Vascular sheathing with adjacent nerve fiber layer hemorrhages is seen in most patients. The sheathing can manifest as thin white lines, limiting the blood column on both sides of the sheathed vessel to heavy exudative sheathing that can cause vascular occlusion. Although believed to affect primarily the retinal veins, others have reported the same prevalence of both venules and arterioles. The anterior chamber may exhibit cell and flare with keratic precipitates. Vitreous debris and cells often are seen, even in the absence of vitreous hemorrhage.
Macular edema can occur in eyes with vascular sheathing, and it often is cystoid in nature.
Epiretinal membranes with or without macular edema can compromise visual acuity. The etiology of the macular edema is thought to be associated with low-grade inflammation. Peripheral nonperfusion is a typical feature of Eales disease. The temporal retina is affected most commonly, often in a confluent area. Fine solid white lines occasionally can be seen, representing obliterated larger vessels.