Effect of Visual Crowding on Quality of Life in Glaucoma Patients

Purpose: To investigate the association between visual crowding and vision-related quality of life (QoL) in patients with glaucoma. Methods: This cross-sectional study included 50 patients diagnosed with POAG. Visual crowding was quantified by measuring the critical spacing (Scritical). The Scritical was assessed in each visual field quadrant. For each eye, a global Scritical was calculated as the mean of the eligible quadrant-specific values. Vision-related QoL was assessed using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), scored using Rasch analysis. Associations between the Scritical and the NEI VFQ-25 Rasch-calibrated scores were examined using generalized estimating equations, with multivariable models adjusted for age and standard automated perimetry 24-2 mean deviation. Results: Among 50 patients with POAG (93 eyes; mean age, 67.9 ± 9.2 years), the mean Rasch-calibrated NEI VFQ-25 score was 59.9 ± 18.8. In univariable analyses, each 1-degree increase in the better-eye global Scritical was associated with a 5.69-point lower NEI VFQ-25 score (95% confidence interval, −10.43 to −0.96; P = 0.018), and each 1-degree increase in the worse-eye Scritical was associated with a 2.23-point lower score (95% confidence interval, −4.38 to −0.08; P = 0.042). In multivariable analysis adjusting for age and standard automated perimetry mean deviation, the better-eye Scritical remained independently associated with a worse QoL (−5.02 points per degree; 95% confidence interval, −9.59 to −0.45; P = 0.031). Conclusions: Visual crowding is independently associated with worse vision-related QoL in patients with glaucoma, even after adjustment for standard perimetric loss. These findings suggest that visual crowding captures clinically meaningful aspects of visual dysfunction beyond conventional perimetry.