Posters

Asymmetry in severity of corneal tomographic abnormality between right and left eye in patients with keratoconus

Poster Details

First Author: K.Yatsui JAPAN

Co Author(s):    N. Maeda   R. Toda   M. Fuchihata   S. Koh   M. Tsujikawa   K. Nishida     

Abstract Details

Purpose:

Asymmetry of the corneal shape is one of the most important findings for detecting keratoconus. Although keratoconus is generally bilaterally involved, disparity in keratoconus severity is frequently observed. The severity of corneal tomographic abnormality was compared between the right and left eye in patients with keratoconus using anterior segment optical coherence tomography (OCT).

Setting:

This study included 560 eyes of 280 patients with keratoconus (KC group) and a control of 100 eyes of 50 normal subjects (control group).

Methods:

Corneal tomography was conducted with the swept-source OCT (CASIA®, TOMEY Corporation, Japan). Tomographic indices including simulated keratometric readings (SimKs, SimKf, SimCYL, and AveK), average central corneal power 3 mm (ACCP), anterior and posterior eccentricity, anterior and posterior best-fit-sphere, corneal thickness (apex, thinnest point), and the locations of the apex and thinnest point from the corneal vertex were obtained. The differences between severe eye and mild eye in these tomographic indices were compared in both groups.

Results:

The differences of all indices between the severe eyes and mild eyes were significantly larger in the KC group than in the control group (P < 0.05, unpaired t-test). When the difference between the eyes was outside the mean ± 2 SD of the difference in each index for the control group, it was defined as asymmetry. The highest asymmetry was for ACCP (88.2%), and the lowest asymmetry was for the location of the thinnest point (22.5%).

Conclusions:

Keratoconus does not only involve an asymmetry of the corneal tomography in the eye but also reveals an asymmetry in the severity of the corneal shape between both eyes. Comparison of the corneal tomography between the right and left eye may be useful for the early keratoconus diagnosis.

Financial Disclosure:

NONE