Comparison of Anterior Segment Measurements Using Scanning-Slit Topography and Optical Low-Coherence Reflectometry (OLCR) Biometry

ABSTRACT

PURPOSE: To compare the results of anterior segment biometry including white-to-white (WTW) between scanning-slit topography (ORBscan IIz(R), Bausch & Lomb), optical low-coherence reflectometry (OLCR) biometry (Lenstar(R), Haag-Streit), and Castroviejo calipers. METHODS: Measurements on 72 eyes of 36 patients that underwent refractive surgery were measured using ORBscan(R), Lenstar(R), and calipers and compared. Ocular biometry parameters used in this study included the WTW, central corneal thickness, anterior chamber depth (ACD), keratometry, and pupil size. RESULTS: The WTW measurements using ORBscan(R) and calipers (11.57 +/- 0.35 mm and 11.58 +/- 0.34 mm, respectively) were statistically similar. However, the measurement using Lenstar(R) (12.05 +/- 0.40 mm) was significantly greater than with the other methods (p < 0.001). Central corneal thickness and keratometry measurements using ORBscan(R) were greater than when using Lenstar(R) (p = 0.01 for both). ACD and pupil size measurement using Lenstar(R) were greater than when using ORBscan(R) (p < 0.001 for both). CONCLUSIONS: Because WTW and ACD measurements using Lenstar(R) were greater than when using ORBscan(R) and calipers, unexpected high-vaulting may be observed due to the selection of a larger-sized posterior chamber phakic intraocular lens. Therefore, the differences in measurements obtained when using these methods should be considered.