Comparison of pretreatment measurements of anterior segment parameters in eyes with acute and chronic primary angle closure

PurposeTo compare pretreatment anterior segment parameters between eyes with acute primary angle closure (APAC) and chronic primary angle closure (CPAC), and to identify the characteristics of eyes with APAC.Study designRetrospective.MethodsWe measured pretreatment anterior chamber depth (ACD), iris convexity (IC), and pupil diameter in eyes with APAC and CPAC using anterior segment optical coherence tomography. The risk of APAC associated with anterior segment parameters was investigated using multiple logistic regression. Eyes with APAC were discriminated from eyes with CPAC using the receiver-operating characteristic (ROC) curve and area under the curve (AUC). The best cutoff for these variables was determined.ResultsThirty-four eyes with APAC and 60 eyes with CPAC were included. The mean intraocular pressure was 52.312.6mmHg in APAC and 15.5 +/- 3.5mmHg in CPAC (P<.001). Eyes with APAC had a shallower ACD (1.407 +/- 0.301mm vs. 1.960 +/- 0.205mm, P<.001) and less IC (0.233 +/- 0.087mm vs. 0.294 +/- 0.068mm, P<.001) than eyes with CPAC. In multivariate analysis, significant variables associated with APAC were ACD (P<.001) and IC (P=.001). The AUC for ACD was 0.931 and for IC, 0.742. The best cutoff for ACD was 1.699mm (sensitivity 0.824, specificity 0.917) and for IC, 0.282mm (sensitivity 0.853, specificity 0.533).Conclusions Eyes with APAC had a shallower ACD and less IC. Eyes with an ACD<1.7mm may be at risk for APAC.