Evaluation of a new self-screening chart for cytomegalovirus retinitis in patients with AIDS

AIDS patients often present without visual symptoms despite severe vision-threatening cytomegalovirus (CMV) retinitis. A new self-examination chart, the Teich Target (copyright 1993, Steven A. Teich, pat. no. 370259), which tests the central 45° of vision, was evaluated for its ability to screen AIDS patients for CMV retinitis. It was compared with the Amsler grid (which tests the central 20° of vision) in 50 consecutive AIDS patients referred for ophthalmologic evaluation by a single practitioner. Of 19 patients found to have CMV retinitis, 12 (63%) noted scotomas with the Teich Target compared with 7 (37%) with the Amsler grid (p < 0.05). Overall, 13 of 20 (65%) infectious retinitis cases were detected by the Teich Target and 7 of 20 (35%) with the Amsler grid (p < 0.05). All scotomas noted on the Amsler grid were detected by the Teich Target. Four visually asymptomatic patients with newly diagnosed CMV retinitis noted scotomas only with the Teich Target. Both methods detected a branch retinal artery occlusion, but only the Teich Target detected a quadrantanopsia due to cerebral toxoplasmosis. There were no false positives with either method. In this small series, the Teich Target was more effective than the Amsler grid in screening AIDS patients for CMV retinitis primarily because it detected lesions beyond the central 20° of vision. Peripheral CMV retinitis beyond the central 40° occurred in 37% of patients and was not detected by either method. The Teich Target therefore augments but does not replace periodic ophthalmologic evaluations. The Teich Target may have potential utility for home use as a patient self-screening test for CMV retinitis or for mass screening in an AIDS clinic.