Eales Disease Clinical Presentation

Updated: Sep 28, 2018
  • Author: Jonathan C Tsui, MD; Chief Editor: Hampton Roy, Sr, MD  more...
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Presentation

History

Most Eales disease patients present with symptoms of floaters, specks, cobwebs, blurring, or decreased vision associated with vitreous hemorrhage. Other Eales disease patients have blurring associated with retinal vasculitis or uveitis, but without hemorrhage. Often, patients report uniocular symptoms, but ophthalmic examination reveals early changes of Eales disease in the other eye. Bilateral involvement is evident in 80-90% of patients.

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Physical

The physical findings in Eales disease mostly involve the retina and vitreous. 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. Areas of vascular sheathing often leak dye on fluorescein angiography (FA).

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. The surrounding vasculature is tortuous with microvascular abnormalities, which include the following: microaneurysms, arteriovenous shunts, venous beading, hard exudates, and cotton-wool spots. Fine solid white lines occasionally can be seen, representing obliterated larger vessels.

Branch retinal vein occlusion (BRVO) can be seen in patients with Eales disease and may be limited to one area or may be multifocal. BRVO alone can be differentiated from BRVO in the presence of Eales disease by the more extensive peripheral retinal involvement in Eales disease. BRVO alone usually is confined to a single affected quadrant. BRVO alone also respects the anatomical distribution of the horizontal raphe, unlike Eales disease.

Neovascularization of the disc (NVD) or neovascularization elsewhere (NVE) in the retina is observed in up to 80% of patients with Eales disease. The NVE usually is located peripherally, at the junction of perfused and nonperfused retina. The neovascularization often is the source of vitreous hemorrhage in these eyes, compromising vision. Rubeosis iridis or neovascularization of the iris can develop and may lead to neovascular glaucoma. Fibrovascular proliferation on the surface of the retina may accompany retinal neovascularization. These eyes have associated anteroposterior traction that could lead to retinal detachment.

Cystoid macular edema can occur in patients with Eales disease due to increased capillary permeability. This can often be associated with significant vision loss.

A posterior vitreous separation has been reported in 27% of patients with Eales disease, and several patients have been found to have concomitant macular holes. Macular hole surgery may effectively repair this abnormality and lead to significant visual improvement similar to that seen in patients with idiopathic macular holes.

Systemic abnormalities have been reported in association with Eales disease, mostly neurologic findings. Myelopathy, [4, 5] ischemic stroke, [6] hemiplegia, [7] and multifocal white matter abnormalities have been reported. [8, 9] A higher incidence of vestibuloauditory dysfunction is seen in patients with Eales disease when compared to the general population of the same age. It is presumed that a similar mechanism of vascular occlusion and hypoxia leads to these systemic findings.

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Causes

The cause of Eales disease is unknown. Eales disease is a diagnosis of exclusion and is thought to be idiopathic. No causative drugs, environmental factors, or infectious agents for Eales disease have been identified. Although a hypersensitivity to tuberculin protein has been reported, no clear relationship to tuberculosis has been found. Nonetheless, limited data have shown that elevated erythrocyte sedimentation rate (ESR), high tuberculin skin test (TST) result, and vitreous polymerase chain reaction (PCR) positive for Mycobacterium tuberculosis indicated a more likely diagnosis of Eales disease. [10]

An 88-kd acute phase reactant protein has been found in patients with Eales disease that is immunologically identical to that found in patients with posterior uveitis, tuberculosis, leprosy, and rheumatoid arthritis. This protein complex consists of haptoglobin, complement C3, and galectin-1, although its exact role is yet to be determined. [11]

Increasing data implicate interleukin (IL)–1 and tumor necrosis factor-alpha (TNFα) in the inflammatory stage of Eales disease. [12] In addition, inflammatory cytokines IL-6, IL-8, MCP-1, and VEGF have been found in Eales disease and proliferative diabetic retinopathy (PDR), suggesting similar pathophysiology. [13] Genetic polymorphism studies suggest low IL-10 expression and high TNFα may increase the occurrence and severity of Eales. [14] Furthermore, copper is known to have pro-oxidant characteristics when body copper levels are excessive. A study of copper transporter 1 (CTR1) protein levels in Eales disease found elevated expression in the retina and peripheral blood mononuclear cells (PBMCs) involved in inflammation. [15]

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Complications

Complications of retinal neovascularization can lead to severe visual loss due to persistent vitreous hemorrhage and retinal detachment.

Anterior segment neovascularization can cause neovascular glaucoma with resultant visual loss and, occasionally, even loss of the eye.

Peripheral retinal nonperfusion can limit a patient's visual field, and, if the area of nonperfusion extends into the macula, severe visual loss may result. No effective treatment exists to prevent capillary nonperfusion.

Macular puckering has been reported to occur in 3% of eyes after scatter laser photocoagulation treatment of Eales disease.

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