This study of 16 keratoconus patients aimed to investigate the impact of long-term scleral contact lens (ScCL) wear on corneal curvature, corneal thickness, tear film function and ocular surface in patients with keratoconus. Corneal topography, tear osmolarity test, Schirmer 1 test, tear film break-up time (TBUT) test, and impression cytology analysis were assessed at baseline and follow-up examinations following six months of ScCL use. There was no significant change in visual acuity, keratometric and pachymetric values after six months of ScCL wear (p>0.05 for all). Tear osmolarity, Schirmer 1 test, and TBUT test results showed no significant change during follow-up (p>0.05 for all). Median goblet cell density and grade of squamous metaplasia did not differ significantly at one month. However, there was a gradual deterioration in goblet cell density and Nelson grade until the third-month visit compared to baseline (p for goblet cell, p=0.003; p for Nelson grade, p=0.003). These changes persisted at six-month visit (p for goblet cell, p=0.008; p for Nelson grade, p<0.001). As such, the authors concluded that six months of ScCL wear did not induce any changes in corneal curvature and thickness and also did not affect tear function tests in keratoconic eyes. However, they observed a decrease in goblet cell density and metaplastic changes in conjunctival epithelium in impression cytology analysis, recommending further investigations to understand reasons for this and its clinical implications.
