title: Predictability of horizontal versus vertical muscle surgery outcomes in thyroid eye disease.
abstract: Surgical repair of vertical muscles in thyroid eye disease (TED) is believed to yield more unpredictable results than horizontal muscle surgery. The purpose of this study is to determine if the short-term outcomes for strabismus surgery in TED are equally predictable for horizontal and vertical muscle surgery. We retrospectively reviewed the charts of 27 consecutive patients who underwent strabismus surgery for TED from a single surgeon's practice. Eligibility for inclusion in the study included biochemically stable thyroid disease for at least a year and stable orthoptic measurements for at least 6 months prior to surgery. Nine patients had surgery only on vertical rectus muscles, three only on horizontal, and fifteen on both vertical and horizontal rectus muscles. Mean follow-up was 2.4 ± 5.2 months. In primary gaze at 6 m, a mean horizontal deviation of 16.6 ± 22.3 PD, and a mean vertical deviation of 19.7 ± 14.1 PD were measured pre-operatively. Post-operatively, this measured 2.3 ± 8.4 PD horizontally and 2.1 ± 7.8 PD vertically (p = 0.933). There was no statistically significant difference between post-operative horizontal and vertical deviations in elevation, depression, adduction, and abduction. Nine patients required reoperation to attain satisfactory ocular alignment; seven of these cases involved repeat surgery on vertical muscles, while two cases required operation on both horizontal and vertical muscles. Results suggest that surgical outcomes of both horizontal and vertical muscle surgery are equally predictable in stable TED; however, reoperation rates were higher for vertical muscles compared to horizontal muscles.
authors.affiliation: Ivey Eye Institute, St. Joseph's Health Care London, University of Western Ontario, 268 Grosvenor Street, London, ON, N6A4V2, Canada. Yiannis.Iordanous@londonhospitals.ca.
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Iordanous
authors.affiliation: Ivey Eye Institute, St. Joseph's Health Care London, University of Western Ontario, 268 Grosvenor Street, London, ON, N6A4V2, Canada.
authors.forename: Sapna
authors.initials: S
authors.lastname: Sharan
authors.affiliation: Department of Ophthalmology, Dalhousie University, Halifax, NS, Canada.
authors.forename: Johanne
authors.initials: J
authors.lastname: Robitaille
authors.affiliation: Department of Ophthalmology, Dalhousie University, Halifax, NS, Canada.
authors.forename: Leah
authors.initials: L
authors.lastname: Walsh
authors.affiliation: Department of Ophthalmology, Dalhousie University, Halifax, NS, Canada.
authors.forename: G Robert
authors.initials: GR
authors.lastname: LaRoche
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D049970:Graves Ophthalmopathy / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D012086:Reoperation; D012189:Retrospective Studies; D013285:Strabismus / Q000601:surgery*; D016896:Treatment Outcome
keywords: Strabismus; Surgical outcomes; Thyroid eye disease