Clinical Results of Intacs(R) Ring Implantation in Keratoconus or Keratectasia

ABSTRACT

PURPOSE: To report the clinical results after the implantation of intrastromal corneal ring segments (Intacs(R)) for the correction of keratoconus or keratectasia. METHODS: This retrospective study was comprised of 16 eyes treated by insertion of intrastromal corneal ring and 30 eyes treated by penetrating keratoplasty (PKP) who were diagnosed with keratoconus or keratectasia. Visual acuity, refractive outcome, keratometric values were evaluated before and at 3 months, 6 months, and 12 months postoperatively. In addition, the implanted ring segment depth was measured by anterior segment optical coherence tomography and the results were compared based on the depth of the ring. RESULTS: Twelve months after treatment, best corrected visual acuity (BCVA) was log MAR 0.32 at the ring group and log MAR 0.20 at the PKP group. BCVA change was larger at the PKP group than the ring group. Postoperative keratometric value was smaller at the ring group than at the PKP group. 3 mm irregular astigmatism was larger at the ring group than at the PKP group. The shallowly implanted ring group had a larger effect than the deeply implanted ring group. CONCLUSIONS: Intrastromal corneal ring segment implantation appears to be effective in improving the visual acuity and refractive outcome, although it cannot substitute for PKP.