eale's disease

as i was sitting in front of my laptop, suddenly something struck my mind to do some findings on the internet about the uncommon eye disease called "eale". so there i go with my searches in google and it returned heaps of links. there are a couple of links that i look into but i find this particular one called emedicine that describes best about the disease. although, there were a lot of medical names used in the description, on-line medical dictionary is where i go to better understand what does each of the names meant.

for your information, eale's disease is an eye disease that affect young adult at early ages of 20 and over. after reading the disease background, symptoms and treatment, the disease was diagnosed as early as 1880 and up till now, there isn't any proven factor of the cause and cure.

Background:

Eales disease is an idiopathic obliterative vasculopathy that usually involves the peripheral retina of young adults. In 1880, Henry Eales first described it in healthy young men with abnormal retinal veins and recurrent vitreal hemorrhages.

Clinical findings are characterized by avascular areas in the retina periphery, followed posteriorly by microaneurysms, dilatation of capillary channels, tortuosity of neighboring vessels, and spontaneous chorioretinal scars. It is a diagnosis of exclusion, as many other retinal disorders can mimic Eales disease, especially conditions of retinal inflammation or neovascularization.

Pathophysiology:

The pathophysiology of Eales disease is mostly unknown. It is believed to be a primary, noninflammatory disorder of the walls of peripheral retinal vessels, namely the shunt vessels. This often leads to vascular occlusions, peripheral neovascularization, and vitreous hemorrhage. The microvascular abnormalities are seen at the junction of perfused and nonperfused zones of the retina. Although associations with tuberculosis and multiple sclerosis have been suggested, these findings have not been substantiated in other studies. It is possible that the association of Eales disease with both ocular inflammation and sensitivity to tuberculin protein suggests that this disease may be associated with immunologic phenomena whose mechanisms remain unknown.

Frequency:
In the US - Uncommon disease, with most reports based upon a series of cases
Internationally - Most commonly seen in India and portions of the Middle East

Mortality/Morbidity:

No known mortality is associated with Eales disease. Visual compromise is seen in patients with recurrent vitreous hemorrhage, but resolves to better than 20/200 in greater than 70% of patients. If retinal nonperfusion extends into the macula, the visual acuity usually is worse than 20/400.

Race:

No racial predilection is known in Eales disease; however, the disease is more prevalent in India and portions of the Middle East.

Sex:

Young adult males have been reported to have an increased prevalence; however, a study of 55 patients by Murphy and colleagues found that men and women are affected equally.

Age:

Peak age of onset is 20-35 years, with a reported range of 13-63 years.

History:

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

Physical:
The physical findings 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, ischemic stroke, hemiplegia, and multifocal white matter abnormalities have been reported. 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.

Causes:

The cause of Eales disease is unknown. It is a diagnosis of exclusion and is thought to be idiopathic. No causative drugs, environmental factors, or infectious agents have been identified. Although a hypersensitivity to tuberculin protein has been reported, no clear relationship to tuberculosis has been found.

Sources taken from emedicine