Long Term Outcomes Of Intra-Corneal Ring Segments

To assess the long term visual and topographic outcomes of intra-stromal corneal ring segment  (ICRS) implantation in patients of keratoconus

Tertiary eye care centre 

A retrospective record review was performed for all cases that underwent ICRS implantation between 2011 to 2016 for which >5 year follow up data was available. The baseline uncorrected vision (UCVA), best corrected visual acuity (BCVA) with glasses, cycloplegic and manifest refraction, intra-ocular pressure, slit lamp examination finding and fundus findings were recorded. Corneal topography data (Pentacam HR, OCULUS, Wetzlar,Germany) were  entered in Excel spreadsheet. The follow up data of 1 month, 1 year, 3 year, 5 year and 10 year (if available) were recorded for comparison with baseline. Intra-operative and post-operative complications if any were noted.

25 eyes of 21 patients underwent ICRS with corneal cross-linking for keratoconus. The mean age of patients was 25.8 ±5.5 years. The mean follow up duration was 7.1 years (range 5 years to 11 year). The mean sphere, cylinder and manifest refractive spherical equivalent changed from -1.4 D, -3.8 D and -3.35 D at baseline to -1.29 D, -2.8D and -2.6 D at final follow-up (p<0.05). The mean keratometry and Kmax showed a significant improvement from 49.1D and 58.6D at baseline to 46.8 and 55.5D at final follow-up. The best corrected visual acuity (BCVA) improved from 0.29 logmar at baseline to 0.19 logMAR at final follow-up. Three cases underwent ICRS explant due to corneal melt. None of the cases had a loss of BCVA at final follow-up

Intra-corneal ring segment implantation results in significant improvement in visual and topographic outcomes in keratoconus patients.