Uveal effusion syndrome.

The terms uveal effusion, choroidal effusion, ciliochoroidal effusion, ciliochoroidal detachment, and choroidal detachment have been used interchangeably in the literature. These labels all describe an abnormal collection of fluid that expands the suprachoroidal space, producing internal elevation of the choroidal. There are various inflammatory and hydrostatic conditions that can cause uveal effusion, but in some cases no obvious cause exists. In this setting, patients are thought to have a distinct, primary abnormality of the choroid or sclera, called uveal effusion syndrome (UES). UES may be idiopathic, or associated with hypermetropia, and should be considered a diagnosis of exclusion. Histological studies show amorphous glycosaminoglycan-like material filling the interfibrillary spaces of excised scleral tissue, with disruption of collagen fibers. In some patients there may be reduced macromolecular diffusion that interferes with the normal transscleral egress of albumin out of the eye, perhaps causing choroidal fluid retention due to altered osmotic forces. An alternative, and perhaps complementary hypothesis, is that swollen sclera compresses the transscleral vessels with resulting fluid retention. Patients with UES are most typically middle-aged men who have a relapsing remitting clinical course. There is often co-existing, shifting subretinal fluid that may involve the macula. Chronic disease may lead to secondary retinal pigment epithelial (leopard spot) changes and permanently reduced visual acuity. Treatment with systemic steroids does not appear to be effective. Surgical decompression of the vortex veins as they pass through the sclera has been described, but the most common treatment is full-thickness sclerectomies to provide an exit for choroidal fluid. The largest case series suggests that this produces an anatomic improvement in approximately 83% of treated eyes after a single procedure and in about 96% after one or two procedures. Final visual acuity improves by two or more lines in 56% of the eyes, is stable in 35%, and worsens in 9%. Although extremely rare, UES is a serious condition that is difficult to treat and can lead to severe and permanent visual loss in both eyes.