Intrasubject repeatability of epithelial thickness and its relation to visual acuity in keratoconus patients

Session Details

Session Title: Presented Poster Session: Corneal Cross-Linking

Venue: Poster Village: Pod 3

First Author: : A.Vega-Estrada SPAIN

Co Author(s): :    M. Mimouni   E. Espla   J. Alió Del Barrio   J. Alió              

Abstract Details

Purpose:

To evaluate intra-subject repeatability of anterior segment optical coherence tomography (AS-OCT) combined with placido disc MS-39 (CSO, Firenze, Italy) and correlate epithelial thickness measurements and the degree of visual limitation in keratoconus patients.

Setting:

Vissum Innovation, Alicante. Spain

Methods:

Prospective, observational, clinical study including167 eyes of which 107 were from keratoconus patients and 60 were healthy. Three repeated consecutive epithelial thickness measurements were taken: central 3.0 mm and the nasal, temporal, superior, and inferior regions at 3.0-6.0 mm and 6.0-8.0 mm. Intra-subject repeatability of epithelial indices was assessed and correlated to the degree of corrected visual acuity (BCVA)

Results:

The intraclass correlation coefficient was ≥ 0.90 indicating highly repeatable measurements for both keratoconus and healthy eyes. In multivariate analysis, epithelial indices associated with worse BCVA were: thinner 3mm central (p=0.04), thicker 8mm superior (p<0.001) and thinner 8mm inferior (p<0.001). Thickness central 3mm decreased as keratoconus grading increased (p=0.002). The superior-inferior ratio at 8mm significantly increased as keratoconus grading increased (p<0.001). Multivariate analysis thinner 3mm central (R2=6.19%, p=0.04), greater superior-inferior 8mm ratio (R2=8.37%, p=0.004), greater superior-inferior 6mm ratio (R2=2.67%, p=0.02), and steeper K2 (R2=21.51%, p<0.001) were associated with keratoconus with combined area under the curve of 0.92.

Conclusions:

High repeatability of epithelial thickness measurements may be achieved in both keratoconus and healthy eyes with the MS-39. There is a significant correlation between epithelial thickness measurements and BCVA. These measurements may be of additional value in discriminating between keratoconus and healthy eyes.

Financial Disclosure:

None