Clinical trial of topical disodium cromoglycate in vernal kerato-conjunctivitis

The results of a double blind placebo-controlled clinical trial of topical administration of disodium cromoglycate drops to one eye and placebo drops to the other eye in the treatment of vernal kerato-conjunctivitis in twenty-two patients indicates that the drug has a significant therapeutic effect. Patients vary in the degree of their response, but nearly all are helped. From long-term uncoded administration of the drug to both eyes in sixty-one patients, it has been found that supplementation with topical steroid may be required for short periods to control acute exacerbations of the disease. However, it is now possible to reduce or avoid the use of steroids in many cases, and thus greatly reduce the dangers of steroid-induced glaucoma or steroid-enhanced herpetic keratitis. No side effects have been noted other than occasional irritation apparently due to thiomersal, the bacteriostatic agent used in the trial preparation. This irritancy, which was not detected in preliminary animal experiments, or in trials in volunteers, occurred only during periods of exacerbation of vernal disease. The findings suggest that there is an important Type I hypersensitivity phenomenon in the pathogenesis of the disease, and although other mechanisms are probably also involved, modification of this Type I reaction is of therapeutic benefit.