Long term outcome of Intrastromal corneal ring segment in keratoconus

Abstract

PurposeThe Intrastromal corneal ring segment (ICRS) has been widely used to correct the astigmatism and to halt the progression in keratoconus. Although short term outcomes are well known to be effective, long term outcomes have been rarely reported and showed no consensus. Therefore, we planned to evaluate the effectiveness of ICRS in keratoconus for 5 years.MethodsThe retrospective chart review was done. In total, 23 eyes of keratoconus which received ICRS were included. Visual acuity, refraction, keratometer, thinnest corneal thickness and higher order aberration were evaluated at preoperative, 2 months, 1 year, 3 years and 5 years of postoperative day.ResultsBoth uncorrected (UCVA) and best corrected visual acuity (BCVA) was improved at 1 year and maintained until 3 years (p < 0.05). UCVA worsened at 5 years but similar to preoperative measurement. On the other hand, BCVA maintained until 5 years (p < 0.05). Spherical equivalent and anterior corneal keratometer were improved at 2 months and maintained until 3 years, but it was worsened similar to preoperative level (p < 0.05). Vertical coma was improved consistently for 5 years (p < 0.05).ConclusionsBoth Refractive and topographic findings were improved at 2 months and the effect was maintained until 3 years. Although both of it have worsened at 5th year, the level of the measurements was not worsen than that of the preoperative day. The ICRS in keratoconus is effective in correcting astigmatism and visual acuity for 3 years and also helpful in halting the progression for 5 years.