Comparison Of Three Optical Biometers In Keratoconus Patients: Nidek®️, Lensstar®️ Ls 900 And Aladdin®️
Published 2025 - 43rd Congress of the ESCRS
Reference: PP23.03 | Type: Free paper | DOI: 10.82333/bpnr-p043
Authors: Farhad Nejat* 1 , Shima Eghtedari 2
1Ophthalmology,Vision health research clinic,Tehran,Iran, Islamic Republic Of, 2Biomedical engineering,Vision health research clinic,Tehran,Iran, Islamic Republic Of
Purpose
To compare the optical biometry measurements obtained by Nidek®️ (Co, Ltd., Gamagori, Japan), Lensstar®️ LS 900 (Haag-Streit, Koeniz, Switzerland) and Aladdin®️ (Topcon, Tokyo, Japan) systems in patients with keratoconus and to evaluate the consistency of these measurements across the three systems.
Setting
This single-center, retrospective study was conducted at the Refractive Surgery Unit of Beyoglu Eye Training and Research Hospital, a tertiary referral center in Istanbul, Turkey.
Methods
The measurements of three different biometers were retrospectively compared in 66 eyes of 66 keratoconus patients (46 males, 20 females). Pairwise comparisons were made for flat keratometry (K1), steep keratometry (K2), corneal astigmatism (CYL), axial length (AL), the lowest target refractive value for a single intraocular lens (IOL) model (MA60AC) and the intraocular lens (IOL) power that could provide this value.
Results
The mean patient age was 30.6 ± 7.10 years (range: 18–45). Significant differences were found among the three devices for K1 (p=0.007), K2 (p<0.001), and IOL power (p<0.001), while AL (p=0.212), CYL (p=0.611), and IOL target (p=0.733) showed no significant differences. Post-hoc analysis revealed significant pairwise differences only for K2. Nidek®️ measured lower K1 values than Lensstar®️ LS 900 (p<0.001), while Aladdin®️ measurements were statistically similar to both (p>0.05). Aladdin®️ showed significant IOL power differences from Nidek®️ (p=0.004) and Lensstar®️ LS 900 (p=0.007), while Nidek®️ and Lensstar®️ LS 900 did not differ (p=0.659). Strong correlations were found for all parameters (p<0.001).
Conclusions
Although the three optical biometers demonstrated strong correlations for all measured parameters in keratoconus patients, significant differences were observed in K1, K2, and IOL power calculations. These discrepancies highlight the need for caution when interpreting biometry data from different devices, particularly in the context of IOL power selection for keratoconus patients undergoing cataract surgery. Standardization or cross-referencing measurements between devices may improve surgical planning accuracy in this challenging patient population.