Potential blindness from nutritional xerophthalmia in autistic patients.

BACKGROUND: Vitamin A is vital to retinal rod function and epithelial cell differentiation. Although uncommon in the developed world, vitamin A deficiency (VAD) secondary to poor diets or gastrointestinal disease has been reported and can lead to xerophthalmia, which is characterized by night blindness and a spectrum of ocular surface changes. Patients with autism spectrum disorder have been shown to have restrictive diets secondary to sensory issues leading to rejection of foods except for those of certain color or texture. METHODS: We present a case series of 6 pediatric patients with autism who developed varying degrees of xerophthalmia due to VAD, which resulted from restrictive eating. RESULTS: All patients presented with a history of eye irritation that was not relieved by antibiotic or allergy eye drops. Further questioning revealed they had restrictive diets consisting of only or mostly white and tan foods, and serum vitamin A testing confirmed severe VAD. Most stages of xerophthalmia were completely reversed with vitamin A supplementation, but in 2 patients more advanced xerophthalmia resulted in irreversible blindness and ocular damage. CONCLUSIONS: Both pediatricians and pediatric eye care providers must be vigilant for VAD as an etiology of eye irritation, photophobia, or new-onset visual impairment in autistic children. A review of the child's diet must be implemented as a standard part of routine history taken in this vulnerable population. Early identification and vitamin A supplementation can prevent irreversible ocular compromise and vision loss.

Increased risk of Parkinson's disease amongst patients with age-related macular degeneration and visual disability: A nationwide cohort study.

BACKGROUND AND PURPOSE: The association between Parkinson's disease (PD) and age-related macular degeneration (AMD) has been shown in previous reports. However, the association between the severity of AMD and PD development is unknown. The aim was to evaluate the association of AMD with/without visual disability (VD) with the risk of PD occurrence using the National Health Insurance data in South Korea. METHODS: A total of 4,205,520 individuals, 50 years or older and without a previous diagnosis of PD, participated in the Korean National Health Screening Program in 2009. AMD was verified using diagnostic codes, and participants with VD were defined as those with loss of vision or visual field defect as certified by the Korean Government. The participants were followed up until 31 December 2019, and incident cases of PD were identified using registered diagnostic codes. The hazard ratio was calculated for groups (control and AMD with/without VD) using multivariable adjusted Cox regression analysis. RESULTS: In total, 37,507 participants (0.89%) were diagnosed with PD. Amongst individuals with AMD, the risk of PD development was higher in individuals with VD (adjusted hazard ratio [aHR] 1.35, 95% confidence interval [CI] 1.09-1.67) than in those without (aHR 1.22, 95% CI 1.15-1.30) compared with controls. Additionally, an increased risk of PD was observed in individuals with AMD compared with controls, regardless of the presence of VD (aHR 1.23, 95% CI 1.16-1.31). CONCLUSIONS: Visual disability in AMD was associated with the development of PD. This suggests that neurodegeneration in PD and AMD may have common pathways.

Incidence and Risk Factors for Blindness in Uveitis: A Nationwide Cohort Study from 2002 to 2013.

Purpose: To investigate the incidence and risk factors of blindness in uveitis.Methods: From a national sample cohort (n = 1,025,340), we selected 9,036 new-onset uveitis patients. Incidences of unilateral and bilateral blindness (visual acuities ≤20/400) were estimated and socioeconomic and clinical risk factors for unilateral blindness in uveitis patients were identified.Result: Incidence of unilateral and bilateral blindness was 2.93 and 0.42 per 1,000 person-years, respectively. The risk factors for unilateral blindness were age >40 (hazard ratio [HR], 2.77, 95% CI [confidence interval], 1.11-6.92) and low household income (HR, 1.50; 95% CI, 1.02-1.98) in uveitis overall, and Behçet's disease (HR, 4.49; 95% CI, 1.59-12.71) in non-anterior uveitis, respectively.Conclusions: Low household income and Behçet's disease influence the risk of blindness in uveitis patients. These findings will help in assessing blindness-related socioeconomic burdens and planning health-care strategies for uveitis patients.

Surgical outcomes of macular hole and epimacular membrane treatment in patients with intraoperative amaurosis under sub-Tenon's anesthesia.

OBJECTIVE: Some patients have been found to develop intraoperative amaurosis under sub-Tenon's anesthesia. We explored whether these patients have poor surgical outcomes during mid- to long-term postoperative follow-up. METHODS: In this case series, 74 of 85 patients with macular diseases who underwent phacoemulsification combined with vitrectomy under sub-Tenon's anesthesia developed intraoperative amaurosis. The surgical outcomes at the 2- and 4-month follow-ups in these patients were investigated and compared with the outcomes in patients without amaurosis using best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and pattern visual evoked potential (PVEP). RESULTS: Both BCVA and the OCT-based macular structure in patients with intraoperative amaurosis showed significant postoperative improvement comparable with that of patients without amaurosis. The presence of intraoperative amaurosis was not associated with either macular hole closure or macular edema regression. PVEP revealed no significant changes in the wave latency or amplitude before and after surgery. CONCLUSION: Intraoperative amaurosis following sub-Tenon's block is commonly seen but does not predict a poor surgical prognosis. When a patient develops amaurosis during surgery, the surgeon should increase patient comfort through verbal communication rather than perform an additional intervention to help relieve the patient's anxiety.

Correlation between sub-Tenon's anesthesia and transient amaurosis during ophthalmic surgery.

PURPOSE: To verify the correlation between sub-Tenon's anesthesia and intraoperative visual loss in ophthalmic surgery. METHODS: Sixty-four patients underwent phacoemulsification combined pars plana vitrectomy under sub-Tenon's anesthesia. Participants were investigated about their light perception at several time points: before anesthesia, immediately after anesthesia, 10 min after anesthesia without any surgical intervention or microscope illumination, and after the whole surgery. Intraoperative amaurosis was determined as that a patient could not see any light from their operative eye. The incidence rate of amaurosis at different time points and among different anesthetists was analyzed. RESULTS: The rate of intraoperative amaurosis was 0%, 1.56%, 48.44%, and 95.31% at several time points, respectively: before anesthesia, immediately after anesthesia, 10 min after anesthesia without any surgical intervention or microscope light exposure during the interval, and immediately after the whole surgery, presenting a significantly time-dependent increase (P < 0.01). There was no correlation between the amaurosis and different diseases and anesthesiologists. The amaurosis was transient, and all operative eyes could perceive light on the first postoperative day. CONCLUSIONS: Sub-Tenon's anesthesia contributes to the intraoperative amaurosis during operation. Temporary interruption of optic nerve conduction by the anesthetic could be a credible explanation. The amaurosis is transient and reversible, requires no additional treatment, and should not be considered as a surgical complication.

Retinopathy of prematurity: Overview and highlights of an initiative to integrate prevention, screening, and management into the public health system in India.

Purpose: In India, more than 800 special newborn care units (SNCUs) have been established since 2008 in government facilities. More preterm infants are now surviving and blindness from retinopathy of prematurity (ROP) is increasing. The aim of the Queen Elizabeth Diamond Jubilee Trust's initiative (2012-1019) was to improve the quality of neonatal care and integrate ROP services into the government health system using expertise in the government and nongovernment sector in four states in a sustainable and scalable manner. Methods: State Ministries of Health were engaged and collaboration was established between three government programs (Ministry of Health and Family Welfare, Rashtriya Bal Swasthya Karyakram, and blindness prevention) and relevant professionals. Extensive training took place and equipment was provided. Implementation was guided by a multidisciplinary National Task Force and was monitored by state coordination committees. The Task Force appointed technical expert groups to support implementation through advocacy, information, education and communication materials, operational guidelines, a competency-based training curriculum, and an online database and website. Results: Twenty-two ophthalmologists in government facilities were trained to screen for ROP and nine to treat ROP. Almost 13,500 preterm infants were screened in 17 SNCUs and 86% of the 456 infants with sight-threatening ROP were treated. An educational resource using latest pedagogy based on key domain areas for best practices for small and preterm neonates including ROP has been developed and pilot tested and is being evaluated and scaled up. Conclusion: All four states are scaling up services or have plans to scale up, and several other states have started the initiatives.

Epidemiology of Microbial Keratitis in Uganda: A Cohort Study.

Purpose: To describe the epidemiology of Microbial Keratitis (MK) in Uganda.Methods: We prospectively recruited patients presenting with MK at two main eye units in Southern Uganda between December 2016 and March 2018. We collected information on clinical history and presentation, microbiology and 3-month outcomes. Poor vision was defined as vision < 6/60).Results: 313 individuals were enrolled. Median age was 47 years (range 18-96) and 174 (56%) were male. Median presentation time was 17 days from onset (IQR 8-32). Trauma was reported by 29% and use of Traditional Eye Medicine by 60%. Majority presented with severe infections (median infiltrate size 5.2 mm); 47% were blind in the affected eye (vision < 3/60). Microbiology was available from 270 cases: 62% were fungal, 7% mixed (bacterial and fungal), 7% bacterial and 24% no organism detected. At 3 months, 30% of the participants were blind in the affected eye, while 9% had lost their eye from the infection. Delayed presentation (overall p = .007) and prior use of Traditional Eye Medicine (aOR 1.58 [95% CI 1.04-2.42], p = .033) were responsible for poor presentation. Predictors of poor vision at 3 months were: baseline vision (aOR 2.98 [95%CI 2.12-4.19], p < .0001), infiltrate size (aOR 1.19 [95%CI 1.03-1.36], p < .020) and perforation at presentation (aOR 9.93 [95% CI 3.70-26.6], p < .0001).Conclusion: The most important outcome predictor was the state of the eye at presentation, facilitated by prior use of Traditional Eye Medicine and delayed presentation. In order to improve outcomes, we need effective early interventions.

Bioactive Properties of Carotenoids in Human Health.

Research shows that certain bioactive compounds in our diet have beneficial effects on humanhealth[...].

Incidence and impact factors of intraoperative loss of light perception under sub-Tenon's anesthesia in patients with macular diseases.

PURPOSE: To investigate the incidence and impact factors of intraoperative loss of light perception (LP) under sub-Tenon's anesthesia in patients with macular diseases. METHODS: Eighty-five consecutive patients received standard phacoemulsification combined pars plana vitrectomy (PPV) under sub-Tenon's anesthesia. At several checkpoints during the surgery (the end of phacoemulsification, the end of vitrectomy, and the end of surgery), participants were interviewed about whether they had LP or not after removing the influence of contralateral eye and the photo-bleaching effect. In patients treated with retinal photocoagulation, visual experience on laser flashes was evaluated. RESULTS: Under routine draping, no patients reported loss of LP at all the checkpoints. When the contralateral eye was tightly covered, the rates of LP loss were 84.7%, 97.6%, and 87.1% at the end of phacoemulsification, the end of vitrectomy, and the end of surgery, respectively. When the photo-bleaching effect was also removed, the rates of LP loss were 61.2%, 82.4%, and 56.5% at each checkpoint, respectively, and there were 87.1% (74/85) of patients reporting visual loss in at least one checkpoint. In addition, 76.9% (50/65) of patients could not feel laser flashes during retinal photocoagulation. CONCLUSION: Intraoperative loss of LP under sub-Tenon's anesthesia was a relatively common and reversible event. The conduction block of optic nerve by anesthetic mainly contributed to the visual loss during surgery. Photo-bleaching effect also has some effect on the LP evaluation. Surgeons need to inform and counsel the patients about the intraoperative loss of LP, to prevent any sudden panic attacks in them.

Inequitable coverage of vitamin A supplementation in Nigeria and implications for childhood blindness.

BACKGROUND: Vitamin A deficiency (VAD) is of major public health significance; it is a risk factor for childhood deaths from diarrhoea and measles in low and middle-income countries and an important cause of preventable childhood blindness in low income countries. Vitamin A supplementation (VAS) is being implemented in many LMICs and high coverage reduces the prevalence of blinding corneal diseases in children. However, national estimates of coverage may not reveal any inequities in intra country coverage. The aim of this study is to assess factors influencing VAS coverage and also assess the relationship between VAS coverage and childhood corneal blindness in Nigeria. METHODS: Data were collected from the Nigeria Demographic and Health Survey (NDHS) 2013 and the published literature on population-based childhood blindness surveys in Nigeria. The main outcome measure was the proportion of eligible children who received VAS in the last 6 months preceding the survey. Study factors comprised a range of socioeconomic, and individual factors. Data were analysed using STATA V.12.1 (Statcorp, Texas). To explore the effects of the independent variables on VAS coverage, bivariate and multivariate regression was done. Variables with p < 0.05 in the final multivariable model were considered as independent factors. For the population-based childhood blindness surveys, aggregated and disaggregated data were used. Causes of blindness were stratified into corneal blindness and 'others'. Odds ratios were computed to determine the odds of developing corneal blindness in each geopolitical region. Tests of significance were set at the 95% level. RESULTS: The total VAS coverage in 2013 was 41.5%. VAS coverage was inequitable. Children with very educated mothers (OR 3.27 p < 0.001), from the south-south region (OR 2.38 p < 0.001) or in the highest wealth quintile (OR 2.81 p < 0.001) had higher odds of receiving VAS. The northwest zone had the lowest VAS coverage and the highest prevalence of corneal blindness. CONCLUSION: Regional and socioeconomic inequities in VAS exist in Nigeria and these may have grave implications for the causes of childhood blindness. The development and implementation of context specific and effective strategies are needed to reduce these inequities in VAS.

[Ophthalmological rehabilitation of visually impaired children]. / Ophthalmologische Rehabilitation sehbehinderter Kinder.

BACKGROUND: There are very few studies on visually impaired children in Germany; therefore, the aim of this study was to investigate the current spectrum of diseases of visually impaired children and the care of these children in schools and kindergartens with aids and integrative support. PATIENTS AND METHODS: In a retrospective study all children (n =303) who attended the outpatient department for the visually impaired of the University Eye Hospital Tübingen in 2013 and 2014 were evaluated. The target values were ophthalmological diagnosis, best corrected visual acuity, needs for magnification, prescribed aids, measures for early support and integrative care and inclusion during schooltime. RESULTS: The most frequent diagnosis in this collective which led to visual impairment in children was optic atrophy (22.4%) followed by hereditary retinal dystrophy (18.5%), congenital nystagmus (9.9%), albinism (8.6%), retinopathy of prematurity (ROP, 7.9%), aniridia (4.6%), cerebral visual impairment (CVI, 4.3%) and severe myopia (3%). Of the children 21% suffered from multiple disabilities, 66% were visually impaired (visual acuity ≤0.3 and >0.05), 9% were severely visually impaired (visual acuity ≤0.05) and 6% were legally defined as blind (visual acuity ≤0.02). Of the schoolchildren 52% (n = 241) were able to visit a mainstream school within the framework of integrative care. For 77% of these schoolchildren integrative care was already provided by a special pedagogic institution at the time of presentation for school entry and 73% of all the schoolchildren needed magnifying aids at school: 20% used optical magnifying aids (e.g. reading stones) and 53% needed electronic magnifying aids, such as screen magnifiers or camera reading systems. CONCLUSION: Particularly for children, the use of magnifying aids for reading is essential for education in schools and 73% of the children used optical or electronic devices for reading. Of the children 52% attended a mainstream school and were additionally supported by special pedagogic counseling services.

A preliminary descriptive analysis of Corneal Transplant Registry of National Eye Bank in India.

PURPOSE: To describe and analyze the Corneal Transplant Registry of National Eye Bank and also evaluate graft outcomes in India. METHODS: All patients who underwent corneal transplant at our center within six months of setting up of Corneal Transplant Registry and installation of database at National Eye Bank were included in the study. The established database was analyzed for utilization, donor and recipient details and graft outcomes. Outcome was assessed at the end of one year follow up. The influence of various donor and recipient factors affecting outcome were evaluated. Visual outcome was analyzed in terms of shift in visual handicap category. Statistical tests like analysis of variance, Kruskal-Wallis test and Chi square tests were applied for determination of clinical significance wherever required. RESULTS: 326 corneas were received from 168 donors; of these, 234 (71.7%) were utilized for transplantation. Out of 177 patients with adequate (one year) follow up (75.6% patients), optical corneal replacement was performed in106 patients and therapeutic keratoplasty in71. 78% (82/106) patients in the optical group retained clear grafts at the end of follow up. 59.7% (49 of 82) of patients who attained clear grafts belonged to visual disability category 3 or worse pre-operatively. 59.1% of these achieved BCVA of ≥6/60 at the end of follow up; thus shifting up their visual handicap category. Primary graft failure was found to be associated with full thickness keratoplasty and not with lamellar procedures (p<0.05) and occurred in 4.2% patients (5) with optical corneal replacement whereas 7.5% patients (8) developed secondary graft failure. Age of donor (p=0.54), death enucleation time (p>0.05), cause of donor death (p=0.15), type of surgical procedures (p=0.538) and indication for surgery did not have any significant effect on outcome. 76% patients who underwent therapeutic graft achieved elimination of corneal infection. CONCLUSIONS: The development of corneal graft registry established an effective means to evaluate our corneal transplantation services. Outcomes of sight restoring corneal transplants performed were comparable to results of graft registries from developed nations.

Vitamin a deficiency in pregnancy: perspectives after bariatric surgery.

This study aims to describe the clinical consequences of vitamin A deficiency (VAD) in pregnant women after bariatric surgery. Included are studies on VAD during pregnancy and after bariatric surgery conducted in humans from 1993 to 2011. There are few investigations on the relationship between pregnancy and bariatric surgery and on the damage to the binomial mother-child resulting from VAD in this relationship. The high percentage of VAD in the postoperative period is a cause for concern, especially considering the function of this vitamin in certain biological moments and in moments of intense nutritional demand. This vitamin serum evaluation is recommended during the prenatal period.

Social factors determining the experience of blindness among pregnant women in developing countries: the case of India.

Approximately 10 million pregnant women around the world develop night blindness annually. In India, one in 11 pregnant women suffers from night blindness. This study used a nationally representative sample of 35,248 women from India between the ages of 15 and 49 who had given birth in the past five years to understand the effect of women's empowerment on developing blindness during pregnancy. Findings from logistic regression showed that several empowerment-related factors, including women's increased age at the birth of their first child, high school education, and participation in their own health care decisions, significantly reduced the odds of developing blindness, whereas their experience of spousal control, humiliation, and physical abuse significantly increased the odds of developing blindness during pregnancy. Interestingly, antenatal care visits that included nutritional advice and iron supplements during pregnancy had no effect on blindness after controlling for other factors. To reduce blindness during pregnancy in India, more attention should be given to delaying age at marriage and first birth; improving women and girl's education and autonomy; and implementing strategies to reduce spousal control, humiliation, and abuse.

Integrated model of primary and secondary eye care for underserved rural areas: the L V Prasad Eye Institute experience.

Blindness is a major global public health problem and recent estimates from World Health Organization (WHO) showed that in India there were 62 million visually impaired, of whom 8 million are blind. The Andhra Pradesh Eye Disease Study (APEDS) provided a comprehensive estimate for prevalence and causes of blindness for the state of Andhra Pradesh (AP). It also highlighted that uptake of services was also an issue, predominantly among lower socio-economic groups, women, and rural populations. On the basis of this analysis, L V Prasad Eye Institute (LVPEI) developed a pyramidal model of eye care delivery. This article describes the LVPEI eye care delivery model. The article discusses infrastructure development, human resource development, and service delivery (including prevention and promotion) in the context of primary and secondary care service delivery in rural areas. The article also alludes to opportunities for research at these levels of service delivery and the amenability of the evidence generated at these levels of the LVPEI eye health pyramid for advocacy and policy planning. In addition, management issues related to the sustainability of service delivery in rural areas are discussed. The article highlights the key factors required for the success of the LVPEI rural service delivery model and discusses challenges that need to be overcome to replicate the model. The article concludes by noting the potential to convert these challenges into opportunities by integrating certain aspects of the existing healthcare system into the model. Examples include screening of diabetes and diabetic retinopathy in order to promote higher community participation. The results of such integration can serve as evidence for advocacy and policy.

Visual impairment in children in middle- and lower-income countries.

Reducing visual impairment and blindness in children in resource-poor countries is one of the key components of the major global prevention of blindness initiative, VISION 2020 the Right to Sight. Although visual impairment and blindness among children is much less common than among adults, the potential lifespan of a child means that the lifelong impact of such impairment is very large. Over 10 years ago, it was estimated that, globally, 1.4 million children were blind. Much has changed in the past 10-20 years and there is a need to reassess both the magnitude and causes of global childhood blindness and visual impairment. While the widespread implementation of vitamin A supplementation and measles immunisation programmes have led to a reduction in vitamin A deficiency-related blindness in many poor countries, retinopathy of prematurity is now undergoing a third wave of endemicity, particularly in newly industrialising countries in Latin America and Asia. Childhood cataract is better recognised as an important potentially avoidable problem, as is paediatric glaucoma and refractive error in some populations. Trained paediatric ophthalmologists, although still too few, are growing in number in poor countries. A programmatic approach with a multidisciplinary team is essential to reducing childhood blindness. The elements of such programmes and the need for planning are discussed.

Estimating incidence of vision-reducing cataract in Africa: a new model with implications for program targets.

OBJECTIVE: To estimate the incidence of vision-reducing cataract in sub-Saharan Africa and use these data to calculate cataract surgical rates (CSR) needed to eliminate blindness and visual impairment due to cataract. METHODS: Using data from recent population-based, standardized, rapid-assessment surveys, we calculated the age-specific prevalence of cataract (including operated and unoperated eyes) from surveys in 7 "districts" across Africa. This was done at 3 levels of visual acuity. Then we used the age-specific prevalence data to develop a model to estimate age-specific incidence at different visual acuities, taking into account differences in mortality rates between those with cataract compared with those without. The model included development of opacity in the first eye and second eye of people older than 50 years. The incidence data were used to calculate target cataract surgical rates. RESULTS: Incidence and CSR needs varied significantly in different sites and were lower in some than expected. Cataract surgical rates may depend on genetic, environmental, or cultural variations and will vary with population structure, which is not uniform across Africa. CONCLUSION: Africa should not be viewed as homogeneous in terms of cataract incidence or CSR needed. These CSR calculations should be useful for more appropriate planning of human resources and service delivery on the continent. The methodology can be applied to other population-based data as they become available to determine appropriate CSR targets.

Couching in Nigeria: prevalence, risk factors and visual acuity outcomes.

PURPOSE: Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria. METHODS: Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging. RESULTS: Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60). CONCLUSIONS: Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country.

[Characteristics of cup/disc ratios in a population of northern Togo aged 20-40 years]. / Caractéristiques de l'excavation papillaire dans une population jeune de 20 à 40 ans du Nord Togo.

AIM: To describe the characteristics of cup/disc ratio in a young population belonging to a homogenous ethnic group in northern Togo. PATIENTS AND METHODS: The study population comprising 1010 persons (550 men and 460 women aged 20-40 years) was selected in 12 villages in the Doufelgou area. Eye assessment was conducted in the local health center facilities using a visual acuity chart, an ophthalmoscope, and light magnification for exploration of the anterior segment. RESULTS: The mean age of the participants was 30.4 years. The mean cup/disc ratio was 0.36 (range, 0.3-0.9). The most frequently found cup/disc ratio was 0.3, in both eyes, and was predominant in the 20- to 24-year age group: 56.6% of the right eyes and 58.7% of the left eyes. Cup/disc ratios over 0.5 were found in 14.4% of the right eyes and 12.4% of the left eyes; a cut-off point over 0.7 gave an abnormal cup/disc ratio prevalence of 3.2% in the right eye and 3.5% in the left eye. In 75% of the cases, the cupping appeared round and was elliptic in 25% of the patients. The cupping position was central in 63%, temporal in 18.3%, and nasal in 18.7% of the cases. In 7.8%, cupping was asymmetric. CONCLUSION: More than 3% of the young population of northern Togo has a 0.7 or higher cup/disc ratio, which shows a high prevalence of primary open-angle glaucoma if cup/disc ratio is considered a criterion for definition.

A neural mechanism for exacerbation of headache by light.

The perception of migraine headache, which is mediated by nociceptive signals transmitted from the cranial dura mater to the brain, is uniquely exacerbated by exposure to light. We found that exacerbation of migraine headache by light is prevalent among blind individuals who maintain non-image-forming photoregulation in the face of massive rod/cone degeneration. Using single-unit recording and neural tract tracing in the rat, we identified dura-sensitive neurons in the posterior thalamus whose activity was distinctly modulated by light and whose axons projected extensively across layers I-V of somatosensory, visual and associative cortices. The cell bodies and dendrites of such dura/light-sensitive neurons were apposed by axons originating from retinal ganglion cells (RGCs), predominantly from intrinsically photosensitive RGCs, the principle conduit of non-image-forming photoregulation. We propose that photoregulation of migraine headache is exerted by a non-image-forming retinal pathway that modulates the activity of dura-sensitive thalamocortical neurons.