title: Diode laser thermal keratoplasty for hyperopia and hyperopic astigmatism in patients younger than 40 years.
abstract: OBJECTIVE
  We performed a prospective, nonrandomized investigation of contact continuous wave diode laser thermal keratoplasty (DTK) for correction of hyperopia and hyperopic astigmatism. The goal of surgery was not to achieve emmetropia but to investigate the refractive effect in patients younger than 40 years.
  
  
  METHODS
  Twenty eyes with spherical hyperopia (Group A) and 15 eyes with hyperopic astigmatism (Group B) were treated with two rings; treatment zone diameter of the inner ring was 6 or 7 mm. Each ring consisted of eight spots for hyperopia correction; for astigmatism correction four additional pairs of spots were applied around the flat corneal meridian.
  
  
  RESULTS
  Mean change in manifest spherical equivalent refraction 18 months postoperatively in Group A was 2.00 +/- 0.90 D (Group B, 15 mo, 1.80 +/- 0.60 D). Mean increase in keratometric power was 1.20 +/- 0.60 D (1.30 +/- 0.60 D). Mean refractive astigmatism reduction was 0.10 D (1.70 D). Mean paired differences per month for regression between spherical equivalent manifest refraction/keratometric power was 0.12/0.04 D (0.06/0.05 D) from 9 to 12 months, 0.01/0.04 D (0.06/0.06 D) from 12 to 15 mo, and -0.03/ +/- 0 D from 15 to 18 months. Mean uncorrected visual acuity improved from 20/100 to 20/32 (20/63 to 20/32). No eye lost more than 1 line of BSCVA. The amount of correction showed an age dependency.
  
  
  CONCLUSIONS
  DTK is a minimally invasive, low-risk procedure, and was effective for correction of low hyperopia and low to moderate hyperopic astigmatism in patients less than 40 years.
authors.affiliation: University Eye Hospital Tuebingen, Dept. I, Division Experimental Ophthalmic Surgery, Germany. DEOS@Berret.De
authors.forename: Rudolf
authors.initials: R
authors.lastname: Berret
authors.forename: Benedikt
authors.initials: B
authors.lastname: Jean
authors.forename: Thomas
authors.initials: T
authors.lastname: Bende
mesh_terms: D000328:Adult; D000367:Age Factors; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000601:surgery*; D017075:Laser Coagulation / Q000379:methods*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012449:Safety; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology