Are topical antihistamines and mast cell stabilisers for treating allergic conjunctivitis effective and safe?

Cochrane: Are treatments with eye drops of antihistamines and mast cell stabilisers, alone or in combination, effective and safe in people with seasonal and allergic conjunctivitis? The main outcome measure was eye symptoms reported by participants, including eye itching, irritation (burning sensation), watering eyes (tearing), and photophobia (dislike of light). We found 30 trials. Conjunctivitis refers to inflammation of the conjunctiva, which is the thin tissue that covers the sclera (white part of the eye). Seasonal and perennial allergic conjunctivitis is the most common type of allergic conjunctivitis. Although this condition does not cause sight loss, it can cause intense itching and eye watering. Eye drops with antihistamines or mast cell stabilisers, or both are commonly used.


The evidence is current to July 2014. Among the 30 studies reviewed there were 17 different comparisons, including 4344 participants ranging in age between 4 and 85 years. The duration of treatment ranged from one to eight weeks. Ten out of 30 studies were funded by the drug manufacturer (8 totally and 2 partially funded); 20 studies did not report any source of funding. There was inconsistency in the way the effect of treatment was measured and reported. Overall risk of bias was low.

Topical antihistamines and mast cell stabilisers, alone or in combination, are safe and effective for reducing symptoms of seasonal and perennial allergic conjunctivitis. We found insufficient evidence to discern which topical antihistamines and mast cell stabilisers are the most effective.

 

Authors' conclusions: 

It seems that all reported topical antihistamines and mast cell stabilisers reduce symptoms and signs of seasonal allergic conjunctivitis when compared with placebo in the short term. However, there is no long-term data on their efficacy. Direct comparisons of different antihistamines and mast cell stabilisers need to be interpreted with caution. Overall, topical antihistamines and mast cell stabilisers appear to be safe and well tolerated. We observed a large variability in outcomes reported. Poor quality of reporting challenged the synthesis of evidence.