Comparison of 2 intrastromal corneal ring segment models in the management of keratoconus.

PURPOSE To compare the outcomes of implantation of 2 models of intrastromal corneal ring segments (ICRS) to manage keratoconus. SETTING Kartal Training and Research Hospital, Istanbul, Turkey. METHODS This study evaluated eyes with keratoconus that had implantation of Keraring ICRS (Group A) or Intacs ICRS (Group B). The corneal tunnels were created mechanically or with a femtosecond laser. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, keratometry (K) readings (Orbscan II), and complications in the 2 groups were compared. RESULTS Group A comprised 100 eyes and Group B, 68 eyes. The postoperative increase in UDVA and CDVA was statistically significant in both groups (P<.05). Group A had greater improvement in CDVA than Group B at 6 months and 1 year (both P<.001). At 1 year, the decrease in the mean maximum K power was statistically significant in Group A (51.27 diopters [D] +/- 4.46 [SD] to 47.87 +/- 3.39 D) and in Group B (51.12 +/- 4.54 D to 47.58 +/- 3.66 D) (P<.05). The mean reduction in maximum K was statistically significantly greater in Group A at 6 months and 1 year (P = .018 and P = .024, respectively). There were no statistically significant differences in visual or refractive results between femtosecond laser and mechanical tunnel creation. CONCLUSION Although both ICRS models were effective and safe in managing keratoconus, the Keraring ICRS led to more improvement in CDVA and UDVA and a greater reduction in the maximum K value.