Abstract
Purpose:
To evaluate medical histories and ophthalmic features in patients with dysthyroid optic neuropathy (DON).
Methods:
Seventy two eyes from 42 patients with DON (17 males and 25 females, 58 ±12 years old), who were contentiously treated at Olympia Eye Hospital from 2006 to 2007, were involved in this study. Medical and smoking history and data for thyrotrophin receptor antibodies (TRAb) and thyroid stimulating antibodies (TSAb) by blood test were obtained from the patients in addition to ophthalmic examination, including visual acuity, visual field, funduscopy and MRI examination of the orbit.
Results:
Among the 42 patients, 40 had Graves’ disease, and 2 had hypo Graves’ disease. Six and 4 patients had diabetes and hepatitis, respectively, while 27 patients were smokers or ex-smokers (64.3%). In patients with Graves’ disease, 2 pregnant patients and 4 patients with post-radioiodine therapy were found. TRAb and TSAb were positive in 31 of 37 patients (83.8%) and 38 of 38 (100%), respectively. The best corrected visual acuity was less than 20/200 in 15 eyes (20.8%) and 20/25 or better in 19 eyes. In all patients, abnormal visual field and reduction of critical flicker fusion frequency were obtained. Proptosis measured by Hertel exophthalmometer was revealed as 18.1 ± 2.8 mm (range 12-24 mm). In 36 eyes (50%) optic disc was normal appearance. Orbital MRI demonstrated optic nerve compression for the rectus muscle enlargement in all eyes. Enlargement of all 4 rectus muscle was seen in 4 eyes, 3 rectus muscle in 21 eyes, 2 rectus muscle in 5 eyes, and 1 rectus muscle in 1 eye. In T2 image of MRI, 25 of 67 eyes showed superior ophthalmic vein enhancement.
Conclusions:
In patients with DON, proptosis was not severe. In all eyes with DON, there was visual field loss, TSAb positive, and compressed optic nerve on orbital MRI. Thus those tests are recommended for patients with dysthyroid ophthalmopathy, especially when DON is suspected.