Patterns of damage in chronic angle-closure glaucoma compared to primary open-angle glaucoma.

PURPOSE: To compare patterns of damage in chronic angle-closure glaucoma (CACG) to a control group of patients with primary open-angle glaucoma (POAG).

DESIGN

Retrospective cross-sectional study.

METHODS

setting: Academic tertiary-care glaucoma clinic. study population: Thirty-two eyes of 32 patients with CACG and good-quality Heidelberg Retina Tomograph (HRT) images (pixel standard deviation <50 μm) and stereoscopic disc photographs within 1 year of a visual field showing reproducible glaucomatous field loss (mean deviation ≥-15.0 dB) were enrolled. Control eyes with POAG meeting similar criteria and matched for severity of field loss (±1 dB) and race were selected. outcome measures: Presence of focal rim loss (≤1 clock hour), HRT stereometric parameters, and extent and location of field loss.

RESULTS

The average mean deviation was -5.1 dB in both groups. Patients with CACG were more hyperopic (0.6 ± 0.4 vs -1.4 ± 0.5 D; P < .001) and had higher IOP at the time of imaging (15.8 ± 0.8 vs 13.9 ± 0.9 mm Hg; P = .015). Focal disc damage was not less frequent in PACG eyes (19% vs 24%; P = .545). Eyes with PACG had smaller cup area, cup volume, and mean cup depth and larger rim/disc area ratio (P < .05 for all), which persisted after adjusting for disc size, age, refractive error, and IOP. The average (±SD) number of abnormal test locations was similar in the 2 groups (P = .709), although CACG eyes were less likely to have paracentral points involved (47% vs 72%; P = .04).

CONCLUSIONS

Patterns of glaucomatous damage seem to be different in CACG compared with POAG. This difference in patterns of damage may adversely affect detection of early disease or its progression in CACG.