An upcoming systematic review aims to assess the clinical characteristics of ocular myasthenia gravis (MG) as well as the proportion of patients with ocular MG that progress to secondary generalized MG.

Approximately half of the patients have positive antibodies against the neuromuscular junction receptors, acetylcholine receptors, and muscle-specific kinase receptors. However, the true proportion of patients with ocular MG that eventually present with generalized MG remains unknown, with outcome reports varying between 30% and 80%.

The authors consider that a precise understanding of the clinical characteristics of ocular MG and of the proportion of patients that later present with generalized MG is required to guide future clinical trials regarding ocular MG management. 

Read more about MG comorbidities

The study protocol was recently published in BMJ Open.

The review will include studies on adults with ocular MG, with data collected from either the clinical setting or population registries. Studies focusing only on interventions will be excluded from the analysis. Although there will be no geographic or demographic limitations in the analysis, pediatric patients and patients with congenital MG will be excluded.

The primary outcome included in the review will be the proportion of patients that convert to generalized MG. Secondary outcomes include the interval between the time of onset and secondary generalization, immunosuppressive therapy, or thymic surgery for ocular MG, and if the study fulfilled the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis criteria. 

After conducting an extensive search of randomized controlled trials, prospective studies, observational studies, and retrospective studies in medical databases, 2 independent reviewers will individually appraise the studies using the appropriate critical appraisal tools.

The Joanna Briggs Institute critical appraisal forms will be used to perform a methodological quality assessment. The Grading of Recommendations, Assessment, Development, and Evaluation 18 approach for grading the certainty of evidence will be used to create a summary of findings.

“We anticipate this work to demonstrate the value and need for a global collaborative strategy among researchers for the benefit of our patients with ocular MG,” the authors wrote.

Reference

Fang CE, Bokre D, Wong SH. Clinical characteristics of ocular myasthenia gravis and outcomes of secondary generalisation: a systematic review protocol. BMJ Open. Published online September 14, 2022. doi:10.1136/bmjopen-2021-060259