Endothelial precipitates and laser flare photometry in patients with acquired immunodeficiency syndrome: a screening test for cytomegalovirus retinitis?

Patients with acquired immunodeficiency syndrome (AIDS) who present with cytomegalovirus (CMV) retinitis show pathognomonic endothelial precipitates suggestive of primary anterior uveitis or secondary changes due to a spill-over from the posterior chamber. Laser flare photometry allows quantification of the intensity of anterior affection. We wanted to establish anterior-chamber flare values in AIDS patients with and without CMV retinitis and to find out whether CMV retinitis is preceded by an elevation of the flare value. In all, 25 men with AIDS who presented with CMV retinitis and 27 who did not have CMV retinitis but showed a CD4 count of < or = 200 cells/microliter blood were enrolled in a prospective study. Slit-lamp examination was performed, followed by indirect ophthalmoscopy and laser flare photometry after dilation of the pupil with tropicamide eye drops. Patients with CMV retinitis were followed every 10 days and the others, every 4 weeks. A group of 51 human immunodeficiency virus (HIV)-negative men served as a control group. AIDS patients with CMV retinitis showed a significantly higher flare count in the affected eye (12.4 photons/ms; n = 26) as compared with the unaffected partner eye (4.2 photons/ms; P < or = 0.0001; n = 18) and with eyes of AIDS patients without CMV retinitis (4.1 photons/ms; P < or = 0.0001; n = 50). The count in the latter eyes was also significantly higher than the control value (3.1 photons/ms; P < or = 0.0001; n = 102). Typical reticulate endothelial precipitates were found in 92% of AIDS patients with CMV retinitis. During the study, five eyes of three patients developed a fresh CMV retinitis, but a preceding rise in the flare count was not observed. Laser flare photometry follows the occurrence of pathognomonic reticulate endothelial precipitates. It lags behind the development and the extension of CMV retinitis. Therefore, it cannot be used as a screening test for early detection of CMV retinitis.