Approximately 10 percent of blindness in persons younger than 65 years is caused by uveitis and its complications. Although uveitis is about 250 times less common than diabetes, it causes an equivalent number of patients to lose their sight each year. McCluskey and colleagues reviewed the clinical implications of prompt recognition and management, including indications for and types of treatment, and management of complications.

Chronic uveitis is defined as intraocular inflammation lasting more than three months. It is associated with vision-threatening complications such as cataract, macular edema and glaucoma. Many cases are idiopathic, and others are eye manifestations of systemic diseases. Chronic uveitis can affect the anterior, intermediate or posterior regions of the eye. Anterior uveitis tends to have an insidious onset and may be associated with juvenile arthritis, sarcoidosis or

Behçet's disease. Intermediate uveitis may be idiopathic or associated with multiple sclerosis, syphilis, Lyme disease or ocular lymphoma. Symptoms include floaters and blurred vision caused by swelling of the optic disc and macular edema. Posterior uveitis has a range of clinical manifestations and is associated with several conditions, including syphilis, tuberculosis, human immunodeficiency virus (HIV) infection, toxocariasis and fungal diseases. Initial diagnostic testing of any patient believed to have chronic uveitis should be limited to chest radiograph, syphilis serology and HIV status testing. Additional testing should be selected on the basis of risk for other causes of the condition.

The goal of management is to prevent blindness, control inflammation and minimize long-term complications of the disease and its treatment. Anterior uveitis usually is managed with topical corticosteroids. Uveitis also may be treated with periocular injection of corticosteroids; however, this technique is contraindicated if the patient has glaucoma or steroid-induced elevation of intraocular pressure. Corticosteroids are the principal systemic treatment, with an initial maximum daily dosage of 1.0 to 1.5 mg per kg body weight of prednisone for two to three weeks, if tolerated. The dosage is then tapered by about 5 mg per week until the lowest dosage that maintains vision is achieved. Other systemic immunosuppressive drugs, such as cyclosporine, azathioprine and methotrexate, may be added to steroid therapy. Surgery usually is indicated for complications of uveitis, but it should be considered only when the uveitis is controlled for at least three months.

Complications include macular edema, cataract, glaucoma, intraocular synechiae, band keratopathy, vitreous opacities and hemorrhage, retinal and subretinal neovascularization, and retinal detachment.