گزارش وقوع كراتكتازي پس از ليزيك و عدم وقوع آن پس از كراتكتومي فوتورفركتيو در دو چشم يك بيمار

Keratectasia after LASIK versus PRK: A Case Report

Purpose: To report a case who had undergone LASIK in his right eye and PRK in the fellow eye for correction of equivalent myopia but developed progressive post-operative keratectasia only in the right cyc. Patient and findings: A 30-year-old man had undergone LASIK in right eye 3 years ago for correction of refractive error of -1.75 -1.50@48° and PRK in left eye 2 years ago for correction of refractive error of -1.00 -1.75@100°. Preoperative pachymetry was 447 p.m in the right eye and 446 pm in left eye. However, post-operative pachymetry decreased to 341 pm in the right and 384 p.m in the left eye, but only the right eye revealed progressive corneal ectasia that led to severe visual loss (20/400). Conclusion: PRK may he a better choice for surgical correction of low amounts of myopia due to lack of flap creation; a factor that may weaken the anterior corneal structure and subsequently lead to progressive keratectasia. However, it is prudent to avoid any refractive surgery in eyes with central corneal thickness less than 500 p.m.