Background: The advantages of the Intrastromal Corneal Ring Segments (ICRS) as compared to the frequently used methods for the correction of low to moderate myopia (RK, PRK, LASIK) are the intact optical zone and nearly complete reversibility.
Patients and methods: Two ICR-Segments, made of PMMA (with an arc length of 150 degrees each) are placed in the deep stromal layers via a small radial incision. At the Landesaugenklinik Salzburg 25 continuous surgeries were performed as part of the European "MECCA-trial".
Results: Refractive results, intra- and postoperative complications with a follow-up of 12 months are presented. There was no visual loss after one year. In 40% (10/25) the best corrected visual acuity remained unchanged. In 56% (14/25) one line was gained, once two lines were gained. The spherical equivalent was slightly in the range of undercorrection--as wanted. The refractive astigmatism increased (0.5 dpt). The keratoscopy image showed positive aspheric appearance.
Conclusion: The ICRS (Kera Vision Ring) seems to offer a precise and stable method to correct low myopia. The procedure is reversible to a large extent, potentially adjustable within certain limits and carries a minimal risk only. Although long-term follow-up is not available yet, initial results of the technique seem very promising.