Adult-onset Coats’ disease: a review

Abstract

In 1908, George Coats published a paper about a rare form of outer retinopathy with massive exudation. Until today, the causes of the Coats’ disease (CD) has not been revealed and there is no generally accepted model of its pathogenesis. It was hypothesized that the condition could be caused by an infectious process or an inflammatory reaction, but there is no consensus about that. Genetic determinants of CD have not been identified, either. A histological examination of CD revealed “cholesterol fissures”, subretinal exudate, massive gliosis, retinal disorganization, vasodilation and hyalinization, diffuse thickening of retinal capillaries and areas of complete absence of pericytes and vascular endothelium, as well as inflammatory infiltrates. The main component of subretinal exudate is intense cell reaction of the macrophages. A study of the cytokine profile showed an increased concentration of VEGF in the subretinal fluid, the level of IL-6 was significantly higher in adult patients and correlated with the degree of exudative retinal detachment. In the eye fundus of CD patients, vascular telangiectasias followed by exudate deposition in these areas have been revealed. Complications of CD include vasoproliferative tumors, neovascular glaucoma, intraretinal and intraocular hemorrhages, vitreous fibrosis, traction retinal detachment, anterior chamber cholesterolosis. CD treatment includes laser coagulation, cryotherapy, intravitreal administration of glucocorticosteroids and angiogenesis inhibitors. In severe forms and advanced stages of CD, vitreoretinal surgery is resorted to. Enucleation may be necessary in some cases.