En Face Optical Coherence Tomography Analysis to Assess the Spectrum of Perivenular Ischemia and Paracentral Acute Middle Maculopathy in Retinal Vein Occlusion

En face OCT may illustrate a remarkable perivenular pattern of PAMM in eyes with retinal vascular obstruction even in the absence of significant funduscopic findings. Perivenular PAMM with en face OCT demonstrates a wide spectrum of variation with narrow fern-like perivenular lesions at the mildest end and more diffuse lesions with only periarterial sparing at the most severe end of the spectrum. Arterial hypoperfusion secondary to outflow obstruction from a central retinal vein obstruction appears to be the most common cause of this presentation, although primary arterial hypoperfusion may also be an etiology.