Original StudiesSAFETY TESTING OF EPIMACULAR BRACHYTHERAPY WITH MICROPERIMETRY AND INDOCYANINE GREEN ANGIOGRAPHY 12-Month ResultsPetrarca, Robert MBBS, BSc (Hons)*,†; Richardson, Matthew BSc*; Douiri, Abdel PhD†; Nau, Jeffrey MMS‡; McHugh, Dominic MD, FRCOphth*; Stangos, Alexandros N MD, FEBO*; Jackson, Timothy L. PhD, FRCOphth*,†Author Information *King's College Hospital, London, United Kingdom †King's College London, University of London, United Kingdom ‡NeoVista, Newark, California. Reprint requests: Timothy L. Jackson, PhD, FRCOphth, Department of Ophthalmology, King's College Hospital, London SE5 9RS, United Kingdom; e-mail: [email protected] King's College Hospital received a research grant from NeoVista, Inc. A. Douiri receives financial support from the Department of Health via the National Institute for Health Research (NIHR) comprehensive Biomedical Research Centre award to Guy's and St Thomas' NHS Foundation Trust in partnership with King's College London and King's College Hospital NHS Foundation Trust. J. Nau was an employee of NeoVista, Inc, and is presently employed by Genentech. Retina: June 2013 - Volume 33 - Issue 6 - p 1232-1240 doi: 10.1097/IAE.0b013e3182794b22 Buy Metrics AbstractIn Brief Purpose: To determine if epimacular brachytherapy is associated with reduced retinal sensitivity or choroidal nonperfusion. Methods: A prospective intervention case series of 12 participants with neovascular age-related macular degeneration requiring frequent ranibizumab underwent vitrectomy and epimacular brachytherapy. The Strontium 90/Yttrium 90 source delivered a single 24-Gy dose at the center of the treatment zone. The dose attenuated with increasing distance from the source. Microperimetry and indocyanine green angiography were performed at baseline and 12 months. The main outcome measures were mean sensitivity and choroidal nonperfusion. A linear mixed model was used to assess the association between the dose of radiation and the change in mean sensitivity. Results: Mean visual acuity remained within 1 letter of baseline at 12 months (−0.33 ± 13.2 letters). There was no statistically significant change in mean sensitivity within the neovascular age-related macular degeneration lesion area (gain of 0.94 ± 3.25 dB; P = 0.339) or in neighboring unaffected retina (0.66 ± 4.14 dB; P = 0.594), defined using fluorescein angiography. Within the lesion area, mean sensitivity improved by an average of 0.23 ± 0.16 dB (P = 0.006) for every additional gray of radiation received. Indocyanine green angiography failed to demonstrate any choroidal nonperfusion or radiation damage at 12 months after the treatment. Conclusion: Stable retinal sensitivity in areas not manifestly affected by neovascular age-related macular degeneration suggests that epimacular brachytherapy does not damage retinal function. The presence of a dose response suggests that the positive effect of epimacular brachytherapy relates more to beta irradiation than vitrectomy. Epimacular brachytherapy did not produce any deleterious effects on macular function or choroidal perfusion, tested using microperimetry and indocyanine green angiography. Wet age-related macular degeneration areas receiving higher doses of radiation showed greater improvement in retinal sensitivity. © 2013 by Ophthalmic Communications Society, Inc.