Timothy L. Jackson, Pravin Dugel, Robert Petrarca, Jeff Nau for the MERITAGE study group (London, UK)


Radiation has the potential to eliminate the proliferating endothelial cells, fibroblasts, and inflammatory cells that cause vision loss in wet age-related macular degeneration (AMD), and may therefore produce a more durable therapeutic effect than anti-VEGF therapy.


53 subjects with classic, minimally classic, and occult AMD were enrolled. Inclusion criteria stipulated that patients were already receiving regular anti-VEGF therapy, defined as at least 3 retreatment injections in the 6 months prior to enrolment, or 5 injections in 12 months prior to enrolment.  Subjects had received a mean of 12 injections prior to enrolment.  Subjects underwent pars plana vitrectomy with targeted beta irradiation of the macula using an endoscopic probe (NeoVista, Freemont, USA) that delivered a dose of 24 Gray over 4.5 minutes. Anti-VEGF therapy was administered based on predefined retreatment criteria. Monthly OCT and fluorescein angiograms (0, 1, and 6 months) were read centrally, with monthly ETDRS visual acuity undertaken by certified examiners.

Effectiveness / Safety:

Mean ETDRS visual acuity was maintained (<1 letter loss) at 6 months. The mean number of retreatment injections was 1.9 over this period, half that in the corresponding 6 months prior to enrolment. If injections given at the time of surgery (based on pre-existing disease) were excluded, subjects received a mean of 1.2 retreatment injections.  To date there have been no unexpected safety concerns and no radiation retinopathy.