Prevelence and causes of visual impairment and blindness in older adults in an area of India with a high cataract surgical rate.

BACKGROUND: The cataract surgical rate (CSR) in Gujarat, India is reported to be above 10,000 per million population. This study was conducted to investigate the prevalence and causes of vision impairment/blindness among older adults in a high CSR area. METHODS: Geographically defined cluster sampling was used in randomly selecting persons >or= 50 years of age in Navsari district. Subjects in 35 study clusters were enumerated and invited for measurement of presenting and best-corrected visual acuity and an ocular examination. The principal cause was identified for eyes with presenting visual acuity < 20/32. RESULTS: A total of 5158 eligible persons were enumerated and 4738 (91.9%) examined. Prevalence of presenting visual impairment < 20/63 to 20/200 in the better eye was 29.3% (95% confidence interval [CI]: 27.5-31.2) and 13.5% (95% CI: 12.0-14.9) with best correction. The prevalence of presenting bilateral blindness (< 20/200) was 6.9% (95% CI: 5.7-8.1), and 3.1% (95% CI: 2.5-3.7) with best correction. Presenting and best-corrected blindness were both associated with older age and illiteracy; gender and rural/urban residence were not significant. Cataract in one or both eyes was the main cause of bilateral blindness (82.6%), followed by retinal disorders (8.9%). Cataract (50.3%) and refractive error (35.4%) were the main causes in eyes with vision acuity < 20/63 to 20/200, and refractive error (86.6%) in eyes with acuity < 20/32 to 20/63. CONCLUSIONS: Visual impairment and blindness is a significant problem among the elderly in Gujarat. Despite a reportedly high CSR, cataract remains the predominant cause of blindness

Assistive technology for students with visual disability in schools for the blind in Delhi.

Background: To understand the awareness and utilization of assistive technology in students at schools for the blind in Delhi.Methods: A cross sectional study was conducted among 250 students selected randomly from 10 blind schools in Delhi. Binocular distance presenting and pinhole vision acuity were assessed using Snellen "E" chart and a multiple pinhole occluder. Students were also interviewed using a questionnaire about 42 assistive devices to understand their awareness and use.Results: Male participants were 72.8%. Of the total, 27.6% students had best corrected visual acuity <6/18 to 1/60, and the rest had <1/60 vision. The awareness about tactile and sound-based technology was good among students: Braille books (98%), Braille slate and stylus (99.2%), handheld audio recorders (77.6%) and screen readers (77.2%). Good awareness was reported for abacus (88.8%), walking long canes (94.4%) and smart cane (89.6%), audible balls (96%), Braille chess (82.8%) and talking watch (98%). Among the students with <6/18 to 1/60 vision, the awareness of visual based technology ranged from 0.8% (typoscope) to 43.6% (video magnifiers). Braille technology was used for reading by 96.4% (books) and for writing by 96.8% (Braille slate and stylus) irrespective of visual status. Other devices were poorly used ranging from nil (typoscope) to 55% (screen readers). The use of math and science learning devices was poor (<20%). Walking canes were used by 59% of students whereas 87.2% students used audible ball for games.Conclusion: The results showed that majority of students used tactile based technology irrespective of visual status.Implications for rehabilitationStudents with visual disability need assistive technology for a wide range of activities including academic learning.Students in schools for the blind who have binocular best corrected vision acuity of 1/60 or better should be encouraged to use visual based assistive technology instead of tactile based.Students with binocular best corrected vision acuity less than1/60 should be encouraged to use other available tactile and sound-based assistive technologies as well as Braille books and Braille slate and stylus for their academic activities including maths and sciences.Teachers should be trained in the use of various assistive technologies for reading, writing, maths, sciences, sports, mobility and activities of daily living

Polymorphisms in ARMS2/HTRA1 and complement genes and age-related macular degeneration in India: findings from the INDEYE study.

PURPOSE: Association between genetic variants in complement factor H (CFH), factor B (CFB), component 2 (C2), and in the ARMS2/HTRA1 region with age-related macular degeneration (AMD) comes mainly from studies of European ancestry and case-control studies of late-stage disease. We investigated associations of both early and late AMD with these variants in a population-based study of people aged 60 years and older in India. METHODS: Fundus images were graded using the Wisconsin Age-Related Maculopathy Grading System and participants assigned to one of four mutually exclusive stages based on the worse affected eye (0 = no AMD, 1-3 = early AMD, 4 = late AMD). Multinomial logistic regression was used to derive risk ratios (RR) accounting for sampling method and adjusting for age, sex, and study center. RESULTS: Of 3569 participants, 53.2% had no signs of amd, 45.6% had features of early amd, and 1.2% had late amd. CFH (RS1061170), C2 (RS547154), OR CFB (RS438999) was not associated with early or late AMD. In the ARMS2 locus, RS10490924 was associated with both early (adjusted RR 1.22, 95% confidence interval [CI]: 1.13-1.33, P < 0.0001) and late AMD (adjusted RR 1.81, 95% CI: 1.15-2.86; P = 0.01); rs2672598 was associated only with early AMD (adjusted RR 1.12, 95% CI: 1.02-1.23; P = 0.02); rs10490923 was not associated with early or late AMD. CONCLUSIONS: Two variants in ARMS2/HTRA1 were associated with increased risk of early AMD, and for one of these, the increased risk was also evident for late AMD. The study provides new insights into the role of these variants in early stages of AMD in India

Rapid Assessment of Avoidable Visual Impairment in Two Coastal Districts of Eastern India for Determining Effective Coverage: A Cross-Sectional Study

Purpose: To measure the prevalence and causes of visual impairment (VI) among the 40+ age population in two coastal districts of India and to determine the levels of effective cataract surgical coverage (eCSC) and effective refractive error coverage (eREC) in the study population. Methods: A cross-sectional study was done on 4200 people chosen using cluster sampling in two coastal districts of Odisha, an eastern state in India. A team consisting of trained optometrists and social workers conducted the ocular examination which included unaided, pinhole, and aided visual acuity assessments followed by examination of the anterior segment and lens. Results: Overall, 3745 (89.2%) participants were examined from 60 study clusters, 30 in each district. Among those examined, 1677 (44.8%) were men, 2554 (68.2%) were educated and number? (17.8%) used distance spectacles during the survey. The prevalence of VI adjusted for age and gender was 12.77% (95% CI 11.85–13.69%). Multiple logistic regression showed that older age (OR 3.1; 95% CI 2.0–4.7) and urban residence (OR 1.2; 95% CI 1.0–1.6) were associated with VI. Being educated (OR 0.4; 95% CI 0.3–0.6) and using glasses (OR 0.3; 95% CI 0.5–0.2) were found to provide protection; therefore, resulting in lower instances of VI. Cataract (62.7%) and uncorrected refractive errors (27.1%) were the two main causes of VI. The eCSC was 35.1%, the eREC for distance was 40.0%, and the eREC for near was 35.7%. Conclusion: VI remains a challenge in Odisha, as the prevalence is high and the surgical coverage is poor. Nearly 90% of VI is avoidable indicating that targeted interventions are required to address this problem

Genetic variants in a sodium-dependent vitamin C transporter gene and age-related cataract.

BACKGROUND: Cataract is a major health burden in many countries and a significant problem in India. While observational studies show lower cataract risk with increasing dietary or plasma vitamin C, randomised controlled trials of supplements have been negative. Genetic variants in vitamin C transporter proteins (SLC23A1), especially rs33972313, may provide evidence on a causal association of vitamin C with cataract. METHODS: We used data from a randomly selected population-based study in people aged 60 years and above in north and south India. Of 7518 sampled, 5428 (72%) were interviewed for socioeconomic and lifestyle factors, attended hospital for lens imaging and blood collection and were subsequently genotyped for rs33972313 and rs6596473. Mixed or pure types of cataract were graded by the Lens Opacity Classification System III as nuclear (2404), cortical (494) or posterior subcapsular cataract (PSC) (1026); 1462 had no significant cataract and no history of cataract surgery and 775 had bilateral aphakia/pseudophakia. RESULTS: rs33972313 was associated with cortical (OR 2.16; 95% CI 1.34 to 3.49, p=0.002) and PSC (OR 1.68; 95% CI 1.06 to 2.65, p=0.03) but not with nuclear cataract. In analyses of pure cataracts, associations were found only between rs33972313 and pure cortical cataracts (OR 2.29; 95% CI 1.12 to 4.65, p=0.03) and with a standardised cortical opacity score. There was no association with rs6596473 and any cataract outcomes. CONCLUSIONS: Using an established genetic variant as a proxy for lifetime ascorbate concentrations, our results support a causal association of vitamin C with cataract

Association of cataract and sun exposure in geographically diverse populations of India: The CASE study. First Report of the ICMR-EYE SEE Study Group.

PURPOSE: To determine the prevalence of cataract and its association with sun exposure and other environmental risk factors in three different geographically diverse populations of India. DESIGN: Population based cross sectional study during 2010-2016. PARTICIPANTS: People aged ≥ 40 years residing in randomly sampled villages were enumerated (12021) and 9735 (81%) underwent ophthalmic evaluation from plains, hilly and coastal regions (3595, 3231, 2909 respectively). METHODS: A detailed questionnaire-based interview about outdoor activity in present, past and remote past, usage of sun protective measures, exposure to smoke, and detailed ophthalmic examination including assessment of uncorrected and best corrected visual acuity, measurement of intraocular pressure, slit lamp examination, lens opacities categorization using LOCS III and posterior segment evaluation was done. Lifetime effective sun exposure was calculated using Melbourne formula and expressed as quintiles. These were supplemented with physical environmental measurements. MAIN OUTCOME MEASURES: Lifetime sun exposure hours, smoking, indoor kitchen smoke exposure and their association with cataract and subtypes. Prevalence of cataract calculated based on lens opacities or evidence of cataract surgery. RESULTS: Cataract was identified in 3231 (33.3%) participants. Prevalence of cataract in males (32.3%) and females (34.1%) was similar. Nuclear cataract was the commonest sub-type identified in 94.7% of affected eyes. Sun exposure had a significant association with cataract with odds ratio (OR) increasing from 1.6 (95% Confidence Intervals [CI]: 1.4, 1.9) in 3rd quintile, to 2.6 (CI: 2.2, 3.1) in 4th quintile and 9.4 (CI: 7.9, 11.2) in 5th quintile (p<0.0001). Cataract also showed a significant association with smoking (OR: 1.4, CI: 1.2, 1.6) and indoor kitchen smoke exposure (OR: 1.2, CI: 1.0-1.4). Nuclear cataract showed a positive association with increasing sun exposure in 3rd (β coefficient 0.5, CI:0.2-0.7), 4th (β: 0.9, CI: 0.7-1.1) and 5th (β: 2.1, CI:1.8-2.4) quintiles of sun exposure, smoking (β: 0.4, CI: 0.2-0.6) and indoor kitchen smoke exposure (β: 0.3, CI: 01-0.5) while cortical cataract showed a positive association with sun exposure only in 5th quintile (β: 2.6, CI:1.0-4.2). Posterior subcapsular cataract was not associated with any of the risk factors. CONCLUSION: Cataract is associated with increasing level of sun exposure, smoking and exposure to indoor kitchen smoke

Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study.

BACKGROUND: Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited. OBJECTIVES: To examine the association of biomass cooking fuels with cataract and type of cataract. METHODS: We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), anthropometry, and blood collection. Years of use of biomass fuels were estimated and transformed to a standardized normal distribution. RESULTS: Of the 7,518 people sampled, 94% were interviewed and 83% of these attended the hospital. Sex modified the association between years of biomass fuel use and cataract; the adjusted odds ratio (OR) for a 1-SD increase in years of biomass fuel use and nuclear cataract was 1.04 (95% CI: 0.88, 1.23) for men and 1.28 (95% CI: 1.10, 1.48) for women, p interaction = 0.07. Kerosene use was low (10%). Among women, kerosene use was associated with nuclear (OR = 1.76, 95% CI: 1.04, 2.97) and posterior subcapsular cataract (OR = 1.71, 95% CI: 1.10, 2.64). There was no association among men. CONCLUSIONS: Our results provide robust evidence for the association of biomass fuels with cataract for women but not for men. Our finding for kerosene and cataract among women is novel and requires confirmation in other studies. Citation: Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, Chakravarthy U, Fletcher AE. 2016. Use of cooking fuels and cataract in a population-based study: the India Eye Disease Study. Environ Health Perspect 124:1857-1862; http://dx.doi.org/10.1289/EHP193

Association of dry eye disease and sun exposure in geographically diverse adult (≥40 years) populations of India: The SEED (sun exposure, environment and dry eye disease) study - Second report of the ICMR-EYE SEE study group.

PURPOSE: To estimate the prevalence and determine risk factors for dry eye disease (DED) in geographically diverse regions of India. METHOD: A population based cross-sectional study was conducted on people aged ≥40 years in plain, hilly and coastal areas. Dry eye assessment by objective [tear film break-up time (TBUT), Schirmer I, corneal staining] and subjective [Ocular Surface Disease Index (OSDI)] parameters was performed with questionnaire-based assessment of exposure to sunlight, cigarette smoke, indoor smoke. The prevalence of DED with age, sex, occupation, location, smoking, exposure to sunlight, indoor smoke, diabetes, hypertension, was subjected to logistic regression analysis. RESULTS: 9,735 people (age 54.5 ± 0.1 years; range 40-99, males 45.5%) were included. The prevalence of DED was 26.2%, was higher in plains (41.3%) compared to hilly (24.0%) and coastal area (9.9%) (p < 0.001) and increased with age (p < 0.001), female gender (p < 0.001), smoking (p < 0.001), indoor smoke (p < 0.001), diabetes (p-0.02), hypertension (0.001), occupations with predominant outdoor activity (p-0.013) and increasing exposure to sunlight (trend). Multi-logistic regression showed a positive association with female sex (OR-1.2, CI-1.01, 1.4), exposure to indoor smoke (OR-1.3, CI-1.1, 1.5), smoking (OR-1.2; CI-1.03, 1.3), prolonged exposure to sunlight (OR-1.8, CI-1.5, 2.2), hypertension (OR 1.3, CI-1.2, 1.4), diabetes (OR-1.2, CI-1, 1.5) and negative association with region - hilly (OR-0.5, CI-0.4, 0.6) and coastal (OR-0.2; CI-0.1, 0.2), and BMI (OR-0.8, CI-0.7, 0.9). CONCLUSION: DED is common in population ≥40 years of age. Its prevalence is affected by extrinsic (geographic location, exposure to sunlight, smoking, indoor smoke) and intrinsic (age, sex, hypertension, diabetes, BMI) factors

Genetic risk factors for late age-related macular degeneration in India.

BACKGROUND/AIMS: There are limited data from India on genetic variants influencing late age-related macular degeneration (AMD). We have previously reported associations from a population-based study in India (the India age-related eye disease study (INDEYE)) of early AMD and single nucleotide polymorphisms (SNPs) in ARMS2/HTRA1 and no association with CFH, C2 or CFB. Late AMD cases were too few for meaningful analyses. We aimed to investigate SNPs for late AMD through case enrichment and extend the loci for early AMD. METHODS: Fundus images of late AMD hospital cases were independently graded by the modified Wisconsin AMD grading scheme. In total 510 cases with late AMD (14 geographic atrophy and 496 neovascular AMD (nvAMD)), 1876 with early AMD and 1176 with no signs of AMD underwent genotyping for selected SNPs. We investigated genotype and per-allele additive associations (OR and 95% CIs) with nvAMD or early AMD. Bonferroni adjusted P values are presented. RESULTS: We found associations with nvAMD for CFHY402H variant (rs1061170) (OR=1.99, 95% CI 1.67 to 2.37, P=10-6), ARMS2 (rs10490924) (OR=2.94, 95% CI 2.45 to 3.52, P=10-9), C2 (rs547154) (OR=0.67, 95% CI 0.53 to 0.85, P=0.01), ABCA1 (rs1883025) (OR=0.77, 95% CI 0.65 to 0.92, P=0.04) and an SNP near VEGFA (rs4711751) (OR=0.64, 95% CI 0.54 to 0.77, P=10-3). We found no associations of TLR3 (rs3775291), CFD (rs3826945), FRK (rs1999930) or LIPC (rs10468017) or APOE ε4 alleles with nvAMD or early AMD, nor between early AMD and rs1883025 or rs4711751. CONCLUSIONS: The major genetic determinants of nvAMD risk in India are similar to those in other ancestries, while findings for early AMD suggest potential differences in the pathophysiology of AMD development

EPHA2 Polymorphisms and Age-Related Cataract in India

Objective: We investigated whether previously reported single nucleotide polymorphisms (SNPs) of EPHA2 in European studies are associated with cataract in India. Methods: We carried out a population-based genetic association study. We enumerated randomly sampled villages in two areas of north and south India to identify people aged 40 and over. Participants attended a clinical examination including lens photography and provided a blood sample for genotyping. Lens images were graded by the Lens Opacification Classification System (LOCS III). Cataract was defined as a LOCS III grade of nuclear >= 4, cortical >= 3, posterior sub-capsular (PSC) >= 2, or dense opacities or aphakia/pseudophakia in either eye. We genotyped SNPs rs3754334, rs7543472 and rs11260867 on genomic DNA extracted from peripheral blood leukocytes using TaqMan assays in an ABI 7900 real-time PCR. We used logistic regression with robust standard errors to examine the association between cataract and the EPHA2 SNPs, adjusting for age, sex and location. Results: 7418 participants had data on at least one of the SNPs investigated. Genotype frequencies of controls were in Hardy-Weinberg Equilibrium (p > 0.05). There was no association of rs3754334 with cataract or type of cataract. Minor allele homozygous genotypes of rs7543472 and rs11260867 compared to the major homozygote genotype were associated with cortical cataract, Odds ratio (OR) = 1.8, 95% Confidence Interval (CI) (1.1, 3.1) p = 0.03 and 2.9 (1.2, 7.1) p = 0.01 respectively, and with PSC cataract, OR = 1.5 (1.1, 2.2) p = 0.02 and 1.8 (0.9, 3.6) p = 0.07 respectively. There was no consistent association of SNPs with nuclear cataract or a combined variable of any type of cataract including operated cataract. Conclusions: Our results in the Indian population agree with previous studies of the association of EPHA2 variants with cortical cataracts. We report new findings for the association with PSC which is particularly prevalent in Indians