title: Phototherapeutic keratectomy for granular and lattice corneal dystrophies at 1.5 to 4 years.
abstract: BACKGROUND
  The capability of the 193-nm excimer laser to ablate the cornea and to remove opacities and various other corneal diseases in a procedure called phototherapeutic keratectomy (PTK) has been demonstrated. In this study we evaluated the long-term results of PTK for treatment of granular and lattice corneal dystrophies.
  
  
  METHODS
  Four eyes with granular or lattice corneal dystrophy were treated with a mean follow-up of 47.8 months (range, 36 to 58 months). Focal ablations of the central cornea with an ablation zone of 5.5 to 6.0 mm were performed. Ablation depth was 110 microns in three eyes and 140 microns in one eye.
  
  
  RESULTS
  Removal of corneal opacities allowed for improvement in corrected visual acuity in all patients. Mean corneal thickness in the area of pathology decreased from 0.583 mm before surgery to 0.449 mm after surgery. Spherical equivalent of the manifest refraction measurements increased by a mean of +5.09 D. There were no major complications, but all patients developed slight haze. There was a hyperopic shift in three eyes.
  
  
  CONCLUSIONS
  Our long-term results suggest that PTK is a safe and effective alternative to penetrating and lamellar keratoplasty in patients with granular or lattice corneal dystrophies.
authors.affiliation: Doheny Eye Institute, Los Angeles, Calif 90033, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Nassaralla
authors.forename: J
authors.initials: J
authors.lastname: Garbus
authors.forename: P J
authors.initials: PJ
authors.lastname: McDonnell
mesh_terms: D000328:Adult; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D003317:Corneal Dystrophies, Hereditary / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy / Q000379:methods*; D016896:Treatment Outcome; D014792:Visual Acuity; D014945:Wound Healing