Adenoviral Conjunctivitis

Adenoviral conjunctivitis is a very common eye infection that is easily transmitted. Though not usually a cause of vision loss, it does have considerable morbidity as well as high social costs measured in time lost from school and work.

Causes

Adenovirus is the most common cause of viral conjunctivitis and accounts for almost 90 percent of cases. Other causes include herpes simplex, herpes zoster and picornaviral infection. Adenovirus presents milder morbidity than these, although there is the risk of sub-epithelial corneal infiltrates that persist after the acute phase of adenoviral conjunctivitis has ended. The infiltrates can trigger an irregular astigmatism and other symptoms on the ocular surface.

Diagnosis

There are features to help the professional determine what type of conjunctivitis is presenting. A viral conjunctivitis often presents with lid swelling and follicular conjunctivitis. Findings may also include preauricular lymphadenopathy as well as epiphora. Bacterial conjunctivitis is characterized by a mucopurulent discharge. Itching may be the presenting factor in allergic conjunctivitis. Clinical signs of viral and bacterial conjunctivitis may overlap, making an accurate diagnosis challenging.

Until recently the culture and polymerase chain reaction, or PCR, has been the state of the art for diagnosing viral pathogens, but it is slow, expensive, and not suitable for office testing.  Results can take days. Now however, there is a simple, in-house test, the RPS Adeno Detector Plus, which has sped up and simplified the testing and diagnosis. This immunochromotographic assay is accurate and easy to use. It produces results in approximately ten minutes, so that the patient may be sent home with appropriate treatment and counseling.

Counseling is very important because adenovirus conjunctivitis is very contagious and the virus is resilient, and able to live for long periods on almost any surface. Epidemics have been known to break out in daycare centers, barracks, swimming pools, and offices. Having a simple and speedy test for the virus is a real advantage for both patient and clinician, as it enables proper counseling, and since it can rule out bacterial conjunctivitis it spares the patient the possible risk of antibiotic use if the pathogen proves to be viral.

Treatment

Once viral conjunctivitis has been diagnosed, there is little a doctor can offer in the way of treatment. Palliative care, such as eye washes and cold compresses to soothe the swollen lids, is about all that can be suggested. Though in the past topical steroids were often prescribed, recent studies have shown that these agents can lengthen the number of days of viral shedding. In the case of subepithelial infiltrates topical steroids have their use. Animal studies demonstrate that topical steroid and diluted povidone iodine may neutralize extracellular virus as well as speed healing. This regime also has the ability to reduce viral load on the eye surface.

Most anti-virals have no effect on adenoviral conjunctivitis, though there is some promise in ganciclovir ophthalmic gel. Ganciclovir has been shown to be effective against some adenoviral serotypes in animal experiments. If the studies bear out, it may soon be another weapon in the arsenal to treat adenoviral conjunctivitis.