Low CD4+ count increases risk for CMV retinitis in patients with HIV/AIDS

Review looks at risk factors for developing ocular complications in these patients.

Issue: January 2013

Despite the overall effectiveness of highly active antiretroviral therapy, patients infected with HIV/AIDS remained at risk for developing cytomegalovirus retinitis, a chief cause of ocular morbidity and predictor of mortality in this patient population, according to a review.

In particular, the incidence rate of cytomegalovirus (CMV) retinitis in patients with a CD4+ T-cell count of 50/µL or less was nearly 100 times the rate for the entire cohort of 1,600 patients with AIDS enrolled in the Longitudinal Study of the Ocular Complications of AIDS (LSOCA), who did not have CMV retinitis at enrollment, according to the review, published in Current Opinion in Ophthalmology.

Although the overall rate of new cases of CMV retinitis has decreased 80% to 90% since the introduction of highly active antiretroviral therapy (HAART) in 1996, the rate seems to have stabilized, Jennifer E. Thorne, MD, PhD, study co-author, told Ocular Surgery News.

“Because mortality has declined, an increasing number of patients are living with HIV and AIDS. Those patients could be at risk for developing CMV retinitis if they experience a drop in CD4+ count, by HAART therapy becoming less effective over time due to viral resistance or the need to stop therapy due to side effects or because of patient noncompliance,” Thorne said.

Patients who develop CMV retinitis or other ocular opportunistic infections may experience rapid visual acuity and visual field loss, as well as an increased risk of death, Thorne said.

CMV retinitis was associated with an increased risk of death among patients with low CD4+ T-cell counts who do not achieve immune recovery, according to a 5-year outcomes study published by LSOCA. The review authors said, “In multivariate analysis, CMV retinitis confers a 60% increase in overall mortality, and, in those patients not immune recovered, a 110% increase.”

Thorne said that early screening or detection of CMV retinitis with adequate follow-up treatment is a key strategy for preventing severe vision loss in patients with HIV/AIDS. In patients with a CD4+ count of less than 50/µL, a dilated fundus exam is recommended approximately every 3 months; for a count less than 100/µL, examination is recommended every 6 months, she said.

Syphilitic uveitis

Another ocular opportunistic infection is syphilis, which appears to be on the rise, Thorne said.

“But CD4+ count is less of a risk factor. Patients with HIV are at risk for syphilis and ocular complications due to syphilis, regardless of their CD4+ count,” she said.

HAART may have a less dramatic impact on the epidemiology and clinical ramifications of ocular syphilis than on CMV retinitis in HIV-infected patients, according to the study. A meta-analysis of ocular syphilis in this population found that luetic eye disease was found in more than 50% of cases.

Vision changes

Thorne said it is important that ophthalmologists be aware of the neuroretinal disorder — declines in color vision and contrast sensitivity and minor changes in visual field due to vascular changes of the retina — that can be seen in patients with HIV or AIDS.

Such changes are more subtle than ocular infections, but they can cause symptoms for the patient, Thorne said.

“In fact, some studies suggest worsening of contrast sensitivity can also be a risk factor for mortality in AIDS patients,” she said.

In the 12 years that she has spent researching the ocular complications of HIV/AIDS, Thorne said she has observed changes in the eyes of patients with HIV/AIDS that are similar to age-related changes but occur at younger ages in these patients.

“We have seen an increase in the number of eyes with narrowing of the retinal blood vessels and cataract. These findings appear to be occurring in AIDS patients at a younger age than what has been reported in the general population,” Thorne said. – by Bob Kronemyer

References:

Butler NJ, et al. Curr Opin Ophthalmol. 2012;doi:10.1097/ICU.0b013e328358ba85.
Jabs DA, et al. Ophthalmology. 2010;doi:10.1016/j.ophtha.2010.03.031.
Jabs DA, et al. Ophthalmology. 2005;doi:10.1016/j.ophtha.2004.10.049.

For more information:

Jennifer E. Thorne, MD, PhD, can be reached at The Wilmer Eye Institute, Johns Hopkins University, 600 N. Wolfe St., Woods Bldg., Room 476, Baltimore, MD 21287; 410-955-1966; email: jthorne@jhmi.edu.
Disclosure: Thorne receives grant funding from the National Eye Institute of the National Institutes of Health.