Abstract
Purpose: :
To test retinal sensitivity in patients undergoing epimacular brachytherapy for previously treated neovascular age-related macular degeneration (nAMD).
Methods: :
A prospective study of 12 subjects enrolled on the MERITAGE study at one UK site. At baseline, subjects underwent pars plana vitrectomy and 24 Gray epimacular brachytherapy using a Strontium-90 source (NeoVista, Newark, CA). Patients received ranibizumab therapy monthly if predefined retreatment criteria were met. Microperimetry (MP-1; Nidek Technologies, Padova, Italy) was performed pre-operatively and at month 12.
Results: :
Mean age was 75 (SD 8) years. ETDRS VA remained stable over 12 months (-0.33 letters; SD 13.2; P=0.932) with a mean of 3.5 ranibizumab injections, including those given at baseline for pre-existing disease activity. Both mean sensitivity (MS) and mean defect improved slightly by 0.79 dB (SD, 3.92 dB; P=0.499) and 1.71 dB (SD, 4.26 dB; P=0.192) respectively. The increase in MS was evident both within the treated lesions (0.88 dB; SD 3.17; P=0.357), and in neighbouring unaffected retina (0.65 dB; SD 4.23; P=0.606), as defined using fluorescein angiography and fundus photographs. Fixation stability and location were unaffected.
Conclusions: :
The fact that retinal sensitivity remained stable in areas not visibly affected by nAMD suggests that epimacular brachytherapy does not produce a deleterious effect in healthy retina.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00809419
Keywords: age-related macular degeneration • radiation therapy • lesion study