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 eye. 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 mm in the right eye and 446 mm in left eye. however, post-operative pachymetry decreased to 341 mm in the right and 384 mm in the left eye, but only the right eye revealed progressive corneal ectasia that led to severe visual loss (20/400). conclusion: prk may be 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 mm.