Modeling the risks of age-related eye diseases in a population in South India

The objective of this research was to determine whether an artificial intelligence methodology such as artificial neural network (ANN), a new type of predictive model offers an increased performance over a conventional logistic regression model (LR) in predicting the ranking of risk factors for irreversible age-related chronic eye diseases age-related macular degeneration (AMD), diabetic retinopathy (DR), primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) in a South Indian population. The LR and ANN models were derived and validated for their respective models predictive accuracy based on a sample (n=3,723) aged >=40 years old by using a large scale population-based epidemiologic study. Sub-population data were drawn from this sample by appropriate standard techniques that used for modeling. The LR based risk score models (RS) were derived and the model fit was assessed in a standard manner including the bootstrap method for internal validity. The ANN model was built by using the multi-layer feed-forward back propagation network. The ANN models predictive ability was compared with that of traditional model with respect to the Area under the Receiver Operating Characteristic Curve (AUROC). The sensitivity and specificity of the fitted models with a threshold criterion ranged from 70% to nearly 99% overall for all models. The ANN model outperformed the traditional LR model in a sub-population analysis in predicting AMD and DR. The predictive accuracy of ANN and LR model in predicting AMD was statistically significant (AUROC=89% vs 79%; p=10 year (RS ranged from 29 to 42) was a highest priority predictor for DR. The modifiable risk factor intraocular pressure was in order of highest priority predictor for POAG and PACG. Population attributable risk percentage and population attributable fractions revealed that there is an urgent need of prioritizing modifying the modifiable factors as a public health approach. This was supported by a sensitivity analysis of the ANN model which indicated the relative importance of prioritizing modifiable risk factors on which to base preventive interventions to reduce the impact of onset or progression of these diseases

Cataract, visual impairment and long-term mortality in a rural cohort in India: the Andhra Pradesh Eye Disease Study.

BACKGROUND: A large-scale prevalence survey of blindness and visual impairment (The Andhra Pradesh Eye Diseases Study [APEDS1]) was conducted between 1996-2000 on 10,293 individuals of all ages in three rural and one urban clusters in Andhra Pradesh, Southern India. More than a decade later (June 2009-March 2010), APEDS1 participants in rural clusters were traced (termed APEDS2) to determine ocular risk factors for mortality in this longitudinal cohort. METHODS AND FINDINGS: Mortality hazard ratio (HR) analysis was performed for those aged >30 years at APEDS1, using Cox proportional hazard regression models to identify associations between ocular exposures and risk of mortality. Blindness and visual impairment (VI) were defined using Indian definitions. 799/4,188 (19.1%) participants had died and 308 (7.3%) had migrated. Mortality was higher in males than females (p<0.001). In multivariable analysis, after adjusting for age, gender, diabetes, hypertension, body mass index, smoking and education status the mortality HR was 1.9 (95% CI: 1.5-2.5) for blindness; 1.4 (95% CI: 1.2-1.7) for VI; 1.8 (95% CI: 1.4-2.3) for pure nuclear cataract, 1.5 (95% CI: 1.1-2.1) for pure cortical cataract; 1.96 (95% CI: 1.6-2.4) for mixed cataract, 2.0 (95% CI: 1.4-2.9) for history of cataract surgery, and 1.58 (95% CI: 1.3-1.9) for any cataract. When all these factors were included in the model, the HRs were attenuated, being 1.5 (95% CI: 1.1-2.0) for blindness and 1.2 (95% CI: 0.9-1.5) for VI. For lens type, the HRs were as follows: pure nuclear cataract, 1.6 (95% CI: 1.3-2.1); pure cortical cataract, 1.5 (95% CI: 1.1-2.1); mixed cataract, 1.8 (95% CI: 1.4-2.2), and history of previous cataract surgery, 1.8 (95% CI: 1.3-2.6). CONCLUSIONS: All types of cataract, history of cataract surgery and VI had an increased risk of mortality that further suggests that these could be potential markers of ageing

Customization of spectacle frames for individuals with facial deformities by altering conventional spectacle frames – Phase I

Purpose: Manufacturing a spectacle frame for a facially deformed individual is challenging because of facial asymmetry. One of the solutions is the customization of spectacle frames. Customization of spectacle frames for facially deformed individuals requires a better understanding of the facial anthropometry of deformed faces. This study aimed to analyze the facial anthropometry of deformed faces to understand the range of variability. The results of this study will be used to find customization methods in the future. Methods: We measured and analyzed the 12 facial parameters of individuals with facial deformities using the ImageJ software. Results: The data collected were normally distributed. Paired sample test revealed a statistically significant difference between innercanthus distances (right innercanthus distance [RICD] and left innercanthus distance [LICD]). Correlation analysis showed a positive difference between horizontal and vertical pupillary distance-innercanthus distance (PD-ICD) (0.68, 0.75, and 0.81) and pupillary distance-helix distance (PD-HD) (0.57, 0.68, and 0.59) relations. PD-ICD correlations are stronger compared to the PD-HD relation. Conclusion: Altering the frame center distance and the temple heights are the most important for asymmetric faces. Large population-based data are required to make concrete decisions to design a spectacle frame for asymmetric faces

Prevalence and risk factors for refractive errors in the South Indian adult population: The Andhra Pradesh Eye disease study

Sannapaneni Krishnaiah1,2,3, Marmamula Srinivas1,2,3, Rohit C Khanna1,2, Gullapalli N Rao1,2,31L V Prasad Eye Institute, Banjara Hills, Hyderabad, India; 2International Center for Advancement of Rural Eye Care, L V Prasad Eye Institute, Banjara Hills, Hyderabad, India; 3Vision CRC, University of New South Wales, Sydney, NSW, AustraliaAim: To report the prevalence, risk factors and associated population attributable risk percentage (PAR) for refractive errors in the South Indian adult population.Methods: A population-based cross-sectional epidemiologic study was conducted in the Indian state of Andhra Pradesh. A multistage cluster, systematic, stratified random sampling method was used to obtain participants (n = 10293) for this study.Results: The age-gender-area-adjusted prevalence rates in those &amp;ge;40 years of age were determined for myopia (spherical equivalent [SE] &amp;lt; &amp;minus;0.5 D) 34.6% (95% confidence interval [CI]: 33.1&amp;ndash;36.1), high-myopia (SE &amp;lt; &amp;minus;5.0 D) 4.5% (95% CI: 3.8&amp;ndash;5.2), hyperopia (SE &amp;gt; +0.5 D) 18.4% (95% CI: 17.1&amp;ndash;19.7), astigmatism (cylinder &amp;lt; &amp;minus;0.5 D) 37.6% (95% CI: 36&amp;ndash;39.2), and anisometropia (SE difference between right and left eyes &amp;gt;0.5 D) 13.0% (95% CI: 11.9&amp;ndash;14.1). The prevalence of myopia, astigmatism, high-myopia, and anisometropia significantly increased with increasing age (all p &amp;lt; 0.0001). There was no gender difference in prevalence rates in any type of refractive error, though women had a significantly higher rate of hyperopia than men (p &amp;lt; 0.0001). Hyperopia was significantly higher among those with a higher educational level (odds ratio [OR] 2.49; 95% CI: 1.51&amp;ndash;3.95) and significantly higher among the hypertensive group (OR 1.24; 95% CI: 1.03&amp;ndash;1.49). The severity of lens nuclear opacity was positively associated with myopia and negatively associated with hyperopia.Conclusions: The prevalence of myopia in this adult Indian population is much higher than in similarly aged white populations. These results confirm the previously reported association between myopia, hyperopia, and nuclear opacity.Keywords: refractive errors, risk factors, population attributable risk percent, population-based cross-sectional study, southern Indi

Prevalence of ophthalmic disorders among hearing-impaired school children in Guntur district of Andhra Pradesh

Purpose: To estimate the prevalence, causes, and risk factors for visual impairment (VI) among children of school for hearing-impaired (HI) in Guntur district of Andhra Pradesh, India. Methods: Children between 6 and 16 years of age available in all the 12 special schools for HI were examined. Visual acuity (VA) testing, ocular motility, and examination of anterior and posterior segment for all children were done. Those having VA of less than 6/12 in better eye underwent cycloplegic refraction. For definition of VI, as per World Health Organization (WHO), VA of better eye was considered. HI was also classified as mild, moderate, severe, and profound as per WHO definitions. Examination for systemic diseases and other associated disabilities was also done. Results: In all, 402 children underwent examination. Ophthalmic abnormality was seen in 64 children with a prevalence of 15.9% [95% confidence interval (CI) 14.9%–16.8%], and VI was seen in 29 children with a prevalence of 7.2% (95% CI 4.9%–10.2%). Refractive errors [29 (7.2%)], retinitis pigmentosa (RP) [16 (4%)], and squint [8 (2%)] were the major ophthalmic abnormalities. Thirty-five (54.7%) of the abnormalities were either preventable or treatable. The major cause of VI was refractive error (18) followed by RP (5). Twenty of them (69%) with VI in this study group were treatable. Twenty-two (75.9%) children with eye problem were newly diagnosed. The only risk factor for VI was being mentally challenged (odds ratio: 5.63; 95% CI: 1.89–16.8). Conclusion: The prevalence of ophthalmic abnormalities and VI in school for HI was high, and the majority of them were not detected so far. As most of them are easily treatable, it is highly recommended to conduct regular eye examinations in these schools

Barriers to accessing eye care services among visually impaired populations in rural Andhra Pradesh, South India

<b>Purpose:</b> To understand the reasons why people in rural south India with visual impairment arising from various ocular diseases do not seek eye care. <b> Materials and Methods:</b> A total of 5,573 persons above the age of 15 were interviewed and examined in the South Indian state of Andhra Pradesh covering the districts of Adilabad, West Godavari and Mahaboobnagar. A pre-tested structured questionnaire on barriers to eye care was administered by trained field investigators. <b> Results:</b> Of the eligible subjects, 1234 (22.1&#x0025;, N=5573)) presented with distant visual acuity &#60; 20/60 or equivalent visual field loss in the better eye. Of these, 898 (72.7&#x0025;, N=1234) subjects had not sought treatment despite noticing a decrease in vision citing personal, economic and social reasons. The analysis also showed that the odds of seeking treatment was significantly higher for literates [odds ratio (OR) 1.91, 95&#x0025; confidence interval (CI) 1.38 to 2.65], for those who would be defined as blind by visual acuity category (OR 1.35, 95&#x0025; CI 0.96 to 1.90) and for those with cataract and other causes of visual impairment (OR 1.50, 95&#x0025; CI 1.11 to 2.03). Barriers to seeking treatment among those who had not sought treatment despite noticing a decrease in vision over the past five years were personal in 52&#x0025; of the respondents, economic in 37&#x0025; and social in 21&#x0025;. <b> Conclusion:</b> Routine planning for eye care services in rural areas of India must address the barriers to eye care perceived by communities to increase the utilization of services