Comparison of Anterion, MS-39, Pentacam, and Sirius in Corneal Assessment Prior to Refractive Surgery.

Abstract

Background: Accurate corneal evaluation is crucial for determining candidacy for refractive surgery.Devices combining diverse technologies, such as Scheimpflug imaging (Pentacam, Sirius), swept-source OCT (Anterion), and hybrid OCT/Placido systems (MS-39), offer distinct advantages and limitations in screening.

Purpose: This study was conducted to compare corneal assessment with two Scheimpflug camera devices (Oculus Pentacam and CSO Sirius) and two spectral domain anterior segment optical coherence tomography devices (Heidelberg Engineering Anterion and CSO MS-39) in the preoperative screening of the cornea before refractive surgery.

Methods: In this retrospective, consecutive case series, we enrolled 110 patients undergoing refractive surgery. Simulated keratometry (Sim-K), posterior keratometry (PK), central corneal thickness (CCT), keratometric astigmatism magnitude (KAM), Corneal diameter, Anterior chamber depth (ACD), and total corneal power (TCP) were compared using different instruments. To compare the mean values of the measurements, a repeated measures ANOVA was used.

Results: Simulated keratometry (Sim-K), central corneal thickness (CCT), keratometric astigmatism magnitude (KAM), and total corneal power (TCP) showed a good agreement (ICC > 95%, ANOVA p > 0.05). Although posterior keratometry (PK) showed no significant differences, its Cronbach's alpha and ICC were low, indicating limited agreement. Corneal diameter showed moderate to poor ICC (p<0.001). Anterior chamber depth (ACD) showed the highest values when assessed with the Anterion; however, the results did not show a statistical significance (p > 0.05).

Conclusion: Both Scheimpflug camera devices and AS-OCT were suitable instruments for evaluating the cornea before refractive surgery. A strong correlation was seen for Sim-K, CCT, CD, and TCP; however, notable discrepancies were identified in posterior keratometry, astigmatism magnitude, and ACD. These findings underscore the importance of device-specific factors in assessing corneal and anterior segment measures during refractive surgery evaluations.