|
Eales disease is a retinal vasculopathy that was first described in 1880 by H. Eales. The disease occurs mainly in men between 20 and 30 years, and is more frequent in the Indian subcontinent. The underlying causes are poorly understood but some evidences suggest a multifactorial etiology including auto immunity, oxidative stress, mycobacterium tuberculosis genome and possibly coagulopathy. Initially patients present an inflammatory stage with retinal periphlebitis affecting especially peripheral retina, then an ischemic stage with sclerosis of retinal veins, and finally a proliferative stage characterized by neovascularization, hemorrhage and retinal detachment. Macular and choroidal involvements are rare. Lesions are most commonly bilateral. Eales disease is often asymptomatic at the early stage, and then clinical features are variable from blurry vision to severe, painless vision decrease. As Eales disease is a diagnosis of exclusion, other entities such as sarcoïdosis, branch retinal vein occlusion and other proliferative retinopathies must be excluded. Fundus fluorescein angiography is the main diagnostic test, but ultrasonography is also required in presence of retinal detachment or vitreous hemorrhage. Coagulation tests are recommended by few investigators. Clinical course is quite variable, being either regressive or progressing to the proliferative stage with recurrent complications leading to sequelae. Nevertheless blindness is uncommon: in a study conducted in 800 patients (1214 eyes), only 0.33% had a vision less then 20/200. Treatment in perivasculatis stage is based on corticosteroids (systemic or periocular), and/or immunosuppressants (azathioprine, cyclosporine). Although recommended by some authors, anti-tubercular therapy remains controversial. Photocoagulation is the mainstay therapy in proliferative stage. Vitreoretinal surgery is required in vitreous hemorrhage persisting beyond 3 months or in presence of adherences causing retinal traction. |