Intermediate uveitis.

Intermediate uveitis is an intraocular inflammation involving the anterior vitreous, peripheral retina and pars plana. It usually affects patients from 5 to 30 years old, without gender or racial preferences. The etiology is unknown but there are several associated diseases: multiple sclerosis, idiopathic optic neuritis, autoimmune corneal endotheliopathy, sarcoidosis, thyroid diseases and inflammatory bowel diseases. Symptoms are blurry vision, floaters and distortion of central vision. The syndrome is bilateral in 80% of the patients and chronic with periods of exacerbation and remission. Clinical presentation includes: mild to moderate anterior chamber inflammation, thin keratic precipitates in the inferior portion of the cornea, autoimmune endotheliopathy, vitreitis, vasculitis in the peripheral retina, intravitreal "snowballs," retinal "snowbanking," optic neuritis and cystoid macular edema. Cataract and glaucoma are frequent complications. Treatment of intermediate uveitis is based on periocular and oral corticosteroids. Cryotherapy or laser photocoagulation of the peripheral retina are options in patients with snowbanking when there is an insufficient response to periocular or systemic corticosteroids. Imunosuppression may also be used when other therapies fail, and Cyclosporin A is the first drug of choice. Pars plana vitrectomy is indicated in patients with chronic significant inflammation, non-responsive cystoid macular edema, non-clearing vitreous hemorrhage, tractional retinal detachment and epiretinal membranes. The long-term prognosis of intermediate uveitis is usually good, particularly with strict control of inflammation and with proper management of complications. Patients can often maintain a vision of 20/50 or better.