PURPOSE: To investigate the characteristics of peripapillary atrophy in primary angle-closure glaucoma and to compare peripapillary atrophy in primary angle-closure glaucoma with that in primary open-angle glaucoma.

METHODS: Twenty-one eyes (of 21 patients) with chronic primary angle-closure glaucoma that had no evidence of an acute attack or combined-mechanism glaucoma and 31 eyes (31 patients) with primary open-angle glaucoma were enrolled in this study. The cup-to-disk area ratio and the visual field mean deviation were matched in both groups. The prevalence of peripapillary atrophy and peripapillary atrophy-to-disk area ratio of eyes with primary angle-closure glaucoma and eyes with primary open-angle glaucoma were compared. The correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation was also evaluated.

RESULTS: Eight (38%) of 21 eyes with primary angle-closure glaucoma and 21 (68%) of 31 eyes with primary open-angle glaucoma had peripapillary atrophy. The peripapillary atrophy-to-disk area ratio averaged 0.16 in primary angle-closure glaucoma and 0.41 in primary open-angle glaucoma. There were statistically significant differences regarding the prevalence of peripapillary atrophy (P = .048) and peripapillary atrophy-to-disk area ratio (P = .005) between the two groups. There was no significant correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation in primary angle-closure glaucoma. In contrast, the peripapillary atrophy-to-disk area ratio significantly correlated with the cup-to-disk area ratio (P = .003) and the mean deviation (P = .0001) in primary open-angle glaucoma.

CONCLUSIONS: The peripapillary atrophy in primary angle-closure glaucoma has a different relationship to the structural and functional optic disk changes than that in primary open-angle glaucoma. Different mechanisms seem to be involved in the development of the optic disk damage in the two types of glaucoma.