A new nomogram and web-based survival calculator can accurately predict generalization-free survival in patients with adult-onset ocular myasthenia gravis, according to a new study published in the journal Neurological Sciences. The calculator has “favorable applicability,” the authors of the study said.

To identify risk factors associated with progressing from ocular myasthenia gravis to generalized myasthenia gravis in patients with adult-onset disease, a team of researchers from China conducted a retrospective, observational cohort study in 435 patients with ocular myasthenia gravis with an age of onset of more than 14 years.

Read more about the types of myasthenia gravis

The disease of more than half of these patients (54.5%) transformed into generalized myasthenia gravis after a median of 1.1 years. The 6-month generalized conversion rate was 31.7%, while the 1-year rate was 49.8% and the 2-year rate was 65.4%.

The researchers identified factors that were significantly associated with the generalized conversions as being early age of disease onset, male gender, concomitant autoimmune diseases, presence of anti-acetylcholine receptor antibodies, repetitive nerve stimulation abnormalities, presence of thymoma, and prednisone treatment.

The nomogram that the researchers developed showed good performance in predicting the possibility of generalization-free survival.

When they performed a subgroup analysis based on whether or not the patients were treated with prednisone, the researchers found that the treatment could better predict generalized conversions in male patients with no thymoma and those with no other concomitant autoimmune diseases.

“The model provides an optimal estimation in predicting the probability of [generalization-free survival] in adults with [ocular myasthenia gravis], with favorable accuracy and predictability,” the researchers concluded.

Myasthenia gravis is a rare autoimmune disease affecting the neuromuscular junction. The disease mostly affects the muscles of the eyes, face, throat, neck, and limbs but may progress to generalized myasthenia gravis.

Reference

Bi Z, Cao Y, Gui M, et al. Dynamic nomogram for predicting generalized conversion in adult-onset ocular myasthenia gravis. Neurol Sci. Published online December 5, 2022. doi:10.1007/s10072-022-06519-5