EFFECTS OF ORBITAL RADIOTHERAPY ON OCULOM OTOR-MUSCLES IN GRAVES-DISEASE

Purpose Orbital radiotherapy is recognised to be effective in the trea tment of acute Graves' disease. The effect on the oculomotor muscles i s still contraversial. Material and methods To assess this effects, we conducted a prospective study on 15 patients with acute Graves' ophth almopathy. Patients were investigated before radiotherapy, 3 months la ter and at long term (mean = 2 years). To study the extent of the opht halmopathy we chose the following criteria: class IV in the NOSPECS cl assification system, amplitude of gaze, measurement of the thickness o f oculomotor muscles (CT-scan). Results Improvement of the amplitude o f gaze and reduction of the thickness of oculomotor muscles were not s tatistically significant. The oculomotor disorder was unchanged 3 mont hs after radiotherapy. After a long term follow up (mean: 2 years), on ly 5 patients, among those who complained of diplopia before radiother apy, had to be operated, especially large deviations. Conclusion Orbit al radiotherapy does not appear as a direct treatment for oculomotor d isorder in active thyroid related ophthalmopathy, however favorable in direct effects may be effective due to reduction of inflammation. As i t is a harmless treatment, orbital radiotherapy may be proposed as pri mary treatment in active thyroid related ophthalmopathy.