Comparison of Optical Low-Coherence Reflectometry and Swept-Source OCT-Based Biometry Devices in Dense Cataracts

To investigate agreement between biometric measurements obtained from the Lenstar LS 900 (Haag-Streit AG) based on optical low-coherence reflectometry (OLCR) and the Tomey OA-2000 (Tomey Corporation) based on swept-source optical coherence tomography (SS-OCT) in dense cataracts.

In this prospective observational study, axial length, keratometry, anterior chamber depth (ACD), lens thickness, and central corneal thickness (CCT) were measured in 124 eyes of 76 patients. Intraocular lens prediction errors and absolute prediction errors were assessed based on postoperative manifest refraction. Analyses used were paired t test, Pearson correlation coefficient (r), and Bland-Altman plots.

Failure in axial length measurements was noted in 28 eyes (22.58%) with OCLR compared to 2 eyes (1.6%) with SS-OCT. Although not statistically significant, axial length measurements were clinically higher with SS-OCT (23.78 ± 1.76 mm) compared to OCLR (23.72 ± 1.58 mm) (P = .81) (r = 0.23; P = .01). There was a significant trend toward myopic intraocular lens prediction with SS-OCT (-0.09 ± 0.48) compared to OLCR (0.09 ± 0.41, P < .01) (r = 0.25, P = .01). There was good agreement for keratometric and ACD values between the two devices. SS-OCT gave significantly higher values of lens thickness compared to OCLR (4.44 ± 0.44 vs 4.18 ± 0.48 mm, P < .01) (r = 0.39, P < .01). CCT measured with OCLR was significantly higher than SS-OCT (525.64 ± 27.0 vs 513.21 ± 29.24 µm; P < .01) (r = 0.98, P < .01).

One-fifth of the patients with dense cataracts failed axial length measurement on OCLR. SS-OCT gives clinically higher axial length measurements leading to more myopic intraocular lens prediction errors postoperatively. OCLR provides higher pachymetry and lower lens thickness values compared to the SS-OCT device. [J Refract Surg. 2020;36(8):557-564.].