A standardized logarithm of the minimum angle of resolution visual acuity chart in Hindi.

Purpose: The purpose of this study to develop and calibrate a new Hindi logarithm of the minimum angle of resolution (logMAR) visual acuity chart. Methods: A new Hindi visual acuity chart was designed to logMAR specifications using Hindi optotypes experimentally selected to have similar relative legibility under equivalent spherical and cylindrical defocus. The chart calibration study was carried out in a large clinical setup in India. Participants who were literate in English and Hindi participated in the study. Visual acuity was measured with the new Hindi logMAR chart and a modified ETDRS (m-ETDRS) logMAR chart. The method of presentation was randomized between the charts. Repeat visual acuity was measured on a subsequent day with a second version of the Hindi logMAR chart. Results: The Hindi logMAR chart correlated highly with the m-ETDRS logMAR chart (r2 = 0.92); however, the mean visual acuity difference (Hindi logMAR-m-ETDRS logMAR) was nearly one and half lines (0.13 logMAR, 95% confidence interval [CI] = ±0.15 logMAR). The Hindi logMAR chart also proved to be highly repeatable (r2 = 0.99; mean difference 0.005, 95% CI = ±0.04 logMAR). Conclusion: This study reports the first standardized visual acuity chart developed in Hindi incorporating equal letter legibility and logMAR chart design features. The Hindi logMAR visual acuity chart provides a valid and repeatable tool for the measurement of visual acuity in native Hindi language speakers. Future use of the new Hindi chart should incorporate an increase in optotype size of 0.13 logMAR.

Height, weight, body mass index and ocular biometry in patients with sickle cell disease.

PURPOSE: To investigate the effects of physical size on refractive error and the dimensions of optical components in sickle cell disease (SCD). METHODS: The design was cross sectional. Height and weight of adult patients suffering from SCD were measured, and body mass index (BMI) was calculated. Anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD) and axial length (AL) were measured using A-scan ultrasonography. Corneal radius of curvature (CR) was measured using a keratometer. Non-cycloplegic refractive error was determined subjectively. RESULTS: Subjects with SC genotype were significantly taller than those with SS genotype. In the unadjusted data, height was correlated with VCD [p = 0.02, 0.44 mm deeper per 10 cm increase in height, 95% CI (0.65, 8.25)] and AL [p = 0.03, 0.42 mm longer for every 10 cm increase in height, 95%CI (0.49, 7.99)]. The relationship between height, VCD and AL was absent after adjustment for age, gender, genotype and weight. BMI (kg m(-2)) was correlated with AL/CR ratio in both unadjusted (p = 0.04, -0.10 decrease per 1 kg m(-2), 95% CI (-0.018, -0.001) and adjusted data (p = 0.05, -0.10 decrease per 10 kg m(-2), 95% CI (-0.0189, 0.0001). Refractive error was not related to height, weight or BMI. CONCLUSIONS: Physical size does not affect refractive error or optical components in adult patients with SCD.