Diagnostic Utility of Ocular Symptoms and Vision for Cytomegalovirus Retinitis

Abstract

Purpose: CMV retinitis remains a leading cause of blindness in countries with a high burden of AIDS. Although dilated fundus examinations are recommended for those with CD4 counts below 100 cells/µL, in practice only those with poor vision and/or symptoms are routinely referred for screening. Therefore, the predictive value of this common practice should be assessed. Methods: This is a prospective cross-sectional study. Patients with known HIV and a CD4 count of less than 100 cells/µL attending an HIV clinic in Chiang Mai, Thailand completed a standardized questionnaire about visual symptoms and underwent visual acuity testing and dilated fundus examination. Participants without CMV retinitis were invited for repeated examinations every 3 months until their CD4 count exceeded 100 cells/µL. Patient-level statistical analyses were conducted to calculate diagnostic test characteristics, with bootstrapping to account for correlated data. Results: HIV patients with CMV retinitis were more likely to complain of visual symptoms (p = 0.01) compared to those without CMV retinitis, including scotoma (p = 0.0002), itchy or watery eyes (p < 0.0001), and eye pain (p = 0.003); they were also more likely to have visual acuity worse than CF (p = 0.0003). However, the absence of eye symptoms and the absence of poor vision did not strongly affect the probability that a patient did not have disease (negative likelihood ratio 0.56 and 0.76, respectively). Conclusions: Ocular symptoms and poor visual acuity were poor diagnostic indicators for the presence of CMV retinitis. Systemic screening for HIV patients with CD4 count below 100 cells/µl should be carried out to catch the disease at its early stage to avoid blindness