Analysis of diplopia associated with thyroid-associated ophthalmopathy requiring surgical treatment

The purpose of this study was to analyze diplopia associated with thyroid-associated ophthalmopathy requiring surgical treatment. Five hundred patients operated upon for diplopia by a single surgeon were included in this study. Stretching of extraocular muscles was evaluated by orbital magnetic resonance imaging (MRI) or computed tomography (CT). Ocular motility was evaluated in 9 positions of gaze using the Hess chart and field of fixation and duction test. Surgical treatment for diplopia was placement of an adjustable suture. Two hundred-twenty-four patients were male (mean age 53.9 years) and 276 patients were female (mean age 52.1 years). Three hundred-seventy patients (70%) had unilateral ocular motility dysfunction and 130 patients had bilateral dysfunction. In patients with unilateral dysfunction, the frequency of each direction of gaze dysfunction was as follows: upward gaze, 63.2%; outward, 6.8%; downward, 16.5%; inward, 0.8%; and complex, 12.7%. In patients with bilateral dysfunction, the frequency of each direction of gaze dysfunction was as follows: 11.5%, 41.5%, 5.4%, 0%, and 41.5% respectively. The majority of patients in this study had unilateral ocular motility. The most frequent direction of gaze restriction was upward in those with unilateral diplopia and outward and complex in those with bilateral diplopia. Stretching of the lateral or medial rectus muscle alone occurred very rarely in this population. (author)