Binocular vision disturbances and eye movement restrictions in patients with thyroid associated ophthalmopathy(TAO)

Abstract

Abstract Purpose To investigate the incidence and associations of various types of double vision and limitations of gaze among patients presenting with ocular complaints related to thyroid associated ophthalmopathy. Methods We included 325 patients (268 female and 57 male) aged 42 to 78 (mean 51.1 +/‐5.2) referred with ocular symptoms and the diagnosis of TAO. 156 sex and age matched, healthy volunteers served as a control group. Eye movements restrictions were investigated and recorded in the four point scale. The degree of exophthalmos was recorded, as well as the degree of horizontal and vertical disparation. Results 59.8% of patients reported significant double vision. 96% of patients complaining of double vision trported that it is intermittent,(29% in primary gaze position and 67% in other than primary). The most common limitation of eye movement was elevation(49%). There is a significant correlation between clinically significant double vision and vertical disparation (P=0.30) as well as asymmetrical exophthalmos (p=0.34). There is no correlation between the amount of exophthalmos and double vision. Conclusion Diplopia is an extremely common presenting sign of TAO. Most patients are troubled by diplopia in different than primary gaze direction. Asymmetrical exophthalmos, and asymmetrical vertical eye muscle involvement are the most significant factors associated with symptomatic diplopia.