ESCRS - FP16.04 - Real Corneal Power Analysis Of 387 Eyes After Radial Kerototomy Using Anterior Segment Oct Ms-39

Real Corneal Power Analysis Of 387 Eyes After Radial Kerototomy Using Anterior Segment Oct Ms-39

Published 2024 - 42nd Congress of the ESCRS

Reference: FP16.04 | Type: Free paper | DOI: 10.82333/wspr-4127

Authors: Umberto Camellin* 1 , Massimo Camellin 2 , Ivan Ninotta 3 , Federico Merlin 4 , Gabriele Vizzari 4 , Piero Ceruti 4 , Pasquale Aragona 1

1Ophthalmology,University of Messina,Messina,Italy, 2Sekal Microchirurgia,Rovigo,Italy, 3Ophthalmology,Ophthalmic Hospital of Torino,Torino,Italy, 4Ophthalmology,Hospital of Legnago,Legnago,Italy

Purpose

Radial keratotomy (RK) results in a reduction in anterior and posterior curvatures and an increase in corneal thickness. Therefore, there is an alteration in the relationship between the corneal surfaces and the variation in the corneal power.The variation in corneal power and the high irregularity of the surface of the cornea induce errors in IOL power calculation. This study aimed to assess the evaluation of the relationship between SimK, the total corneal power (TCP) calculated with the Gaussian formula and the mean pupil power measured (MPP) with Ray-Tracing.

Setting

Sekal Microchirurgia Rovigo, Italy

Methods

In this study, the tomographic data obtained using MS-39 (CSO, Italy) were analyzed from 387 eyes of 387 RK patients using anterior and posterior keratometry at 3 mm (SimK, Kpost), central corneal thickness (CCT) and MPP at 3. The calculated total corneal power (TCP) at 3 mm was obtained using the Gaussian formula.

Results

The mean and standard deviation with the MS-39 device were for SimK 36.30 ± 3.09 D, for Kpost -3.89 ± 1.44 D, for TCP 36.62 ± 3.00 D and for MPP 34.69 ± 3.85 D, respectively. Statistically significant differences were found between SimK, TCP, and MMP (p<.001).Significant correlations were observed between SimK and TCP (R2 = 0.8331, p<0.05) and SimK and MPP (R2 = 0.7334, p<0.05). Additionally, significant correlations were observed between MPP and TCP (R2 = 0.5821, p<0.05).

Conclusions

Measurements do not appear to be interchangeable possibly due to posterior flattening of the cornea, changing asphericity and angle Kappa; but linear regression formulae using only anterior surface data (SimK) can predict TCP and MMP with good approximation in eyes with RK in cases where posterior surface parameters are unavailable. In conclusion, flattening of the posterior surface affects the real power of the cornea in RK eyes.