Association Of Asymmetric Patterns Between Anterior Corneal Topography And Epithelial Thickness Distribution In Suspicious Corneas For Refractive Surgery

Published 2022 - 40th Congress of the ESCRS

Reference: PO482 | Type: Free paper | DOI: 10.82333/cqe9-cd94

Authors: David Smadja* ¹ , Samer Abu Tair ¹ , Itai Lavy ¹ , Jamel Corredores ¹ , Marcony Santhiago ²

¹Ophthalmology,Hadassah Medical Center,Jerusalem,Israel, ²Ophthalmology,Rio University,Rio,Brazil

Purpose

To analyze the association of asymmetric patterns in epithelial thickness distribution and corneal anterior suspicious topography

Setting

Ophthalmology Department

Refractive Surgery Unit

Ein Tal Hadassah Laser Institute

Hadassah University Medical Center

Methods

Retrospective study including 84 eyes labeled as suspicious corneas during refractive surgery screening with corneal asymmetric topographic pattern (Galilei G6, Ziemer Ophthalmics). All the eyes were sent to complementary epithelial thickness mapping evaluation using corneal optical coherence tomography (Optovue Inc., Fremont, CA). Based on the epithelial thickness pattern: The prevalence of corneas screened-out by keratoconus suspicious patterns or screen-in by warpage-like patterns was recorded. The Asymmetric related indices in both, anterior corneal topography and epithelial mapping OCT, were collected and correlations were tested to analyze whether anterior corneal asymmetry was associated to a strong epithelial asymmetric pattern.

Results

Among the asymmetric topographic corneas, 5.74% (5/84) were finally screened out to refractive surgery due to epithelial pattern suggestive of ectasia disease. Among the remaining corneas that finally underwent laser refractive surgery, low to moderate correlations were found between the epithelial asymmetry index (Epi Min-Max) and the corneal asymmetry topography indices such as corneal coma (r = 0.53), I-S ratio (r = 0.43) or surface asymmetry index (r = 0.52). The epithelial thickness standard deviation metrics (Epi SD) was found with stronger correlations (p< 0.05) with the same topography asymmetry indices: r = 0,6, r = 0,47, r = 0,62, respectively.

Conclusions

Although moderate correlations were found between asymmetric anterior corneal topography and epithelial thickness asymmetry, the level of corneal curvature asymmetry observed in non-ectatic suspicious topographies is only partially explained by the epithelial asymmetric pattern.