Comparison of Immersion Ultrasound, Partial Coherence Interferometry, and Low Coherence Reflectometry for Ocular Biometry in Cataract Patients

PURPOSE: To compare ocular biometry parameters measured with immersion ultrasound, partial coherence interferometry, and low coherence reflectometry in cataract patients. METHODS: Measurements of axial length and anterior chamber depth were analyzed and compared using immersion ultrasound, partial coherence interferometry, and low coherence reflectometry. Keratometry (K), flattest axis, and white-to-white measurements were compared between partial coherence interferometry and low coherence reflectometry. Seventy-eight cataract (LOCS II range: 1 to 3) eyes of 45 patients aged between 42 and 90 years were evaluated. A subanalysis as a function of cataract degree was done for axial length and anterior chamber depth between techniques. RESULTS: No statistically significant differences were noted for the study cohort or within each cataract degree among the three techniques for axial length and anterior chamber depth (P>.05, ANOVA test). Measurements between techniques were highly correlated for axial length (R=0.99) and anterior chamber depth (R=0.90 to 0.96) for all methods. Keratometry, flattest axis, and white-to-white measurements were comparable (paired t test, P>.1) and correlated well between partial coherence interferometry and low coherence reflectometry (K1 [R=0.95), K2 [R=0.97], flattest axis [R=0.95], and white-to-white [R=0.92]). CONCLUSIONS: Immersion ultrasound, partial coherence interferometry, and low coherence reflectometry provided comparable ocular biometry measurements in cataractous eyes.