Ocular Myasthenia Gravis Treatment Response and Conversion Rate in a Tertiary Neuro-Ophthalmology Clinic in Indonesia

Purpose: To evaluate ocular myasthenia gravis(OMG)treatment response and conversion rate of OMG to generalized myasthenia gravis(GMG)in a neuro-ophthalmology clinic of an ophthalmology unit in a tertiary referral hospital in Indonesia. Methods: This is a retrospective chart review. Study subjects were new OMG patients who had not received treatment previously. The clinical profile of patients, initial and final treatment regimen, treatment response, final diagnosis, and OMG conversion rate and duration were evaluated. Treatment response was evaluated as improvement in diplopia or ptosis after one month of initial treatment, and were categorized as optimal improvement, partial improvement, unchanged, and inconclusive. OMG conversion rate and duration were determined by evaluating the final diagnosis and were classified as OMG, GMG, and conversion to GMG. Results: Among the 50 patients with OMG, 74% were prescribed pyridostigmine monotherapy, while 26% were prescribed an additional oral steroid as the initial treatment regimen. While the majority of patients(75.9%)experienced improvement, 24.1% patients showed no change in ocular symptoms following initial treatment administration. Neither the presence of diplopia or limited ocular movement in the initial clinical presentation nor the initial steroid use was associated with treatment response(p≥ 0.05). OMG to GMG conversion rate was 12.8%, with a mean conversion duration occurring at 11.9±9.3 months since diagnosis. Conclusions: The majority of OMG patients experienced improvement following initial treatment regimen administration. While OMG conversion rate was low, conversion to GMG mainly occurred during the first year since diagnosis.