Comparison of near vision in glaucoma patients using standard and reversed-contrast charts

Abstract

Clinical relevance: Reversed-contrast testing is easy to perform via electronic devices and may improve reading performance and the quality of life of most glaucoma patients.

Background: Electronic devices are becoming increasing popularity and most devices have easily adjustable contrast settings. This study investigated near vision acuity and preference between the standard visual acuity chart (black text on white background) and a reversed-contrast chart (white text on black background) in glaucoma patients with decreasing contrast sensitivity.

Methods: This cross-sectional study evaluated 177 eyes of 177 patients from a single glaucoma clinic. The better eye of primary glaucoma patients (visual acuity of 6/20 or better) was evaluated. Patients with any other condition affecting visual acuity or reading performance were excluded. Near visual acuity was measured using a device with an anti-glare screen at 40 cm distance for both standard and reversed-contrast charts.

Results: Glaucoma patients had a significantly better average near visual acuity using the reversed-contrast chart than using the standard chart (median best-corrected visual acuity, LogMAR = 0.12; interquartile range = 0.18 vs median best-corrected visual acuity, LogMAR = 0.2; interquartile range = 0.26; respectively; P < 0.01), with more prominent differences in the advanced glaucoma group (median best-corrected visual acuity of reversed contrast chart: median best-corrected visual acuity of standard chart = 0.12:0.2, 0.12:0.13, and 0.18:0.22 in the early, moderate, and severe groups, respectively, P < 0.01 in early and severe group and P = 0.02 in moderate group). One hundred and nine (109) out of 177 patients (61.58%) preferred the reversed contrast version.

Conclusion: Reversed contrast materials may improve the reading performance and quality of life of patients with glaucoma, especially those with severe disease.

Keywords: Contrast sensitivity; glaucoma; near vision; reading performance; reversed-contrast pattern.