title: BRANCH RETINAL VEIN OCCLUSION SECONDARY TO A RETINAL ARTERIOLAR MACROANEURYSM: A NOVEL MECHANISM SUPPORTED BY MULTIMODAL IMAGING.
abstract: OBJECTIVE
  To report a case of a branch retinal vein occlusion secondary to a retinal arteriolar macroaneurysm (RAM).
  
  
  METHODS
  Retrospective case report describing examination findings, treatment outcome and unique multimodal imaging features demonstrated on fluorescein angiography, optical coherence tomography, optical coherence tomography angiography and adaptive optics photography of the retinal vessels and RAM.
  
  
  RESULTS
  A 61-year-old man presented with 20/200 vision in the right eye because of a branch retinal vein occlusion secondary to a RAM. After sector panretinal photocoagulation and a course of 24 intravitreal antivascular endothelial growth factor injections over 4 years, visual acuity improved to 20/25. Fluorescein angiography showed filling of the RAM even after 4 years. Optical coherence tomography angiography demonstrated venous collateral vessels in both the superficial and deep capillary plexuses, and adaptive optics imaging revealed a gap between the RAM wall and occluded vein.
  
  
  CONCLUSIONS
  Multimodal imaging of this unusual presentation illustrated a novel mechanism of branch retinal vein occlusion in which a primary RAM adjacent to the junction of two retinal veins led to obstruction of venous flow without evidence of direct compression. This supports the theory that perianeurysmal microenvironment changes may be of importance in the pathogenesis of venous occlusion.
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Perth, Western Australia, Australia.|Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Vision Eye Institute, Chatswood, New South Wales, Australia.
authors.forename: Simon D M
authors.initials: SDM
authors.lastname: Chen
authors.affiliation: Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Perth, Western Australia, Australia.|Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Fred K
authors.initials: FK
authors.lastname: Chen
mesh_terms: D000783:Aneurysm / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D000068258:Bevacizumab / Q000008:administration & dosage; D005451:Fluorescein Angiography / Q000379:methods*; D005654:Fundus Oculi; D006801:Humans; D058449:Intravitreal Injections; D017075:Laser Coagulation; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D000069579:Ranibizumab / Q000008:administration & dosage; D012161:Retinal Artery; D012169:Retinal Vein / Q000473:pathology*; D012170:Retinal Vein Occlusion / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D041623:Tomography, Optical Coherence / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors
chemical_list: D020533:Angiogenesis Inhibitors; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab; D000069579:Ranibizumab