Comparison of deep anterior lamellar keratoplasty and intrastromal corneal ring segment implantation in advanced keratoconus

Abstract

To compare the visual and refractive results in eyes with advanced keratoconus having deep anterior lamellar keratoplasty (DALK) with those having intrastromal corneal ring segment (ICRS) implantation. Dr. Lütfi Kırdar Kartal Training and Research Hospital, Istanbul, Turkey. Comparative case series. Records of advanced keratoconus patients with a clear central cornea and contact lens intolerance who had DALK or ICRS implantation were reviewed. Preoperatively and after 24 months, the uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and Orbscan II keratometry (K) readings in the 2 groups were comparable. The DALK group comprised 36 eyes and the ICRS group, 30 eyes. Both groups had a statistically significant increase in UDVA and CDVA from preoperatively to 24 months postoperatively (P<.001). The DALK group had a statistically significantly greater improvement in UDVA and CDVA than the ICRS group 24 months postoperatively (P<.001). The improvement in spherical equivalent (SE) refractive error, manifest sphere, and manifest cylinder was statistically significant in both groups (P<.001). The mean reduction in SE and manifest cylinder were significantly greater in the DALK group (P<.05). The postoperative reduction in the maximum and minimum K values was statistically significant in both groups (P<.001); the mean reduction in K values was significantly greater in the DALK group (P<.001). Although DALK provided greater improvement in visual acuity and refractive errors in advanced keratoconus cases, ICRS implantation may be an alternative treatment with satisfactory outcomes and less visual impact.