Peripapillary atrophy after acute primary angle closure.

Aim: To determine the changes in peripapillary atrophy after episodes of acute primary angle closure (APAC).

Methods: Prospective observational study of 40 eyes in 38 patients of predominantly Chinese ethnicity. The mean (SD) intraocular pressure at the time of presentation was 51.7 (12) mm Hg (median, 55 mm Hg) and the mean duration of the symptoms was 37.7 (69.4) hours. A laser iridotomy was undertaken 3.2 (8.4) days after the APAC episode, leading to normalisation of intraocular pressure in all cases. Colour optic disc photographs taken at 2 and 16 weeks after APAC were examined morphometrically. Peripapillary atrophy was divided into alpha and beta zones.

Results: Comparing measurements at baseline with week 16, the minimum width of the alpha zone (0.013 (0.056) v 0.016 (0.001) arbitrary units; p = 0.23), the maximum width of the alpha zone (1.11 (1.31) v 1.31 (0.79) arbitrary units; p = 0.22), the minimum width of the beta zone (0.030 (0.122) v 0.033 (0.166) arbitrary units; p = 0.93), and the maximum width of the beta zone (0.62 (0.94) v 0.73 (0.98) arbitrary units; p = 0.42) did not vary significantly. The mean cup to disc ratio increased from 0.56 (0.05) to 0.62 (0.07) (p<0.0001) at the end of follow up.

Conclusions: The alpha and beta zones of peripapillary atrophy did not enlarge markedly in patients after APAC, despite an enlargement of the optic cup during a follow up of four months.