title: Visual acuity after Gamma-Knife radiosurgery of choroidal melanomas.
abstract: OBJECTIVE
  To report on conservation of visual acuity after Gamma-Knife radiosurgery of choroidal melanoma.
  
  
  METHODS
  A total of 189 patients with choroidal melanoma were treated with Gamma-Knife stereotactic single-fraction radiosurgery at a single institution between June 1992 and May 2010. The main outcome measure of our retrospective analysis was conservation of pretreatment visual acuity of 20/40 or better, 20/200 or better and counting fingers (CF) or better, over time of follow-up. Patient, tumour and treatment parameters were evaluated as potential risk factors for visual loss.
  
  
  RESULTS
  Five years after treatment, the actuarial probability of keeping visual acuity better than 20/40, 20/200 and CF was 13%, 14% and 36%, respectively. The majority of patients (84.7%) encountered a deterioration of vision after treatment. The most important risk factors for visual loss were tumour height, longest basal diameter, distance to the optic disk and/or foveola, and retinal detachment before treatment. Treatment dose, and patient characteristics (age, sex, concurrent systemic diseases) were less important. Local tumour control rate was 94.4% after a median follow-up of 39.5 months.
  
  
  CONCLUSIONS
  Visual outcome after single-fraction Gamma-Knife radiotherapy is comparable with linear accelerator (LINAC) based fractionated stereotactic radiotherapy, inferior to proton beam radiotherapy, and depends primarily on tumour size, location and pre-existing retinal detachment.
authors.affiliation: Department of Ophthalmology, Medical University Graz, Auenbruggerplatz, Graz 4A-8036, Austria. werner.wackernagel@medunigraz.at
authors.forename: Werner
authors.initials: W
authors.lastname: Wackernagel
authors.forename: Etienne
authors.initials: E
authors.lastname: Holl
authors.forename: Lisa
authors.initials: L
authors.lastname: Tarmann
authors.forename: Alexander
authors.initials: A
authors.lastname: Avian
authors.forename: Mona Regina
authors.initials: MR
authors.lastname: Schneider
authors.forename: Karin
authors.initials: K
authors.lastname: Kapp
authors.forename: Gerald
authors.initials: G
authors.lastname: Langmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002830:Choroid Neoplasms / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008545:Melanoma / Q000503:physiopathology / Q000601:surgery*; D008875:Middle Aged; D011184:Postoperative Period; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult