Correlation between visual acuity and contrast sensitivity in early cataract and glaucoma. A comparative cross-sectional study

Background: The study investigates the correlation between visual acuity (VA) and contrast sensitivity (CS) in patients with early cataracts and glaucoma, comparing these findings with a control group. This aims to identify visual impairments associated with each condition to enhance diagnostic and therapeutic strategies. Methods: A cross-sectional study of 213 patients using non-probability consecutive sampling included 75 with early cataracts, 75 with early glaucoma, and 63 controls, all with a best corrected visual acuity (BCVA) of ≥1.0 logMAR. Pre-dilation assessments included medical history, glaucoma status, and lens opacification; BCVA was recorded post-refraction. CS was measured with the MARS chart at 1 m. Data were analysed using SPSS version 21. Results: Glaucomatous eyes showed mean VA of 0.72 (±0.85) (right eye) and 0.86 (±1.02) (left eye), with CS of 0 (±0) and 4 (±5) respectively. A strong negative correlation was observed between VA and CS in glaucomatous (r = -0.69; p <0.001) and cataract eyes (r = -0.71; p <0.001). Glaucomatous eyes significantly differed in VA from controls: mean 0.45 (±0.28), Z score 7.6; p <0.001, as did cataract eyes: mean 0.4 (±0.3), Z score -5.8; p <0.001. CS in glaucomatous eyes deviated significantly: mean 0.84 (±0.33), Z score -9.05; p <0.001, as did cataract eyes: mean 0.89 (±0.3), Z score -8.63; p <0.001. Conclusion: Both glaucomatous and cataract eyes showed negative correl