![]() The symptoms of retinal detachment vary with the amount of damage that has occurred. READ MORE: Signs a Dog is Pregnant Symptoms of Retinal Detachment Dogs can develop detached retinas for other reasons, but sometimes the condition seems to develop without an underlying cause. Retinal detachments are also a possible post-operative complication with some types of eye surgery. This disorder is called immune-mediated retinochoroiditis and is probably the most common cause of retinal detachment in an otherwise healthy adult dog. A dog can also develop an abnormal immune response against its own retina or choroid. These infections may be limited to the eye or have spread there from elsewhere in the body. Diseases that weaken the walls of blood vessels.ĭeep eye infections can cause inflammatory cells and debris to collect under the retina.High blood pressure, which may be secondary to kidney disease, hyperadrenocorticism (Cushing’s disease), or other disorders.Trauma to the eye, resulting in retinal tears or bleeding behind the retina. ![]() 3 Treatment and Prevention of Retinal Detachment in Dogs.Vessels underneath the retina may leak blood or fluid and separate the layers of tissue. Other cases of retinal detachment occur as a result of injury or illness that affects an otherwise normal eye. For example, retinal detachment can be part of the syndrome known as collie eye anomaly, a common inherited disease affecting collies, Shetland sheep dogs, and border collies. In some cases, the retina and/or other parts of the eye may not form normally during development. Many different diseases can lead to retinal detachment. If the retina begins to lift away from the back of the eye, the tissue can no longer perform its functions, and depending on the degree of retinal detachment, blindness may result. The retina receives nourishment through its close attachment to underlying parts of the eye (the choroid). When light passes through the eye and strikes the retina, special cells within the tissue convert light energy into nerve impulses, which are then transmitted to the brain via the optic nerve. Causes include ocular larva migrans (due to strongyles, ascarids, Baylisascaris larvae), toxoplasmosis, leishmaniasis, neosporosis, and possibly babesiosis.The retina is a layer of tissue that covers the inside of the back wall of the eye. ![]() Parasitic inflammation of the choroid and retina is more likely to cause smaller areas of detachment (i.e., multifocal chorioretinitis). and geotrichosis), algae (protothecosis), and, rarely today, canine distemper virus. In the dog chorioretinitis with RD may be caused by bacteremia or septicemia (e.g., leptospirosis, brucellosis), rickettsial agents (ehrlichiosis, Rocky Mountain spotted fever, bartonellosis, anaplasmosis), fungal organisms (aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, cryptococcosis, and less commonly infection with Acremonium spp. When choroidal inflammation is severe and diffuse, large segmental or complete RDs may occur. As discussed previously, small areas of inflammation are technically RDs, but this type of lesion is best termed chorioretinitis (see Chapters 254 and 255). Retinitis or chorioretinitis may cause focal or multifocal RDs. The term retinochoroiditis is used to imply that retinal tissue was inflamed primarily with choroidal inflammation occurring secondarily, whereas the reverse is true for the term chorioretinitis. Liquid from the vitreous then moves through the hole or tear into the subretinal space and exacerbates the RD. Since the vitreous hydrogel is attached to the lens and retina, perturbations of the vitreous (e.g., caused by inflammation or surgery) or of the lens can contribute to the development of rhegmatogenous RD by creating retinal traction, which can lead to tear or hole formation. The vitreous is more firmly attached in three locations: the peripheral posterior lens capsule, the vitreous base that overlies the peripheral edge of the retina (the pars plana and ora ciliaris retinae), and the margin of the optic nerve. The vitreous gel is a homogeneous collagen fibril network with hyaluronic acid molecules filling the interfibrillar spaces. The pathogenesis of rhegmatogenous RD involves the presence of an abnormal retina (i.e., thinned as a result of degeneration, age, or other diseases) that is predisposed to formation of tears or holes, combined with an abnormal vitreous, as with vitreous syneresis (liquefaction), traction (from vitreal floaters or postinflammatory debris), or vitreous detachment. ![]() This type of RD is less common than exudative RD in small animals and occurs more frequently in dogs than in cats. Rhegmatogenous RD is associated with the formation of one or more retinal tears or holes. Small areas of active chorioretinitis are associated with focal, low retinal detachments. Web Figure 76-1 Chorioretinitis in a dog caused by blastomycosis. ![]()
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