[Peripapillary atrophies in primary open-angle glaucoma and glaucoma-like normal disks]

Abstract

Objective: To evaluate the variety of peripapillary atrophy (PPA) and its relationship with visual field among primary open angle glaucoma (POAG), normal tension glaucoma (NTG), and normal subjects with glaucoma-like disk (GLD) that had no evidence of visual field defect and retinal nerve fiber layer defect.

Methods: The study included 42 eyes of 42 patients with POAG, 40 eyes of 40 patients with NTG, and 45 eyes of normal subjects with GLD. Stereo color optic disc photographs were morphometrically evaluated by a video camera and computer system. The refractive range ( spherical equivalent) of all these subjects was between + 3.00D and -3.00D.

Results: The alpha-zone and beta-zone of PPA occurred significantly (P <0. 05) more frequent in both patients with POAG( 100. 0% ,48. 9% )and with NTG(95.0% ,37. 5% )than that of normal subjects with GLD(85.4% ,19. 1% ) , but no difference was found between the POAG and NTG groups (P > 0. 05). The beta-zone area of PPA was significantly ( P < 0. 05) enlarged in POAG compared with GLD normal subjects. While there is no significant difference in alpha-and beta-zone area between all other groups. In glaucoma patients, The alpha-zone or the beta-zone area of PPA weakly correlated with the glaucomatous visual field defect While cup/disk area ratio showed a relatively strong correlation. Cup/disc area ratio and age were the only two risk factors for the occurrence of glaucomatous visual field defect among all the factors including PPA by logistic regression analysis.

Conclusions: Our results demonstrate that cup/disc area ratio is well correlated with glaucomatous visual field defect. The occurrence of alpha-zone, beta-zone, and beta-zone areas of PPA may not be a clinically useful parameter, for diagnosing or differentiating POAG and NTG .