What is it?
Conjunctivitis is the medical term for inflammation of the conjunctiva. There are many causes, the most common of which are infectious conjunctivitis and allergic conjunctivitis.
The conjunctiva is a thin layer of transparent tissue that covers the white of the eye and lines the inside of the eyelids.
Infectious conjunctivitis usually starts in one eye and spreads to the other in a day or two. Patients with conjunctival infection complain of watery, red, gritty and uncomfortable eyes.
The commonest causes of conjunctival infection are bacteria and virus. Most bacterial conjunctivitis will settle in a week without complications. Antibiotic drops may hasten recovery a little.
There are many viruses that can cause conjunctivitis. The most important are the adenoviruses, the same viruses that give rise to chest infections and diarrhoea in children.
There are two types of adenoviral conjunctivitis – pharyngoconjunctival fever and epidemic keratoconjunctivitis. Both are highly contagious.
Pharyngoconjunctival fever is a flu-like illness. Patients usually have a sore throat, a mild conjunctivitis, fever and swollen lymph glands. Severe eye disease is rare.
Epidemic keratoconjunctivitis is a much more severe disease with a greater risk of complications. The conjunctivitis usually develops very quickly and is often quite spectacular. Marked redness and patchy haemorrhages are common. Most patients are otherwise well. Severe corneal disease occurs in 80% of cases.
Testing for adenoviral conjunctivitis
It is now possible to do an on-the-spot’ test for adenovirus, using an ‘immunochromatographic’ test, much the same as a pregnancy test. This is followed up with PCR testing, a slower but ‘Gold standard’ test that takes up to 7 days to perform.
Traditionally the treatment of viral conjunctivitis simply aimed to relieve symptoms and stop the disease spreading to others. Affected individuals were advised that they would be contagious for ten days and should be off work for two weeks. Cool compresses and artificial tears were prescribed to keep the eyes comfortable. Strict hand and face washing practices were encouraged.
These measures are important but new research has also shown that Povidone-Iodine is an effective treatment.
Povidone-Iodine is a very safe antiseptic that is used all over the world to prevent infections in patients having eye surgery.
There is good evidence that Povidone-Iodine eye drops are an effective treatment for patients with adenoviral conjunctivitis and possibly all types of infectious conjunctivitis.
Povidone-Iodine lowers the risk of infecting others, lessens the likelihood of severe visual loss and decreases the time needed off work from fourteen to five days.
Current treatment of viral conjunctivitis in Christchurch
Dr McKellar has developed a protocol for the treatment of viral conjunctivitis which is used by other eye specialists around New Zealand.
Patients with possible viral conjunctivitis are examined at his rooms. If it seems likely that viral conjunctivitis is present an immunochromatographic test is performed and swabs taken for PCR.
Patients are then offered immediate treatment with Povidone-Iodone and are issued with specially compounded eye drops containing Povidone-Iodine and steroids for ongoing use at home. Ongoing reviews are arranged if necessary.