title: Corneal ectasia after photorefractive keratectomy.
abstract: BACKGROUND
  Corneal ectasia after photorefractive keratectomy (PRK) has only been occasionally reported, and its incidence has not been assessed.
  
  
  METHODS
  In a retrospective, non-comparative case series, incidence of corneal ectasia was evaluated in a personal consecutive 6453-case series of myopic PRK with a minimum follow-up of 18 months. Features and prognosis were evaluated in all patients with ectasia after PRK (in both personal and referred cases).
  
  
  RESULTS
  Ectasia was detected in three eyes of two patients (patients 1 and 2) 3 years and 1 year after PRK performed elsewhere. In addition, in the personal PRK series, two eyes of two patients (patients 3 and 4) developed corneal ectasia 5 months after surgery (incidence: 0.03%). Pre-operatively, forme fruste keratoconus was present in patients 1, 3 and 4; keratoconus in the fellow eye in patient 2; pachymetry <500 micron in patients 2 and 3. In patient 1, rigid contact lenses were prescribed, and in patient 2 deep anterior lamellar keratoplasty was needed; in patients 3 and 4, low induced astigmatism resulted, requiring driving spectacles in patient 3.
  
  
  CONCLUSIONS
  PRK induced corneal ectasia in predisposed eyes, even after low myopic ablations. Forme fruste keratoconus and keratoconus in the fellow eye were the main pre-operative findings. Prognosis varies according to severity.
authors.affiliation: Ophthalmic Surgery Unit, Casa di Cura Rugani, Piazza 5 Bersaglieri 2, Siena, Italy. leccisotti@libero.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Leccisotti
mesh_terms: D000328:Adult; D003261:Contact Lenses; D003315:Cornea / Q000473:pathology*; D003316:Corneal Diseases / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D019781:Corneal Topography; D016039:Corneal Transplantation; D004108:Dilatation, Pathologic / Q000175:diagnosis / Q000209:etiology; D005139:Eyeglasses; D005260:Female; D006801:Humans; D015994:Incidence; D007640:Keratoconus / Q000175:diagnosis; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D014792:Visual Acuity