Prevalence of myopic retinopathy in rural Central India.

PURPOSE: The aim of this study was to determine the prevalence of myopic retinopathy (MR) in rural Central India. METHODS: The population-based Central India Eye and Medical Study included 4711 subjects (aged 30+ years). The participants underwent a detailed eye examination, including fundus photography. Myopic retinopathy was defined according to the Pathologic Myopia Study Group. RESULTS: Readable fundus photographs were available on 4561 (96.8%) subjects (8846 eyes). Myopic retinopathy was present in 15 (0.17 ± 0.04%; 95% confidence interval (CI):0.08%, 0.26%) eyes of 11 (0.24 ± 0.07%; 95%CI: 0.01, 0.04) individuals. Myopic retinopathy occurred only in eyes with an axial length of >26 mm. Eyes with MR had significantly larger optic discs than eyes without MR (3.69 ± 1.22 mm2 versus 2.52 ± 0.77 mm2 ; p < 0.001). In binary regression analysis, higher prevalence of MR was associated with longer axial length (p < 0.001; odds ratio (OR): 19.6; 95%CI: 4.6, 82.9), higher prevalence of open-angle glaucoma (p = 0.02; OR: 16.1; 95%CI: 1.51, 170), lower best-corrected visual acuity (expressed in logMAR) (=0.03; OR: 0.06; 95%CI: 0.004, 0.75) and female gender (p = 0.002). If level of education was added to the model, educational level was not significantly associated with MR (p = 0.17; OR: 0.53; 95%CI: 0.22, 1.31). If gender was dropped from the model, higher prevalence of MR was associated with lower educational level (p = 0.04; OR: 0.44; 95%CI: 0.20, 0.97). CONCLUSIONS: Prevalence of MR in rural Central India was low (11/4561 or 0.2%), and correlated with a 16 times higher risk of open-angle glaucoma, after adjusting for axial length and gender. If gender was excluded from the analysis, higher prevalence of MR was associated with lower educational level. This latter finding distinguishes adult MR from today's school children myopia which is strongly associated with higher educational level.

Retinal nerve fibre layer cross-sectional area, neuroretinal rim area and body mass index.

PURPOSE: To examine associations between body mass index, neuroretinal rim area and retinal nerve fibre layer cross-sectional area (RNFLCRA) in a population-based setting. METHODS: The Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study included 4711 subjects (aged 30 + years). A detailed ophthalmic and medical examination was performed. Inclusion criteria for this study were an intra-ocular pressure ≤21 mmHg, open anterior chamber angles and an axial length ≤26.5 mm. Neuroretinal rim area and RNFLCRA were measured by confocal laser scanning tomography. RESULTS: The study included 3959 subjects fulfilling the inclusion criteria. Larger neuroretinal rim area (mean: 1.63 ± 0.32 mm(2) ) was significantly (p = 0.004) associated with a higher body mass index after adjusting for larger disc area (p < 0.001), younger age (p < 0.001), lower intraocular pressure (p < 0.001), and hyperopic refractive error (p < 0.001). Larger retinal nerve fibre layer cross-sectional area (mean:1.29 ± 0.39 mm(2) ) was significantly associated with higher body mass index (p = 0.001) after adjusting for younger age (p < 0.001), shorter axial length (p < 0.001), larger optic disc area (p < 0.001), taller body height (p < 0.001) and male gender (p = 0.04). CONCLUSIONS: In a rural Central Indian population, neuroretinal rim area and RNFLCRA as surrogates of the optic nerve fibres were related to a higher body mass index. Because body mass index is associated with cerebrospinal fluid pressure, the higher cerebrospinal fluid pressure may be associated with a larger neuroretinal rim area. It may vaguely point towards an association between cerebrospinal fluid pressure and glaucomatous optic neuropathy.

Pseudoexfoliation: normative data and associations. The Central India Eye and Medical Study.

PURPOSE: To assess the prevalence of pseudoexfoliation (PEX) and its associations in a population-based setting. DESIGN: Population-based, cross-sectional study. METHODS: The Central India Eye and Medical Study included 4711 individuals. All study participants underwent a detailed ophthalmological examination. After medical pupil dilation, PEX was assessed by an experienced ophthalmologist using slit-lamp based biomicroscopy. RESULTS: Slit lamp examination results were available for 4646 (98.6%) study participants with a mean age of 49.3 ± 13.3 years (range: 30-100 years). PEX was detected in 87 eyes (prevalence: 0.95 ± 0.10% (95%CI: 0.75, 1.15) of 69 subjects (prevalence: 1.49 ± 0.18% (95%CI: 1.14, 1.83). PEX prevalence increased significantly (P<0.001) from 0% in the age group of 30-39 years, to 2.85 ± 0.56% in the age group of 60-69 years, to 6.60 ± 1.21% in the age group of 70-79 years, and to 12.3 ± 4.11% in the age group of 80+ years. In multivariate analysis, PEX prevalence was associated with higher age (P<0.001; regression coefficient B:0.11; odds ratio (OR): 1.11 (95%CI: 1.09, 1.13)), lower body mass index (P = 0.001; B: -0.12; OR: 0.88 (95CI: 0.82, 0.95)) and higher diastolic blood pressure (P = 0.002; B: 0.02; OR: 1.03 (95%CI: 1.01, 1.04)). In the multivariate analysis, PEX was not associated with retinal nerve fiber layer cross section area (P = 0.76) and presence of open-angle glaucoma (P = 0.15). CONCLUSIONS: In a rural Central Indian population aged 30+ years, PEX prevalence (mean: 1.49 ± 0.18%) was significantly associated with older age, lower body mass index and higher diastolic blood pressure. It was not significantly associated with optic nerve head measurements, refractive error, any ocular biometric parameter, nuclear cataract, early age-related macular degeneration and retinal vein occlusion, diabetes mellitus, smoking, and dyslipidemia.

Prevalence of optic disc hemorrhages in rural central India. The Central Indian Eye and Medical Study.

PURPOSE: To determine the frequency of optic disc hemorrhages in a rural Indian population. METHODS: The population-based Central Indian Eye and Medical Study included 4711 subjects. Mean age was 48.5±12.9 years (range: 30-100 years). Color optic disc photographs were examined. RESULTS: Optic disc photographs were available for 4570 (97.0%) subjects. Prevalence of disc hemorrhages was 17/8869 (0.19%; 95%CI:0.10,0.28) per eye and 16/4570 (0.35±0.09%; 95%CI:0.18,0.52) per subject. Prevalence of disc hemorrhages increased from 0.05% (95%CI:0.00,0.13) in the age group of 30-39 years to 0.25% (95CI:0.00,0.49) in the age group of 60-69 years and to 0.91% (95%CI:0.24,1.58) in the age group of 70+ years. After adjusting for older age, higher systolic blood pressure, diabetes mellitus, myopic refractive error, smaller neuroretinal rim area and thinner retinal nerve fiber layer, occurrence of disc hemorrhages was associated only with glaucomatous optic nerve damage (P<0.001; Odds ratio: 87; 95%CI:32,239). Eleven of the 17 (65%; 95%CI:39,90) disc hemorrhages were found in glaucomatous eyes. Out of 193 glaucomatous eyes, 11 eyes (5.7%; 95%CI:2.4,9.0) showed a disc hemorrhage. Out of the 8676 non-glaucomatous eyes, 6 eyes (0.07%; 95%CI:0.01,0.12) had an optic disc hemorrhage. CONCLUSIONS: Prevalence of disc hemorrhages (0.2% per eye; 0.4% per subject) in Indians aged 30+ years was strongly associated with glaucoma after adjustment for age, blood pressure and diabetes mellitus. A disc hemorrhage suggested glaucomatous optic nerve damage with a positive predictive value of 65%. About 6% of glaucomatous eyes showed a disc hemorrhage at the time of clinical examination highlighting the importance of optic disc hemorrhages for the diagnosis of glaucoma.

Prevalence and associated factors of glaucoma in rural central India. The Central India Eye and Medical Study.

PURPOSE: To assess the prevalence of glaucoma in rural Central India. METHODS: The population-based Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study included 4711 subjects (aged 30+ years). A detailed ophthalmic and medical examination was performed. Glaucoma was defined by glaucomatous optic disc morphology, and in a second step, by the criteria of the International Society of Geographical and Epidemiological Ophthalmology (ISGEO). RESULTS: Optic disc photographs were available for 4570 (97.0%) subjects. Glaucoma was detected in 122 subjects (51 unilateral) (2.67% (95%CI: 2.20, 3.14). Glaucoma prevalence for the age groups of 30-39yrs, 40-49yrs, 50-59yrs, 60-69yrs, 70-79yrs, and 80+ years was 0.54% (95%CI: 0.11, 0.98), 1.03% (95%CI: 0.49, 1.57), 1.40% (95%CI: 0.58, 2.23), 6.62% (95%CI: 4.92, 8.31), 8.71% (95%CI: 5.55, 11.75), and 14.3% (95%CI: 4.13, 24.4), respectively. In multivariable analysis, glaucoma was associated with higher age (P<0.001), lower body mass index (P = 0.025), lower blood hemoglobin concentration (P = 0.03), higher intraocular pressure (P<0.001), disc hemorrhages (P<0.001), higher prevalence of myopic retinopathy (P<0.001), lower level of education (P = 0.03), longer axial length (P<0.001), thinner retinal nerve fiber layer (P<0.001), higher vertical cup/disc diameter ratio (P<0.001), and narrow anterior chamber angle (P = 0.02). Ratio of open-angle glaucoma to angle-closure glaucoma was 7.7:1 (1.93% (95%CI: 1.64, 2.22) to 0.24% (95%CI: 0.14, 0.34)). Using the ISGEO criteria, glaucoma prevalence was 2.8% (95%CI: 2.3, 3.3) with a less clear association with older age. CONCLUSIONS: Glaucoma prevalence in remote rural Central India is comparable to other regions. Associated factors were older age, lower body mass index, lower blood concentration of hemoglobin, lower level of education, higher intraocular pressure, disc hemorrhage, myopic retinopathy, and longer axial length. The ratio of open-angle glaucoma to angle-closure glaucoma was about 8:1.

Intraocular pressure and associated factors: the central India eye and medical study.

PURPOSE: To determine the range of intraocular pressure (IOP) in a rural Central Indian population and to evaluate existing and identify potential new ocular, medical, and socioeconomic factors associated with IOP. METHODS: This is a population-based study carried out in Nagpur in Central India. A single IOP measurement was taken using Goldmann applanation tonometry and population IOP was described using standard descriptive statistics. RESULTS: Of 5885 eligible patients, 9338 eyes of 4686 patients were included in the study. The mean IOP was 13.6±3.4 mm Hg (median: 14 mm Hg; range: 2 to 56 mm Hg). In multivariate regression analysis, the following factors, with correlation coefficients (r) and P values reported in parenthesis, were found to be associated with IOP. Ocular factors included higher corneal power (0.12; P=0.004), lower central corneal thickness (0.02; P<0.001), and higher myopic refractive power (-0.13; P=0.001). Medical factors included diastolic blood pressure (0.05; P<0.001), pulse rate (0.02; P=0.005), and body mass index (0.05; P=0.01). Socioeconomic factors included level of education (0.15; P=0.05) and livestock ownership (-0.18; P=0.008). CONCLUSION: Low mean IOP was found when compared with other epidemiologic studies and this may be explained by the low central corneal thickness found in the study population. Several known ocular and medical factors and new socioeconomic factors were found to be associated with IOP. Identifying risk factors associated with IOP in different populations may allow clinicians to better define and recognize subgroups of patients at risk of elevated IOP. Newly identified socioeconomic-IOP associations will need to be validated in future studies.

Prevalence and associations of keratoconus in rural maharashtra in central India: the central India eye and medical study.

PURPOSE: To evaluate the prevalence and associated factors of keratoconus in the adult Indian population. DESIGN: Population-based study. METHODS: The Central India Eye and Medical Study is a population-based study performed in a rural region close to Nagpur in Central India. It included 4,711 subjects (aged 30 years and above) out of 5,885 eligible subjects (response rate, 80.1%). The participants underwent a detailed ophthalmic and medical examination. This study was focused on the prevalence of keratoconus, defined as an anterior corneal refractive power exceeding 48 diopters (D). RESULTS: Out of the 4,711 subjects, corneal refractive power measurements were available for 4,667 subjects (99.1%). Keratoconus was detected in 212 eyes (2.3%) of 128 subjects (prevalence rate, 2.3% +/- 0.2%). In multivariate analysis, the presence of keratoconus was significantly associated with lower body height (P < .001), lower level of education (P= .03), higher myopic refractive error (P = .004), and thinner central corneal thickness (P = .006). It was not significantly associated with alcohol consumption (P = .99) or smoking (P = .08) nor with questions relating to the psychiatric status. Defining a keratoconus as corneal refractive power of > or =49 D or of > or =50 D, a keratoconus was detected in 58 eyes (0.6%) and 10 eyes (0.1%), respectively. CONCLUSIONS: Keratoconus defined as corneal refractive power of 48+ D has a prevalence of 2.3% +/- 0.2% among Indians aged 30 years and above and living in the rural region of Central India. The prevalence of keratoconus was associated with lower body height, lower level of education, myopic refractive error, and thinner central cornea.

Optic disc size in a population-based study in central India: the Central India Eye and Medical Study (CIEMS).

PURPOSE: To determine optic disc size and its associations in an adult population in central India. METHODS: The Central India Eye and Medical Study (CIEMS), Part 1 is a population-based, cross-sectional cohort study and included 1000 subjects out of 1314 (76.1%) subjects from a rural area of Maharasthra/India, aged 30+ years, invited to participate. Confocal laser scanning tomographic optic disc images were morphometrically examined. RESULTS: Mean optic disc area (2.25 +/- 0.51 mm2, range 1.12-4.61 mm2) was significantly correlated with myopic refractive error (p < 0.001) and axial length (p < 0.001), whereas gender (p = 0.14), body height (p = 0.44) and best corrected visual acuity (p = 0.59) were not significantly associated in multiple regression analysis. CONCLUSIONS: Mean optic disc area is larger in the central Indian population than in White people. Axial length and myopic refractive error are independent factors that influence optic disc size.