Case Description
A 43-year-old female presented with right eye redness and pain of
gradual onset and insidious course. She had diabetes mellitus for 25
years controlled by insulin. Her best corrected vision was 20/20
bilaterally with 12/12 color vision and no afferent pupillary defect.
She had mild right ocular motility limitation. External exam showed
eyelid edema and 23 mm protrusion of the right eye compared to 20 mm in
the left by exophthalmometry. There was also mild right upper eyelid
retraction with increased inferior scleral show (Figure 1A). Slit-lamp
examination showed dilated right conjunctival vessels with normal
anterior and posterior segments. Orbital MRI revealed right extraocular
muscle enlargement with tendon sparing (Figure 1B). Laboratory
investigations showed normal free-T3, free-T4, and thyroid-stimulating
hormone (TSH) levels but positive TSH-receptor antibodies and she was
diagnosed with unilateral active thyroid-related eye disease (TED) and
prescribed 60 mg/day of oral prednisone. After 2 weeks, however, she was
intolerant to steroid due to uncontrollable blood sugar levels and was
rapidly tapered off treatment and prescribed 10 mg of methotrexate
weekly as monotherapy. Six months later she experienced marked
improvement (Figure 1C) and was gradually tapered off methotrexate
without relapse.
TED usually occurs with hyperthyroidism but can also rarely occur with
hypothyroidism or euthyroidism.1 It can be unilateral
or bilateral, and in cases of euthyroidism, requires the detection of
anti-thyroid antibodies for diagnosis. The mainstay of treatment of
moderate to severe active TED is glucocorticoids, however, methotrexate
monotherapy can be safe and effective in cases of glucocorticoid
intolerance.2