Comparison Of Epithelial And Total Corneal Aberrations In Normal And Abnormal Nibut

To correlate non invasive breakup time (NIBUT) with epithelial and total corneal aberrations in patients with normal and abnormal NIBUT group.

Nethradhama Super speciality Eye Hospital, Bangalore, India.

A total  of 104 eyes of 104 patients (n=52 eyes in each group) were enrolled. Based on the NIBUT value , eye were divided into 2 groups normal (NIBUT ≥10.1sec) and abnormal (NIBUT ≤10 sec). Both the groups were compared for epithelial and total corneal aberrations using OCT- based corneal tomographer (MS_39, CSO, Italy).

The mean NIBUT(sec) in normal group was 17.37 ±1.69 and in abnormal group was 6.33 ±1.79 and difference was statistically significant (p < 0.00). The epithelial HOA (0.18± 0.11) and corneal HOA (0.16± 0.09) of abnormal group was found more than epithelial HOA (0.16± 0.06) and corneal HOA(0.14± 0.06) of normal NIBUT group but the result was not statistically significant. On individual group analysis, spherical aberrations (SA) was mainly contributed by epithelium, irrespective of normal or abnormal NIBUT. In normal group epithelial and corneal SA was 0.06± 0.04 and 0.04± 0.02 (p< 0.00) while in abnormal NIBUT group it was 0.07± 0.05 and 0.04± 0.03 respectively (p< 0.00). The major contributor of total corneal aberrations was from epithelium.

In this study with limited sample size, non invasive tear break up time did not significantly appear to effect either epithelial or total corneal aberrations. Total HOA and SA appears to be mainly contributed by the epithelium, this might have an clinical implication in pre operative decision making for refractive surgery and cataract surgery with premium IOL.

 

Finanacial Disclosure: Dr Sri Ganesh and Dr Sheetal Brar are consultants for Carl Zeiss Meditec.