Glucose-induced temporary visual recovery in primary open-angle glaucoma: a double-blind, randomized study.

To investigate the effect of topical glucose on visual parameters in individuals with primary open-angle glaucoma (POAG).Double-blind, randomized, crossover study.Nondiabetic pseudophakic patients with definite POAG were recruited; 29 eyes of 16 individuals participated in study 1. A follow-up study (study 2) included 14 eyes of 7 individuals.Eyes were randomly allocated to receive 50% glucose or saline eye drops every 5 minutes for 60 minutes.The contrast sensitivity and best-corrected logarithm of the minimum angle of resolution (logMAR).The 50% glucose reached the vitreous in pseudophakic but not phakic individuals. Glucose significantly improved the mean contrast sensitivity at 12 cycles/degree compared with 0.9% saline by 0.26 log units (95% confidence interval [CI], 0.13-0.38; P < 0.001) and 0.40 log units (95% CI, 0.17-0.60; P < 0.001) in the follow-up study. The intraocular pressure, refraction, and central corneal thickness were not affected by glucose; age was not a significant predictor of the response.Topical glucose temporarily improves psychophysical visual parameters in some individuals with POAG, suggesting that neuronal energy substrate delivery to the vitreous reservoir may recover function of "sick" retinal neurons.