A 1-year-old male Indian rhesus macaque offered a bilateral blindness. Upon ocular examination the intraocular pressure was 11 mm Hg in the right eye and 20 mm Hg in the left eye. The left eye showed phthisis bulbi with aqueous flare and retinal detachment. The AMG 073 (Cinacalcet) right eye showed buphthalmos with severe miosis. Fluorescein staining was unfavorable in both eyes. Routine serology showed that the animal had serum antibody titers of 1 1:640 to West Nile virus (WNV) by hemagglutination-inhibition assay. A decision to humanely euthanasia the animal was made due to the lack of responsiveness to antibiotic treatment and deteriorating physical condition. This animal received prior approval from the institutional animal care AMG 073 (Cinacalcet) and use committee (IACUC) of the TNPRC in Covington LA. This study was conducted within the guidelines for ethical use of animals in United States Public Health Support policy as outlined in the Guide for the Care and Use of Laboratory Animals. Grossly the animal had poor body condition with little body fat and moderately skeletal muscle atrophy. The left eye was small with a cloudy anterior chamber corneal opacity and a lens cataract. (Fig. 1) The vitreous fluid was yellow-brown made up of the detached coiled retina. The TCF1 right eye was mildly enlarged with comparable but AMG 073 (Cinacalcet) milder lesions to those noted in the left eye. All other organs were grossly unremarkable. Fig. 1 One-year-old male Indian rhesus macaque (macaca mulatta). Eyes. Shrunken left eye with cloudy anterior chamber corneal opacity and a lens cataract. The right eye was characterized by buphthalmos with a cataract and an irregular iris. Histopathologically the irregular coiled retina of the left eye was completely detached from the retinal pigmented epithelia. The subretinal space was filled with an exudate composed of fibrin hemosiderin-laden macrophages and rare cholesterol clefts surrounded by multinucleate giant cells. (Fig. 2) Multifocally the inner plexiform layer was expanded by edema fibrin and numerous vacuoles. The capillaries and mid-sized vessels were irregular moderately to severely dilated and lined by a thin layer of endothelial cells (telangiectasia). These blood vessels often had moderate to severe perivascular edema and/or moderate lymphoplasmacytic perivasculitis. (Fig. 3) Some of the retinal vessels showed considerably endothelial fenestration and interendothelial cell separation. Marked telangiectasia with the loss of basement membrane integrity produced the abnormality of vascular permeability and formation of saccular dilation to microaneurysms. (Fig. 4) AMG 073 (Cinacalcet) Occasionally lymphoplasmacytic vasculitis was also noted. The cells with vacuolar degeneration (lipid-laden macrophages) in the retina and brown pigmentation (hemosiderin-laden macrophages) in the subretinal space were positive for the macrophage marker CD68 by immunohistochemistry (Fig. 5). Other lesions in the left eye included multifocal keratitis cataract lens rupture broad anterior and posterior synechia and anterior uveitis. Comparable but milder lesions were noted in the right eye. All other organs were histologically unremarkable. Fig. AMG 073 (Cinacalcet) 2 Subgross photography of the left eye. The retina is completely detached (arrows) and the subretinal space is usually filled with an exudate (*). Anterior and posterior synechia and keratitis are also present. Insert. Cholesterol clefts with multinucleate giant … Fig. 3 Histology of the retina of the left eye. Retinal blood vessels (arrows) were dilated with perivascular edema. Vacuolization predominantly in the inner plexiform layer (<) of the retina was observed and the subretinal space was filled with large ... Fig. 4 Histology of the retina of the left eye. The retinal vessel showed greatly endothelial fenestration and interendothelial cell separation with the loss of basement membrane integrity and formation of microaneurysm (arrow). HE. 400×. Fig. 5 Immunohistochemistry of the left eye. Immunohistochemistry revealed that this vacuolated cells observed in the H&E of the retina were CD68-positive macrophages (arrows). Macrophages were also found in the infiltrates in the subretinal space. Magnification ... First described by Gorge Coats in 1908 Coats disease is an idiopathic congenital ocular disease mainly characterized by retinal telangiectasia and exudative retinopathy. Coats disease occurs more commonly in children and has a clear male predominance and usually unilateral manifestation [17]. However bilateral Coats-like disease has also been reported in young and adult patients [1 14 The.