Abstract
Purpose: :
To assess the safety and efficacy of epimacular brachytherapy for previously treated neovascular age-related macular degeneration (nAMD)
Methods: :
50 subjects with classic, minimally classic and occult lesions were enrolled. Entry criteria included a minimum of 3 intravitreal anti-VEGF retreatment injections in the 6 months preceding enrolment, or 5 injections in 12 months preceding enrolment. Subjects had received a mean of 12 injections prior to enrolment. Subjects underwent pars plana vitrectomy and 24 Gray beta irradiation for 4-5 minutes, using a retractable Strontium-90 source in an endoscopic probe (NeoVista, Freemont, CA). Anti-VEGF injections were administered if there was a 5 ETDRS letter loss, >50 micron central retinal thickness increase on optical coherence tomography (OCT), new macular hemorrhage, or new activity visible with fundus fluorescein angiography (FFA). Subjects were retreated with the same anti-VEGF agent they were receiving prior to enrolment (bevacizumab 1.25 mg or ranibizumab 0.5 mg). Monthly OCTs and regular FFAs (0, 1, 6, 12 months) were read centrally. Co-primary outcome measures were mean ETDRS visual acuity and mean number of anti-VEGF retreatment injections.
Results: :
To date, 16 subjects have reached the 6 month milestone. Subjects received a mean of 2 retreatment injections with 88% maintaining vision and 63% gaining vision. Mean visual gain was 1.2 letters (+3.0 in pseudophakes). There was a favourable safety profile with no retinal breaks, detachments or radiation retinopathy.
Conclusions: :
These interim results suggest that epimacular brachytherapy may reduce the need for anti-VEGF retreatment, whilst maintaining vision, however further follow-up is needed. Epimacular brachytherapy has the potential to reduce the treatment burden that patients face, and the financial cost to healthcare providers. A large (n 363) multicentre RCT (MERLOT) is now underway.
Clinical Trial: :
www.clinicaltrials.gov NCT00809419
Keywords: age-related macular degeneration • radiation therapy • vitreoretinal surgery