IN the era of highly active antiretroviral therapy (HAART), a symptom-oriented screening approach is both efficient and effective for the evaluation of cytomegalovirus retinitis (CMV-R) in patients with human immunodeficiency virus (HIV) disease, a new study confirms.

Speaking at the annual meeting of the Association for Research in Vision and Ophthalmology, Charles David Brodrick MD presented the results of a prospective study of 197 consecutively examined HIV patients seen at the Parkland Eye Clinic in Dallas , Texas , US between October 2001 and January 2003.

Researchers employed standardised forms to collect subjective patient data, including the reason for visit and documentation of any new ocular symptoms. All patients received a complete ophthalmic examination including slit lamp biomicroscopy and a dilated fundus examination with an indirect ophthalmoscope.

The investigators assessed the presence of CMV-R and prepared a detailed drawing of the retinal findings. Patients with new ocular symptoms were compared to routine visit patients to determine which symptoms were statistically significant.

At the time of the initial examination, 72% of the HIV patients were symptom-free. Of the patients with new ocular symptoms, 21% had

CMV-R compared to 0.8% of asymptomatic patients. The symptoms of visual field defect and flashes, along with retinal haemorrhages on examination, were the most significant predictors of disease.

"What we found is that based on a symptom-oriented approach, we had a high detection rate for CMV-retinitis, especially based on visual field defects. We also found that with the symptom-oriented screening approach we missed one patient who had

CMV-retinitis, who did not report any symptoms.

"I think that is one of the limitations of the study - that we did miss an asymptomatic patient with CMV-retinitis. We need an updated screening system which combines symptomatology with a new HAART era guideline based on CD4+ counts," Dr Brodrick said.

One aim of the current study was to re-evaluate the relevance of older screening guidelines that were established before HAART became the standard of care for HIV disease. The old screening guidelines were strictly based on CD4+ T-cell counts. Low CD counts indicate immune depletion with an associated increase in the risk for opportunistic infections.

The introduction of HAART has broadly increased CD4+ cell counts in AIDS patients. It allows AIDS patients with initially lower CD4+ counts to live longer and decreases the number and incidence of opportunistic infections.

"We believe patients affected by CMV-retinitis will have symptoms which can aid in the detection of CMV-R without sole reliance on CD4+ counts. The symptoms which are presented, such as blurred vision, visual field defects, flashes and floaters, are seen in patients with CMV retinitis as a natural course of the disease.

"We are suggesting that a visual field defect could be a significant predictor of disease because, any area of the retina that is affected by CMV-R will present as a scotoma, a blind spot in the vision; with immune reconstitution therapy, we now don't know the appropriate CD4+ cutoffs for screening." he explained.

The current study results point to the need for new guidelines that will have to incorporate a symptom-oriented approach with the CD4+ count. Dr Brodrick thinks this approach will avoid routine screening in patients who are not at risk for CMV-R. That will relieve some of the time and inconvenience of sending patients to be screened just because they have HIV when they are not at risk for cytomegalovirus retinitis.

"I think this will streamline the process and really narrow down screening for CMV to the population we think is at risk. The message for the clinician is that based on symptoms and a revised CD4+ strata, a better job can be done screening the HIV patient population for CMV retinitis," Dr Brodrick told EuroTimes.