PURPOSE: This pilot study aimed to compare ocular biometric data obtained from Pentacam AXL and IOL Master 700 in patients with keratoconus who underwent intracorneal ring segment (ICRS) implantation. METHOD: In this pilot study, patients who underwent ICRS implantation (between 2013 and 2021) at Khalili Hospital were assessed using pre-surgical examinations and biometry and keratometry measurements performed with the Pentacam AXL and the IOLMaster 700. The devices were used in random order, and measurements were conducted by expert operators who were blinded to each other's results. Data were analyzed using SPSS version 23. RESULT: A total of 21 patients (mean age: 35.47 ± 6.43 years) who underwent ICRS implantation surgery were included. Significant mean differences between Pentacam AXL and IOL Master 700 were observed in anterior chamber depth (ACD), mean keratometry (KM), steep keratometry (K2), and white-to-white distance (WTW) (p <
0.05). No significant differences were found for axial length (AL), flat keratometry (K1), K1 and K2 meridians, or intraocular lens (IOL) power calculated using Haigis and SRK/T formulas (p >
0.05). CONCLUSION: Significant differences in ACD, KM, K2, and WTW were observed between Pentacam AXL and IOL Master 700 in patients with ICRS implantation, while AL, K1, K1 meridian, K2 meridian, and IOL power calculations (Haigis and SRK/T) showed no differences. These findings underscore the importance of device selection tailored to specific clinical and biometric needs and suggest the necessity of larger studies to confirm these results.