objective and subjective parameters of meibomian gland function and symptoms.
Patients and Methods
In this randomized, open-label, controlled, multicenter clinical trial, both eyes of 142 patients aged ≥18 years with Ocular Surface Disease Index (OSDI) scores ≥23, total meibomian gland scores (MGS) ≤12 in the lower eyelid of each eye, and tear break-up time (TBUT) <10 s were randomized 1:1 to iLUX or LipiFlow treatment, with stratification by test center. The primary effectiveness endpoints were changes in total MGS (masked) and TBUT from baseline to 4 weeks. The secondary effectiveness endpoint was changed in OSDI score from baseline to 4 weeks.
Results
Both devices significantly improved effectiveness outcomes, with no differences between the two devices. At the 4-week visit, mean MGS, TBUT, and OSDI scores improved at least 16.9 ± 11.5, 2.6 ± 3.2 s, and 28.0 ± 22.8, respectively, across treatment groups and treated eyes. Four device/procedure-related events occurred in the iLUX group, compared with none in the LipiFlow group, but there were no device-related adverse events that involved changes in lid margins, eyelids, or lash integrity. Corneal staining, intraocular pressure, and visual acuity did not differ in the two groups.
Conclusion
Both treatments produced significant improvements in meibomian gland function and symptoms. For all effectiveness measures, there were no statistically significant differences between the two treatments.
... 32 Similar trends were also observed in corneal and eyelid temperatures. 33 The tarsal conjunctival or eyelid temperature of MGD patients measured in the 2 studies was lower than the meibum melting point of 35°C ...
Objectives:
To evaluate recent studies on available therapies for meibomian gland dysfunction (MGD).
Methods:
A literature search on recent publications, within the last five years, concerning treatment options for MGD was performed.
Results:
A total of 35 articles were reviewed after curation by the authors for relevance. In general, all modalities of treatments were shown to have clinical efficacy in alleviating dry eye signs and symptoms, although the extent of improvement and persistency of outcomes varied between the different treatments. Evidence from published studies demonstrate that thermal pulsation produces the longest lasting effect per treatment, but it also incurs the highest per-treatment cost. Reusable methods for warm compress with lipid/semi-fluorinated alkane-containing eye drops are recommended as first-line treatment for mild-to-moderate dry eye patients, because this option is most technically feasible and cost-effective in clinical practice. Intense pulsed light (IPL) therapy and thermal pulsation may be suitable as second line for patients unresponsive to warm compress therapy; however, their respective limitations need to be considered. For refractory MGD with features of periductal fibrosis or severe blepharitis, supplementary treatment with meibomian gland probing or oral antibiotics may be used.
Conclusions:
All eight forms of treatments, including self-applied eyelid warming, thermal pulsation, IPL, MG probing, antibiotics, lipid-containing eye drops, and perfluorohexyloctane, were effective against MGD, although with varying extent of clinical improvements. A better understanding on the mechanisms of actions may guide physicians to make better treatment decisions targeting the root causes.
... 23 An average increase of 0.8 C was observed in the OST of Meibomian Gland Dysfunction (MGD) patients when compared to matched controls. 32 Attempts were made in DED screening by OST measurement. 24,25 The OST was found to increase as a response to peripheral vasoconstriction, suggesting OST monitoring as a promising method to evaluate ocular vasoregulation. ...
Temperature variation is a ubiquitous medical sign to monitor ocular conditions including dry eye disease (DED), glaucoma, carotid artery stenosis, diabetic retinopathy, and vascular neuritis. The ability to measure OST in real time is desirable in point-of-care diagnostics. Here, we developed minimally invasive contact lens temperature sensors for continuous monitoring of the corneal temperature. The contact lens sensor consisted of a laser patterned commercial contact lens embedding temperature-sensitive Cholesteric Liquid Crystals (CLCs), which exhibited a fully reversible temperature-dependent color change in the visible spectrum. The contact lens allowed the corneal temperature to be mapped in four key areas, at distances of 0.0, 1.0, 3.0, and 5.0 mm from the pupil's edge. Liquid crystals exhibited a wavelength shift from 738 AE 4 nm to 474 AE 4 nm upon increasing the temperature from 29.0 C to 40.0 C, with a time responsivity of 490 ms and a negligible hysteresis. Readouts were performed using a smartphone, which output RGB triplets associated to temperature values. Contact lens sensors based on CLCs were fitted and tested on an ex vivo porcine eye and readouts were compared with infrared thermal measurements, resulting in an average difference of 0.3 C.
... The TearCare System delivers heat (41°C-45°C) to the outer surface of the eyelid for 12 minutes. This temperature range is intended to allow effective melting of obstructed meibum, 18,19,36 while at the same time posing no risk to the patient. 37,38 The safety of this level of heat applied to the eyelids has been demonstrated by Blackie et al in which WCs heated to 45°C were successively applied for 30 minutes with no reported heat-related injury. ...
Purpose
The objective of this study was to evaluate the safety and effectiveness of the TearCare® System in adult patients with clinically significant dry eye disease (DED).
Patients and methods
This was a prospective, single-center, randomized, parallel-group, clinical trial. Subjects with DED were randomized to either a single TearCare treatment conducted at the clinic or 4 weeks of daily warm compress (WC) therapy. The TearCare procedure consisted of 12 minutes of thermal eyelid treatment immediately followed by manual expression of the meibomian glands. WC therapy consisted of once daily application of the compresses to the eyelids for 5 minutes. Subjects were followed until 6 months post-treatment. The primary effectiveness end point was defined as change from baseline to 4 weeks for tear breakup time (TBUT). Secondary effectiveness end points included meibomian gland assessment, corneal and conjunctival staining scores, and assessment of dry eye symptoms using validated questionnaires. Safety was evaluated by collecting device-related adverse events, intraocular pressure, and best spectacle-corrected Snellen Visual acuity.
Results
Twenty-four subjects were enrolled and all subjects completed 6 months follow-up. At the 1-month follow-up, TearCare subjects demonstrated an improvement from baseline in mean (±SD) TBUT of 11.7±2.6 seconds compared with an average worsening of −0.3±1.1 seconds for subjects in the WC group (p<0.0001). Significantly greater improvements in the change from baseline in meibomian gland scores, as well as corneal and conjunctival staining scores, were observed in the TearCare group. Subjects in the TearCare group also showed significantly greater improvement in dry eye symptoms as measured by the 3 questionnaires. Both treatments were well-tolerated.
Conclusion
The findings of this pilot study suggest that the TearCare System is an effective treatment option for patients with DED, with the effects on the signs and symptoms of DED persisting for at least 6 months.
... The wavelength of light used in IPL for patients with DED owing to MGD is partially infrared, which can penetrate skin to the meibomian glands, generating enough heat to melt the solid secretions in the dysfunctional glands. 49 The M22 model uses the cooling sapphire crystal tip to cool the skin, allowing higher-temperature pulses without epidermal burning. 50 Secondly, optimized pulse technology (OPT) is a feature on the fifth-generation M22 unit that may confer outcome advantages. ...
Purpose:
To investigate the change from baseline of inflammatory markers in tears of dry eye disease(DED) subjects due to meibomian gland dysfunction(MGD) after IPL(intense pulsed light) treatment and meibomian gland expression(MGE) compared to sham treatment, and the correlations with ocular surface parameters.
Design:
Randomized, double-masked, controlled study.
Methods:
Those randomized into the active treatment arm received 3 consecutive treatments(14∼16J/cm(2)) approximately 4 weeks apart in the periocular region. Control eyes received 3 treatments in the same intervals of 0J/cm(2). Tear samples in all eyes were collected and analyzed at baseline, Week 12 and/or Week 4 for interleukin(IL)-17A, interleukin(IL)-6, and prostaglandin E2(PGE2).The correlations between cytokines and ocular surface parameters were analyzed before and after IPL treatment.
Results:
All of the inflammatory markers declined in value compared to baselines. IL-17A and IL-6 showed statistically significant decreases compared to sham treatment at each measured time point. PGE2 showed statistically significant decreases compared to sham at Week 12. Results showed that the expressions of IL-17A and IL-6 correlated well with ocular surface parameters of the lower eyelid before IPL. The changed values of IL-6 and PGE2 in tears correlated with the changed values of partial ocular surface parameters after IPL treatment in study eyes, respectively.
Conclusions:
The study results suggest IPL can significantly reduce inflammatory markers in tears of patients suffering with DED due to MGD after IPL treatment. These findings indicates that IL-17A and IL-6 play roles in the pathogenesis of DED due to MGD, and the reduction of the inflammatory factors is consistent with the improvement of partial clinical symptoms and signs.
... 20,27 This temperature allows for effective heating of the meibomian gland contents, 6 while operating within a safe zone so as not to cause thermal injury. 28,29 As such, the LipiFlow ® System is designed to evacuate the meibomian glands of the upper and lower eyelids simultaneously and with minimal discomfort, on average. 20,27 The numerous peer-reviewed reports on the LipiFlow ® System in both randomized controlled and uncontrolled clinical trials consistently show that the single 12-minute procedure is surprisingly effective and that the effect can be sustained. ...
Purpose
To evaluate the sustained effect (up to 1 year) of a single, 12-minute vectored thermal pulsation (VTP) treatment in improving meibomian gland function and dry eye symptoms in patients with meibomian gland dysfunction and evaporative dry eye.
Methods
The prospective, multicenter, open-label clinical trial included 200 subjects (400 eyes) who were randomized to a single VTP treatment (treatment group) or twice-daily, 3-month, conventional warm compress and eyelid hygiene therapy (control group). Control group subjects received crossover VTP treatment at 3 months (crossover group). Effectiveness measures of meibomian gland secretion (MGS) and dry eye symptoms were evaluated at baseline and 1, 3, 6, 9, and 12 months. Subjects with inadequate symptom relief could receive additional meibomian gland dysfunction therapy after 3 (treatment group) and 6 months (crossover group).
Results
At 3 months, the treatment group had greater mean improvement in MGS (P<0.0001) and dry eye symptoms (P=0.0068), compared to controls. At 12 months, 86% of the treatment group had received only one VTP treatment, and sustained a mean improvement in MGS from 6.4±3.7 (baseline) to 17.3±9.1 (P<0.0001) and dry eye symptoms from 44.1±20.4 to 21.6±21.3 (P<0.0001); 89% of the crossover group had received only one VTP treatment with sustained mean improvement in MGS from 6.3±3.6 to 18.4±11.1 (P<0.0001) and dry eye symptoms from 49.1±21.0 to 24.0±23.2 (P<0.0001). Greater mean improvement in MGS was associated with less severe baseline MGS (P=0.0017) and shorter duration of time between diagnosis and treatment (P=0.0378).
Conclusion
A single VTP treatment can deliver a sustained mean improvement in meibomian gland function and mean reduction in dry eye symptoms, over 12 months. A single VTP treatment provides significantly greater mean improvement in meibomian gland function and dry eye symptoms as compared to a conventional, twice-daily, 3-month regimen. Early VTP intervention for meibomian gland dysfunction is associated with improved treatment outcomes.
... Although management options vary for MGD treatment, warm compresses (WC) are regarded as a primary home-based therapy [2,[4][5][6]. Warm compresses aiming to provide a thicker lipid layer by softening the stagnant meibum in the glands in order to facilitate it's expression upon blinking [2,7,8]. The challenge in heating the eyelid surface is to have the appropriate temperature reach the meibomian glands (MG). ...
Purpose:
Meibomian gland dysfunction (MGD) is one of the most common causes of evaporative dry eye. Warm compresses (WC) are recommended as adjunct therapy to slowly transfer heat to the meibomian glands to melt or soften the stagnant meibum with targeted temperatures of 40-45°C. This clinical study evaluated the heat retention profiles of commercially available eyelid warming masks over a 12-min interval.
Methods:
Five eyelid-warming masks (MGDRx Eyebag(®), EyeDoctor(®), Bruder(®), Tranquileyes XR™, Thera°Pearl(®)) were heated following manufacturer's instructions and heat retention was assessed at 1-min intervals for 12min. A facecloth warmed with hot tap water was used as comparison.
Results:
Twelve (n=12) subjects participated in the study (10F:2M, ranging in age from 21 to 30 with an average of 23.2±3.8years). Each mask demonstrated a unique heat retention profile, reaching maximum temperature at different times and having a different final temperature at the end of the 12-min evaluation. After heating, all eyelid warming masks reached a temperature near 37°C within the first minute. The facecloth was significantly cooler than all other masks as of the 2-min mark (p<0.05).
Conclusions:
Reusability, availability and heat retention profiles should be considered when selecting an eyelid warming masks for adjunct WC therapy in the management of MGD. All masks tested, with the exception of the facecloth, demonstrated stable heat retention throughout the 12min, bringing further awareness that patient education is required to discuss the shortcomings of the heat retention of the facecloth, if only heated once.
... In patients with MGD, the meibum has an altered chemical structure that increases its melting point compared to the physiological 32 • C [2,9,10]. The exact melting point of meibum in those suffering from MGD has yet to be determined, as the chemical composition of the secretions is variable and in turn affects its physical attributes [11]. ...
Meibomian gland dysfunction (MGD) appears to be the most common cause of evaporative dry eye, in which the meibum has an altered chemical structure that increases its melting point. Eyelid warming masks slowly transfer heat, preferably between 40 and 45°C to the inner meibomian glands, in an attempt to melt or soften the stagnant meibum. This ex vivo study evaluates the heat retention properties of commercially available masks over a 12-min interval.
Five eyelid-warming masks (MGDRx EyeBag(®), EyeDoctor(®), Bruder(®), Tranquileyes™, Thera°Pearl(®)) were heated following manufacturer's instructions and heat retention was assessed at 1-min interval for 12min on a non-conductive surface. A facecloth warmed with hot tap water was used as comparison.
All masks reached above 40°C within the first 2min after heating and remained so for 5min, with the exception of the facecloth, which lasted only 3min and quickly degraded to 30°C within 10min. The Bruder(®) and Tranquileyes™ reached >50°C, after heating and the Bruder(®) maintained >50°C for nearly 6min. The MGDRx EyeBag(®), and Thera°Pearl(®) had the most stable heat retention between 2 and 9min, remaining between the targeted temperature.
Heat retention profiles are different for commercially available eyelid warming masks. This ex vivo study highlights that despite the popularity of the time-honored facecloth, it is poor at retaining the desired heat over a 5-10min interval. Clinical studies need to corroborate these results, remembering that ocular tissue parameters may be factors to consider.
Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
... Earlier, using a totally different experimental approach we demonstrated that the T 1/2 of meibum was about 32 °C, with approximately 90% of meibum melted at 35 °C (Butovich et al., 2010). In recent studies, the mean eyelid temperature in healthy people with no ocular disorders was measured to be between 30.7 ± 1.2 °C (Pult et al., 2012), 32.2 ± 0.8°C (Shih et al., 2010) and 33.4 ± 0.1 °C (Nagymihalyi et al., 2004), the mean corneal surface temperature was between 31.7 ± 0.9 °C (Shih et al., 2010), 32.3 ± 0.5 °C (Terada et al., 2004), and 34.8 ± 0.8 °C (Efron et al., 1989;Klamann et al., 2013). All these temperatures are falling between the T m values of human meibum (~30 °C) and its effective completion temperature of transition (~35.5 ± 0.5 °C). ...
Meibomian gland secretions (or meibum) are produced by holocrine meibomian glands and are secreted in melted form onto the ocular surface of humans and animals to form a protective tear film lipid layer (TFLL). Its protective effect strongly depends on the composition and, hence, thermotropic behavior of meibum. The goal of our study was to quantitatively evaluate the melting characteristics of human meibum and model lipid mixtures using differential scanning microcalorimetry. Standard calorimetric parameters, e.g. changes in calorimetric enthalpy, transition temperatures T(m), cooperativity of melting etc. were assessed. We found that thermotropic behavior of meibum resembled that of relatively simple mixtures of unsaturated wax esters, but showed a lower change in calorimetric enthalpy, which can be indicative of a looser packing of lipids in meibum compared with pure standards and their simple mixtures. The cooperativity of melting of meibomian lipids was comparable to that of an equimolar mixture of four oleic-acid based wax esters. We demonstrated that the phase transitions in meibum start at about 10 to 15°C and end at 35-36°C, with T(m) being about 30°C. The highly asymmetrical shape of the thermotropic peak of meibum is important for the physiology and biophysics of TFLL.
... at the various v eff in saline 6 were within 6616% and 1624%, (mean6SD), respectively, of those in saline 5 for the same cornea (Fig. 4). It should also be noted that because of technical challenges, the tests were conducted at room temperature (;22°C), which is lower than the corneal surface temperature (;32°C) 47 and could theoretically affect fluid film viscosity and molecular interactions between bearing surfaces. 7 As such, the reported friction coefficient values should be viewed as relative to each other and perhaps not as absolute values that reflect conditions of physiologic articulation of ocular tissues. ...
Proteoglycan 4 (PRG4), also known as lubricin, is a boundary lubricating mucin-like glycoprotein present on several tissue surfaces in the body. The objectives of this study were to (1) implement and characterize an in vitro boundary lubrication test at a human cornea-polydimethylsiloxane (PDMS) biointerface and (2) determine the dose-dependent and synergistic effects of PRG4, with hyaluronan (HA), on ocular surface boundary lubrication using this test.
Human corneas and model PDMS material were articulated against each other, at effective sliding velocities v(eff) between 0.3 and 30 mm/sec under physiologic loads of approximately 8 to 25 kPa. Samples were tested serially in (1) saline, PRG4 at 30, 100, 300 μg/mL resuspended in saline, then saline again or (2) saline, AQuify Comfort Eye Drops (containing 0.1% HA), 300 μg/mL PRG4 in saline, 300 μg/mL PRG4 in AQuify, then saline again. Both static and kinetic friction coefficients were calculated.
PRG4 effectively lowered friction at the cornea-PDMS biointerface, both alone in a dose-dependent manner and in combination with HA. PRG4 reduced kinetic friction coefficients, <μ(kinetic, Neq)>, from approximately 0.30 in saline, to approximately 0.30, 0.24, and 0.17 in 30, 100, and 300 μg/mL PRG4, respectively. Values of <μ(kinetic, Neq)> in AQuify, approximately 0.32, were similar to those in saline; however, when combined with 300 μg/mL PRG4, values of <μ(kinetic, Neq)> were reduced to approximately 0.15.
PRG4 functions as an effective ocular surface boundary lubricant, both alone in a dose-dependent manner and in combination with HA.
... It is known that a typical melting range of normal meibum as measured in vitro in bulk is 19 to 40°C. 35,36 Moreover, Butovich 37 has reported that the melting range of meibomian lipids is 20 to 45°C, with a transition point of approximately 32 to 33°C. It is thought that raising the temperature of approximately the eyelid area to 40°C before digital expression will increase the temperature of the meibomian lipids and, therefore, modify their consistency from a paste to a liquid-like material. ...
To evaluate the effect of excess meibum on tear evaporation rate in patients with and without dry eye.
Eleven healthy subjects and 16 patients with dry eye were tested. The dry eye group was divided into 2 subgroups: classic keratoconjunctivitis sicca (KCS) with clear and easily expressed meibum and KCS with meibomian gland dysfunction (MGD) with turbid secretions and difficult-to-express meibum. Evaporative measurements were performed at baseline and after digital expression of meibomian glands at 12, 24, 36, and 48 minutes. Two ranges of relative humidity were used, 25% to 35% and 35% to 45%. The data were expressed as microliters per square centimeter per minute.
An increase in the evaporation rate of the tear film was noted for all measurements at both relative humidities in the classic KCS and KCS with MGD groups compared with healthy subjects (P < 0.05). The average evaporation rates at relative humidities of 25% to 35% and 35% to 45% were 0.056 ± 0.016 and 0.040 ± 0.008 for the classic KCS group; 0.055 ± 0.026 and 0.037 ± 0.019 for the KCS with MGD group and 0.033 ± 0.012 and 0.023 ± 0.008 for the healthy group. Also, a decrease in the evaporation rate was observed in the healthy and KCS with MGD groups between baseline and the first measurement after digital expression for both relative humidities (P < 0.05). The classic KCS group did not show any changes after expression.
Classic KCS and KCS with MGD groups showed an increase in tear evaporation rates compared with the healthy group. Aqueous tear evaporation diminished in the healthy and KCS with MGD groups after expression of meibomian glands. However, this effect was transient and negligible after the second measurement.
PURPOSE
This study aims at comparing the efficacy of a single-dose vectored thermal pulsation (VTP) procedure versus 5 days once daily oral azithromycin in patients with meibomian gland disease (MGD) by measuring the symptomatology and ocular surface parameters.
MATERIALS AND METHODS
The study was conducted as a prospective, nonrandomized, comparative study over a period of 17 months at a tertiary care center. In this study, 60 patients with MGD were enrolled after they gave their informed consent according to the inclusion–exclusion criteria and were divided into two groups, 30 each in the azithromycin group and the VTP, i.e., the LipiFlow group. One group was treated with oral azithromycin for 5 days and the other group was given LipiFlow treatment. Postprocedure, follow-up was done for 2 weeks, 3 months, and 6 months.
RESULTS
A statistically significant difference was noted in the score Standard Patient Evaluation of Eye Dryness questionnaire after 3 months of treatment in both the azithromycin and LipiFlow group ( P < 0.0001), and the LipiFlow group showed sustained improvement at 6-month follow-up as score improved to 8.83 ± 2.32, whereas it deteriorated in azithromycin group to 13.77 ± 1.65. Pretreatment Ocular Surface Disease Index score ( P = 0.126) and posttreatment ( P < 0.0001) showed significant differences in both groups. The LipiFlow group showed an improved score of 25.65 ± 6.11 after 6 months of treatment, whereas it deteriorated to 34.79 ± 4.98 in the azithromycin group. Pretreatment, tear film break-up time ( P = 0.28) and 6 months posttreatment score ( P < 0.0001) showed significant differences in both groups, but in the LipiFlow group, it improved to 15.30 ± 1.76 after 6 months, whereas in the azithromycin group, it was 10.07 ± 1.60. The pretreatment MG score was 4.10 ± 0.99 and 4.23 ± 1.07 ( P = 0.62) in the azithromycin and LipiFlow group, respectively. After 2 weeks, 3 months, and 6 months, the MG score was 24.20 ± 3.38, 21.67 ± 3.46, and 15.83 ± 2.41, respectively, in azithromycin group. In the LipiFlow group, the score was 13 ± 1.88, 14.27 ± 2.07, and 14.37 ± 1.85 at 2 weeks, 3 months, and 6 months, respectively, suggestive of improvement in all visits.
CONCLUSION
Both oral azithromycin and LipiFlow treatment are effective in patients with MGD. The effect of LipiFlow treatment lasted longer as compared to azithromycin. The efficacy of azithromycin in resolving the symptoms of MGD was greater compared to LipiFlow in the initial 2 weeks of treatment. However, the effect deteriorated in the subsequent follow-up at 3 months and 6 months.
Background
Meibomian gland dysfunction (MGD) is defined as functional abnormalities of the meibomian gland and is commonly caused by meibomian gland hyposecretion or obstruction. This results in an improper tear lipid layer which increases the tear evaporation and makes the tear film instability, leading to qualitative dry eye disease. In humans, a mainstay of the management of MGD is eyelid warming. This improves meibum secretion by melting pathologically altered meibomian lipids. While nearly ubiquitous in human medicine, there are no reports of the effects of warming therapy on the eyelids in veterinary medicine. This study is to evaluate the effect of warm compress therapy on canine tear film quality parameters. Eight systemically healthy male Beagle dogs with normal ophthalmic examinations (16 eyes) were used for this study. The temperature of the outer upper eyelid, the upper palpebral conjunctiva, and the central cornea were evaluated with an infrared thermometer, and tear film quality was assessed with meibometry and evaluation of the tear film break up time (TFBUT). These parameters were measured before and immediately following the application of the warm compress. A paired t-test was used to compare the data before and after warm compress treatment. For statistical analysis, SPSS was used and a P value < 0.05 was considered significant.
Results
All parameters increased after warm compression. The temperature of the outer and upper palpebral eyelid, and the central cornea increased significantly, from 34.0±1.0°C to 35.3±1.0°C, from 34.2±0.8°C to 35.5±0.8°C, from 34.2±0.8°C to 35.0±0.7°C, respectively. In meibometry, the mean±SD meibomian level at the baseline was 109.0±44.1 MU, whereas after warm compress therapy, it significantly increased to 155.9±71.3MU (p<0.05). TFBUT increased from 8.9±3.0 to 10.5±2.3 seconds.
Conclusions
Application of warm compress to the external eyelids has a significant effects of tear film quality parameters and may be useful to improve tear film stability in dogs.
Our study compared treatment efficacy between cut-off and notch filters in intense pulsed light (IPL) therapy for meibomian gland dysfunction (MGD) through a prospective, randomized paired-eye trial. Additionally, the efficacy of IPL treatment alone was investigated by restricting other conventional treatments. One eye was randomly selected for an acne filter and the other for a 590-nm filter. Identical four regimens of IPL treatments were administered. The tear break-up time (TBUT), Oxford scale, Sjögren’s International Clinical Collaborative Alliance (SICCA) staining score, tear matrix metalloproteinase-9 (MMP-9) expression, tear osmolarity, and Ocular Surface Disease Index (OSDI) questionnaires were evaluated before and after IPL. Meibomian gland (MG) parameters were measured. When combining the results from both filters, the TBUT, SICCA staining score, OSDI score, and upper and lower lid meibum expressibility were improved after IPL. No significant differences were found between the two filters in the TBUT, Oxford scale, SICCA staining score, MMP-9 expression, tear osmolarity, and MG parameters. Although not significant, the acne filter showed better treatment efficacy than that in the 590-nm filter. IPL alone is efficacious in terms of ocular surface parameters, MG function, and subjective symptoms. Regarding filter selection, both acne and 590-nm filters are promising options for MGD treatment.
Tear evaporation is a normal physiological phenomenon that has an important role in regulating blink activity and tear production. An altered tear evaporation rate (TER) is a defining characteristic of evaporative dry eye disease (DED), and the measurement of tear evaporation is a useful clinical test for diagnosis. Reported values for a normal TER cover a broad range, which may be due to the influence of ocular, environmental, and systemic factors. For improved disease diagnosis, a fuller understanding of the normal TER range is essential. This paper reports on a literature review of the current knowledge of these normal influences on TER.
Purpose
Our study compared treatment efficacy between cut-off and notch filters in intense pulsed light (IPL) therapy through a prospective, randomized paired-eye trial. Additionally, under strict environment allowing only artificial tear, the efficacy of IPL treatment alone was investigated.
Methods
One eye was selected for an acne filter and the other for a 590 nm filter. Identical IPL treatments were applied during four regimens of IPL. Tear break up time (TBUT), Oxford scale, SICCA staining score, tear matrix metalloproteinase-9 expression, tear osmolarity, and OSDI questionnaires were evaluated before and after IPL. Meibomian gland (MG) parameters were measured.
Results
Regardless of filter, TBUT (1.95 ± 1.07 to 4.02 ± 1.58, p < 0.001), OSDI score (65.34 ± 20.66 to 41.34 ± 18.84, p < 0.001), upper lid meibum expressibility (3.08 ± 2.29 to 7.38 ± 1.28, p < 0.001), and lower lid meibum expressibility (2.88 ± 1.86 to 7.49 ± 1.00, p < 0.001) were markedly improved after IPL. Between acne and 590 nm filters, the former tended to show better efficacy in lower lid expressibility (4.94 ± 1.52 vs 4.36 ± 1.58, p = 0.279) and lower lid meibum secretion score (-11.6 ± 4.45 vs -10.1 ± 5.16, p = 0.271), although not statistically significant.
Conclusions
IPL without additional treatment is efficacious in terms of ocular surface, MG, and subjective symptoms. In addition, an acne filter may be a promising option for more MG targeted effect.
Purpose:
We investigated the change in skin temperature of treated areas during intense pulsed light (IPL) treatment in patients who have meibomian gland dysfunction (MGD) to determine whether there is superficial telangiectatic blood vessel ablation.
Methods:
The medical records of 90 patients (90 eyes) with MGD who underwent IPL treatment were reviewed. The patients had undergone IPL treatment four times every 4 weeks. Ocular Surface Disease Index (OSDI) scores, dry eye (DE), and MGD parameters were obtained before the first and after the fourth IPL treatments. The skin temperatures of the upper and lower lids were measured before every IPL treatment.
Results:
The skin temperatures of the lower lids were 31.89 ± 0.72°C at the first IPL (IPL#1), 30.89 ± 0.63°C at the second IPL (IPL#2), 30.14 ± 0.95°C at the third IPL (IPL#3), and 29.74 ± 0.87°C at the fourth IPL (IPL#4) treatments. The skin temperatures of upper lids were 32.01 ± 0.69°C at IPL#1, 31.13 ± 0.75°C at IPL#2, 30.34 ± 1.07°C at IPL#3, and 29.91 ± 0.76°C at IPL#4. The skin temperature of the upper and lower lids significantly decreased with every IPL treatment. Schirmer 1 test (ST) result was 12.97 ± 10.22 mm before IPL#1 and 14.45 ± 9.99 mm after IPL#4. Tear break-up time (TBUT) was 3.15 ± 1.38 s before IPL#1 and 5.53 ± 2.34 s after IPL#4. Corneal staining scores (CFS) was 1.61 ± 3.09 before IPL#1 and 0.50 ± 0.78 after IPL#4. Lipid layer thickness (LLT) was 71.88 ± 26.34 nm before IPL#1 and 68.38 ± 24.16 nm after IPL#4. Lid margin abnormality score (LAS) was 1.96 ± 0.62 before IPL#1 and 0.86 ± 0.67 after IPL#4. Meibum expressibility (ME) was 1.67 ± 0.87 before IPL#1 and 1.03 ± 1.67 after IPL#4. Meibum quality (MQ) was 18.18 ± 6.34 before IPL#1 and 10.16 ± 5.48 after IPL#4. OSDI was 35.38 ± 19.97 before IPL#1 and 15.48 ± 34.32 after IPL#4. OSDI scores, DE, and MGD parameters significantly improved after the fourth IPL treatment but not ST and LLT.
Conclusion:
Our study showed that the occurrence of superficial telangiectatic vessels were indirectly reduced by the decrease in skin temperature accompanying IPL treatments in patients with MGD.
The treatment of meibomian gland dysfunction (MGD) first requires both proper diagnosis of the condition and identification of contributory ocular surfaces disorders that may confuse proper attribution of both patient symptoms and signs. Nomenclature remains confusing as many clinicians alternate between diagnosing patients with dry eye, evaporative dry eye, MGD, ocular rosacea, or, more generically, ocular surface disease. While all of these terms are valid descriptors of ocular surface disease, this chapter will focus on treatment of MGD, to be understood as the evaporative dry eye caused by the tear film dysfunction created by stagnant and/or dysfunctional meibum as well as ocular surface inflammation, whether present within occluded glands in the eyelid, conjunctival and corneal epithelium, and the tear film itself.
The surface of the human eye is covered with a protective tear film that refreshes with each blink. Natural blinking occurs involuntarily, but one can also voluntarily blink or refrain from blinking. The maximum time one can refrain from blinking until the onset of discomfort is the maximum inter-blink period (MIBP). In between blinks the tear film thins and evaporates from the ocular surface. Tear film evaporation can be measured with various instruments. Infrared thermography provides a non-invasive measure of the ocular surface temperature (OST). Due to evaporation, ocular surface cooling (OSC) generally occurs when the eyes are open and exposed to the environment. The purpose of our study was to investigate the effect of OSC on the MIBP, and to investigate the association of the MIBP with tear film characteristics in subjects who do and do not exhibit OSC. The MIBP was measured simultaneously with OST over time. Non-invasive tear breakup time, tear meniscus height, tear lipid layer thickness, and Schirmer I test strip wetted lengths were measured on a day prior to the thermography visit. Subjects were divided into cooling and non-cooling groups based on OSC rate, and demographic and tear film characteristics were tested for inter-group differences. A faster rate of OSC was associated with an exponentially shorter duration of the MIBP overall and within the cooling group alone. Faster non-invasive tear breakup time was significantly associated with a shorter MIBP in both groups. These results suggest that tear film evaporation initiates a pathway that results in the onset of ocular discomfort and the stimulus to blinking. The presence of a subset of subjects with no or minimal OSC who nevertheless have a short MIBP indicates that evaporative cooling is not the only mechanism responsible for the onset of ocular discomfort.
The uniformity of deposited film is a critical quality indicator for the product by chemical vapor deposition (CVD). Quality control of deposited film remains a challenging task, especially for a CVD reactor used in the glass coating process, which often needs to simultaneously process multiple substrate surfaces. So far, an effective method for simulating the multi-substrate CVD reactor used in the glass coating process is unavailable excluding costly direct numerical simulation in real geometry. The numerical simulation and optimization of such a CVD reactor are also lacking. In this paper, a new CFD model was developed to investigate a special industrial-scale multi-substrate CVD reactor for the production of coated glass products. The unique porous media based modeling approach allowed us to efficiently address hundreds or even thousands of spatially-distributed surfaces in one batch of production. Simulation results demonstrate that the mixing performance of the gas reactant in the reactor can be improved significantly by implementing the top-injection scheme, introducing natural convection, and redistributing the substrate surfaces, which can indirectly improve the uniformity of deposited film on the glass. The introduced method is generic and should be an effective tool to understand quality problems in large-scale multi-substrate CVD reactors and hence improve their design and operation.
Bionics is a fascinating subject that has inspired many inventions through learning from biological structures and functions. In this work, a coupled multi-physics model has been developed to characterize ocular water evaporation with realistic eyelash structures taken into account. From a chemical engineering perspective, the protective function of human eyelashes in terms of evaporation inhibition has been rationally revealed. Systematic investigations were carried out to elucidate the effects of different eyelash lengths, orientations and inlet air directions on water evaporation on the ocular surface. The results clearly demonstrate that regardless of inlet air directions and eyelash orientations, increasing eyelash length from zero to an optimal length can effectively reduce water evaporation. However, further increase in the eyelash length can lead to enhanced evaporation. For the normal and parallel inlet air directions, the optimal eyelash length is around 15-30% of the eye width and can offer approximately 10-30% evaporation reduction when compared with the cases without eyelashes. These values are independent of the eyelash orientation. This investigation provides valuable data for in-depth understanding of the protective function of the eyelashes, which can be used in the future to improve and optimize bionic designs inspired by human eyelashes.
Objective: To investigate the association between corneal temperature on ocular surface and stability of tear film, and define the normal reference range of corneal surface temperature in the population of Pudong New Area, Shanghai, China.
Methods: Temperature of cornea (TOC) and tear film break-up time (BUT) were measured among 515 volunteers with or without dry eye. The association between TOC and tear film stability was analyzed, and the normal reference range of TOC was determined.
Results: TOC was 32.6 ± 0.97°C among the 318 subjects without dry eye including 147 males (TOC = 32.6 ± 0.70°C) and 171 females (TOC = 32.64 ± 1.16°C). Significant differences existed in TOC on ocular surface among three separated groups according to BUT measurement. Age was positively related to TOC, whereas BUT was negatively correlated with TOC.
Conclusion: It is recommended to consider 32.6 ± 0.70°C as the normal reference value for human central corneal temperature. Instability of tear film is concomitant with elevated TOC in the population of Pudong New Area, Shanghai.
Objective: To measure the temperature of cornea (TOC) on ocular surface of healthy people with non-contact infrared thermometer, and determine the reference range. Methods: Large sample single center random sampling was adopted to select healthy volunteers from medical examinees of Pudong New District of Shanghai. With environment temperature of (26 ± 2) °C and relative humidity of (60 ± 5) %, non-contact infrared thermometer was used to measure TOC on ocular surface of right eyes after blinking. Results: A total of 3 288 subjects were enrolled after random sampling and screening, with 1 978 males and 1 310 females. Three hundred and ninety-six subjects aged no more than 15 years, 942 aged between 15 and 30 years, 1 482 aged between 30 and 50 years, and 468 aged more than 50 years. TOC on ocular surface of total sample was ( 32.06 ± 1.24) °C. TOC on ocular surface exhibited an increased tendency with age stages. There were significant differences in TOC of ocular surface between males and females [(32.26 ± 1.11) °C vs (31.75 ± 1.36) °C, P < 0.01]. However, there was no significant difference in TOC of ocular surface between males and total sample and between females and total sample (P > 0.05). Conclusion: With environment temperature of (26 ± 2) °C and relative humidity of (60 ± 5) %, (32.06 ± 1.24) °C may serve as the normal range of TOC on ocular surface measured by non-contact infrared thermometer in clinics, and there may exist differences between males and females.
Meibomian gland dysfunction (MGD) is commonly encountered among eye care professionals. Our understanding of the pathophysiology for the development of MGD has greatly expanded in recent years, which helped increase awareness of the disease. Despite increased awareness, it is essential for eye care professionals to make a conscious effort to properly examine the meibomian glands through gland expression even for asymptomatic patients. At minimum, early management should include patient education and supportive therapy such as warm compresses, lid hygiene, and gland expression. As patients become more symptomatic and as the ocular surface becomes more affected, employing additional therapeutic management is recommended and may include oral omega-3 essential fatty acids, topical azithromycin, oral tetracycline, and topical anti-inflammatories to improve clinical signs and patient comfort. In addition to treatment of MGD, clinicians should be mindful of the comorbid conditions of MGD and simultaneously manage them in conjunction of MGD treatment.
Meibomian gland dysfunction (MGD) is understood to be a highly prevalent, chronic progressive disease and the leading cause of dry eye. All available published peer-reviewed results of the novel vectored thermal pulsation therapy for patients with MGD are investigated.
The PubMed and meeting abstract search revealed a total of 31 peer-reviewed reports on vectored thermal pulsation therapy at the time of the search (eight manuscripts and 23 meeting abstracts). All manuscripts evidence a significant increase in meibomian gland function (∼3×) and symptom improvement post a single 12-min treatment. Additional reported objective measures such as osmolarity, tear break-up time, or lipid layer thickness also increased as a result of the therapy; however, not all findings were statistically significant. The randomized controlled studies evidence sustained gland function and symptom relief lasting out to 12 months. The uncontrolled case series evidence significantly longer duration of effect.
A single 12 minute vectored thermal pulsation treatment allows for reducing dry eye symptoms, improving meibomian gland function and other correlates of the ocular surface health.
To evaluate the effects of commercially available eyelid warming devices on ocular temperatures, tear film function, and meibomian glands in normal subjects and patients with meibomian gland dysfunction (MGD).
Ten healthy volunteers were enrolled to evaluate the effects of a single warming and of repeated warming for 2 weeks. Ten MGD patients were enrolled for evaluation of repeated warming over 1 month. Two non-wet (Azuki no Chikara, Eye Hot R) and three wet (hot towel, Hot Eye Mask, Memoto Este) devices were compared in a masked manner. Visual analog scale (VAS) score for ocular symptoms, tear film breakup time (TFBUT), meibum grade, temperatures (eyelid skin, tarsal conjunctiva, central cornea), Schirmer test value, and meibomian gland area were measured before and after warming application.
The single application of the five warming devices improved the VAS score, TFBUT, and ocular temperatures. In the repeated warming application, Azuki no Chikara as a representative non-wet warming device induced a stable and significant improvement in TFBUT and increased the tarsal conjunctival temperature and meibomian gland area in both normal subjects and MGD patients. It also improved meibum grade in MGD patients.
Our results suggest that repeated eyelid warming with a non-wet device improves tear film function in normal individuals and may have beneficial effects on both tear film and meibomian gland function in MGD patients.
Copyright © 2015 Elsevier Inc. All rights reserved.
Purpose Our aim was to explain the molecular level basis of the ability of wax ester (WE) films to retard evaporation close to their bulk melting temperature. We studied the surface behavior of behenyl palmitoleate (BP), a WE representing the most abundant meibum WEs.
Methods Isotherm and isochor measurements coupled with imaging by Brewster angle microscopy (BAM) were used to study BP films at the air‐water interface. In addition, evaporation rates through BP films were measured.
Results Close to room temperature, BP formed solid, non‐spreading islands when applied to the air‐water interface. Between 35 and 38 °C, a fluid, effectively spreading monolayer phase coexisted with solid domains of BP. At higher temperatures, BP formed completely fluid films. Mean molecular areas of the fluid and solid films were determined to be approximately 50 Å2 and 18 Å2, respectively. The thickness of a solid BP monolayer was determined to be 42 ± 6 Å by BAM measurements. A fluid BP monolayer only had minimal evaporation resistance, while a solid monolayer retarded evaporation by > 50%.
Conclusion Below 35 °C, BP assumes an extended conformation at the air‐water interface, similar to the bulk crystal structure of WEs. The extended conformation allows tight packing of hydrocarbon chains, which hinders the permeation of water molecules and leads to the evaporation retarding effect. Although the solid islands effectively retard evaporation, they do not spread at low temperatures and water evaporation proceeds through the uncovered areas of the surface. Coexistence of fluid and solid monolayer phases between 35 and 38 °C allows the film to spread, leading to a complete coverage of the interface by the solid phase and effective evaporation retardation.
To evaluate eyelid temperature change and short-term effects on tear film stability and lipid layer thickness in healthy patients using a commercially available warm compress (MGDRx EyeBag) for ophthalmic use.
Eyelid temperature, noninvasive tear film breakup time (NITBUT), and tear film lipid layer thickness (TFLLT) of 22 healthy subjects were measured at baseline, immediately after, and 10 minutes after application of a heated eyebag for 5 minutes to one eye selected at random. A nonheated eyebag was applied to the contralateral eye as a control.
Eyelid temperatures, NITBUT, and TFLLT increased significantly from baseline in test eyes immediately after removal of the heated eyebag compared with those in control eyes (maximum temperature change, 2.3 ± 1.2°C vs. 0.3 ± 0.5°C, F = 20.533, p < 0.001; NITBUT change, 4.0 ± 2.3 seconds vs. 0.4 ± 1.7 seconds, p < 0.001; TFLLT change, 2.0 ± 0.9 grades vs. 0.1 ± 0.4 grades, Z = -4.035, p < 0.001). After 10 minutes, measurements remained significantly higher than those in controls (maximum temperature change, 1.0 ± 0.7°C vs. 0.1 ± 0.3°C, F = 14.247, p < 0.001; NITBUT change, 3.6 ± 2.1 seconds vs. 0.1 ± 1.9 seconds, p < 0.001; TFLLT change, 1.5 ± 0.9 vs. 0.2 ± 0.5 grades, Z = -3.835, p < 0.001). No adverse events occurred during the study.
The MGDRx EyeBag is a simple device for heating the eyelids, resulting in increased NITBUT and TFLLT in subjects without meibomian gland dysfunction that seem to be clinically significant. Future studies are required to determine clinical efficacy and evaluate safety after long-term therapy in meibomian gland dysfunction patients.
Purpose:
Obstructive meibomian gland dysfunction (MGD) frequently induces a chronic complaint with various symptoms related to dry eye and discomfort. Previous research indicates a pivotal role for heat therapy for melting the meibum as part of any successful management plan, but delivery of constant temperature during treatment is vital. This study evaluated the performance of a novel device designed to deliver controlled, latent, moist heat to the eyelids and surrounding area.
Methods:
The signs, symptoms and ocular temperature of 25 normal subjects (M8, F17; age 29.2±5.7 years) were recorded before and after a 10min application of the Blephasteam(®) device. Ocular temperature (non-invasive ocular thermography; A40 Flir, UK), tear film stability (NIBUT), intra-ocular pressure (IOP), and ocular surface staining and hyperaemia were recorded. Results were checked for normality and compared using paired t-tests.
Results:
Temperatures in both eyelids were significantly greater after device application (upper +1.7±0.9°C; lower +2.1±0.7°C, p<0.0005). Bulbar conjunctival hyperaemia significantly decreased after treatment (p<0.005), but limbal and palpebral hyperaemia remained similar (p=0.33 and p=0.11, respectively). Ocular surface staining (p=0.74) and tear film stability (p=0.12) were unchanged in this normal cohort, and there was no significant change in IOP (13.8±2.0mmHg vs 12.9±2.2mmHg; p=0.092).
Conclusions:
The Blephasteam(®) device provides effective levels of warming that would be sufficient to melt meibum, and no adverse ocular responses were recorded in this cohort, indicating that this is a safe device. Interestingly, even in this normal cohort, ocular surface redness appears less after treatment.
Objective:
The aim of this study was to investigate whether a single case of meibomian gland dysfunction (MGD), with significant MG dropout resulting in evaporative dry eye, could be effectively treated with the LipiFlow (a new Food and Drug Administration-approved thermodynamic pulsatile treatment).
Materials and methods:
A 39-year-old white woman experienced severe dry eye symptoms because of MGD with considerable MG dropout resulting in evaporative dry eye. Standardized diagnostic MG expression and meibography led to the tentative diagnosis of nonobvious MGD (only 1 functional MG on each lower lid) and MG dropout (∼50% of the lower lid MGs were missing with the remaining MGs being severely truncated). The patient underwent a single 12-min LipiFlow treatment per eye and returned for follow-up at 1 and 7 months posttreatment.
Results:
The LipiFlow treatment increased the number of functional lower lid MGs from 1 to 5 glands OD and 1 to 7 glands OS at 1 month with slight regression at 7 months (4 OD and 4 OS); increased fluorescein break-up time from 4 to 7 sec OD and 4 to 9 sec OS at both 1 and 7 months; and decreased symptom scores by approximately 50% at 1 month and approximately 75% at 7 months.
Conclusions:
These results demonstrate the effectiveness of the LipiFlow in restoring MG function and improving ocular comfort even in this particular case of significant MG dropout and MG truncation.
To evaluate the effect of a single treatment with the LipiFlow(®) Thermal Pulsation System on signs of meibomian gland dysfunction (MGD) and dry eye symptoms over a 9-month period.
Patients (n = 42 eyes, 21 subjects) diagnosed with MGD and dry eye symptoms were recruited for a non-significant risk, prospective, open-label, 1-month clinical trial. Patients received a single 12-minute treatment using the LipiFlow(®) Thermal Pulsation System on each eye. The LipiFlow(®) device applies heat to the conjunctival surfaces of the upper and lower inner eyelids while simultaneously applying pulsatile pressure to the outer eyelid surfaces to express the meibomian glands. Patient symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Standard Patient Evaluation for Eye Dryness (SPEED) dry eye questionnaires; tear break-up time was measured with the dry eye test (DET™); and meibomian gland function was evaluated using a standardized diagnostic expression technique. Data are presented for patient's pre-treatment (baseline) and at 1-month and 9-month post-treatment.
Meibomian gland secretion scores improved significantly from baseline (4.4 ± 4.0) to 1-month post-treatment (11.3 ± 6.2; p < 0.0001) and this improvement was maintained with no significant regression at 9 months (11.7 ± 5.9). Similarly, baseline tear break-up time (4.8 ± 3.2) was significantly increased at 1 month (9.6 ± 7.6; p < 0.001) and this increase was maintained with no significant regression at 9 months (7.1 ± 5.6). Symptom scores on both OSDI and SPEED questionnaires improved significantly at 1 month (p < 0.0001) and this improvement was maintained at 9 months.
With such prolonged improvement in signs and symptoms of dry eye disease, the LipiFlow(®) Thermal Pulsation System offers a technological advancement for the treatment of dry eye disease secondary to meibomian gland dysfunction. A single 12-minute LipiFlow(®) treatment results in up to 9 months of sustained improvement of meibomian gland function, tear break-up time and dry eye symptoms that are unparalleled with current dry eye treatments.
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