Radiotherapy for thyroid orbitopathy. Effects on extraocular muscle balance
W. B. Wilson and M. Prochoda
Department of Ophthalmology, University of Colorado Health Sciences Center, Denver, USA.
OBJECTIVE: To investigate the effects of radiotherapy on the restrictive
ophthalmopathy and strabismus that occur with Graves' orbitopathy. DESIGN:
A prospective study of patients with motility disturbances due to thyroid
orbitopathy, followed by serial quantitative measurements of ocular
restrictions and deviations, both before and at 1 and 6 months after
treatment with high-energy radiotherapy. SETTING: Urban subspecialty
private practice. PATIENTS: Thirty-three consecutive patients with
restricted extraocular movements and diplopia secondary to thyroid
orbitopathy who were treated with radiotherapy were seen during an 8-year
period. MEASURES: Maximal horizontal and vertical ductions, plus ocular
deviations in primary and reading positions of gaze, were quantitatively
evaluated by one clinical investigator to ensure consistency. RESULTS:
Statistically significant improvement in gaze restriction on supraduction
and improvement of vertical and horizontal strabismus were demonstrated at
follow-up visits after treatment. CONCLUSIONS: Although statistically
significant improvement of motility disturbances were demonstrated after
radiotherapy, there was less than desirable functional improvement of
restrictive ophthalmopathy and strabismus; thus the usefulness of
radiotherapy was limited when it was used alone to treat diplopia.
