Intrastromal corneal ring segments for advanced keratoconus and cases with high keratometric asymmetry.

PURPOSE: To report the safety and efficacy of intrastromal corneal ring segment (ICRS) implantation to manage keratoconus.

SETTING

Singleton Hospital Abertawe Bro Morgannwg University NHS Trust, Swansea, United Kingdom

DESIGN

Case series.

METHODS

Intacs SK ICRS were implanted manually for moderate to severe keratoconus and contact lens intolerance or ineffectiveness. Postoperative examinations were at 2 and 4 weeks; 3, 6, 9, and 12 months; and every 6 months thereafter. Outcome measures included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, corneal topography, and slitlamp examination.

RESULTS

This study enrolled 31 eyes (29 patients; mean age 30 years). The mean UDVA was significantly better 12 months postoperatively (0.88 logMAR) than preoperatively (1.40 logMAR) (P=.001), as was the mean CDVA (0.29 logMAR versus 0.44 logMAR) (P=.04). The mean spherical equivalent was -6.57 diopters (D) preoperatively and -2.84 D at 12 months (P=.01). The mean keratometry (K) reading decreased from 52.07 D (range 45.9 to 63.1 D) to 46.15 D (range 39.2 to 52.9 D) for K1 (P<.0001) and from 57.9 D (range 52.5 to 69.7 D) to 51.2 D (range 46.8 to 58.3 D) for K2 (P<.0001). There were no intraoperative complications; however, 6 patients had segment extrusion.

CONCLUSION

Implantation of ICRS was useful in managing keratoconus, producing up to 12.00 D of corneal flattening, which improved CDVA and allowed contact lens tolerance in all cases.