CD4 and cytomegalovirus retinitis: In 1992, Pertel et al6 reported that based on Kaplan–Meier survival curves, the percentage of patients developing CMV retinitis by 27 months with baseline CD4 lymphocyte counts of 0–50, 51–100, and 101–250 cells/mm3 was 41.9%, 26.3%, and 14.7%, respectively (log-rank test, P=0.003).