MG commonly presents with diplopia and ptosis. There are limited studies assessing the validity and performance of multimodal ocular MG assessments. 

We enrolled patients with confirmed MG in the US and Canada. Patients completed questionnaires including demographics, the ocular component of the Myasthenia Gravis Impairment Index (OMGII), the diplopia questionnaire, and symptom satisfaction. Raters assessed extra-ocular movements (EOM), ptosis, and diplopia in different positions; centers with neuro-ophthalmologists quantified ocular alignment using the prism cover test. Patients with a second visit were reassessed with all measures and patient impression of change.  We assessed correlations between the different assessments and compared mean scores between patients satisfied vs. dissatisfied with current symptoms.

We enrolled 52 subjects (37% female; mean age 67± 13 years); mean disease duration 8 years± 9.6, 15 (29%) had generalized disease.  Thirty-two subjects had 2 visits, for a total of 84 assessments. In 56 (71.8%) assessments, diplopia was reported, and in 41 (52.6%) ptosis.  On examination, 32.1% had abnormal EOM, 55.1% diplopia and 70.5% ptosis.  The OMGII total score correlated moderately (r 0.51-0.69, p < 0.05) with most assessments. The OMGII ptosis and diplopia questions correlated highly with ptosis (r 0.73-0.83, p < 0.05), diplopia on exam (r 0.75-0.86, p < 0.05) and prism assessment (r:0.64-0.71, p<0.05). EOM exam had low correlation (r 0.36, p <0.05) with OMGII and diplopia questionnaires (r 0.29, p < 0.05). In 41 (49%) of assessments, subjects reported satisfaction with symptoms, and this was associated with OMGII, diplopia questionnaire, diplopia and prism examination scores, but not to ptosis or EOM examination.

We found varying strengths in relationship between patient-reported outcomes and examination. Patient-satisfaction was associated with patient-reported measures and diplopia/prism scores during examination, but not with ptosis or EOM examination.