title: Radiotherapy for recurrent choroidal neovascularisation complicating age related macular degeneration.
abstract: OBJECTIVE
  To report the safety and visual outcome data of external beam irradiation for recurrent choroidal neovascularisation complicating age related macular degeneration.
  
  
  METHODS
  Eighteen consecutive eyes received external beam irradiation with seven fractions of 2 Gy (total dose 14 Gy). The next 16 consecutive eyes received external beam irradiation with five fractions of 3 Gy (total dose 15 Gy). Main outcome measure was change in visual acuity. Secondary outcome variables were contrast sensitivity and fundus photographic/fluorescein angiographic progression.
  
  
  RESULTS
  The 3 Gy fraction group lost fewer lines of distance visual acuity at the three and six month follow up. At one year follow up, this difference was not maintained with 2 Gy fraction and 3 Gy fraction eyes. At one year follow up a decrease in visual acuity of three or more lines (moderate visual loss) occurred in 58% of 2 Gy and 42% of 3 Gy fraction eyes (p<0.36). At one year follow up a decrease in visual acuity of six or more lines (severe visual loss) occurred in 41% of 2 Gy eyes and 17% of 3 Gy eyes (p<0.23). At three months follow up, 3 Gy eyes were less likely (0%) than 2 Gy eyes (47%) to show moderate visual loss (p<0.003). However, Kaplan Meier curves estimate a significantly lower rate of severe visual loss in the 3 Gy group (p = 0.02). There were no significant differences in contrast sensitivity loss or fluorescein angiographic stabilisation rates. No evidence of radiation toxicity was observed.
  
  
  CONCLUSIONS
  Our results are consistent with trends for a palliative benefit with higher fraction sizes and doses. The radiobiologic differences between low and high fraction size groups in this study are modest and correlate with the modest and short term difference in visual outcomes. These trends support further investigation of radiotherapy using fraction sizes of 4 Gy or higher.
authors.affiliation: Department of Ophthalmology, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912, USA. dmarcus@mail.mcg.edu
authors.forename: D M
authors.initials: DM
authors.lastname: Marcus
authors.forename: W C
authors.initials: WC
authors.lastname: Sheils
authors.forename: J O
authors.initials: JO
authors.lastname: Young
authors.forename: S B
authors.initials: SB
authors.lastname: McIntosh
authors.forename: M H
authors.initials: MH
authors.lastname: Johnson
authors.forename: J
authors.initials: J
authors.lastname: Alexander
authors.forename: C N
authors.initials: CN
authors.lastname: Samy
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020256:Choroidal Neovascularization / Q000209:etiology / Q000503:physiopathology / Q000532:radiotherapy*; D015350:Contrast Sensitivity; D018450:Disease Progression; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D008268:Macular Degeneration / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D012008:Recurrence; D016896:Treatment Outcome; D014792:Visual Acuity