Strabismus following endoscopic orbital decompression for thyroid eye disease

Abstract

Endoscopic orbital decompression may be used to treat disfiguring proptosis or sight threatening optic nerve compression in patients with thyroid eye disease. Strabismus is common in thyroid eye disease and frequently follows decompression surgery. We retrospectively reviewed patients undergoing endoscopic decompression for thyroid eye disease, by a single surgeon, from 1994 to 2000. Twenty-three patients (21 female, 2 male) were identified with a mean age of 47.5 years. At presentation, 21 patients had proptosis, 8 optic nerve compression (2 without proptosis) and 11 strabismus (9 complained of diplopia) with a mean BSV score of 24.5 before decompression. Forty orbits were decompressed with a mean decrease in proptosis of 3.3mm. Following decompression, the mean BSV score was 25, and 17 patients had manifest strabismus in primary gaze (3 at near only) of whom 10 had pre-existing strabismus. Five patients had new diplopia (22%). Eleven patients ultimately required strabismus surgery of whom 8 had manifest strabismus before decompression. Following strabismus surgery, the mean BSV score was 37. The final BSV score for those not requiring strabismus surgery was 29. Mean follow-up was 28 months. Endoscopic orbital decompression can effectively treat disfiguring proptosis. Diplopia is a common complication, but pre-existing diplopia may improve.