Prevalence of blindness and visual impairment in a coastal region of Southern India: A cross-sectional survey in Prakasam district, Andhra Pradesh.

PURPOSE: To estimate the magnitude, determinants, and causes of visual impairment (VI) and blindness among people >40 years. METHODS: In this cross-sectional survey, 2,968 people >40 years from 34 clusters were examined. A cluster random sampling method with a compact segment sampling technique was used to select the study participants. Prevalence of any VI (presenting visual acuity (PVA) <6/12 in better eye), severe VI (PVA <6/60 - 3/60), and blindness (PVA <3/60 in better eye) were expressed as percentage with 95% confidence interval. Logistic regression was performed to determine the risk factors associated with blindness. A P value of less than 0.05 was considered statistically significant. RESULTS: The mean age of the participants was 54.6 years (Standard deviation ± 11.2 years). The prevalence of mild, moderate, and severe visual impairment was 14.2% (12.95-15.49), 13.7% (12.46-14.97), and 0.7% (0.47-1.12), respectively. The prevalence of blindness was 1.3% (0.94-1.79, n = 39). The overall prevalence of VI (presenting Visual Acuity <6/12) was 12.0% (95% CI: 10.8-13.2%). The major causes of VI were cataract (78.08%), refractive error (12.07%), and optic atrophy (2.22%), and corneal opacity (2.22%) and the major cause of blindness was cataract (77.27%). Blindness was strongly associated with increasing age- OR 17.1 (95% CI: 4.9-59.8) for people >70 years, and OR 7.6 (95% CI: 2.2-26.5) for people aged between 60 and 69 years compared to those aged 41-50 years and people living near coastal regions (Within 50 km of coast) (OR: 3.9, 95% CI: 1.6-7.3). CONCLUSION: Blindness and vision impairment are of public health concern in this geographic region. Eye care services need to be augmented to address this challenge.

Plateau Iris in Primary Angle Closure Glaucoma: An Ultrasound Biomicroscopy Study.

PURPOSE: To determine prevalence and anterior segment morphology of plateau iris in patients with primary angle closure glaucoma (PACG) after laser peripheral iridotomy using ultrasound biomicroscopy (UBM). METHODS: In this prospective study, 262 PACG patients and 144 normal controls underwent UBM examination. Plateau iris in a quadrant was defined by the presence of anteriorly directed ciliary process, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact in the same quadrant. At least 2 quadrants had to fulfill these UBM criteria. RESULTS: UBM analysis showed plateau iris in 83/262 (31.68%, 95% confidence interval: 26.7%-37.9%) PACG eyes, it was common in female individuals (61.44%), and patients were significantly younger than PACG patients (P=0.006). Plateau iris was found in superior quadrant in 19/83 (22.89%) eyes, inferior quadrant in 19/83 (22.89%) eyes, nasal quadrant in 21/83 (25.3%) eyes, and temporal quadrant in 24/83 (28.91%) eyes. In plateau iris patients, the central anterior chamber depth was shallower, the anterior chamber angle, the scleral-iris angle, and the sclera-ciliary process angle were significantly narrower, and the trabecular ciliary process distance and the iris ciliary process distance were significantly shorter in patients than in PACG subjects. CONCLUSIONS: Patients with plateau iris had significantly shallow central ACD when compared with those with pupillary block and normal eyes. After laser peripheral iridotomy, about a third of PACG eyes had plateau iris. This is clinically important because these patients can develop synechial angle closure and should be followed up closely.