Evaluation of visual acuity and contrast sensitivity in patients of moderate to advance glaucoma with visual disability attending the low vision clinic

Purpose: Aims of this study is to characterise the visual disability of patients of glaucoma in terms of LogMAR visual acuity, contrast sensitivity, optic disc changes and intraocular pressure. Materials & Methods: A total of 30 eyes with the glaucomatous damage having low vision (WHO Criteria) with predefined inclusion and exclusion criteria were included as cases and 40 eyes with normal or near normal visual status correctable by refraction were included as control in the study. The visual acuity and contrast sensitivity were noted and analysed. Results: The best corrected visual acuity (BCVA) of all eyes in control group is less than 0.5 LogMAR units. Among cases, 25(83.3%) eyes have BCVA in the range of 0.5 to 1.0 LogMAR units and 5(16.7%) eyes have BCVA in the range of 1.0 to 1.3 LogMAR units, satisfying the inclusion criteria significantly (p value < 0.001). In case group, direct correlation of association is observed between uncorrected visual acuity and best corrected visual acuity (r = 0.8), near visual acuity (r = 0.73), best corrected near visual acuity (r = 0.48) and cup to disc ratio (r = 0.65) and inverse correlation of association with contrast sensitivity (r = -0.39) and intra ocular pressure (r = -0.51) which are statistically significant (p value <0.05). Conclusions: In patients of glaucoma with visual impairment, there is a negative correlation between contrast sensitivity and visual acuity in logMAR units.