Topography and Higher Order Corneal Aberrations of the Fellow Eye in Unilateral Keratoconus

Abstract

Objectives: Comparison of topography and corneal higher order aberrations (HOA) data of fellow normal eyes of unilateral keratoconuspatients with keratoconus eyes and control group.Materials and Methods: The records of 196 patients with keratoconus were reviewed. Twenty patients were identified as unilateralkeratoconus. The best corrected visual acuity (BCVA), topography and aberration data of the unilateral keratoconus patients’ normal eyeswere compared with their contralateral keratoconus eyes and with control group eyes. For statistical analysis, flat and steep keratometryvalues, average corneal power, cylindrical power, surface regularity index (SRI), surface asymmetry index (SAI), inferior-superior ratio(I-S), keratoconus prediction index, and elevation-depression power (EDP) and diameter (EDD) topography indices were selected.Results: Mean age of the unilateral keratoconus patients was 26.05±4.73 years and that of the control group was 23.6±8.53 years(p>0.05). There was no statistical difference in BCVA between normal and control eyes (p=0.108), whereas BCVA values were significantlylower in eyes with keratoconus (p=0.001). Comparison of quantitative topographic indices between the groups showed that all indicesexcept the I-S ratio were significantly higher in the normal group than in the control group (p