Evaluation of 6 biometers based on different optical technologies

To evaluate repeatability and agreement between various biometric parameters using 6 biometers based on different optical technologies. SETTING: University of Valencia, Spain. DESIGN: Prospective, comparative case series. METHODS: 150 eyes were measured using the Aladdin, AL-Scan, Argos, IOLMaster700, Lenstar LS900, and OA-2000 biometers. Keratometry (K1 and K2), J(0) and J(45), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), white to white (WTW), and pupil size (PS) were measured 5 times with each device. Intrasubject SD, coefficient of variability (CoV), coefficient of repeatability, intraclass correlation coefficient, and Bland -Altman graphs were analyzed. RESULTS: CoV values were <0.30% for K1, K2, and AL and up to 1.61% for CCT, ACD, LT, and WTW. PS values were higher (from 4.2% to 7.68%). There was statistically significant differences between biometers for all parameters evaluated (P < .001), and these differences varied as a function of the parameter analyzed. The limit of agreement (LoA) width of some comparisons for K1 and the majority for K2 were >0.50 diopter. A similar pattern was found for J(0)/J(45). For CCT, many comparisons showed LoA width values of >25 μm. The LoA width for ACD ranged from 0.366 mm to 0.175 mm and for LT was about 0.2 mm. AL showed a highest LoA width of 0.225 mm. The LoA width for WTW was, in most cases, about ≥0.50 mm. The LoA width for PS ranged from 1.578 mm to 3.541 mm. CONCLUSIONS: The 6 biometers provided repeatable measurements for the different parameters analyzed. The LoA obtained for each comparison should be analyzed carefully to consider the interchangeability of these devices.