Ciliary Sulcus Diameter and Two Anterior Chamber Parameters Measured by Optical Coherence Tomography and VHF Ultrasound

Purpose: To evaluate the relationship between two anterior chamber anatomical parameters, angle-to-angle and iris pigment end-to-iris pigment end distances, and sulcus-to-sulcus diameter. Methods: Twenty eyes without active ocular pathologies or previous ocular surgeries from 20 patients ranging in age from 23 to 51 years were included in this study. Mean spherical equivalent refraction ranged from +5.50 to −7.00 diopters. Angle-to-angle and iris pigment end-to-iris pigment end distances were measured in all cases three times consecutively using two technologies: optical coherence tomography (OCT) and very high-frequency ultrasonography. Sulcus-to-sulcus diameter was additionally obtained by ultrasonography. Correlation, linear regression, intrasession, and interchangeability analysis between parameters was performed. Results: Mean sulcus-to-sulcus diameter was 11.92±0.80 mm. Mean angle-to-angle distance was 12.14±0.52 mm for ultrasonography and 12.23±0.59 mm for OCT. Mean iris pigment end-to-iris pigment end distance was 12.18±0.51 mm for ultrasonography and 12.29±0.61 mm for OCT. No statistically significant differences were found among these anatomical parameters (unpaired Student t test, all P >.10). Statistically significant correlations were found between sulcus-to-sulcus diameter and angle-to-angle distance and between sulcus-to-sulcus diameter and iris pigment end-to-iris pigment end distance for both imaging techniques. For ultrasonography, range of agreement was 0.90 mm between sulcus-to-sulcus diameter and angle-to-angle distance and 0.74 mm between sulcusto-sulcus diameter and iris pigment end-to-iris pigment end distance. These ranges increased to 1.22 mm and 1.14 mm, respectively, for OCT measurements. Conclusions: Angle-to-angle and iris pigment end-toiris pigment end distances are correlated with sulcus-to-sulcus diameter, but they cannot be used as equivalent parameters. [ J Refract Surg. 2009;25:1017–1025.]