Comparison of corneal reconstruction between CASIA2 and Pentacam: Impact on IOL power calculation

This research aims to comprehensively compare the outcomes of anterior segment optical coherence tomography (CASIA2) and Scheimpflug imaging (Pentacam) for computational reconstruction of the anterior and posterior corneal surfaces. A secondary objective is to evaluate their clinical relevance in estimating intraocular lens (IOL) power. Through this analysis, the distinct advantages of each technology are highlighted, providing insights into their complementary roles in enhancing ophthalmic modelling capabilities.

A total of 65 right eyes of 65 subjects (52 females and 13 males) with a mean age of 34 ± 8 years were studied across two separate sessions. Geometric parameters were extracted by fitting a biconic surface to the elevation maps obtained from both devices. Intra- and inter-session variability, as well as inter-device variability, were analyzed. Additionally, IOL power calculations were performed to evaluate the clinical applicability of each imaging system.

For the anterior corneal surface, CASIA2 showed greater intra-session variability compared to Pentacam, whereas Pentacam demonstrated higher variability for the posterior surface. However, inter-session variability was similar for both devices on both surfaces. Inter-device variability revealed close agreement for the anterior surface, while the posterior surface exhibited more variability. On the other hand, while IOL power calculations showed statistically significant differences (Δ = 0.35 D; p < 0.001), these were not clinically significant.

Pentacam may offer greater precision in reconstructing the anterior corneal surface. However, its clinical impact on both anterior and posterior corneal surface reconstruction appears minimal, with both devices providing comparable results for IOL power calculations.