Purpose: To determine 1) clinical predictors of an inflammatory syndrome associated with cytomegalovirus (CMV) retinitis (immune recovery vitritis or uveitis [IRV or IRU]); 2) clinical sequelae of IRV; and 3) the effect of corticosteroid treatment on visual acuity.
Methods: A cohort study from the AIDS Ocular Research Unit of the University of California, San Diego, and a case series from the Cleveland Clinic consisted of patients who had acquired immunodeficiency syndrome and inactive CMV retinitis who responded to highly active antiretroviral therapy (HAART) with CD4 T-lymphocyte levels >60 cells/mm3. The cohort was followed for a median of 13.5 months following increase in CD4 count. The authors studied the occurrence of IRV, defined as symptomatic (vision decrease and/or floaters) vitritis of 1+ or greater severity associated with inactive CMV retinitis. Macular edema or epiretinal membrane formation was determined by clinical examination and fluorescein angiography. Five eyes were treated with sub-Tenon corticosteroid injections.
Results: In the cohort study, 19 (63%) of 30 HAART responders developed IRV (26 eyes). The clinical spectrum of inflammation included vitritis, papillitis, macular edema, and epiretinal membranes. Eyes with CMV surface area >30% of the retina were at the highest risk (relative risk = 4.5) of developing IRV (P = 0.03). During follow-up, inflammation persisted without treatment for a median of 20 weeks and 14 patients (16 eyes) developed macular changes. Treatment resulted in vision improvement without reactivation of retinitis. Histology and immunohistochemistry of associated epiretinal membranes showed evidence of chronic inflammation with a predominant T-lymphocyte cell population. In the case series, 3 (38%) of 8 HAART responders developed IRV (4 eyes). All four eyes were treated and resulted in visual acuity improvement of one line.
Conclusions: Symptomatic IRV or IRU develops in a significant number of patients with CMV retinitis following successful HAART. Eyes with CMV surface area >30% of the retina are at the greatest risk. Eyes with IRV respond favorably to antiinflammatory therapy without reactivation of retinitis. Immune recovery vitritis may be the result of an immunologic reaction to latent CMV antigens in the eye in which T-lymphocytes play a role.