Comparison Of Corneal Parameters In Healthy Subjects Using Placido-Based, Scheimpflug-Based, And Combined Placido-Scheimpflug-Based Corneal Topography Systems
Published 2025 - 43rd Congress of the ESCRS
Reference: PO768 | Type: Free paper | DOI: 10.82333/qq88-2v43
Authors: Dan Reinstein* 1 , Timothy Archer 2 , Joseph Potter 2 , Ruchi Gupta 2
1Centre Hospitalier National d’Ophtalmologie,Paris,France;London Vision Clinic,London,United Kingdom;Columbia University Medical Center,New York,United States, 2London Vision Clinic,London,United Kingdom
Purpose
To compare corneal topography measurements obtained by Placido-based (Aladdin®️ Topcon, Tokyo, Japan), Scheimpflug-based (Pentacam®️ Oculus, Wetzlar, Germany) and combined Placido-Scheimpflug-based (Sirius®️ Costruzione Strumenti Ophthalmici, Florence, Italy) systems in healthy subjects and to evaluate the consistency of these measurements between the three systems.
Setting
This single-center, observational cross-sectional study was conducted at Refractive Surgery Unit of Beyoglu Eye Training and Research Hospital, a tertiary referral center in Istanbul, Turkey.
Methods
Corneal topography measurements obtained from three different devices were analyzed in 72 eyes of 36 healthy subjects. The parameters compared included flat keratometry (K1), steep keratometry (K2), anterior chamber depth (ACD), central corneal thickness (CCT), and white-to-white distance (WTW).
Results
Mean age of the patients was 30.16±6.12(range,24to45 years).ACD (p<0.001),CCT (p=0.009),and WTW (p<0.001) differed significantly across devices.By contrast, neither K1 (p=0.388)nor K2 (p=0.397)showed significant differences across the three devices.Post-hoc comparisons indicated that all pairwise comparisons were significant for WTW (each p<0.001).For ACD,measurements from Aladdin differed significantly from both Pentacam (p<0.001)and Sirius (p<0.001),while Pentacam and Sirius did not differ significantly(p=0.386).Aladdin measured significantly thicker CCT than Pentacam and Sirius(both p<0.05),but Pentacam and Sirius didn't differ(p=0.513).Correlation analyses showed strong agreement among all three devices for each parameter(each p<0.001).
Conclusions
In conclusion, while strong correlations were observed between the three devices for most topographic parameters in healthy subjects, the Placido-based Aladdin®️ device yielded significantly higher values for anterior chamber depth (ACD) and central corneal thickness (CCT) compared to the Scheimpflug-based devices. Clinicians should consider these discrepancies when interpreting data from different corneal topography systems, particularly in patients undergoing refractive surgery or phakic intraocular lens implantation.