Posters

A study of relation between anterior and posterior corneal astigmatism across age groups in the Indian population

Poster Details

First Author: T.Haldipurkar INDIA

Co Author(s):    S. Haldipurkar   V. Shetty   M. Setia              

Abstract Details

Purpose:

Corneal astigmatism is a collective contribution of anterior and posterior curvature, thickness, and refractive indices. The purpose of this study is to estimate the mean posterior corneal astigmatism (PCA) and its relation with anterior corneal astigmatism (ACA).

Setting:

The study was conducted in Laxmi Eye Institute, Panvel, Maharashtra, India.

Methods:

This is a cross-sectional study of 392 eyes from 215 patients. We obtained Scheimpflug analyzer scans in patients with no ocular injury, surgery, and active corneal disease. We classified the axis as: oblique; with the rule; and against the rule. We used vector analysis to calculate the mean ACA and PCA across age groups, and linear regression models to assess the relation between them.

Results:

The mean ACA and PCA was 0.195 D × 89.44º and 0.016 D × 89.34º respectively. The mean ACA (1.824 D × 89.57º) and PCA (0.188D × 0.24º) was highest in young children (5-9 years).The agreement between direction of ACA and PCA axes was maximum in younger (87%, 95% CI: 78% - 93%) and minimum in older (32%, 95% CI: 19%-48%) age groups. One Diopter increase in ACA was associated with increase of 0.145 D (95% CI: 0.125 to 0.165) in PCA in younger age group and 0.053 D (95% CI: 0.022 to 0.083) in older age group.

Conclusions:

Though there is an association between the PCA and ACA, the relationship is not similar across age groups. Thus, age-specific models should be used for predicting PCA from the ACA values. These will be useful for an estimation of the PCA before any refractive intervention to provide good visual and structural outcomes.

Financial Disclosure:

NONE