Association between abnormal contrast sensitivity and mortality among people with acquired immunodeficiency syndrome

Purpose: To investigate the relationship between contrast sensitivity (CS) and mortality among people with acquired immunodeficiency syndrome (AIDS); and to explore the hypothesis that abnormal CS is a marker of systemic, life-threatening microvascular disease.

Design: Longitudinal, observational cohort study.

Methods: We evaluated 3395 eyes of 1706 individuals enrolled in the Longitudinal Study of the Complications of AIDS (1998-2008). CS was evaluated as a risk factor for death, and was compared to the presence of systemic diseases characterized by microvasculopathy (diabetes, cardiovascular disease, stroke, renal disease) and to laboratory markers of those diseases. Abnormal CS was defined as logCS <1.5 (lower 2.5th percentile for a normal control population).

Results: CS was abnormal in 284 of 1691 (16.8%) study participants at enrollment. There was a positive relationship between the presence of abnormal CS at study entry and mortality (relative risk 2.0, 95% confidence interval 1.7-2.3, P < .0001). Abnormal CS was related to the presence of cardiovascular disease, stroke, and renal disease (all P values <or= .01), but abnormal CS remained associated with death even after adjustment for these diseases and for other known predictors of death among people with AIDS. Diseases characterized by microvasculopathy were more often identified as causes of death among individuals with abnormal CS than among those with normal CS, although the strength of the association was moderate (P = .06).

Conclusions: Abnormal CS among people with AIDS is associated with increased mortality, and is independent of other risk factors for death that are monitored routinely. The relationship may indicate life-threatening microvascular disease in other organs.