Corneal Collagen Crosslinking for Ectasia after Refractive Surgery.

The development of corneal ectasia has been recognized as a complication after LASIK since the first case report from Seiler and Quurke in the late 1990s. The clinical picture of iatrogenic corneal ectasia resembles that of progressive keratoconus with reduced corneal biomechanical strength, increasing central corneal steepness, irregular refractive errors, and decreasing visual acuity. Since the first reports, the phenomenon has gained substantial scientific interest, and more than 500 articles have been published on the subject. Ways to reduce the risk for this complication include avoiding cases with too high myopia and forme fruste/manifest keratoconus, and leaving sufficient residual stroma after the LASIK treatment. Despite taking these and other safety measures, however, iatrogenic ectasia keeps occurring also in cases with lower myopia, cases without any obvious preoperative signs of keratoconus, and even after photorefractive keratectomy. An early 2000 review from Sugar et al concluded that treating low-grade myopia with LASIK is predictable and