To determine immunochemical and clinical differences in thyroid-associated ophthalmopathy (TAO) patients with restrictive strabismus and without strabismus.

A retrospective chart review of 15 TAO patients with strabismus (25 eyes) and 24 TAO patients without strabismus (39 eyes) who presented to the Ophthalmology Clinic between August 2011 and December 2013 was performed. Visual acuity, intraocular pressure (IOP), Hertel exophthalmometry, soft tissue score, and enlargement of extraocular muscles on computed tomography (CT) were obtained and compared in each group. Thyroid related autoantibody (thyroid-stimulating hormone receptor antibody, TRAb; thyroid peroxidase antibody, TPOAb; anti-thyroglobulin antibody, TgAb) titers and positive rates were obtained at the time of diagnosis or before treatment and analyzed.

The gender and smoking proportion were not significantly different between the 2 groups. The mean age of TAO patients with strabismus was 52.53 years and of TAO patients without strabismus 40.33 years ( p = 0.004). The differences in visual acuity and IOP between the 2 groups were not significant. Hertel exophthalmometry showed less proptotis in the TAO with strabismus group than the TAO without strabismus group (16.84 mm versus 18.67 mm). The soft tissue score was not significantly different. The extraocular muscle enlargement rate of TAO with strabismus was significantly higher than in TAO without strabismus group. In the TAO with strabismus group, TRAb level was higher than in the TAO without strabismus group ( p = 0.021).

The TAO with strabismus group was older and had higher positive rate, level of TRAb, and extraocular muscle enlargement rate on CT than the TAO without strabismus group. Furthermore, proptosis was less definite in the TAO with strabismus group.