Migration of perivenous opacities during retinal vasculopathy and retinal vasculitis

To report the migration of perivascular opacities, in patients with retinal vasculopathy, with and without clinical evidence of ocular inflammation.

Retrospective case series of four patients with either idiopathic retinal vasculitis or presumed retinal vascular inflammation. Patients were imaged with wide-field fundus photographs, infrared fundus images, fundus fluorescein angiography (FA), and flood-illumination adaptive optics (FIAO). Successive fundus images were registered and compared over follow-up periods ranging from 2 to 10 months. Displacement of identifiable perivascular opacities between imaging sessions was measured to estimate migration velocity.

Two patients presented with presumed retinal vasculopathy associated with retinal vein occlusion (RVO). Their fundus images showed disseminated perivenous opacities along veins. In both patients, time-lapse videos recapitulating several months of fundus observations revealed that most of the perivascular opacities shifted along veins with or against the flow at an estimated mean velocity of approximately 15 μm/day, calculated from displacement between imaging sessions. Two patients presented with retinal vasculopathy in the form of retinal vasculitis. Their fundus examination showed perivascular sheathing (arteritis and phlebitis). FIAO demonstrated multiple focal perivascular opacities in the same areas. All 4 patients imaged presented similar focal perivascular cell-like opacities either on infrared or FIAO fundus images.

We describe the migration of presumed immune cell-like perivascular opacities in the human eye. The significance of this process remains to be fully explored, because evidence of ocular inflammation was clinically present in two patients. The close temporal and spatial relationship of these perivascular opacities associated with branch RVO in two of these patients suggests that they may have been involved in the occurrence of RVO.