Primary arteriovenous communications of the retina (AVCR) are usually considered to be stable retinal lesions. Complications were documented in seven cases of AVCR, including intraretinal macular hemorrhage, central and peripheral retinal vein occlusions, neovascular glaucoma, and vitreous hemorrhage. To explain these developments, a hypothesis is presented that AVCR are associated with localized decreased retinal arterial pressure, increased retinal venous pressure, increased turbulence of blood flow, and decreased perfusion of adjacent retinal tissues.