Identify underlying allergy aetiology

Aplethora of effective antihistamines does little to relieve ocular allergies when complicated by other concomitant factors, said Dr Michael B. Raizman, at the 29th annual Current Concepts in Ophthalmology conference held in association with the Wilmer Eye Institute.

"You would think allergy would be easy to treat," said Dr Raizman, associate professor of ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA. "We have the best antihistamines in the world. They are incredibly effective, yet our patients still come in complaining. They've tried everything, and nothing is working. Why is that?"

Obvious allergic conjunctivitis

This condition is seasonal and caused by pollens in the air. Patients may complain that the overthecounter (OTC) eye drops they use no longer work, Dr Raizman said. The most common reason for this type of failure for allergy treatment is the presence of other conditions of the ocular surface.

"[More than] 75% of treatment failures are caused by either dry eye or blepharitis," he said.

"You must treat the allergy and the under­lying dry eye or blepharitis as well," Dr Raizman said. "Sometimes, many patients can have all three of these - to varying degrees."

The presence of dry eye may not always be obvious. In such cases, lissamine green staining and rose bengal staining are often useful.

"Try to think of all three together, and treat all of them," he said. "Patients may be describing what sound to you like allergies. You can treat their allergies all you want, but if their blepharitis is bothering them, they will view the allergy treatment as a failure."