Reference values for anterior chamber morphometrics with swept-source optical coherence tomography in a Caucasian population

Purpose: The aim of this study is to generate reference values for anterior chamber morphometrics to facilitate the interpretation of anterior chamber images acquired with swept-source optical coherence tomography (SS-OCT) in a Caucasian population.

Materials and methods: Non-glaucomatous Caucasian subjects, who were newly referred to the outpatient department of the University Eye Clinic Maastricht UMC+, were asked to undergo anterior segment assessment with SS-OCT imaging prior to routine eye examination (including visual acuity and refractive error measurements, Goldmann applanation tonometry, slit lamp examination and funduscopy).

Results: A total of 647 Caucasian subjects, aged 40-80 years, were included. Mean age (± standard deviation) was 61.7±10.3 years, and 294 were male (45%). Mean refractive error was -0.63±3.17 D. OCT images and measurements were obtained in all cases. The mean temporal trabecular iris angle at 500 µm (TIA500) was 27.04°±12.04°, the mean nasal TIA500 was 27.43°±11.75°, the mean anterior chamber depth (ACD) was 2.75±0.39 mm and the mean lens vault (LV) was 0.44±0.30 mm. A smaller temporal TIA500, shallower ACD and higher LV were found in female and hyperopic subjects.

Conclusion: Reference values for anterior chamber morphometrics in Caucasians were generated, quantified and presented. These values offer tools for the interpretation of anterior segment images of Caucasians and differentiation between presumed mechanisms of angle closure.