Strabismus surgery for internuclear ophthalmoplegia with exotropia in multiple sclerosis

Multiple sclerosis in ophthalmology: beyond optic neuritis

Disorders of the visual system are one of the main features of multiple sclerosis (MS), and have a great impact on the quality of life of patients. Although optic neuritis is the most frequent manifestation, there are other ophthalmological processes not related to neuritis, a knowledge of which is very useful in the management of patients with MS. These abnormalities are described, grouped into impairments of the afferent pathway, efferent pathway, or upper cerebral areas. Additionally, the main ophthalmological side effects of the drugs currently used in the control of MS are described.

Ocular Motor Manifestations of Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system leading to disability, especially in young patients. Acute or chronic lesions of MS within the brainstem and the cerebellum frequently result in ocular motor disorders.

EVIDENCE ACQUISITION

This review encompasses the spectrum of ocular motor disorders in patients with MS emphasizing prevalence, examination findings, diagnostic features, functional consequences, classification of MS course, and management of these disturbances of ocular motility.

RESULTS

Ocular motor manifestations of MS can occur acutely in relapse or chronically, the latter as a consequence of previous relapses or as a chronic course of the disease. The most frequent and specific acute ocular motor manifestation is uni- or bilateral internuclear ophthalmoplegia (INO). The most frequent chronic manifestations include INO and cerebellar ocular motor disorders such as gaze-evoked nystagmus, saccadic hypermetria, and lack of vestibulo-ocular reflex inhibition. The most disabling syndrome is pendular nystagmus.

CONCLUSIONS

The high prevalence of ocular motor manifestations emphasizes the importance of neuro-ophthalmological examination among patients with MS. Because chronic manifestations may cause minimal or no symptoms, a systematic investigation of the most common manifestations should be performed in daily practice. Appropriate treatment may improve visual outcome in some of these ocular motor disorders.

Transposition surgery for internuclear ophthalmoplegia

PURPOSE

To report outcomes of an extraocular muscle transposition procedure for surgical correction of internuclear ophthalmoplegia.

METHODS

Records of patients operated on between January 1999 and May 2011 were reviewed to identify patients treated with an extraocular muscle transposition procedure for internuclear ophthalmoplegia. Indications for this procedure included a known unilateral or bilateral internuclear ophthalmoplegia with a large-angle exotropia, a moderate adduction limitation, and a large-angle exodeviation in primary position. All patients underwent orthoptic evaluation preoperatively and postoperatively. Examination included assessment of subjective complaints, visual acuity, deviation in diagnostic positions of gaze, and limitation of ocular motility.

RESULTS

Five patients were identified. The mean reduction in exodeviation at distance after surgery was 59 ± 25 prism diopters, giving a mean percent reduction in exodeviation of 99.6% ± 0.1%. Four of five patients achieved primary position orthotropia at distance; the remaining patient had 2 prism diopters of exodeviation. One patient who had a residual exodeviation after the initial transposition procedure did not have accompanying ipsilateral lateral rectus recession, but achieved orthotropia with a subsequent ipsilateral lateral rectus recession.

CONCLUSION

Transposition surgery is an effective option for surgical treatment of patients with internuclear ophthalmoplegia with exodeviation and diplopia when combined with ipsilateral lateral rectus recession.

Multiple sclerosis. Part I: neuro-ophthalmic manifestations

PURPOSE OF REVIEW

This update includes topics relating to multiple sclerosis (MS) for the ophthalmologist.

RECENT FINDINGS

Interest in the ophthalmology of MS is highlighted by the substantial amount of original research presented at recent medical conferences. At the 2008 World Congress on Treatment and Research in Multiple Sclerosis, 33 of 898 abstract presentations related to ophthalmology. The most represented topics were optical coherence tomography (OCT) and radiology of the visual system (19/33 posters). The 2009 North American neuro-ophthalmologic society (NANOS) conference featured MS-related topics in 6 of 24 platform presentations. This article reviews recent advancements in the neuro-ophthalmology of MS.

SUMMARY

Multiple sclerosis results in various ophthalmic abnormalities. Optic neuritis is the most widely studied visual disturbance in MS, but other unusual visual manifestations such as Charles Bonnet syndrome or the Pulfrich phenomenon also occur. OCT is used to measure thickness of the retinal nerve fiber layer. Because thinning of this layer in MS represents axonal loss, OCT is being used to evaluate neuroprotective treatments. The efferent visual system, in particular the medial longitudinal fasciculus pathway, may be a way to measure body temperature-induced changes in MS.