Enlargement of parapapillary atrophy in follow-up of chronic open-angle glaucoma

To assess the frequency of an enlargement of parapapillary atrophy in follow-up of eyes with open-angle glaucoma. Prospective observational longitudinal study. Institutional. 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). Optic disk photographs taken annually. Two examiners compared optic disk slides for enlargement of parapapillary atrophy (zone beta) and for signs of progressive disk damage. 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 (5/81or 6.2%) than in eyes with nonprogressive glaucoma (3/354 or 0.8%; P < .001). 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.