Correlation between Intraocular Pressure and Thickness of Extraocular Muscles, the Severity and Activity of Thyroid-associated Orbitopathy.

Aim: To establish the correlation between intraocular pressure (IOP) and thickness of extraocular muscles (EOM), the severity and activity of thyroid-associated orbitopathy (TAO).

Materials And Methods: 50 patients with TAO were included in the study. They all underwent a thorough ophthalmic examination, Goldmann tonometry (mm Hg) and computer tomography of the orbits, the muscle thickness sum (MTS) of each eye being measured in millimeters. According to the activity of TAO, the patients were divided into two groups - with and without activity, and according to the severity of the disease - into 6 groups: Group 1 ('O') had only subjective symptoms, group 2 ('S') had soft tissue symptoms, group 3 ('P') - proptosis, group 4 ('E') - ocular motility disorders, group 5 ('C') - corneal damage, and group 6 ('Si') - visual impairment; Results: TAO activity was registered in 21 patients (42 eyes, 42%) with MTS 23.39±3.81 and IOP 18.43±4.16. Twenty-nine patients (58 eyes, 58%) with MTS 19±3.21 and IOP 15.98±4.59 showed no TAO activity. The IOP within the groups, in terms of severity, was as follows: group 1 - 19.92+4.05; group 2 - 14.5±2.55; group 3 - 18.04±4.51; group 4 - 18.2±5.05; group 5 - 20.5±4.5; group 6 - 21.5±4.95. A correlation between the IOP and MTS was found.

Conclusions: The IOP in patients with TAO depends on the thickness of the EOM, as well as on the activity and severity of the disease.