Posterior corneal features in normal and subclinical keratoconus

Session Details

Session Title: Imaging Anterior Segment

Session Date/Time: Sunday 08/10/2017 | 16:00-18:00

Paper Time: 16:58

Venue: Meeting Center Room I

First Author: : D.Smadja ISRAEL

Co Author(s): :    O. Golan   E. Levinger   M. Santhiago   D. Varssano           

Abstract Details

Purpose:

To compare the posterior corneal features and their discriminating power for differentiating normal corneas from form fruste keratoconus using Placido-Dual Scheimpflug analyzer

Setting:

Tel Aviv Sourasky Medical Center, Tel Aviv

Methods:

A total of 201 normal corneas of 104 subjects with a stable postoperative LASIK follow-up of 36 months were imaged with a Placido-Dual Scheimpflug system and compared to 39 contralateral topographically normal eyes of clinically evident keratoconus in the fellow eye. The posterior surface variables measured were categorized according to the feature of the corneal shape they were characterizing (curvature, elevation, asymmetry and eccentricity) and compared between the two groups using Student two-sample t test.

Results:

Variables that related to asymmetry and elevation of the posterior surface were statistically significantly different between both groups (p<0.05), whereas eccentricity and curvature-related parameters were not significantly different. The posterior I-S value and the Asphericity Asymmetry Index (AAI) were both related to asymmetry and were the variables with the highest area under the curve (AUROC) for differentiating normal corneas and form frust keratoconus, with respectively, 0.88 and 0.96.

Conclusions:

Posterior cornea measured with a dual Scheimpflug Analyzer provides useful parameters for differentiating normal corneas from form fruste keratoconus. Asymmetry seems to be the most sensitive shape modification for differentiating both populations.

Financial Disclosure:

receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented, receives consulting fees, retainer, or contract payments from a competing company