Retinal vessel diameter in normal-tension glaucoma patients with asymmetric progression

Abstract

To investigate the longitudinal changes in the central retinal vessel diameter in asymmetric progressive normal-tension glaucoma (NTG) patients. This study included 27 patients with bilateral NTG without any systemic vascular disease who showed glaucomatous progression in one eye at the mean follow-up of 24.3 months (range, 18-29 months). Progression was determined by the development of new retinal nerve fiber layer (RNFL) defects or widening of pre-existing defects on red-free RNFL photographs. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were measured at baseline and at the mean follow-up of 24.3 months. We classified the eyes of each patient as either progressed or stable eyes, and compared the differences and changes in the CRAE and CRVE. No significant inter-eye difference was observed at baseline in the mean CRAE (167.5 +/- 22.2 mu m vs. 168.2 +/- 15.5 mu m, p = 0.809) and in the mean CRVE (276.3 +/- 18.2 mu m vs. 281.6 +/- 21.9 mu m, p = 0.267) between the progressed and stable eyes. There were significant changes in CRAE in the progressed eyes between baseline and 2 years after baseline (from 167.5 +/- 22.2 mu m to 146.9 +/- 18.0 mu m, p < 0.0001), but there were no significant changes in the stable eyes (from 168.2 +/- 15.5 mu m to 167.5 +/- 14.8 mu m, p = 0.084). In our series of NTG patients with asymmetric progression, central retinal artery diameter decreased over time in the progressed eyes, whereas no significant decrease in the central retinal artery diameter was seen in the stable eyes.