Iris thickness and volume be measured using iris base instead of scleral spur as reference in anterior optical coherence tomography scan

PURPOSE: To compare the iris parameters (iris thickness [IT] and volume) measured at different locations on iris determined using iris base (IB) and scleral spur (SS) in healthy Saudi eyes and factors affecting the differences. METHODS: Healthy eyes of Saudi persons were evaluated using anterior segment optical coherence tomography (AS-OCT). The IT was measured using Image J software and OCT scans in the horizontal axis in light on and light off condition. First IB was used as reference, and then, SS was used as reference for these measurements. RESULTS: One hundred healthy eye's AS-OCT scan was studied. The IT at the temporal side of the horizontal axis at 750 µ away from IB with lights on was 0.526 ± 0.08 µ, whereas it was 0.52 ± 0.08 µ from SS. The difference was significantly more in IB than SS method (P = 0.005). This difference if IT in SS and IB method was not affected by gender (Mann–Whitney P = 0.3), type of refractive error (K W P = 0.7), and level of illumination (K W P = 0.7). CONCLUSION: IT and IV measured using IB provided reliable data but overestimates compared to SS method. In the absence of SS visibility, IB could be alternative to assess iris parameters.