Triamcinolone injections around the eyeballs seen to ease ocular MG
Treatment reduced need for patients to take oral medications, study finds
Periocular (around-the-eyeball) injections of triamcinolone, a corticosteroid, may ease early symptoms of ocular myasthenia gravis (MG) and reduce the need for patients to take oral medications that have more potential side effects, a study has found.
The study, “A controlled clinical study on efficacy and safety of periocular triamcinolone acetonide injection for treating ocular myasthenia gravis,” was published in the journal BMC Ophthalmology.
Unlike generalized MG, which causes widespread muscle weakness and fatigue, ocular MG is limited to the muscles that control the eyes and eyelids, often leading to symptoms like diplopia (double vision) and ptosis (droopy eyelids).
Ocular MG usually treated with oral medications
Treatment generally entails the use of oral medications like pyridostigmine (available as Mestinon and generics), prednisone, or other immunosuppressants. Because these medicines are taken up into the bloodstream, however, they are more likely to cause side effects in the body.
Earlier work suggested periocular injections of the corticosteroid dexamethasone may ease symptoms and help people with ocular MG enter into complete remission, a state where they experience no symptoms of disease. A periocular injection refers to the local administration of a medication directly into the tissues located around the eyeballs, such as the eyelids or the orbits (that is, the eye sockets and surrounding structures).
Now, a team of researchers in China investigated the safety of periocular injections of triamcinolone compared with oral medications, and their effectiveness for treating ptosis and ophthalmoplegia (paralysis of the muscles controlling the eye movements) in ocular MG patients.
The study (ChiCTR1900024285) included 60 patients (37 female and 23 male), ages 13 to 83.
Twenty-two patients were given weekly periocular injections of 20 mg of triamcinolone. Once symptoms eased, injections were given once a month for six months. The remaining 38 patients were treated with an average 60 mg of oral pyridostigmine, taken two to five times daily, alone or in combination with prednisone or an immunosuppressant, for example, tacrolimus (sold as Prograf, among other names), depending on symptoms.
Most patients had positive response after 4 weeks of triamcinolone injections
After four weeks of treatment with triamcinolone, 19 out of the 22 patients had a positive response. Of the 16 patients with ophthalmoplegia, 15 experienced an improvement after treatment, which persisted for up to 12 weeks, or about three months.
Ptosis was scored on a scale from zero (normal) to minus four (completely unable to open the eyelid) before and after treatment. After four weeks of treatment with triamcinolone, the ptosis score had increased by an average of 2.14 points, indicating an improvement.
The degree of ophthalmoplegia was scored on a scale from zero (normal) to minus five (no muscle function). After four weeks of treatment, the score had increased by an average of 2.26 points.
The proportion of patients who had minimal manifestations, defined as having no functional limitations from MG over the course of one year despite some muscle weakness on examination, was higher for triamcinolone-treated patients than for those on oral medications both for ptosis (86.3% vs. 50%) and ophthalmoplegia (75% vs. 30%).
Of the 19 patients who responded well to treatment with triamcinolone for an average of 22.2 months (nearly two years), four (21%) did not relapse and met the criteria for complete stable remission, meaning they had no symptoms and required no treatment for at least one year.
However, among the other 15 patients, nine saw their symptoms return after stopping treatment with triamcinolone. Six (31.6%) relapsed within 2-12 months, and three (15.8%) progressed to mild generalized MG.
Of the 38 patients on oral medications, five (13.1%) entered into complete stable remission. Fifteen (39.4%) experienced a relapse, with nine progressing to mild generalized MG.
At the last follow-up, two patients (10.5%) in the triamcinolone group required oral pyridostigmine to prevent symptoms from coming back compared with 19 patients (50%) who were on oral medications.
Reduced need for maintenance medication in triamcinolone group
“It appears that the treatment in the study [triamcinolone] group was more effective than in the control [oral medications] group in terms of reducing the need for maintenance medication,” the researchers wrote.
Except for intraorbital hematoma (clotted blood in the eye’s orbit), which occurred eight times in five patients, no serious complications with triamcinolone were reported. Side effects reported with oral medications included weight gain (60.5%), headache (13.1%), and impaired glucose tolerance (10.5%).
While the number of patients was small, repeated intraocular injections of triamcinolone “was better and faster at controlling ocular symptoms,” the researchers wrote. “Further research is needed to confirm the long-term efficacy of this treatment and to explore any potential complications.”
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