Evaluation of Functional Visual Acuity in Glaucoma Patients

Purpose: We evaluated the association between functional visual acuity (FVA) and visual fields in glaucoma patients. Patients and Methods: Forty-seven patients with glaucoma were enrolled (28 men, 19 women; mean age: 65.2±7.3 y; range: 38 to 82 y), and their 94 eyes were studied. Inclusion criteria were having glaucomatous optic disc abnormalities, visual field loss with glaucoma, and a best-corrected visual acuity in each eye of 1.0 (equivalent to Snellen 20/20) or better. FVA and visual maintenance ratio evaluations were made with an AS-28 FVA measurement system. To assess FVA, Landolt optotypes were displayed sequentially for 2 seconds each, and the size was reduced when the patient gave the correct answer. Humphrey automated perimetry was performed to determine mean deviation (MD) and foveal threshold, and these values were used to evaluate associations between FVA and visual field. Mean and SD was calculated for all parameters for statistical comparisons. Results: The MD values were −10.1±7.3 (range: −29.87 to 1.05) dB, and foveal thresholds were 34.8±2.8 (mean±SD, range: 25 to 41) dB. The logMAR FVA values were 0.14±0.17 (range: −0.14 to 0.73), and the visual maintenance ratios were 0.92±0.06 (range: 0.73 to 1.02). Linear regression analysis of the logMAR FVA values and visual field gave a MD of R=0.26 (P=0.01), and a foveal threshold of R=0.51 (P<0.001). The corresponding figures for the visual maintenance ratio and visual field were MD: R=0.25 (P=0.01) and foveal threshold: R=0.48 (P<0.001). Conclusions: The results of the current study showed that the logMAR FVA and visual maintenance ratio correlated moderately with foveal threshold.