The utility of entoptic perimetry as a screening test for cytomegalovirus retinitis.

OBJECTIVE To determine the sensitivity and specificity of entoptic perimetry as a noninvasive test for detecting retinal damage due to peripheral cytomegalovirus (CMV) retinitis. DESIGN A masked study comparing entoptic perimetry with fundus photography under 4 experimental conditions (determined by increasing pixel sizes) on 2 separate testing sessions. SETTING Acquired immunodeficiency syndrome Ocular Research Unit at the University of California, San Diego. PATIENTS Twenty-four human immunodeficiency virus-positive and 8 human immunodeficiency virus-negative subjects; 21 eyes with documented CMV retinitis, and 26 eyes that were retinitis free. MEASUREMENTS For each testing session, screening method, and condition, the presence of CMV retinitis was determined for each meridian (i.e., clock hour), each quadrant (consisting of 3 meridians), and each eye (consisting of all meridians); the amount of retinitis was defined as the percentage of meridians or quadrants with CMV retinitis. RESULTS Entoptic perimetry was as sensitive and specific as fundus photography in determining the presence of CMV retinitis. Determination of the amount of CMV retinitis tended to be underestimated by perimetry for larger pixel sizes. CONCLUSION Entoptic perimetry may be an effective and inexpensive alternative to fundus photography for CMV retinitis in hospitals and community clinics.