The relationship between extraocular muscle thickness and exophthalmos degree in patients with thyroid associated ophthalmopathy

Abstract

Objective To study the relationship between extraocular muscle thickness and exophthalmos degree in patients with thyroid-associated ophthalmopathy (TAO),so as to provide a scientific basis for guiding clinical treatment.Methods Forty seven patients diagnosed with TAO from May 2005 to May 2011,in the 451 Hospital of the People's Liberation Army were chosen in this study,and divided into TAO group(23 cases) and treatment group (24 cases).Meanwhile,another 32 healthy people were selected as control.Extraocular rectus muscles (including the medial rectus muscle,lateral rectus muscle,superior rectus muscle and inferior rectus muscle) of all participants were measured with B-scan ultrasonography,and exophthalmos degree with Hertel exophthalmometer.Results The thicknesses of medial rectus in control group,TAO group and treatment group were (3.35 ± 0.25),(4.38 ± 0.85),(3.58± 0.52)mm,respectively; the thicknesses of lateral rectus muscle were (2.95 ± 0.61),(4.24 ± 0.75),(3.65 ± 0.42)mm,respectively; the thicknesses of superior rectus muscle were (3.15 ± 0.20),(4.65± 0.68),(4.01 ± 0.15)mm,respectively; the thicknesses of inferior rectus muscle were (3.17 ± 0.72),(4.75 ± 0.52),(3.71 ± 0.91)mm,respectively; the sums of binocular rectus thickness in these three groups were (21.95 ± 0.65),(28.02 ± 1.51),(22.95 ± 0.65)mm,respectively; the difference between the three groups was statistically significant(F=2.32,2.43,2.25,2.17,5.63,all P ＜ 0.05),and TAO group was significantly higher than that in the control group and in the treatment group(all P ＜ 0.05),while there was no statistically significant between the control group and the treatment group(all P ＞ 0.05).The eyes exophthalmos degree in TAO group and treatment group were (16.82 ± 2.46),(14.52 ± 1.83)mm,respectively.The sum of the rectus muscle thickness and eyes exophthalmos was positively correlated(r =0.65,0.58,all P ＜ 0.05).Conclusions Extraocular muscle thickness in patients with TAO is positively correlated with exophthalmos degree,and using B-scan ultrasonography to detect the changes is practical for clinical diagnosis and treatment. Key words: Thyroid gland; Graves ophthalmopathy; Exophthalmos