Eye-Tracking Reading Patterns Across Different Interventions in Glaucoma Patients Versus Controls

Purpose To evaluate reading performance patterns – specifically saccades, fixations, and reading speed – under three visual interventions (font size, line spacing, and contrast) in glaucoma patients compared to control subjects, using an eye tracker. Methods This cross-sectional study included 111 patients (57 patients with glaucoma and 54 controls), with no ocular diseases other than glaucoma, and collected demographic and ophthalmologic data. Glaucoma was defined as progressive changes on fundus stereophotographs and/or documented compatible visual fields defects. All patients had at least best-corrected visual acuity of 0.5 logMAR in the left eye. Eye tracker data was extracted using the ISCAN software. Participants performed a reading performance exercise using the MNREAD chart displayed on a computer screen, with five slides of each progressive intervention. Reading speed was calculated in words per minute; number and amplitude of saccades, number of fixations, and fixation duration were measured. Results The mean age was 61.8 (± 11.6) and 66.5 (± 13.7) years in the glaucoma and control group, respectively (P = 0.052). Educational level had no difference between the two groups (P = 0.393). Best-corrected visual acuity in the left eye was 0.18 (± 0.16) and 0.04 (± 0.10) logMAR in the glaucoma and control group, respectively (P < 0.001). Increased contrast had the most significant impact in the glaucoma group, improving reading speed (P < 0.05 in 4 out of 5 slides), and reducing both the number of saccades (P < 0.05 in 4 out of 5 slides) and fixations (P < 0.05 in 3 out of 5 slides). Line spacing and font size had a less pronounced effect. Conclusions Higher contrast significantly improves reading performance in Portuguese-speaking glaucoma patients by enhancing eye-movement efficiency, reducing the number of saccades and fixations, and thereby boosting their reading potential.