The Handan eye study: comparison of screening methods for primary angle closure suspects in a rural Chinese population

Objective: To evaluate the van Herick test, anterior segment optical coherence tomography (AS-OCT), Pentacam and scanning peripheral anterior chamber depth analyzer (SPAC) for detecting primary angle-closure suspect (PACS) in a rural Chinese population. Methods: Eligible subjects aged ≥40 years were examined at the 5-year follow-up of the Handan Eye Study. PACS was defined as non-visibility of the posterior pigmented trabecular meshwork for ≥180° of the angle. Sensitivity, specificity, predictive values and receiver operating characteristic curves were used to assess the tests. Results: A total of 425 right eyes of 431 eligible subjects were analyzed. The area under the curve (AUC) for the van Herick test and AS-OCT were 0.711 and 0.799, respectively. The AUC for Pentacam anterior chamber depth was 0.834, while anterior chamber angle and anterior chamber volume had AUCs of 0.680 and 0.800, respectively. The AUC for SPAC was 0.779. AS-OCT had a specificity of 87% with a sensitivity of 73%. The best specificity of 92% (sensitivity 19%) was achieved by the van Herrick test at the 15% cut-off. Conclusions: None of the tests evaluated achieved the combination of specificity and sensitivity needed for population-based screening and their current capability does not realize the objective of case detection in the setting of an ophthalmology clinic