Association Between Epithelial Mapping And Corneal Stress Strain Index In Keratoconus

To study association between epithelial mapping and SSI in keratoconus patients

Private Eye Hospital, India

A retrospective study where subjects diagnosed with keratoconus were enrolled. Subjects with any systemic illness, previous corneal surgery, missing data, poor quality scans were excluded. For all Subjects, corneal stress strain index and corneal epithelial mapping were measured by CORVIS ST and Anterior segment OCT respectively. Pearson correlation was done to assess the relationship between epithelial mapping and SSI. 

59 eyes of 29 patients who had undergone Corvis ST and anterior segment OCT were included. Mean±Sd IOP and pachy were 14.3±2.23 and 475.92 ±37.16.  Mean±Sd central epithelial thickness and SSI were 52.27±5.85 microns and 0.75 ±0.16.  We noted significant positive association of SSI with epithelial thickness at central 2mm (p<0.001), inferonasal (p=0.040), inferotemporal (p=0.005) and temporal (p=0.005) location at 2-5mm. Peripheral epithelial thickness (5-7mm) quadrants did not show any association with SSI (p>0.05). Also, no association was noted between SSI and standard deviation of epithelial thickness (r= -0.20, p=0.06).

We noted significant association between corneal SSI and corneal epithelial thickness in eyes with keratoconus. This also suggests that epithelial mapping could be helpful adjunct to detect eyes with poor corneal biomechanics.