Posters

Comparison of the quality of vision in patients with keratoconus with astigmatic correction on topographic versus coma axis

Poster Details

First Author: M.Henriquez PERU

Co Author(s):    G. Hernandez Sahagun   J. Lopez Aliendres   R. Almeida   A. Mercado   C. Maldonado   L. Izquierdo Jr     

Abstract Details

Purpose:

To evaluate and compare quality of vision by measuring objective light scatter index (OSI) and objective optical quality (Strehl ratio and modulation transfer function cutoff frequency [MTF]) in subjects with keratoconus with astigmatic correction on topographic versus coma axes.

Setting:

Oftalmosalud Eye Institute

Methods:

Prospective, cross-sectional study, included 41 eyes with keratoconus between June to October 2019 at Oftalmosalud Institute de Ojos, Peru. Keratoconus eyes without any treatment were included. All patients underwent slit lamp examination, visual acuity (VA), refraction and quality of vision assessment with the HD Analyzer (Visiometrics) and Scheimpflug imaging. Statistical analysis was performed with R program using Kruskal-Wallis test. Patients were evaluated in two scenarios with astigmatic correction based on topographic axis versus astigmatic correction based on coma axis.

Results:

Mean best corrected visual acuity was 0.091 ± 0.139 and 0.119 ± 0.144 LogMAR when astigmatic correction was performed on topographic and coma axis respectively (p= 0.012). Mean OSI was 3.539 ± 2.987 and 3.688 ± 2.954 when astigmatic correction was performed on topographic and coma axis respectively (p= 0.014). Mean Strehl was 0.119 ± 0.064 and 0.111 ± 0.052 when astigmatic correction was performed on topographic and coma axis respectively (p= 0.292).

Conclusions:

Better quality of vision is achieved when the coma axis is used to correct astigmatism instead of topographic axis in keratoconus patients.

Financial Disclosure:

None