Objective: To assess the frequency of an enlargement of parapapillary atrophy in follow-up of eyes with open-angle glaucoma.

Methods: Prospective observational longitudinal study. Methods: Institutional. Methods: The study included 978 eyes (511 Caucasian subjects) with open-angle glaucoma (n = 548; including 194 eyes with normal-pressure glaucoma), ocular hypertension (n = 289), or without optic nerve disease (n = 141). Highly myopic eyes with a myopic refractive error exceeding -8 diopters were excluded. Mean follow-up was 4.5 +/- 2.4 years (median, 3.8 years; range: 1.5 to 9.8 years). Methods: Optic disk photographs taken annually. Methods: Two examiners compared optic disk slides for enlargement of parapapillary atrophy (zone beta) and for signs of progressive disk damage.

Results: An enlargement of parapapillary beta zone was detected in 16 eyes (1.6%) after 3.9 +/- 2.6 (0.6 to 9.1) years of follow-up. It was observed in 15 eyes (2.7%) with open-angle glaucoma, 1 eye (0.3%) with ocular hypertension, and in none of the normal eyes. After excluding eyes with a myopic refractive error exceeding -3 diopters, enlargement of beta zone was significantly more common in eyes with progressive glaucoma (5/81 or 6.2%) than in eyes with nonprogressive glaucoma (3/354 or 0.8%; P <.001).

Conclusions: Parapapillary atrophy (zone beta) enlarges during follow-up of relatively few eyes with chronic open-angle glaucoma. In the refractive range above -3 diopters, enlargement of beta zone occurs significantly more frequently (P <.001) in progressive glaucoma than in nonprogressive glaucoma. In view of its low frequency, enlargement of beta zone may not be a very useful marker for glaucoma progression.