The authors present a prospective cohort study with the aim of investigating how symptoms of ocular myasthenia gravis (OMG) fluctuate throughout the day, over a 2-month period, and following treatment with pyridostigmine. A total of 12 individuals with myasthenia gravis underwent repeated orthoptic assessments within a 6-month period. The same tests were repeated at several time points within the same day, between 8–10am, 12–2pm and 4–6pm. The assessments included Hess screen testing, palpebral fissure height measurements, quantitative myasthenia gravis (QMG) scoring and activity of daily living (ADL) questionnaire. The study reported that both diplopia and ptosis generally worsened as the day progressed, supporting the well-documented concept of fatigability as a key feature of myasthenia gravis. Ptosis showed a significant response to pyridostigmine, whereas strabismus and diplopia improved less consistently. Over the 2-month follow-up period, most participants experienced gradual improvement in their symptoms, reflected by reductions in both QMG and ADL scores. The authors suggest that orthoptic measurements may provide a useful objective method for monitoring disease activity and treatment response. The use of repeated quantitative assessments throughout the day provides valuable insight into symptom fluctuation and helps explain why diagnosis can sometimes be challenging. The findings regarding the differing response of ptosis and diplopia to pyridostigmine are useful for clinical practice. The authors acknowledge several limitations including a small sample size and a predominance of older male participants, which restricts the generalisability. The majority of patients were already receiving treatment, which may also have influenced the findings. It contributes useful evidence regarding the dynamic nature of OMG and highlights the value of orthoptic assessments as a tool for both diagnosis and monitoring of treatment response.
Fluctuation of ocular myasthenia gravis symptoms characterised by orthoptics
Reviewed by Lauren R Hepworth
The spurious palsy - Fluctuation of ocular myasthenia gravis symptoms characterized by orthoptics.
CONTRIBUTOR
Lauren R Hepworth
University of Liverpool; Honorary Stroke Specialist Clinical Orthoptist, Northern Care Alliance NHS Foundation Trust; St Helen’s and Knowsley NHS Foundation Trust, UK.
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