Ocular movement disorders and extraocular muscle involvement in Iranian Graves' ophthalmopathy patients.

Purpose: The aim of this study was to evaluate movement disorder patterns and extraocular muscle involvement in Iranian Graves' Ophthalmopathy (GO) patients.

Methods: We examined 75 patients (37 women and 38 men) with GO. Female to male ratio was 0.97 among all patients and 0.72 among restrictive myopathic cases (male 18(58.1%), female 13 (41.9%), P=0.2). Their age ranged from 16 to 66 years; mean age was 35.42+/-11.63 and 33.55+/-10,.31 among patients affected by restrictive enlargement and who did not, respectively.

Results: Orbital CT assessment showed EOM enlargement in 124 out of 150 orbits (82.6%). clinical restriction was evident in 31 (41.3%) out of 75 patients. Bilateral restriction was observed in 14 out of 31 (45.1%). The most frequent type of movement limitation was supraduction limitation followed by abduction, inferaduction, and adduction limitations (59%, 40%, 31.1% and 13.3% respectively). This was compatible with Hess screen results and orbital CT reports in regard of IR, MR, SR and LR involvement. Sixteen out of 75 patients reported diplopia. Mean Hertel exophthalmometry readings were higher in eyes with restrictive myopathy.

Conclusion: This study showed more restrictive myopathy in cases with more extraocular enlargement and positive correlation between severity of inferior rectus enlargement and Hertel reading. A higher rate of male patients in our study may be due to ethnic differences in GO in Iranian patients or due to severity of involvement in this group.