Association Between Quantitative Nerve Fiber Layer Measurement and Visual Field Loss in Glaucoma

Abstract

To evaluate the association between quantitative nerve fiber layer measurements and visual field loss in patients with primary open-angle glaucoma. Quantitative retinal nerve fiber layer measurements were obtained in 53 patients with primary open-angle glaucoma by using confocal scanning laser ophthalmoscopy (cross-section area) and confocal scanning laser polarimetry (retardation ratio). For each eye, three images were obtained with each instrument. An image that was the mean of those three was created and used in all analyses. We investigated the association between global, regional, and hemifield differences in retinal nerve fiber layer measurements and visual field loss with linear regression techniques. The retardation ratio decreased with increasing mean visual field loss, measured both globally and regionally; R2 (the amount of variation explained by the model) ranged from 8% to 21%. Retinal nerve fiber layer cross-section area was not significantly associated with global measures of visual field loss. The inferior visual field mean deviation increased with decreasing superior retinal nerve fiber layer cross-section area (R2 = 8.2%, P = .04); superior visual field mean deviation was not associated with inferior retinal nerve fiber layer cross-section area (R2 = 2.6%, P = .25). Hemifield differences in visual field mean deviation increased with increasing hemifield differences in retinal nerve fiber layer cross-section area (R2 = 20.0%, P < .001), but not with retardation ratio (R2 = 0.9%, P = .48). Quantitative measures of the retinal nerve fiber layer using both confocal scanning laser ophthalmoscopy and confocal scanning laser polarimetry were correlated with visual field loss in glaucoma patients.