AIM: To evaluate the lacrimal gland parameters and their correlation with clinical examination in patients with thyroid-associated ophthalmopathy(TAO)using orbital magnetic resonance imaging(MRI).

METHODS: A total of 38 patients(76 eyes)with TAO were selected as case group, and 26 patients(52 eyes)who matched the gender and age with case group and volunteered to accept examination were selected as normal control group. Patients in case group were categorized into active TAO group and inactive TAO group according to the modified clinical activity score(CAS). The exophthalmos was evaluated on T1WI after obtaining the MRI images, the longest lacrimal gland length, width, and the biggest area in axial and coronal images were evaluated on T2WI, and the maximum T2 value and mean T2 value of the lacrimal gland were recorded.

RESULTS: There were no significant differences in age, gender and exophthalmos between active TAO and inactive TAO(P>0.05). The area of lacrimal gland was higher in active TAO than that in inactive TAO, and was higher in inactive TAO than that in control group in coronal and axial section(all P<0.01). The length of lacrimal gland in coronal and axial section was higher in the active TAO than that in the inactive TAO and the control group(all P<0.05). The width of lacrimal gland in coronal and axial section was higher in active TAO and inactive TAO than that in the control group(all P<0.05). The maximum T2 value in the active TAO was higher than that in the inactive TAO and control group, and the inactive TAO was higher than that in the control group(all P<0.05). The average T2 value in the active TAO was higher than that in the inactive TAO and control group(all P<0.05). CAS was positively correlated with lacrimal gland area in axial, coronal section and maximum T2 value(all P<0.01).

CONCLUSION: The lacrimal gland is significantly enlarged in patients with TAO, especially in active TAO. The lacrimal gland area in axial, coronal section and maximum T2 value could be potentially utilized as valuable radiographic biomarkers for the activity of TAO.