Current management of adenoviral conjunctivitis suboptimal, more data may help

By Cheryl Guttman Krader

Las Vegas-Although research has led to improvements in understanding the pathophysiology of adenoviral conjunctivitis and in its diagnosis, there remains a need for further advances, said Anat Galor, MD.

“Adenoviral conjunctivitis remains a significant source of morbidity,” said Dr. Galor, at Cornea 2015 during the annual meeting of the American Academy of Ophthalmology. “It turns out that its pathophysiology is much more complex than previously thought, and we still have a lot to learn in terms of detection and treatment.

“Hopefully, at next year’s meeting, we will have more data from evidence-based research,” said Dr. Galor, associate professor of clinical ophthalmology, Bascom Palmer Eye Institute, University of Miami.

In attempting to diagnose adenoviral conjunctivitis based on signs and symptoms, clinicians are correct only about 50% of the time, and that is because the features of adenoviral conjunctivitis overlap with those of several other infectious entities.

Cell culture represents the gold standard for diagnosing adenoviral infection, but it is expensive and takes a long time to get results. Polymerase chain reaction (PCR) is also a good option, but not standardized.

A new point-of-care test (AdenoPlus, RPS) that detects adenoviral antigens (conserved hexon proteins) is a relatively inexpensive option for rapid, in-office diagnosis.

An initial study including 186 patients with acute conjunctivitis found the test was positive in 25% of patients and had a sensitivity of 89% and specificity of 94% compared with PCR.

Whereas a more recent study found the test’s sensitivity was only about 40%, the trial included patients who had symptoms for up to 2 weeks, which may have been a confounding issue.

“We know that the viral antigens start going down after 7 days,” Dr. Galor explained.

Current management of adenoviral conjunctivitis-which includes use of artificial tears plus cool compresses, membrane debridement, and corticosteroids for patients with membranes and subepithelial infiltrates-is suboptimal. Interventions that have been tested but found ineffective or too toxic include ketorolac, cidofovir, and interferon-alpha.

Dr. Galor said there are 11 treatment trials for adenoviral conjunctivitis registered on clinicaltrials.gov, and these studies are investigating ganciclovir gel, corticosteroids, povidone-iodine, and some novel agents.

She noted there was some initial excitement about the potential for povidone-iodine as it hastens resolution of symptoms.

However, it also causes significant stinging, and the long-term course of the disease in terms of development of subepithelial infiltrates was unaffected.

“The subepithelial infiltrates are the major source of morbidity with this disease,” Dr. Galor said.

Similarly, ganciclovir has been associated with faster symptom resolution in patients with adenoviral conjunctivitis. However, it remains to be seen if it can prevent long-term complications.

“Other approaches include small interfering RNAs, sialic acid constructs, and vaccines. However, we don’t know if these will help with the long-term morbidity,” Dr. Galor said.

Ongoing research is also focusing on understanding more about the virus itself and other factors that predict viral virulence and the clinical course.