Ultrasonic measurement of ocular rectus muscle thickness in patients with Graves’ ophthalmopathy

The aim of this study was to evaluate changes in extraocular muscle thickness and to assess its correlation with the degree of proptosis in patients with Graves’ ophthalmopathy (GO).
Material and methods. A total of 242 patients (207 females and 35 males) with Graves’ ophthalmopathy were enrolled into the study (GO group). Their mean age was 53.83±14.49 years. In addition, we examined an age-matched (53.51±12.79 years) control group of 40 healthy persons. All the participants underwent ophthalmological examination, including eye protrusion measurement and ultrasonographic evaluation of extraocular muscles thickness.
Results. The mean exophthalmos in the GO and control groups was 17.84±2.79 mm and 16.0±1.58 mm, respectively. The enlargement of inferior rectus muscle was recorded in 92.1% of patients, lateral rectus muscle in 81.2%, and medial rectus muscle in 50.8% (P<0.001). A significant correlation between exophthalmos and muscle thickness sum was found in the GO group (Spearman correlation coefficient, 0.515; P<0.0001).
Conclusions. Graves’ ophthalmopathy is more frequent in medium-aged women than men. A significant enlargement of inferior, lateral, and medial straight muscles was noticed in the GO group. With increasing proptosis, the sum of the muscle thickness was increasing, and exophthalmos moderately correlated with muscle thickness sum.