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

Objective: To compare the outcomes of implantation of 2 models of intrastromal corneal ring segments (ICRS) to manage keratoconus.

Methods: 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.

Conclusions: 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.