Incidence of primary open angle glaucoma in the Andhra Pradesh Eye Disease Study (APEDS).

BACKGROUND: To report 15-year incidence rate of primary open angle glaucoma (POAG) in the Andhra Pradesh Eye Disease Study (APEDS). METHODS: A population-based longitudinal study was carried out at three rural study sites. Phakic participants aged ≥40 years who participated at baseline (APEDS I) and the mean 15-year follow-up visit (APEDS III) were included. A comprehensive ophthalmic examination was performed on all participants. Mean intraocular pressure (IOP) was average of IOPs of right and left eyes. The definition of glaucoma was based on the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification. The main outcome measure was incidence of POAG during the follow-up period in participants without glaucoma or suspicion of glaucoma at baseline. RESULTS: Data from the available and eligible participants from the original cohort (1241/2790; 44.4%) were analysed. The mean age (standard deviation) of participants at baseline was 50.2 (8.1) years; 580 (46.7%) were men. Thirty-six participants developed POAG [bilateral in 17 (47.2%)] over 15 years. The incidence rate of POAG per 100-person years (95% confidence interval) was 2.83 (2.6, 3.08). Compared to baseline, the reduction in mean IOP [median (range) mm Hg] was -0.75 (-7.5, 9) in participants with incident POAG and -2.5 (-14.5, 14.5) in those without. The inter-visit difference in mean IOP was a significant risk factor on logistic regression analysis. CONCLUSION: We report the long-term incidence of POAG in rural India. A longitudinal change in IOP, specifically a less pronounced reduction in IOP with increasing age, was a novel risk factor.

Variations in the prevalence of vision impairment across regions among school children in Telangana State, South India.

Purpose: Undetected vision impairment (VI) could negatively affect the overall development in children. School vision screening program is a viable and cost-effective approach for the early identification and management of VI. Aim: This study aims to estimate the prevalence of VI, its risk factors, and ocular morbidity among school children in Telangana, South India. Methods: Children aged 4-15 years attending schools in the study area were screened in this study. The vision screenings were performed in schools by trained community eye health workers using 6/12 tumbling E optotypes. Children who failed the test and/or presented with other eye conditions were referred to vision centers or secondary and tertiary eye care centers. A comprehensive eye examination was conducted in these centers, including cycloplegic refraction and fundus examination. Results: A total of 774,184 children, with a mean age of 9.4 ± 3.27 years, were screened. Overall, 51.49% (N = 398,596) were male. In total, 4.33% [N = 33,528; 95% confidence interval (CI): 4.29-4.38] required referral services, while 1.16% (N = 9,002) had a presenting visual acuity of < 6/12. Multivariate analysis showed a high risk of VI among older children [Adj. odds ratio (OR): 5.75; 95% CI: 5.18-6.38], those with disabilities (Adj. OR: 5.12; 95% CI: 4.14-6.33), female gender (Adj. OR: 1.29; 95% CI: 1.24 - 1.35), and those residing in the urban areas (Adj. OR: 2.87; 95% CI: 2.42-3.39). The main cause of VI was uncorrected refractive errors (74.14%). Conclusion: The prevalence of VI among school children was 1.16% in Telangana, South India, and refractive error was the leading cause of VI among this population. Increasing age, urban location, female gender and other disabilities increase the risk of VI among children.

Regional variation in the incidence of pseudo-exfoliation in the Andhra Pradesh Eye Disease Study (APEDS).

BACKGROUND: To report the 15-year incidence rate of pseudo-exfoliation (PXF),  PXF glaucoma and regional variation among rural participants in the Andhra Pradesh Eye Disease Study (APEDS) III. METHODS: This population-based longitudinal study was carried out at three rural study sites. Individuals of all ages who participated at baseline with a mean 15-year follow-up visit were included. Detailed Comprehensive ophthalmic examination was performed on all participants. The main outcome measure was development of PXF during the follow-up period in participants who were phakic in one or both eyes without PXF at baseline. RESULTS: Among 5395 participants, 5108 (94.6%) met the inclusion criteria. There were 93 (1.82%; 95% confidence interval (CI), 1.47-2.22) cases of incident PXF. Their median baseline age (1st, 3rd quartiles) was 51 (44, 59) years and the male: female ratio was 1.3:1. There was no case of incident PXF in participants aged <30 years at baseline. The incidence rate per 100 person years (95% CI) among all ages and those aged ≥30 years at baseline was 1.73 (1.64-1.82) and 3.73 (3.53-3.93), respectively. PXF material was located on iris as well as anterior surface of lens and it was often bilateral. Participants living in two study sites and increasing age were associated with the incidence of PXF. The 15-year incidence of PXF glaucoma (95% CI) in participants ≥30 years of age at baseline was 0.33% (0.14-0.66). CONCLUSION: There is significant regional variation in incidence of PXF in south India which warrants further investigation.

Visual impairment and refractive errors in school children in Andhra Pradesh, India.

Purpose: Addressing childhood vision impairment (VI) is one of the main goals of the World Health Organization's (WHO) combating blindness strategies. The primary aim of this study was to estimate the prevalence of VI, causes, and its risk factors in school children in Krishna district, Andhra Pradesh, India. Methods: Children aged 4-15 years were screened in schools using the 6/12 Snellen optotype by trained community eye health workers, and those who failed the test and those reported or found to have obvious eye conditions were referred to primary (VC), secondary (SC), or tertiary (TC) care centre appropriately, where they underwent a complete eye examination including cycloplegic refraction and fundus examination. Results: A total of 56,988 children were screened, of whom 51.18% were boys. The mean age was 9.69 ± 3.26 years (4-15 years). Overall, 2,802/56,988 (4.92%) children were referred to a VC, of which 632/56,988 (1.11%) required referral to SC/TC. PVA of <6/12 was found in 1.72% (95% confidence interval [CI]: 1.61-1.83). The prevalence of refractive error (corrected and uncorrected) was 2.38% (95% CI: 2.26-2.51) and myopia was 2.17% (95% CI: 2.05-2.29). In multivariable analysis, older children, those in urban schools, private schools, and children with a disability had an increased risk of VI and myopia. Additionally, the risk of myopia was higher among girls than boys. Of those referred and reached SC/TC, 73.64% were due to avoidable causes. Conclusion: Childhood VI prevalence was 1.72% in this region. Uncorrected refractive error (URE) was the major cause of VI in children. Older age, schools in urban locations, private schools, and the presence of disability were associated with the risk of VI among children.

Fifteen-Year Incidence Rate of Primary Angle Closure Disease in the Andhra Pradesh Eye Disease Study.

PURPOSE: To report on the 15-year incidence of primary angle closure disease (PACD) among participants aged ≥40 years in rural southern India DESIGN: Population-based longitudinal incidence rate study METHODS: Setting: 3 rural study centres. STUDY POPULATION: Phakic participants aged ≥40 years who participated in both examination time points. OBSERVATION PROCEDURES: All participants at the baseline and at the mean 15-year follow-up visit underwent a detailed interview, anthropometry, blood pressure measurement, and comprehensive eye examination. Automated perimetry was attempted based on predefined criteria. Main outcome measures included development of any form of PACD, as defined by the International Society for Geographical and Epidemiological Ophthalmology (ISGEO), during the follow-up period in phakic participants, who did not have the disease at baseline. RESULTS: We analyzed data obtained from 1,197 (81.4% out of available 1,470) participants to calculate the incidence of the disease. The mean age (standard deviation) of the study participants at the baseline was 50.2 (8.1) years, with 670 male (45.5%) and 800 female (54.4%) participants. The incidence rate per 100 person-years (95% confidence interval) for primary angle closure suspect, primary angle closure, and primary angle closure glaucoma was 8.8 (8.4, 9.2), 6.2 (5.9, 6.6), and 1.6 (1.4, 1.8), respectively. Thus, the incidence of all forms of PACD was 16.4 (15.9, 17) per 100 person-years. On logistic regression analysis, female gender was a significant risk factor whereas presence of myopia was protective. CONCLUSIONS: This study reports long-term incidence of PACD from rural India. It has implications for eye health care policies, strategies, and planning.

Fifteen-year incidence rate and risk factors of pterygium in the Southern Indian state of Andhra Pradesh.

PURPOSE: To report 15-year incidence rate and associated risk factors of pterygium among people aged 30 years and above at baseline in the rural clusters of longitudinal Andhra Pradesh Eye Disease Study (APEDS III). METHODS: The baseline APEDS I included 7771 participants of which 6447 (83%) were traced and 5395 (83.7%) were re-examined in APEDS III. To estimate the incidence of pterygium, we selected participants who were 30 years and above at baseline (4188), of which 2976 were traced and 2627 (88.3%) were examined, and based on inclusion criteria, 2290 participants were included in the study. The incidence rate of pterygium was defined as the proportion of people free of pterygium at baseline who had developed the condition at 15-year follow-up (range 13-17 years). Univariate and multivariable analyses for risk factors were undertaken. RESULTS: The sex-adjusted incidence rate of pterygium was 25.2 per 100 person-years (95% CI 24.8 to 25.7) which was significantly higher for men than women (26.3 per 100 person-years (95% CI 25.6 to 27.0) and 24.7 (95% CI 24.1 to 25.3) respectively). At the multivariable analysis, male gender (RR: 1.35, 95% CI 1.0 to 1.83), no formal education (RR: 2.46, 95% CI 1.22 to 4.93), outdoor occupation (RR: 1.47, 95% CI 1.14 to 1.9) and lower body mass index (BMI) (<18.5) (RR: 1.25, 95% CI 1.02 to 1.55) were associated with increased risk of pterygium. CONCLUSIONS: The overall incidence rate of pterygium was high in this rural population, especially in men and those engaged in outdoor activities, lack of formal education and with lower BMI. It is likely that greater exposure to ultraviolet light is a major contributing factor, thus warranting preventive strategies.

Incidence, Incident Causes, and Risk Factors of Visual Impairment and Blindness in a Rural Population in India: 15-Year Follow-up of the Andhra Pradesh Eye Disease Study.

PURPOSE: To report 15-year incidence rate of visual loss (blindness and visual impairment [VI]), causes, and risk factors for participants in Andhra Pradesh Eye Disease Study III (APEDS III). DESIGN: Population-based cohort study. METHODS: From 2012 to 2016, all rural participants were interviewed and underwent a comprehensive eye examination, including dilated fundus examination and imaging. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were measured using a standard logarithm of Minimum Angle of Resolution chart at 3 meters. World Health Organization (WHO) and United States of America (USA) categories of VI and blindness were used. Incident visual loss was defined as the development of or worsening of visual loss of one or more categories. RESULTS: In APEDS I, 7,771 rural participants were examined using stratified, random-cluster systematic sampling; in APEDS III, 5,395 participants (69.4% of rural or 52.4% of total participants) were re-examined. Using WHO categories, the crude incidence rate of any visual loss based on PVA and BCVA were 14.6 (95% confidence interval [CI]:13.6-15.7) and 6.3 (95% CI: 6.1-6.4) per 100 person-years, respectively. Using USA criteria, the values were 22.6 (95% CI: 22.3-23.0) and 10.6 (95% CI: 10.3-10.8) per 100 person-years, respectively. More than 90% of visual loss was attributable to cataract and uncorrected refractive error. Using WHO categories, significant independent risk factors for the incident visual loss were increasing age, female gender, illiteracy, past or current smoker, and current use of alcohol. Using the USA definition, an additional risk factor was lower level of education. CONCLUSIONS: The high incidence likely reflects poor access to eye care in this population, which needs to be taken into account when planning eye care programs.

Agreement and diagnostic accuracy of vision screening in preschool children between vision technicians and spot vision screener.

Purpose: Screening preschool children for vision-related disorders poses a challenge. This study is designed to determine the agreement and diagnostic accuracy of the spot vision screener (SVS) in screening preschool children compared to screening procedure by vision technicians (VT). Methods: This study was conducted as a part of the ongoing study titled "Initiative for Screening Children for Refractive Errors and other Eye Health Needs (I-SCREEN)." Children from 33 Anganwadis (preschools) in two districts, Adilabad district of Telangana and Krishna district of Andhra Pradesh, in South India, underwent eye health screening by a VT and by a trained community eye health workers (CEHW) using the SVS. Findings were compared for agreement and diagnostic accuracy of assessment. Results: A total of 976 preschool children were screened by the VT and separately by the CEHW using the SVS in Adilabad (15 schools) and Krishna (18 schools) districts. The overall mean age of these children was 2.5 years (SD ± 1.3 years). There were 48 (4.9%) referrals by VT compared to 105 (10.8%) referrals by CEHW using SVS. The overall sensitivity of SVS was 91.7% (95% CI: 80%-97.7%) and the specificity was 93.4% (95% CI: 91.6%-94.9%). Positive predictive value was 41.9% (95% CI: 32.3%-51.9%) and negative predictive value was 99.5% (95% CI: 98.8%-99.9%) with a moderate agreement (0.54; 95% CI 0.49-0.64) between VT screening and screening with SVS. Conclusion: The SVS showed good diagnostic accuracy and agreement in screening for possible vision-related disorders in preschool children.

Barriers to uptake of referral services from secondary care to tertiary care and its associated factors in L V Prasad Eye Institute network in Southern India: a cross-sectional study.

OBJECTIVE: To examine barriers to the uptake of referral services from secondary care centres to higher level tertiary care centres. DESIGN: Cross-sectional study. SETTING: Secondary care hospital in Khammam District in the Telangana state of India. PARTICIPANTS: Nine hundred and three patients who were referred from a secondary care centre to tertiary care centres between June 2011 and December 2012, were over the age of 18 and lived within 50 km of the secondary care centre were identified. Six hundred and sixteen (68.2%) of these patients were successfully contacted, and 611 (99%) of those contacted consented to participation in the study. INTERVENTIONS: Those who attended at higher centres after referral (compliant) and those who failed to attend (non-compliant) were interviewed with a standard questionnaire designed for the study. PRIMARY AND SECONDARY OUTCOME MEASURES: Outcome measures were barriers to the uptake of eye care services for the non-compliant participants and the associated risk factors for non-compliance. RESULTS: Of the contacted patients, 418 (68.4%) were compliant and 193 (31.6%) were non-compliant. The mean age of interviewed patients was 48.4 years (SD: 17.9 years) and 365 (59.7%) were male. Of those who did not comply with their referral, the major identified barriers were 'cannot afford treatment cost' (30%) and 'able to see adequately' (20.7%). Multivariable analysis showed that participants in the non-compliant group were more likely to have had only one prior visit to the centre (OR: 2.5, 95% CI 1.6 to 3.9), be referred for oculoplastic services (OR: 3.0, 95% CI 1.0 to 8.8) and to be the main earning member of the family (OR: 1.9, 95% CI 1.2 to 2.8). CONCLUSIONS: Non-compliance with referrals in this population is largely attributable to economic and attitudinal reasons. Focusing on these specific barriers and targeting groups at higher risk of non-compliance could potentially improve uptake of referral services.

Agreement and diagnostic accuracy of vision screening in children by teachers, community eye-health workers and vision technicians.

BACKGROUND: To compare the agreement and diagnostic accuracy of vision screening conducted by trained community eye-health workers (CEHWs) and teachers with reference to vision technicians in Movva Mandal (sub-district) in Krishna District in the Indian state of Andhra Pradesh. METHODS: As part of a large epidemiological study on visual impairment in children, vision screening was conducted in all the schools in a sub-district. The children were screened using a screening card with 6/12 tumbling E optotypes by trained CEHWs, teachers and a vision technician. Teachers were included if they had screened at least 100 children and had at least five children identified with visual impairment. RESULTS: Of a total 6,197 children from 75 schools, 4,929 children were screened by all three categories of examiners (one vision technician, five CEHWs and 79 teachers). The overall agreement between the vision technician and CEHWs was 0.84 (95 per cent CI: 0.79-0.9) with a range of 0.77-0.9. Overall sensitivity of CEHWs to detect visual impairment was 83.3 per cent (95 per cent CI: 73.6-90.6) with a range of 71.4-87.1 per cent. Overall agreement of the five teachers with the vision technician was 0.81 (95 per cent CI: 0.74-0.88) with a range of 0.32-0.92. The overall sensitivity of teachers to detect vision problem was 72.3 per cent (95 per cent CI: 61.4-81.6) with a range from 20 per cent to 85.7 per cent and specificity was near 100 per cent. CONCLUSION: There was no significant difference in the agreement and diagnostic accuracy of CEHWs and teachers compared to those of the vision technician. There was a large variability among teachers, which needs to be considered in school vision screening programs.

Longitudinal Andhra Pradesh Eye Disease Study: rationale, study design and research methodology.

BACKGROUND: The rationale, objectives, study design and procedures for the longitudinal Andhra Pradesh Eye Disease Study are described. DESIGN: A longitudinal cohort study was carried out. PARTICIPANTS: Participants include surviving cohort from the rural component of Andhra Pradesh Eye Disease Study. METHODS: During 1996-2000, Andhra Pradesh Eye Disease Survey was conducted in three rural (n = 7771) and one urban (n = 2522) areas (now called Andhra Pradesh Eye Disease Study 1). In 2009-2010, a feasibility exercise (Andhra Pradesh Eye Disease Study 2) for a longitudinal study (Andhra Pradesh Eye Disease Study 3) was undertaken in the rural clusters only, as urban clusters no longer existed. In Andhra Pradesh Eye Disease Study 3, a detailed interview will be carried out to collect data on sociodemographic factors, ocular and systemic history, risk factors, visual function, knowledge of eye diseases and barriers to accessing services. All participants will also undergo a comprehensive eye examination including photography of lens, optic disc and retina, Optic Coherence Tomography of the posterior segment, anthropometry, blood pressure and frailty measures. MAIN OUTCOME MEASURES: Measures include estimates of the incidence of visual impairment and age-related eye disease (lens opacities, glaucoma and age-related macular degeneration) and the progression of eye disease (lens opacities and myopia) and associated risk factors. RESULTS: Of the 7771 respondents examined in rural areas in Andhra Pradesh Eye Disease Study 1, 5447 (70.1%) participants were traced in Andhra Pradesh Eye Disease Study 2. These participants will be re-examined. CONCLUSIONS: Andhra Pradesh Eye Disease Study 3 will provide data on the incidence and progression of visual impairment and major eye diseases and their associated risk factors in India. The study will provide further evidence to aid planning eye care services.