Chickenpox vaccine may cause eye inflammation

Although rare, a vaccine for chickenpox and shingles which has been in use for more than 20 years and is considered an essential medicine by the World Health Organization, can cause corneal inflammation in some patients, says a new study.

The finding suggests that primary care physicians should be aware of possible vision side-effect of the varicella zoster virus vaccine on patients with a history of eye inflammation.

However, the researchers recommended that the majority of patients still be regularly vaccinated against chickenpox and shingles.

"Keratitis, or inflammation of the clear layer on the front of the eye, is a vision issue that can cause serious complications or even permanent damage to your vision if left untreated," said Frederick Fraunfelder, chair of the department of ophthalmology at University of Missouri School of Medicine in the US.

"By studying case reports from national and international registries, we found at least 20 cases of keratitis occurred in children and adults within a month of administration of the chickenpox and shingles vaccine,” Fraunfelder said.

"While this is a rare occurrence, it is important for physicians to know when giving the vaccine to individuals who have a history of the condition because it could be reactivated by the vaccine," Fraunfelder noted.

Fraunfelder is the director of the National Registry of Drug-induced Ocular Side Effects, an international effort to gather information on adverse ocular events associated with drugs, chemicals or herbs. 

The registry collects data from the US Food and Drug Administration spontaneous reporting database, the WHO spontaneous reporting database and reports from physicians who submit to the registry.

A review of the database and previously published reports found 20 cases of keratitis with a close relationship to administration of the vaccine. 

For adults, symptoms of keratitis developed within 24 days of vaccination. For pediatric patients, symptoms of inflammation developed within 14 days.

The study was presented at the 2015 meeting of the American Academy of Ophthalmology in las Vegas.