Diagnosis and management of postrefractive surgery ectasia.

Postrefractive surgery ectasia is a serious, sight-threatening complication seen after the following procedures: laser in situ keratomileusis, photorefractive keratectomy, small-incision lenticule extraction, radial keratotomy, and/or arcuate keratotomy. Specific risk factors may include age, corneal thickness, degree of refractive error, corneal topographic changes including irregular astigmatism, percent tissue ablation, and residual stromal bed. Biomarkers may be a new option to help indicate who is at greatest risk for ectasia. Visual aids including spectacles or contacts lenses are often required to achieve optimal vision. Collagen crosslinking is the only treatment believed to stop progression of ectasia and prevent keratoplasty. Other surgical options may include topography-guided phototherapeutic keratectomy and intrastromal corneal ring segments. Ultimately, an "ounce of prevention is a pound of cure," so careful preoperative screening and ultimately offering the safest and most effective treatments for patients is arguably the most important job of the refractive surgeon.