Ocular myasthenia presenting as progressive external ophthalmoplegia

Ophthalmologic manifestations in myasthenia gravis: presentation and prognosis

We investigated the ophthalmologic manifestations and factors that influence outcomes in patients with myasthenia gravis (MG). We retrospectively analyzed the prevalence of neuro-ophthalmologic findings and clinical and outcome measures of 100 consecutive patients (53 males, 47 females), aged 55.7 ± 17.5 (range 15-85) years with an established diagnosis of MG. Forty-eight patients had purely ocular symptoms at the onset of disease (OMG) and 52 patients presented with generalized symptoms (GMG). Overall, 21 patients presented with extraocular muscle (EOM) weakness. Bilateral EOM weakness was seen in 12 patients, and unilateral EOM weakness was seen in nine patients. Diplopia responded partially to immunosuppressive treatments in 60% of patients with ophthalmoparesis. Twenty-five (52.1%) patients with ocular-onset MG converted to secondary GMG at a mean time of 14.5 months. Patients who developed secondary GMG were younger and had an earlier age of disease onset when compared with patients with pure OMG (p < 0.05). Patients with secondary GMG presented more frequently with ptosis and diplopia (72% vs. 28%) compared with patients with pure ocular MG who presented more frequently with isolated ptosis (66.7% vs. 33.3%) (p = 0.02). Remission and minimal manifestation status were achieved in 50 (79.3%) of all patients with a clinical follow-up ≥ 3 years. Poor outcome was associated with the presence of thymoma (p < 0.05). Myasthenic ophthalmoparesis is bilateral and heterogeneous and partly responds to treatment with immunotherapy. Younger patients with ptosis and diplopia at disease onset had an increased risk of secondary GMG. The presence of thymoma increases the risk for poor prognosis.

Strabismus in chronic progressive external ophthalmoplegia

PURPOSE

To elucidate the patterns of strabismus and ophthalmoplegia associated with chronic progressive external ophthalmoplegia (CPEO) confirmed by mitochondrial DNA (mtDNA) deletions in Asians.

METHODS

A total of 10 patients confirmed to have mtDNA deletion associated with CPEO were included. Long-range PCR encompassing the entire mtDNA was carried out. In the cases with mtDNA deletion, the exact deletion ranges of mtDNA were identified by sequencing. A full ophthalmologic examination including prism and alternate cover test in the primary position, evaluation of ductions and versions, and binocularity was performed in 10 patients with confirmed mtDNA deletions associated with CPEO.

RESULTS

All of the patients showed ophthalmoplegia as well as ptosis, even after eyelid surgeries. Ophthalmoplegia was symmetric between both eyes in nine patients (90%) while one patient (10%) showed asymmetric ophthalmoplegia with esotropia and left hypotropia. Among the nine patients with symmetric involvement, four patients (44%) showed exotropia, three (33%) had exotropia with vertical deviation, and the remaining two patients (22%) showed orthotropia. Five out of 10 patients (50%) complained of diplopia associated with strabismus, four of whom (80%) had vertical deviation. Three out of five patients (60%) without diplopia showed exotropia of 20 prism diopters (PD) to 50 PD.

CONCLUSIONS

Exotropia with/without vertical deviation is the most common form of strabismus in Asian patients with CPEO and only one of them showed a small angle of esotropia. Ophthalmoplegia could be asymmetric in 10% of CPEO patients.