title: Two-year follow-up of noncontact holmium laser thermokeratoplasty for the correction of low hyperopia.
abstract: OBJECTIVE
  To summarize the 2-year results of laser thermal keratoplasty with a holmium:yttrium-aluminum-garnet (Ho:YAG) laser and the Sunrise Corneal Shaping System and assess the procedure's safety, efficacy and predictability in correcting hyperopia in a phase III clinical intervention case series.
  
  
  METHODS
  The Ho:YAG laser was used to correct low hyperopia (manifest spherical equivalent of +0.75 to +2.50 dioptres [D], with manifest cylinder of 1.00 D or less) in 38 eyes of 28 patients 40 years of age or older. Laser pulses were delivered to the cornea in 2 radially placed, concentric, 8-spot rings 6.0 and 7.0 mm in diameter. The last follow-up was at 2 years.
  
  
  RESULTS
  The preoperative uncorrected visual acuity (UCVA) at distance was less than 20/40 in 82% of the eyes and at near was less than 20/32 in 42%. At 2 years the distance UCVA was 20/40 or better in 100% of the eyes and 20/20 or better in 84%, and the near UCVA was 20/32 or better in 97% of the eyes and 20/20 or better in 8%. The difference between the preoperative and postoperative UCVA was statistically significant (p < 0.01). The correction at 2 years was within 0.50 D of that intended in 92% of the eyes and within 1.00 D in 100%. The reduction in mean spherical equivalent at 2 years was statistically significant (p < 0.0001). No loss of 2 lines or more in best-corrected visual acuity occurred after the 1st month of follow-up.
  
  
  CONCLUSIONS
  The Ho:YAG Sunrise Corneal Shaping System is safe and effective for the treatment of low hyperopia and astigmatism. It provides a predictable refractive outcome at 2 years of follow-up. However, our results show a tendency towards regression by 2 years.
authors.affiliation: Brandon Regional Health Centre, University of Manitoba, Brandon, Man. rochag@westman.wave.ca
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rocha
authors.forename: Juan Miguel
authors.initials: JM
authors.lastname: Castillo
authors.forename: Juan Camilo
authors.initials: JC
authors.lastname: Sánchez-Thorin
authors.forename: Jennifer
authors.initials: J
authors.lastname: Johnston
authors.forename: Rosario G
authors.initials: RG
authors.lastname: Cartagena
mesh_terms: D000328:Adult; D019781:Corneal Topography; D016039:Corneal Transplantation / Q000009:adverse effects; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000473:pathology / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D006979:Hyperthermia, Induced / Q000009:adverse effects; D007431:Intraoperative Complications; D053685:Laser Therapy / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014792:Visual Acuity