Background
Internuclear ophthalmoplegia (INO) is a disabling condition affecting up to 40% of patients with multiple sclerosis (MS). Management of bilateral internuclear ophthalmoplegia (BINO) with exotropia in MS has been controversial due to the uncertain course of MS. Diplopia associated with INO severely impacts the patient’s quality of life, and therefore treatment should be considered.
Methods
Three patients (ages 28, 62, and 82 years) who had BINO with exotropia and disabling diplopia, secondary to MS, underwent bilateral medial rectus resections with either unilateral or bilateral adjustable lateral rectus recession(s). Alignment was measured pre- and post-operatively, and symptoms were recorded.
Results
Pre-operative exotropia ranged from 40 to 64 prism diopters (pd) for distance fixation and from 50 to 70 pd for near fixation. Pre-operatively all patients had diplopia at distance and near fixation. Immediately following surgery, patients were adjusted to 10 to 18 pd ET at distance fixation with the expectation of an exotropic drift. None of the patients had a tropia at distance and near fixation six months following surgery, with single vision in primary position and reading. Two patients had a two-year follow up examination; one required a small amount of base-in prism for comfortable reading.
Conclusions
Three patients who had BINO with exotropia secondary to MS all benefited from surgery. Surgery should be considered as an option for symptomatic patients who have BINO with exotropia due to MS.