What is the new assessment model that can assist in selecting patients for refractive surgery?
• Theo Seiler in 1998 described iatrogenic ectasia for the first time. It is estimated that between 0.2% and 0.6% develop ectasia. Based on a review of 150 cases, there are four pre-operative factors in order of importance: topography, predicated residual bed thickness, age, and preoperative spherical equivalent. Each factor was given a point score of 1 (with 0 to 2 being a low risk) in which LASIK or PRK could be performed. With patients at moderate risk (level 3), the potential hazards of LASIK must be discussed. At level 4 LASIK is contraindicated. Surface ablation is a low or no risk procedure that requires only topography and pacymetry. Other risk factors should include history of Keratoconus, ocular aberrometry. The 4% occurrence of ectasia after PRK is about the same in eyes that did not have any refractive procedure.
