Effect of Pharmacologic Pupil Dilation on OLCR Optical Biometry Measurements for IOL Predictions

PURPOSE: To determine the possible influence of pupil dilation on intraocular lens (IOL) power predictions made using optical biometry with Lenstar LS 900® (Haag-Streit AG, Koeniz, Switzerland). METHODS: A total of 72 eyes of 72 patients scheduled to undergo cataract surgery were prospectively examined using the optical low-coherence reflectometry (OLCR) optical biometer before and after pupil dilation with tropicamide 1%. The measurements made were axial length, central corneal thickness, anterior chamber depth (ACD), lens thickness, mean keratometry, corneal diameter (CD), and pupil diameter. Holladay II and SRK/T formulas were used to calculate IOL power. Agreement between the 2 measurement modes (with and without dilation) was assessed by calculating intraclass correlation coefficients (ICC) and constructing Bland-Altman plots. RESULTS: The mean age of the patients was 74.71 ± 7.53 years (range 56-90). Among the variables determined, only ACD varied significantly according to pupil dilation (p<0.001). The ICC data revealed excellent intraobserver correlation between measurements made with and without dilation, except for CD. The IOL power predictions were unmodified. CONCLUSIONS: The use of pupil dilation does not seem to influence measurements and IOL predictions made using this OLCR optical biometer.