Repeatability of an SD-OCT biometer (MS-39 AL) and agreement with a validated biometer (IOLMaster 700)

PURPOSE: To evaluate the repeatability of biometric measurements obtained with the MS-39 AL (CSO) and to assess their agreement with those provided by the IOLMaster 700 (Carl Zeiss). SETTING: IRCCS Bietti Foundation, Rome, Italy. DESIGN: Prospective evaluation of diagnostic test. METHODS: Patients were classified in Group A (with cataract) and Group B (with clear lens). For repeatability analysis, three measurements were obtained with the MS-39 AL. Agreement was analyzed by comparing the first MS-39 AL measurement with the corresponding measurement by the IOLMaster 700. RESULTS: 111 eyes were enrolled. Group A included 53 eyes (mean age: 69.4 ±7.3 years) and Group B 58 eyes (mean age 35.5 ±9.1 years). In both groups, the MS-39 AL demonstrated high repeatability for all biometric parameters, as the coefficient of variation ranged from 0.04% for axial length to 2.10% for lens thickness, except in the case of corneal astigmatism. Agreement between biometers was high for most parameters, with narrow 95% limits of agreement. Significant differences were observed for anterior chamber depth (MS-39 AL = 3.52±0.44 mm, IOLMaster 700 = 3.42±0.45 mm, p <0.0001), corneal diameter (MS-39 AL = 11.90±0.46 mm, IOLMaster 700 = 12.19±0.49 mm, p <0.0001), central corneal thickness (MS-39 AL = 531.75±31.20 µm, IOLMaster 700 = 534.80±32.79 µm, p <0.001) and lens thickness (MS-39 AL = 4.18±0.55 mm, IOLMaster 700 = 4.13±0.52 mm, p = 0.002). CONCLUSIONS: The MS-39 AL provides highly repeatable biometric measurements and shows good agreement with the IOLMaster 700 for most parameters in both cataractous and clear-lens eyes.