title: Anterior chamber angle biometry with ultrasound biomicroscopy after diode laser thermal keratoplasty.
abstract: OBJECTIVE
  To evaluate the effect of diode laser thermal keratoplasty (DTK) on the geometry of the anterior chamber angle with ultrasound biomicroscopy (UBM).
  
  
  METHODS
  Department of Ophthalmology and Optometry, Paracelsus Private Medical University, Salzburg, Austria.
  
  
  METHODS
  In 9 eyes, a Rodenstock DTK (ProLaser Medical Systems) was used to correct hyperopia (n = 6) or hyperopic astigmatism (n = 3). Hyperopia was treated with a single- or double-ring pattern and hyperopic astigmatism, with additional spots in each of the flat half meridians. Ultrasound biomicroscopy measurements of the chamber angle were obtained preoperatively and 3 months postoperatively using a Humphrey UBM 840 system with a 50 MHz transducer. Quantitative measurements were performed at 3-, 6-, 9-, and 12-o'clock positions using a standardized method.
  
  
  RESULTS
  No statistically significant differences between the preoperative and postoperative chamber angle measurements were detected.
  
  
  CONCLUSIONS
  The results of the UMB measurements were surprising given the flattening of the corneal periphery found by computerized topography, a finding that suggests narrowing of the chamber angle. Shortening of the corneal tissue may result in centripetal traction that affects the trabecular meshwork and results in a relative opening of the chamber angle structures.
authors.affiliation: Department of Ophthalmology and Optometry, St. Johanns-Spital, Landeskliniken Salzburg, Salzburg, Austria. j.stoiber@lks.at
authors.forename: Josef
authors.initials: J
authors.lastname: Stoiber
authors.forename: Johann
authors.initials: J
authors.lastname: Ebner
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hitzl
authors.forename: Josef
authors.initials: J
authors.lastname: Ruckhofer
authors.forename: Günther
authors.initials: G
authors.lastname: Grabner
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D001251:Astigmatism / Q000601:surgery; D001699:Biometry; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D017075:Laser Coagulation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014129:Trabecular Meshwork / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014463:Ultrasonography