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This study focuses onthe refractiveimplications of albinism in Malawi, which is mostly associated with the burden of visual impairment. The main goal was to describe the refractive errors and to analyze whether patients with albinism in Malawi, Sub-Saharan Africa, benefit from refraction.
Age, sex, refractive data, uncorrected and bestcorrected visual acuity (UCVA, BCVA), colour vision, contrast sensitivity, and the prescription of sunglasses and low vision devices were collected for a group of 120 albino individuals with oculocutaneous albinism (OCA). Refractive errors were evaluated objectively and subjectively by retinoscopy, and followed by cycloplegic refraction to reconfirm the results. Best-corrected visual acuity (BCVA) was also assessed binocularly.
One hundred and twenty albino subjects were examined, ranging in age from 4 to 25 years (median 12 years), 71 (59 %) boys and 49 (41 %) girls. All exhibited horizontal pendular nystagmus. Mean visual acuity improved from 0.98 (0.33) logMAR to 0.77 (0.15) logMAR after refraction (p<0.001). The best improvement of VAwas achieved in patients with mild to moderate myopia. Patients with albinism who were hyperopic more than +1.5 D hardly improved from refraction. With the rule(WTR)astigmatismwasmorepresent (37.5 %) than against the rule (ATR) astigmatism (3.8 %). Patients with astigmatism less than 1.5 D improved in 15/32 of cases (47 %) by 2 lines or more. Patients with astigmatism equal to or more than 1.5 D in any axis improved in 26/54 of cases (48 %) by 2 lines or more.
Refraction improves visual acuity of children with oculocutaneous albinism in a Sub-Saharan African population in Malawi. The mean improvement was 2 logMAR units.
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... Udeh et al.  and Ajose et al.,  in other parts of Nigeria. Other developing countries with similar socioeconomic status such as Nepal,  Malawi  and Cameroun  also had similar findings. It is said that the subnormal presenting visual acuity seen in persons with albinism may be due to delayed visual maturation, foveal hypoplasia, nystagmus, strabismus and iris trans-illumination. ...
... This is not surprising as activities associated with contrast sensitivity such as driving at night or in the rain and navigation in unfamiliar surroundings (during business activities) are commonly undertaken by adults. Similar findings of impaired mean contrast sensitivity was noted in Chicago , Malawi  and Egypt . Factors thought to be responsible for the degradation in contrast sensitivity include increased central retinal cone spacing, abnormal decussation of the visual pathway and glare from iris hypopigmentation, nystagmus and foveal hypoplasia. ...
... This higher percentage of nystagmus in Udeh's study may not be unconnected with the inclusion criteria for nystagmus which included minimal nystagmus detectable by slit lamp examination unlike this study where only those with obvious nystagmus were considered. Other differing studies [25,29] with similar methodology as Udeh's also reported universal presence of nystagmus. Underdevelopment of the fovea and delayed visual maturation seen in PWA is often considered to be responsible for the development of nystagmus. ...
Aim: To determine the pattern of ocular disorders in persons with albinism and how they affect visual function. Methods: This was a descriptive cross-sectional study conducted over a five-month period on persons living with albinism in Southern Nigeria. The study participants were randomly selected during the monthly meetings of a support group known as The Albinism Foundation (TAF).Visual acuity and contrast sensitivity were assessed using the ETDRS visual acuity chart and Pelli Robson contrast sensitivity test chart. A comprehensive eye examination including dilated fundoscopy was also carried out to determine other ocular disorders. Data was analyzed using SPSS version 22 and statistical significance was set at a p-value ≤ 0.05. Results: A total of 116 PWA (232 eyes) were examined. There were 44 (37.9%) males and 72 (62.1%) females. The age of the study subjects ranged from 5 to 56 years. Most eyes were visually impaired for both distance (n=228; 98.3%) and near vision (n= 224; 96.6%). Contrast sensitivity in most eyes (n=138; 59.5%) was subnormal. With refraction and Low Vision Aid (LVA), there was significant improvement of the mean VA by 2-3 acuity lines and 6 acuity lines respectively (p=0.000). All the examined eyes had fundus hypo-pigmentation, 91.4% (n=212) had iris trans-illumination, 86.2% (n=200) had nystagmus, and 34.4% (n=80) had strabismus. Nystagmus, strabismus and iris trans-illumination significantly (p=0.00) reduced visual acuity and contrast sensitivity. Conclusion: Most study participants had reduced distance visual acuity and contrast sensitivity but with correction there was a significant improvement in vision. The presence of nystagmus, strabismus and iris trans-illumination were observed to contribute to the poor vision experienced by most persons living with albinism. Hence, early optical intervention and counselling is important in improving the quality of living of persons with albinism.
... [6,7] People with OCA also have a wider range of refractive errors including high with-the-rule astigmatism. [7,8] As compare to the normal pigmented retinas, the photoreceptor outer segment of the retina of people with albinism does not develop normally.  In addition, the lack of pigment in people with OCA also results in the abnormal decussation and misrouting of the optic nerve fibers during the development resulting in poor vision. ...
... Similar improvement in functional vision with low vision aids in people with OCA has been reported in the literature. [8,19,20] As identified in the literature, [8,16,18] this study also showed that higher spherical and astigmatic refractive errors and with-the-rule astigmatism are associated with OCA. The distributions of spherical-equivalent and astigmatic refractive errors are broader in our participants with OCA. ...
... Similar improvement in functional vision with low vision aids in people with OCA has been reported in the literature. [8,19,20] As identified in the literature, [8,16,18] this study also showed that higher spherical and astigmatic refractive errors and with-the-rule astigmatism are associated with OCA. The distributions of spherical-equivalent and astigmatic refractive errors are broader in our participants with OCA. ...
All people with oculocutaneous albinism (OCA) have reduced vision. This study aimed to assess the benefits of low vision aids for people with OCA.
Seventy-seven consecutive people with OCA age 4 years and above examined in a low vision clinic were included in the study. Uncorrected and best-corrected visual acuity (VA), VA with low vision devices, types of low vision aids, and refractive errors data were analyzed.
Of the 77 people with OCA, 57% were in the age group between 4 and 15 years and 43% in the age group of 16 years and above. At the time of presentation, the percentages of visually impaired, severe visually impaired, and blind (using WHO low vision criteria) were 52%, 22%, and 25%. Among them, 39% has near VA of 1 M or better. Difference in the means of the spherical equivalent refractive error in the right eyes and left eyes was -0.494 diopters (-01.686, 0.699; 95% confidence interval). VA improved significantly after adequate refractive correction by more than one log MAR lines in 38.6% (P < 0.01). With low vision devices, in 85.7% (n = 66) participants, VA was enhanced to normal level (6/18 or better) in the better eye while 7.8% still remained in the blind category. Telescopes were prescribed to 61% people for the enhancement of distance VA and hand hold magnifiers were prescribed to 22% people to meet their needs.
Low vision aids can be successfully used in visual rehabilitation of people with OCA to meet their needs.
... An understanding of the visual function in adolescents with OCA and their QoL in terms of their visual ability will assist in the holistic management of these individuals. In this study, the mean best-corrected VA was approximately 0.81 logMAR in each eye and is similar to the results of other studies that included only individuals with OCA (Schwering et al., 2015;Wildsoet et al., 2000). This is noteworthy as individuals with OCA have poor VA as a result of foveal hypoplasia, retinal hypopigmentation, and degradation of the retinal image due to iris transillumination and nystagmus (Healey et al., 2010). ...
... In the present study, the refractive error findings showed interesting trends. In contrast to previous studies, only 40% of participants required spectacles, which is unexpected as OCA is usually associated with high refractive errors (Healey et al., 2010;Jhetam & Mashige, 2019;Schwering et al., 2015;Udeh et al., 2014). Although less than half of the participants had refractive errors, the presence thereof underscores the need for routine eye examinations in the management of VI. ...
... This is supported by a previous study that reported that although the etiology of VI in albinism is multifactorial, refractive anomalies contribute significantly to the vision loss experienced by these individuals (Udeh et al., 2014). A mean myopic refractive error was found in both eyes, and is similar to the results reported in other studies (Khanal et al., 2016;Sampath & Bedell, 2002;Schwering et al., 2015). In this study, WTR astigmatism was most common followed by oblique astigmatism. ...
Individuals with ocular and oculocutaneous albinism (OCA) have significantly reduced visual acuity (VA) resulting in visual impairment (VI). The aim is to report on the visual function of adolescents with OCA and their quality of life (QoL) in terms of their visual ability. A total of 28 adolescents with OCA participated in this study. Tests of visual function included distance VA, refractive error, contrast sensitivity (CS), and colour vision. The Cardiff Visual Ability Questionnaire for Children (CVAQC) was used to assess visual ability. All participants presented with cutaneous hypopigmentation and nystagmus, while only two had strabismus. A mean myopic refractive error was found, and with-the-rule (WTR) astigmatism was most common. The mean best-corrected VA was 0.81 ± 0.17 logMAR and 0.81 ± 0.18 logMAR in the right and left eyes, respectively. The mean CS with the best refractive correction was 1.23 ± 0.33 log CS in the right eye and 1.29 ± 0.33 log CS in the left eye. The mean Cardiff visual ability score was −0.37 ± 0.79 log units. The variation of refractive errors and the magnitude thereof underscores the need for regular eye examinations in individuals with OCA. The majority of participants had moderate VI, and these participants had a better mean Cardiff visual ability score than those with severe VI. Similarly, participants with normal binocular CS had a better Cardiff visual ability score than those with a loss of CS.
... 4 The prevalence of OCA in Southern Africa has been reported to range between 0.02% and 0.1%, with a male to female ratio ranging from 0.8 to 1.4:1. 5,6,7,8,9,10,11 Several eye and vision problems including ocular hypopigmentation, reduced VA, nystagmus, strabismus and photophobia are associated with albinism. 12 Refractive error changes have also been reported to be prevalent in albinism. ...
... 8,13,14,15,23,24 Reduced vision may result from refractive error, misalignment of the eyes, reduced pigments in the macula, misrouting of optic nerve fibres, amblyopia and nystagmus, 15 The results of uncorrected VA obtained in the current study also agree with findings reported in other studies. 11,26,27 Optical correction improved distance logMAR VA up to a range of 0.40 logMAR -1.10 logMAR. Raliavhegwa 8 also reported an improvement in distance logMAR VA following optical correction in a study conducted in the Limpopo province of South Africa among children with OCA. ...
... In addition, Sacharowitz 14 reported significant improvements with optical correction in distance vision of 60% (n = 40) of patients with albinism presenting at a low vision clinic at the university. Other studies 11,27 reported similar improvements in the mean logMAR distance VA following optical correction. Clinically, the improvement of distance vision ranged from 4 letters (0.08 logMAR) to 9 letters (0.18 logMAR). ...
Background: Oculocutaneous albinism results in defects of the visual pathway and ocular structures.
Aim: To determine the ocular findings and vision status of learners with oculocutaneous albinism (OCA) as well as to establish the level of visual acuity, contrast sensitivity and reading rate improvements following optical correction.
Setting: Three special education schools in KwaZulu-Natal, South Africa.
Methods: A total of 81 learners with OCA participated in this study. Testing procedures included logMAR distance and near visual acuity (VA) measurements, cover tests, retinoscopy (dry), subjective refraction, tangent screen, ophthalmoscopy, contrast sensitivity and reading rate determination.
Results: The majority of participants (96.3%) had wheat straw coloured hair and 95.1% had grey irides. All the learners presented with iris-transillumination and an absent foveal reflex and all but one exhibited nystagmus. Esophoria and esotropia represented 72.8% of binocular vision anomalies. Myopic astigmatism was noted in 41.4% of the learners while with the rule astigmatism was predominant (64%). Following optical correction, VA significantly improved from a range of 0.50 to 1.40 logMAR to a range of 0.5 to 1.06 logMAR for distance (p < 0.05) and from a range of 0.40 to 1.30 logMAR to a range of 0.30 to 1.08 logMAR) for near (p < 0.05). In addition, contrast sensitivity improved from a range of 0.48 to 1.92 logCS to a range of 0.88 to 1.92 logCS (p < 0.05). However, the reading rate did not show any significant improvement following optical correction (p> 0.05).
Conclusion: Learners with OCA exhibited various ocular and vision defects which impair visual functions. Their VA and contrast sensitivity could be significantly improved with optical correction; however, their reading rate was not improved.
... Visual function in patients with OCA1 is affected by unpredictable combinations of ocular motor (eccentric null zones, damping with convergence, monocular intensity changes, periodicity, strabismus, poor smooth pursuit and OKN and attentional changes) and sensory system defects (ammetropia, amblyopia, photosensitivity, loss of contrast sensitivity, poor motion perception, decreased temporal luminance, impaired contour interaction, light interference and pre-chiasmal, chiasmal, and post-chiasmal, maldevelopment) [1,2,4,7,11,21,22,38- 40]. Visual functions directly affected include high spatial acuity vision, contrast sensitivity, motion detection, visual recognition time, gaze and time dependent vision, depth and stereopsis, smooth pursuit, and vestibular and proprioceptive functions [1,2,4,7,11,21,22,. ...
... Despite these public interventions, the plight of persons with albinism in Malawi is still a major concern. Scholars such as Braathen and Ingstad (2006), Lynch et al. (2014), and Schwering et al. (2015) have conducted albinism research in Malawi (2015). Despite the fact that such studies have been conducted, little is known about the challenges faced by PWAs in Malawi. ...
Albinism is a genetic condition caused by a deficit in the production of the pigment called melanin, which protects the skin against ultraviolet light and provides the skin with its color production. The condition may predispose persons with albinism (PWAs) to lifelong physical and health problems, such as visual impairment and ultra-violet induced skin damage. Due to this condition, we explored the challenges faced by persons living with albinism as they socialize in Lilongwe District, Malawi.
The study adopted an interpretative phenomenological approach and included 30 participants comprising 13 females and 14 males with albinism and three key informants from Association of People with Albinism in the Lilongwe district in Malawi. Data were collected through in-depth interviews and focus group discussions. Van Manen's (2014) six steps of phenomenological analysis was used to analyze all data.
People with albinism face a variety of problems, the most common of which are financial constraints, health complications due to a lack of adequate medical care, a lack of community support leading to stigma and discrimination, and superstitious beliefs.
People with albinism suffer socially as a result of misconceptions, behaviours, social isolation, labelling, and beliefs that are negatively correlated with their disorder. PWAs face these problems as a result of public misunderstanding about albinism.
... This relationship can also be clearly seen independently in males and females (Fig E in S1 File). The link between corneal astigmatism and deficiency in melanin production has been previously reported for albinism . Our data suggests that darker skin and hence possibly increased melanin production appears protective for corneal astigmatism. ...
To describe corneal astigmatism in the UK Biobank population and to look for associations with other biometric variables and socio-demographic factors.
This analysis included a subsample of 107,452 participants of the UK Biobank study who underwent an enhanced ophthalmic examination including autorefractor keratometry (Tomey RC 5000, Tomey Corp., Nagoya, Japan). Participants were recruited from across the United Kingdom between 2006 and 2010, and all were between 40 to 69 years. After quality control and applying relevant exclusions, data on corneal astigmatism on 83,751 participants were included for analysis. Potential associations were tested through univariable regression and significant parameters carried forward for multivariable analysis.
In univariable analysis, the characteristics significantly associated with higher corneal astigmatism (P<0.001), by order of magnitude were, female gender, white ethnicity, lighter skin colour, use of UV protection, lower alcohol intake, lower corneal-compensated intraocular pressure (ccIOP), older age at completion of education, younger age, higher Townsend deprivation index, lower height and lower systolic blood pressure. After inclusion in the multivariable analysis, gender, skin colour, alcohol intake, age at completion of full-time education, ccIOP, age and Townsend deprivation score remained significant (all P<0.001). Increased corneal astigmatism was also found to be significantly associated with amblyopia or strabismus.
This analysis confirms previous associations with astigmatism such as younger age and female gender, and identified novel risk factors including lighter skin colour, lower alcohol intake, later age having completed full time education later, lower ccIOP and higher Townsend deprivation index. Further research is needed to investigate these novel associations.
... Our observations in this study is similar to the results reported by Udeh., et al. and Ajose., et al. in other parts of Nigeria[11,13]. Other developing countries with similar socioeconomic status such as Nepal, Cameroun and Malawi also had similar findings. It has been postulated that the subnormal presenting visual acuity may be due to delayed visual maturation, foveal hypoplasia, nystagmus, strabismus and iris trans-illumination.Anderson., et al. in the United States of America however, reported a better mean uncorrected distance and near visual acuity of 0.73 logMAR (6/32 Snellen) and 0.31 logMAR (N6) respectively . ...
To describe corneal astigmatism in the UK Biobank population, to look for associations with other biometric variables and socio-demographic factors, and to report the proportion with abnormal keratometry and irregular astigmatism suggestive of pathological corneal ectasias such as keratoconus.
Cross-sectional data were obtained from UK Biobank (www.ukbiobank.ac.uk/). A subsample of 107,452 participants from UK communities had undergone an enhanced ophthalmic examination including autorefractor keratometry (Tomey RC 5000, Tomey Corp., Nagoya, Japan). After quality control and applying relevant exclusions, data on corneal astigmatism on 83,751 participants was available for analysis. Potential associations were tested through univariable regression and significant parameters carried forward for multivariable analysis.
In a univariable analysis, the characteristics significantly protective against corneal astigmatism were gender (male), older age, darker skin colour and increased alcohol intake (all p<0.001). The parameters significantly associated with increased corneal astigmatism were older age at completion of full time education, use of UV protection and lower corrected visual acuity. After inclusion in the multivariable analysis, age, gender, age at completion of full time education, corrected visual acuity and skin colour remained significant (all p<0.001). Increased corneal astigmatism was also found to be significantly associated with amblyopia or strabismus. No individuals with abnormal keratometry or irregular astigmatism were reported.
This analysis of associations with astigmatism in a large cohort of volunteers confirms previous associations including adverse associations with younger age and female gender, and identified novel associations including darker skin colour and frequency of alcohol intake. The highest risk group for corneal astigmatism were younger females of lighter skin colour, having completed full time education later, with higher logMAR corrected visual acuity. We also confirmed that corneal astigmatism is a high risk factor for amblyopia and strabismus. Finally since no cases of keratoconus were identified, this would suggest that simple keratometry indices may not be sufficient for population screening of keratoconus.
To investigate the effects of spectacle and telescope corrections on visual acuity (VA), contrast sensitivity (CS) and reading rates (RR) in students with oculocutaneous albinism (OCA).
An observational study design was conducted on 81 students with OCA. Distance and near VA, CS and RR were measured without correction, with spectacle correction and with a combination of spectacle correction and telescopes.
The mean distance and near VA values with a combination of spectacle correction and telescopes were significantly better than those without correction and with spectacle correction alone (p = 0.01). Mean CS values achieved with spectacles alone were significantly better than those obtained with a combination of spectacles and telescopes (p = 0.01). There was no significant difference between logCS values obtained without correction compared to those obtained with a combination of spectacle correction and telescopes. There were no significant differences between RR values obtained with a combination of spectacles and telescopes and those without and with spectacle correction alone (all p > 0.05).
This article provides valuable information to eye care practitioners on the effects of spectacles and telescopes on visual acuity, contrast sensitivity and reading rate in students with OCA.
People with albinism (PWA) in Africa suffer many challenges, including higher risk of skin cancers and deeply embedded stigma. We conducted interviews with PWA to determine factors influencing their quality of life (QOL) in Botswana. Physical concerns expressed included skin/eye health issues and limited access to health care. Psychosocial concerns included stigma/discrimination and myths/superstitions. Environmental concerns included barriers to personal development of education and employment, safety concerns, financial insecurity, and disability rights issues. Pervasive difficulty in obtaining equal rights to physical, psychosocial, and environmental health affected QOL. Education around albinism and disability rights are needed to improve QOL for PWA.
A 25-year-old woman presented for evaluation of poor vision and photophobia present since childhood. She had fair skin, platinum white hair (Figure 1, left panel), and blue eyes. At age 24 years, she underwent resection of a cutaneous melanoma (stage T1bN1a) from the upper chest, with no signs of recurrence or metastasis. She was of Italian, German, and Slovak ancestry. She had a history of congenital horizontal nystagmus, which was pendular, ie, occurring in 2 phases of equal speed (Video). Best-corrected visual acuities were 20/60 bilaterally. The irides were blue, although by retro-illumination with a light beam perpendicular to the iris plane, they appeared reddish-pink (Figure 1; eFigure in the Supplement).
La responsabilité médicale occupe, aujourd’hui, une place importante dans l’activité judiciaire en Tunisie.
Nous nous proposons, dans ce travail, d’étudier les caractéristiques de la responsabilité médicale et son
évolution. Pour cela, nous avons réalisé une étude de 130 expertises médicales colligées du service de
médecine légale de Sfax, durant une période de 9 ans (2004-2012). A la lumière de nos résultats, le nombre
des affaires en responsabilité médicale avait connu une nette augmentation. La voie pénale était la plus
sollicitée. Les spécialités chirurgicales étaient les plus incriminées. Les experts avaient retenu la faute dans
35% des affaires. Le dommage était en rapport avec un aléa médical dans 25% des cas. Concernant la
prévention, le professionnel de la santé doit impérativement respecter les règles légales, déontologiques et
éthiques de la bonne pratique médicale. De même, il est nécessaire de légiférer l’indemnisation des
dommages secondaires à un aléa médical.
To investigate whether the different role of ocular dopamine was involved in the myopic development between spontaneous myopia (SM) and form deprivation myopia (FDM) in albino guinea pigs.
55 myopic animals were randomly divided into SM, Levodapa (L-DOPA), L-DOPA+carbidopa and vehicle. 70 non-myopic animals were randomly divided into normal control, FDM, L-DOPA+FDM, L-DOPA+carbidopa+FDM and vehicle. Once per day, for 14 days, L-DOPA (10mg/kg) was injected intraperitoneally, and carbidopa (1μg) was injected at the same time into the peribulbar space of the right eye. Refractive parameters and dopamine content in neural retina and RPE/choroid complex were measured.
In SM animals, high myopia was formed at 5 week of ages. L-DOPA treatment could reduce its myopic degree, and inhibit the increase of axial length and vitreous chamber depth with the increase of retinal dopamine in both eyes. Administration of carbidopa could prevent the increase of retinal dopamine induced by L-DOPA, but no influenced on its refractive state in the injected eyes. In non-SM animals, intraperitoneal L-DOPA could inhibit FDM, accompanied by the increase of retinal dopamine. Carbidopa treatment diminished the inhibition of FDM and prevented the increase in retinal dopamine by L-Dopa. Retinal dopamine was highly correlated with ocular refraction in FDM, but not in SM. There was no significant difference in dopamine content of RPE/choroid complex among all groups.
The role of retinal dopamine was different between SM and FDM in albino guinea pigs. Although systemic L-DOPA could inhibit the development of SM and FDM, retinal dopamine was only involved in the L-DOPA inhibition on FDM, but not on SM.
Albinism causes significant eye morbidity and amblyopia in children. The aim of this study was to determine the refractive state in patients with complete oculocutaneous albinism who were treated at the Gynaeco-Obstetric and Paediatric Hospital, Yaoundé, Cameroon and evaluate its effect on vision.
We carried out this retrospective study at the ophthalmology unit of our hospital. All oculocutaneous albino patients who were treated between March 1, 2003 and December 31, 2011 were included.
Thirty-five patients (70 eyes) diagnosed with complete oculocutaneous albinism were enrolled. Myopic astigmatism was the most common refractive error (40%). Compared with myopic patients, those with myopic astigmatism and hypermetropic astigmatism were four and ten times less likely, respectively, to demonstrate significant improvement in distance visual acuity following optical correction.
Managing refractive errors is an important way to reduce eye morbidity-associated low vision in oculocutaneous albino patients.
Skin flora varies from one site of the body to another. Individual's health, age and gender determine the type and the density of skin flora.
A 1 cm2 of the skin on the sternum was rubbed with sterile cotton swab socked in 0.9% normal saline and plated on blood agar. This was cultured at 35°C. The bacteria were identified by culturing on MacConkey agar, coagulase test, catalase test and gram staining. Swabs were obtained from 66 individuals affected by albinism and 31 individuals with normal skin pigmentation. Those with normal skin were either relatives or staying with the individuals affected by albinism who were recruited for the study.
The mean age of the 97 recruited individuals was 30.6 (SD ± 14.9) years. The mean of the colony forming units was 1580.5 per cm2. Those affected by albinism had a significantly higher mean colony forming units (1680 CFU per cm2) as compared with 453.5 CFU per cm2 in those with normally pigmented skin (p = 0.023). The skin type and the severity of sun- damaged skin was significantly associated with a higher number of colony forming units (p = 0.038).
Individuals affected by albinism have a higher number of colony forming units which is associated with sun- damaged skin.
This study investigated the variation in density of macular pigment across the central retina in normal and albino subjects. Luminance profiles were measured using a fundus camera and digital video techniques. The normal group had pigment spatial distributions consistent with previous studies. The albinos had no variation in absorbance across the central retina.
The new standardized form for recording the causes of visual loss in children is accompanied by coding instructions and by a database for statistical analysis. The aim is to record the causes of childhood visual loss, with an emphasis on preventable and treatable causes, so that appropriate control measures can be planned. With this standardized methodology, it will be possible to monitor the changing patterns of childhood blindness over a period of time in response to changes in health care services, specific interventions, and socioeconomic development.
In oculocutaneous albinism (OCA), one can distinguish between a tyrosinase-negative form (no residual activity of the enzyme tyrosinase) and a tyrosinase-positive form (with detectable residual enzymatic activity) and their respective subtypes. In infancy and early childhood the clinical discrimination between tyrosinase-positive OCA and tyrosinase-negative OCA can be very difficult. To date, only the hair-bulb L-dopa incubation test has been helpful in discriminating between the tyrosinase (ty)-negative and ty-positive forms of OCA. In 68 patients with albinism of the eye, 24 had an oculocutaneous form of albinism. We determined the ty relationship either by the L-dopa incubation test (younger patients) or by clinical appearance (older patients). We determined the full cycloplegic refraction in all patients and looked for a possible correlation of the refraction with the ty relationship. Our data suggest that an OCA patient with a hyperopic refractive error of > 4.0 D might have a ty-positive form of OCA. A patient with a moderate to high degree of myopia is more likely to have a ty-negative form of OCA. Determination of ty relationship is more reliable in patients with high degrees of hyperopia and, therefore, in patients with a ty-positive form of OCA. Statistical evaluation of the data was not possible in a sensible way due to the small number of patients involved in the present study.
We report here a clinical study investigating the main visual problems associated with albinism, with a view to determining the best treatment. We came across 42 cases of albinism during the course of this study, corresponding to a prevalence for albinism of 0.15%. One in ten albinos were of the yellow mutant type and more of the albinos were men than were women (sex ratio 1.21). The maximum visual acuity recorded was 3/10 and 40.47% of the patient had a best visual acuity score no higher than 1/10. Vision was best in the yellow mutants and it improved with age. We found that 33.33% of the albino patients had a squint and 35.71% had torticullis at primary fixation. In contrast to the results of previous studies, the most common ametropia was myopic astigmatism (61.9%). These findings have potential implications for the treatment of visual problems in albinos.
The genetic condition albinism has a high frequency among the Sotho people of northern South Africa. Affected children have pale hair, eyes and skin-a dramatic contrast to the normal dark pigmentation. Their visual performance is poor and many attend special schools for the visually impaired. Children with albinism experience problems that are, on the one hand, physiological, and, on the other, social-psychological and educational in nature. In this self-report study 38 children at a rural special school described their eye and skin problems, a direct result of their lack of pigmentation, as well as strategies they adopted to manage their condition. A further section of the study deals with the social adaptation difficulties experienced by these children. The questionnaire tested for local belief systems about albinism and how these impact on the socialization of children with albinism. The intervention strategy proposed in this study is based on the assumption that any attempt to address both the health and social problems should be of a holistic, interactionist nature, and be based on the values and belief systems of the local community. In addressing the physical problems, the proposed intervention programme focuses on sensible sun protection habits from a young age and the active participation of the children. To alleviate the social problems a team (interactionist) approach including children, teachers, parents, health officials and the wider community is recommended.
Oculocutaneous albinism (OCA) is a genetically inherited autosomal recessive condition and OCA2, tyrosine-positive albinism, is the most prevalent type found throughout Africa. Due to the lack of melanin, people with albinism are more susceptible to the harmful effects of ultraviolet radiation exposure. This population must deal with issues such as photophobia, decreased visual acuity, extreme sun sensitivity and skin cancer. People with albinism also face social discrimination as a result of their difference in appearance. The World Health Organization is currently investigating the issues concerning this vulnerable population.
Systematic electronic search of articles in PubMed concerning albinism in Africa. Furthermore, a World Health Organization (WHO) pilot survey of albinism was drafted in English, French and Portuguese, and distributed to African countries through WHO African Regional Offices (AFRO) in an attempt to gather further information on albinism.
Epidemiologic data on albinism, such as prevalence, were available for South Africa, Zimbabwe, Tanzania and Nigeria. Prevalences as high as 1 in 1,000 were reported for selected populations in Zimbabwe and other specific ethnic groups in Southern Africa. An overall estimate of albinism prevalences ranges from 1/5,000-1/15,000. In addition, both the literature review and the survey underscored the medical and social issues facing people with albinism.
The estimated prevalence of albinism suggests the existence of tens of thousands of people living with albinism in Africa. This finding reiterates the need for increased awareness of and public health interventions for albinism in order to better address the medical, psychological and social needs of this vulnerable population.
Color loci in mammals are those genetic loci in which mutations can affect pigmentation of the hair, skin, and/or eyes. In the mouse, over 800 phenotypic alleles are now known, at 127 identified color loci. As the number of color loci passed 100 only recently, we celebrate this 'century' with an overview of these loci, especially the 59 that have been cloned and sequenced. These fall into a number of functional groups representing melanocyte development and differentiation, melanosomal components, organelle biogenesis, organelle transport, control of pigment-type switching, and some systemic effects. A human ortholog has been identified in all cases, and the majority of these human genes are found to be loci for human disorders, often affecting other body systems as well as pigmentation. We expect that a significant number of color loci remain to be identified. Nonetheless, the large number known already provide a treasury of resources for reconstruction of the mechanisms, at the subcellular, cellular and tissue levels, that produce a functional pigmentary system and contribute to the normal development and functioning of many other organ systems. The mutant mice also provide valuable models for the study of human disease.
• The eyes of a 13-year-old leukemic boy with the attributes of tyrosinase-negative oculocutaneous albinism were obtained for light and electron microscopic study. Repeated examinations had failed to reveal WBCs with giant oxidase-positive granules, and leukemic involvement of the fundus never occurred. Light microscopic examination of horizontal and vertical sections through the retina confirms earlier reports that the fovea is absent in albinos. The synaptic apparatus of the photoreceptor terminals appears abnormal. The rough endoplasmic reticulum of the retinal pigment epithelial cells is sparse though the presence of phagosomes suggests that phagocytic function is intact. Suggestions as to the importance that the morphological findings may have on albino visual function are made.
Abstract The Hermansky-Pudlak Syndrome (HPS) is a rare, autosomal recessive condition comprising nine genetically heterogeneous entities that feature oculocutaneous albinism (OCA) and bleeding tendency as their principal clinical manifestations. The pathogenesis of HPS involves disturbances in the biogenesis and trafficking of lysosome-related organelles. While the ophthalmologist is trained to address the ocular manifestations of OCA, it is critical for the provider to consider HPS when examining OCA patients as its systemic sequelae may be associated with morbidity and mortality. If there is suspicion of HPS in a patient with albinism, the ophthalmologist should enlist the aid of consultants to confirm the diagnosis and monitor for systemic features. As the nine HPS subtypes explored in this article vary widely in the character and severity of their associated systemic manifestations, some authors advocate determining the specific gene defect in each HPS patient in order to optimize care and provide anticipatory guidance.
Albinism is a rare genetic condition associated with a variable hypopigmentation phenotype, which can affect the pigmentation of only the eyes or both the eyes and the skin/hair, resulting in ocular (OA) or oculocutaneous albinism (OCA), respectively. At least four forms of OCA and one of OA are known, associated with TYR (OCA1), OCA2 (OCA2), TYRP1 (OCA3), SLC45A2 (OCA4) and GPR143 (OA1) loci, respectively. Additionally, the rarest syndromic forms of albinism, affecting the normal function of other organs, can be grouped in Hermansky-Pudlak syndrome (HPS1-9) and the Chediak-Higashi syndrome (CHS1). In summary, a total of 15 genes are currently associated with various types of albinism. However, new genes have been recently described, associated with autosomal recessive oculocutaneous albinism with highly similar phenotypes but diverse molecular origin, indicating that there are likely to be more than 15 genes whose mutations will be associated with albinism. In this review, we will describe the different types of albinism and comment on its prevalence in European countries. Some preclinical attempts for innovative therapeutic approaches of different types of albinism will be also discussed.
To explore the association between outdoor activity and myopia among 681 primary students from Beijing.
School-based, cross-sectional investigation. Eye examination includes the visual acuity test, auto-refractor, slit lamp, ocular biometry and non-mydriatic fundus camera. Questionnaire includes regular items, near work, outdoor activity and social-economic status.
The mean time spent outdoors was 1.6 ± 0.8 hours daily. Time spent on outdoor sports and outdoor leisure were 0.7 ± 0.1 hours daily, 1.0 ± 0.8 hours daily, respectively. Mean time of outdoor activity in urban was 1.1 ± 0.4 hours daily, compared with 2.2 ± 0.8 hours daily in rural (P = 0.000). In grade-1, total time spent outdoors is significantly different between myopia and non-myopia (1.4 ± 0.6 vs 1.8 ± 0.8 hours daily, P = 0.000), similar to outdoor leisure (0.8 ± 0.6 vs 1.1 ± 0.9 hours daily, P = 0.000). The same trend was also found in grade-4.
The mean time spent outdoors was 1.6 ± 0.8 hours daily. Myopia spent a lower outdoor activity compared with non-myopia. More outdoor activity, e.g., in schools, may potentially be helpful to reduce the high prevalence of myopia in the young generation.
The eye of a 47 year old man with tyrosinase-positive oculocutaneous albinism, photophobia, nystagmus and visual acuity 0,4–0,5 was histologically examined after orbital exenteration for neoplasia. Histologic serial sections of the centre of the retina showed a continuous 6–8 cell-layer of ganglion cells, without any suggestion of a foveolar pit. The outer layers of the macular retina were altered secondarily by tumor-impression-folds; they were unremarkable at the periphery as were the acid mucopolysaccharides in the receptor region. Electron microscopy of the uvea and the retinal pigment epithelium showed a normal number of pigment granules but a deficiency of melanin, as well as structural anomalies. The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia. The etiology is discussed. An identic anomaly has been described in aniridia, similar ones in other congenital ocular diseases.
To evaluate the prevalence of refractive errors in different subtypes of oculocutaneous albinism, and to see if there is any correlation between refractive errors and final visual outcome in this population.
This is a retrospective study of 132 albino patients, ranging in age from 0.5 to 35 years. They were divided into four subtypes: OCA1A, OCA1B and OCA1C, and OCA2. Refractive errors were evaluated objectively by cycloplegic refraction and subjectively in cooperative patients. Best corrected visual acuity was assessed binocularly. Refractive errors were divided into three groups--hypermetropia, myopia and astigmatism--to avoid the use of spherical equivalent.
Refractive errors were mainly astigmatism and hypermetropia. The OCA1A group showed high hypermetropia (≥ 5 dioptres) in 43.4% of patients, reaching significantly higher levels than in other subgroups (p=0.007). Mean visual acuity in logMAR was: OCA1A=0.81, OCA1B=0.64, OCA1C=0.61 and OCA2=0.48. Astigmatism averaged 2.1 dioptres (consistently with-the-rule), and it was homogeneously distributed between all subgroups (53%).
The poorest visual acuity was found in those with OCA1A, which was associated with the highest rate of high hypermetropia (statistically significant different from other subgroups). Astigmatism was the most common visually significant refractive error across all subtypes of albinism. These results may help to clarify the prevalence of refractive errors in albino patients and aid the prediction of visual outcome in this heterogeneous population.
The eyes of a 13-year-old leukemic boy with the attributes of tyrosinase-negative oculocutaneous albinism were obtained for light and electron microscopic study. Repeated examinations had failed to reveal WBCs with giant oxidase-positive granules, and leukemic involvement of the fundus never occurred. Light microscopic examination of horizontal and vertical sections through the retina confirms earlier reports that the fovea is absent in albinos. The synaptic apparatus of the photoreceptor terminals appears abnormal. The rough endoplasmic reticulum of the retinal pigment epithelial cells is sparse though the presence of phagosomes suggests that phagocytic function is intact. Suggestions as to the importance that the morphological findings may have on albino visual function are made.
The eye of a 47 year old man with tyrosinase-positive oculocutaneous albinism, photophobia, nystagmus and visual acuity 0, 4-0, 5 was histologically examined after orbital exenteration for neoplasia. Histologic serial sections of the centre of the retina showed a continuous 6-8 cell-layer of ganglion cells, without any suggestion of a foveolar pit. The outer layers of the macular retina were altered secondarily by tumor-impression-folds; they were unremarkable at the periphery as were the acid mucopolysaccharides in the receptor region. Electron microscopy of the uvea and the retinal pigment epithelium showed a normal number of pigment granules but a deficiency of melanin, as well as structural anomalies. The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia. The etiology is discussed. An identic anomaly has been described in aniridia, similar ones in other congenital ocular diseases.
This paper reviews some studies done on the psychological aspects of albinism. Studies on the intellectual ability of albinos produce equivocal results. Results from personality studies seem more consistent and show albinos to be more emotionally unstable than non-albinos. This paper also reports a study by the author which examines the phenomenon of albinism from the albino's viewpoint. It examined the responses of three undergraduate albino subjects--one female and two males--to the author's request for each to write an essay on the merits and demerits of being an albino based on personal experiences. All consider being an albino to be more of a demerit than a merit. The demerits include conspicuous colour, delicate skin which blisters under the sun, defective sight, interpersonal, especially heterosexual, problems and society's unkind attitude. The paper ends with a discussion of possible future research in the area and a recommendation of the need for psychological rehabilitation as part of the management programme for albinos.
Albinism involves the mutation of one or more of the genes associated with melanin synthesis and has many ramifications for vision. This study focuses on the refractive implications of albinism in the context of emmetropization.
Refractive, biometric, and visual acuity data were collected for a group of 25 albino individuals that included the following: 18 oculocutaneous (13 tyrosine positive, 5 tyrosine negative); 7 ocular (2 autosomal recessive, 5 sex-linked recessive). Their age range was 3 to 51 years. All exhibited horizontal pendular nystagmus.
There were no statistically significant differences relating to albino subtype for any of the measured parameters. All the subjects had reduced visual acuity (mean: 0.90, logMAR) and overall, there was a bias toward hyperopia in their refractive errors (mean: + 1.07 D). However the refractive errors of the group covered a broad range (SD: 4.67 D) and included both high myopia and high hyperopia. An axial origin to the refractive errors is implied by the high correlation between refractive errors and axial lengths. Refractive astigmatism averaged 2.37 D and was consistently with-the-rule and highly correlated with corneal astigmatism, which was also with-the-rule. Meridional analysis of the refractive data indicated that the vertical meridian for hyperopic subjects was consistently nearer emmetropia compared to their horizontal meridian. Myopic subjects showed the opposite trend.
The overall refractive profile of the subjects is consistent with emmetropization being impaired in albinism. However, the refractive errors of hyperopic subjects also can be explained in terms of "meridional emmetropization." The contrasting refractive profiles of myopic subjects may reflect operational constraints of the emmetropization process.
We compared retrospectively the distribution of refractive errors in a sample of adolescent and adult albinos (n = 19) with that in persons with idiopathic congenital nystagmus (CN) (n = 46), whose eye movements are similar to those of albinos but whose visual acuity is better. The distribution of spherical-equivalent refractive errors is more broadly distributed and slightly less myopic in albinos than in persons with idiopathic CN. On average, albinos also have more astigmatism (primarily with-the-rule), than persons with idiopathic CN. Unlike the leptokurtic distribution of refractive error that characterizes the normal adolescent and adult population, the distributions of refractive error for albinos and for persons with idiopathic CN exhibit no significant kurtosis. Moreover, neither group of subjects exhibits significant kurtosis for refractive errors in the vertical meridian, which corresponds to the retinal-image orientation with the least motion smear during horizontal nystagmus. The absence of significant leptokurtosis in the refractive-error distributions of young-adult albinos and persons with idiopathic CN suggests that the presence of nystagmus may interfere with normal refractive development.
Patients with albinism have varying degrees of reduced vision, strabismus, iris transillumination, nystagmus, fundus hypopigmentation, and foveal hypoplasia. High refractive errors are common, but reduced vision persists due to nonrefractive factors, causing reluctance by some clinicians to prescribe spectacles. We sought to evaluate the effect of spectacle correction of refractive error on clinical findings and recorded compliance with refractive corrections, as little detailed data exist.
We prospectively examined 35 consecutive patients with albinism for whom glasses had been prescribed to determine if objective improvement in recognition visual acuity (VA), strabismus, anomalous head posture (AHP), fusion, or stereoacuity occurred with refractive correction. Parents or patients reported compliance with glasses wear (excellent: >75% of awake hours; good: 50-75% of awake hours; fair: 26-50% of awake hours; poor: <25%).
Median age was 9.5 years (range: 3 to 30). Median refractive correction was 1.875 D spherical equivalent (range: -9.75 to +8.88 D). Glasses wear was initiated at a median age of 14 months (range: 3 months to 14 years). Mean binocular VA at distance was 20/80.9 corrected and 20/107.6 uncorrected ( P < 0.001). Mean VA at near was 20/28.4 corrected and 20/41 uncorrected ( P < 0.001). Mean strabismic deviation was 7.2 PD with glasses and 10.0 PD without glasses at distance ( P = 0.006) and 10.8 PD with glasses and 14 PD without glasses at near ( P = 0.042). Mean AHP at distance was 8.3 degrees with glasses and 7.3 degrees without glasses at distance ( P = 0.327) and 4.7 degrees both with and without glasses at near ( P = 0.308). Twenty-one patients had fusion with or without glasses, two had fusion only with glasses, and one patient had fusion only without glasses. The other patients did not have any detectable degree of fusion. Twenty-seven individuals had no stereoacuity with or without glasses, five had gross stereoacuity of 3000 seconds of arc both with and without glasses, and three had gross stereoacuity only while wearing glasses. Compliance was excellent in 29 patients, fair in four, and poor in two.
This prospective study showed a significant improvement in corrected VA and alignment in persons with albinism, despite overall subnormal acuity. Some individuals also experienced improvement in binocular alignment and AHP. Compliance with spectacles was generally good. Therefore, refractive correction should be encouraged in persons with albinism as improvement in visual function is likely to occur.
Education of children and young people with albinism in Malawi
Lynch P, Lund P (2011) Education of children and young people with
albinism in Malawi. Ministry of Education, Science, and Technology
Malawi. Final report. Commonwealth Secretariat, London, pp. 5-6