Correlation of central field index (10-2 visual field analysis) and activity limitation with increasing severity of glaucoma using glaucoma activity limitation-9 questionnaire

Purpose: The purpose of the study was to analyze the correlation between central field index (CFI) and activity limitation in glaucoma using glaucoma activity limitation-9 (GAL-9) questionnaire. Methods: This hospital-based, cross-sectional, noninterventional study, included 50 patients diagnosed with glaucoma, with field defect encroaching onto central 10° in Humphrey field analysis 30-2 program, in at least one eye. These patients underwent central 10-2 field analysis and CFI was calculated with the help of a calculator created by us. Patients with severe cognitive impairment were excluded and the rest completed the GAL-9 questionnaire. The data was analyzed to determine the correlation between the CFI and the GAL-9 scores. Results: There was a moderate correlation between CFI of better eye (r =-0.431, confidence interval 'CI'-0.619 to-0.173, P < 0.002) and worse eye (r =-0.342, CI:-0.575 to-0.058, P < 0.015) with GAL-9, the better eye showing a stronger correlation. Mean deviations (MD) of both better (r =-0.345, CI:-0.556 to-0.069, P < 0.014) and worse eye (r =-0.346, CI:-0.578 to-0.063 P < 0.014) showed similar moderate correlation. Vision of better eye (r =-0.398, CI:-0.577 to-0.210, P < 0.004) showed a stronger correlation with GAL-9 score than worse eye (r =-0.188, CI:-0.475 to 0.100, P < 0.192). Subscales of GAL-9 questionnaire also correlated with better eye status. 'Finding dropped objects' had the strongest correlation to CFI of better eye (r =-0.676) and 'adjusting to dim lights' had the weakest correlation (r =-0.052). Conclusion: The better eye status in glaucoma patients correlated better than worse eye with regard to activity limitation, signifying that the better eye has a greater influence on the quality of life and how patients perceive their disability. Furthermore, CFI showed a better correlation with GAL-9 score than MD.