Comparison of two optical biometers

Purpose. To compare a new optical biometer device, Galilei G6 (Ziemer, Port, Switzerland), with the present optical biometer, Lenstar LS 900 (Haag-Streit, Koeniz, Switzerland), for intraocular lens (IOL) power calculation. Methods. One hundred forty eyes of 140 cataract patients were evaluated with two optical biometers: The Galilei G6 and the Lenstar. The mean keratometry (K), axial length (AL), anterior chamber depth (ACD), crystalline lens thickness (LT), white-To-white (WTW), and IOL powers using the SRK/T, Holladay 1, Hoffer Q, and Haigis formulas were compared. The intrasession repeatability of the Galilei G6 measurements was assessed in 25 eyes. Results. All ocular parameters measured by the Galilei G6 were highly repeatable (all intraclass correlation coefficients 9 0.980). Although K and ACD did not show statistical differences between the two devices (all p 9 0.05), the measurements for AL, LT, and WTW were statistically different for the two devices. The K, AL, ACD, LT, and WTW showed good correlations (r = 0.975, 0.998, 0.973, 0.946, and 0.710, respectively; all p G 0.001); however, the agreements of LT and WTW were not good between the two devices. The IOL powers using four formulas did not show statistical differences (all p 9 0.05); however, agreements between the IOL powers were not strong. The ranges of 95% limit of agreements were between 1.54 and 1.90D according to the formulas. Conclusions. The ocular parameters and IOL powers using the Galilei G6 cannot be used interchangeably with those of the Lenstar in clinical practice.