Parameters predicting outcomes of strabismus surgery in the management of Graves' ophthalmopathy

Abstract

Ocular dysmotility is a common feature of Graves' ophthalmopathy and frequently requires strabismus surgery. We reviewed the short-term results of strabismus surgery for Graves' ophthalmopathy to determine pre- and perioperative parameters predictive of postoperative outcome. A retrospective review of Graves' ophthalmopathy patients who underwent strabismus surgery. Outcomes were correlated with preoperative and operative characteristics. The main outcome measure was field of binocular single vision score. Residual postoperative strabismus was considered a secondary outcome. Preoperative characteristics examined included age and laterality at onset, sex, disease activity, smoking status, and treatment for Graves' ophthalmopathy. Good outcome was defined as field of binocular single vision >50% and heterophoria in the primary position. Moderate outcome was defined as a field of binocular single vision 1% to 50% with heterotropia but with correctable diplopia in the primary position using prisms or head tilt. Poor outcome was defined as no measurable field of binocular single vision and intractable diplopia. Fifty patients were identified: 28 women, 22 men; mean age, 54 years (SD +/- 12.8). Thirty-seven (74%) had good and 13 (26%) had moderate or poor outcomes. Preoperative characteristics that were associated with good outcomes were symmetry of orbitopathy at Graves' ophthalmopathy onset (chi(2) = 7.5, p = 0.001) and earlier timing of surgery (t = -2.9, p = 0.003). Relative symmetry of orbitopathy at onset and a shorter time interval between onset of orbitopathy and surgery, while allowing for disease stability, are predictive of a good outcome following strabismus surgery for Graves' ophthalmopathy.