Author’s Disclosure Block: Edward Tran, none; Gautham Nair, none; Edsel Ing, none

Abstract Body
Purpose: Ocular myasthenia gravis (OMG) is an autoimmune disease characterized by autoantibodies targeting postsynaptic proteins at the neuromuscular junction, leading to weakness and fatigability of the ocular muscles. While OMG is primarily a clinical diagnosis, serological antibody testing is often used, however the diagnostic value of these tests remains uncertain. This meta-analysis aims to assess the diagnostic utility of anti-acetylcholine receptor (AChR) antibodies and anti-muscle-specific kinase (MuSK) antibodies by evaluating their prevalence in patients with ocular myasthenia gravis. Study Design: Systematic Review and Meta-Analysis Methods: Studies were extracted from CINAHL, Embase (Ovid), Medline (Ovid), and additional gray literature. Using R version 4.4.1 on RStudio, the meta-analysis was conducted using the meta package. Depending on the level of heterogeneity, either a fixed-effects or random-effects model was used to pool the data. Funnel plots were used to assess publication bias. Results: A pooled analysis of 44 studies involving 4,937 patients with ocular myasthenia gravis (OMG) revealed that 59% (95% CI: 52–66%) of patients tested positive for anti-AChR antibodies, whereas pooled analysis of 34 studies with 3,380 patients showed that only 5% (95% CI: 2–9%) tested positive for anti-MuSK antibodies. Of the 62 studies (N = 5,180), only 4 patients were double seropositive for anti-AChR and anti-MuSK. Regarding the clinical utility of anti-AChR positivity in OMG, 5 studies of 527 patients indicated a 35% (95% CI: 3–90%) prevalence of thymomas. Four studies (n = 259) showed that anti-AChR positive patients had a 1.82 times greater risk (95% CI: 1.15–2.88) of progressing from OMG to generalized myasthenia gravis. Conclusions: Patients with ocular myasthenia gravis (OMG) commonly test positive for anti-AChR antibodies, although not always, while anti-MuSK antibodies are rarely detected. However, being anti-AChR positive in OMG is associated with a worse prognosis, including a higher prevalence of thymomas and an increased risk of disease generalization.Given the low prevalence of Anti-MuSK positivity, the limited data on differences between seronegative and Anti-MuSK-positive OMG, and the associated cost of Anti-MuSK antibody testing, routine testing may not offer significant clinical insight.