Central Visual Field Sensitivity With and Without Background Light Given to the Nontested Fellow Eye in Glaucoma Patients

Precis: This study showed the difference of monocular visual sensitivity between with and without background light given to the nontested fellow eyes in glaucoma patients. Monocular sensitivity measurements of the worse eyes with fellow eye's background light conditions should carefully be considered when assessing the impact of functional impairment in glaucoma patients. Purpose: The purpose of this study was to investigate the difference between monocular sensitivities measured with and without background light given to the nontested fellow eye in glaucoma patients using a new perimeter named "imo." Methods: In this cross-sectional study, we examined 102 eyes of 51 patients (mean age, 65.1 +/- 14.9 y) with open-angle glaucoma who were affected with at least 1 significant point in the central 10 degrees. We conducted a routine ophthalmic examination and visual field testing using the Humphrey Field Analyzer 24-2 and 10-2 programs. The eyes were assigned to "better" and "worse" categories based on the visual acuity and central visual thresholding. Subsequently, we compared the central visual sensitivities with and without background light given to the nontested fellow eye. Results: The mean sensitivity (MS) in the central 5 points of the visual field of the worse eyes was better when measured with background light than without background light (P=0.037) given to the nontested fellow eye. No significant difference was seen among the MS in the visual field of the better eyes. After dividing the patients into low (n=25) and high sensitivity (n=26) groups, only the low sensitivity group in worse eyes had higher MS with background light than without background light (P<0.05) given to the nontested fellow eye. Conclusions: Monocular sensitivities measured with background light given to the nontested fellow eye were higher than those without background light in the worse eye group of glaucoma patients. Monocular MS measurements of the worse eyes with fellow eye's background light conditions and their related indices should thus carefully be considered when assessing the impact of functional impairment in glaucoma patients.