More research needed to assess early corticosteroid therapy against ocular myasthenia gravis

Large, multicenter, randomized prospective clinical trials are needed to assess the effectiveness of early corticosteroid therapy against ocular myasthenia gravis, agreed participants in a debate about the therapy that was held during a symposium on current and emerging controversies in neuro-ophthalmology.

Fifty percent of patients with this chronic disorder present with ocular myasthenia gravis, and 50% to 60% of patients with ocular myasthenia gravis have disease that will progress to a generalized state in 1 to 2 years, said Carlos Filipe C.C. Chicani, MD, of the Federal University of São Paulo, Brazil. He took the side in favor of corticosteroid use in the debate.

"Most of the patients with myasthenia gravis, when treated, can lead full and productive lives," Dr. Chicani said, noting that steroids are not the only treatment option and that ocular manifestations are treated with local therapy.

Retrospective studies have shown that steroids can produce improvement in patients with all degrees of weakness and are of great short-term benefit in most patients with ocular myasthenia gravis, he said, but there are some adverse effects with long-term use (more than 1 year). Also, in addition to helping to relieve symptoms, corticosteroid therapy may prevent generation of the disease.

"Prednisone is better than acetylcholinesterase inhibitors, decreases progression to generalized disease, and when using low to moderate doses, it's considered safe," Dr. Chicani concluded.

Arguing against the routine use of corticosteroids in patients with ocular myasthenia gravis, however, Mario Luis R. Moneiro, MD, also of the Federal University of São Paulo, said, "Many people get better by themselves. Many people adjust to their situation in live. Not all of them have severe ptosis. Some of them have double-vision during only a few hours in the day or in some situations, and they learn how to adjust to their disease."

Treatment is the subject of great debate, he said.

"The goals would be alleviating symptoms and preventing progression to generalized disease," he said.

Only two randomized controlled trials address whether corticosteroid therapy is effective against symptoms in patients with ocular myasthenia gravis, Dr. Moneiro. One enrolled 43 patients and had an outcome measurement of extension of eye movement, he added, and the other study had three patients, and no primary outcome measurement was specified.

"Given the absence of evidence, it is not possible to make any evidence-based related recommendations regarding the effect of corticosteroids" on visual symptoms, Dr. Moneiro said.

Regarding the effectiveness of corticosteroids in preventing progression of disease, he said that neither of the aforementioned trials addressed this issue. Five observational studies have been conducted, "but most of them are retrospective, and they didn't control for all variables . . . and all lack independent assessment of outcomes," Dr. Moneiro said. "The evidence does not support or refute the use of corticosteroids and/or azathiopine to reduce the risk of progression to generalized myasthenia gravis."

Ocular myasthenia gravis is not life-threatening; many times, symptoms are mild and can be alleviated by other means; and spontaneous remission may occur, he said, adding, "The symptoms, many times, do not justify the potential for significant side effects from prolonged use of corticosteroids."

Concluding the session, Lynn K. Gordon, MD, PhD, associate professor, Jules Stein Eye Institute, University of California, Los Angeles, United States, said, "As in every part of medicine, it's a balance. Whether you tip the balance toward steroids or tip the balance against steroids depends on a careful evaluation."

Following up on the remarks of the previous speakers, she reiterated the need for large, multicenter, randomized prospective clinical trials in this area.