Evaluation of the Van Herick technique for screening for occludable angles in an African population

Abstract

The current gold standard for screening for angle closure and adopting universal approaches to prophylaxis is the assessment of the anterior chamber (AC) angle by gonioscopy, a technique that has substantial interobserver variability and relies on subjective assessment. Slit-lamp estimation of the peripheral anterior chamber depth (ACD) by the Van Herick technique is a noncontact approach for estimating angle width and various authors have commented on its sensitivity and specificity as a screening tool for identifying narrow angles as well as angle closure.This case series draws attention to the fact that as many as 28 out of 36 (77.78%) seemingly open angles on Van Herick test were found to be potentially occludable angles on gonioscopy. Therefore, it may be concluded that gonioscopy is essential even in patients with deep peripheral ACs, before an occludable angle can be ruled out.