Relaxed muscle positioning improves ocular alignment in dysthyroid strabismus surge

J Pediatr Ophthalmol Strabismus. 2011;15(4):321-325

Issue: February 10, 2012

An intraoperative relaxed muscle orientation technique improved ocular alignment and reduced diplopia in a majority of patients undergoing strabismus surgery for thyroid eye disease, a study found.

"Patients with more severe disease were more likely to require reoperation," the study authors said. "In the relaxed muscle positioning technique of treating strabismus for thyroid eye disease, the most restricted muscles, as determined by preoperative assessment of ductions and intraoperative forced ductions, are recessed to the positions where they rest freely on the globe without tension. The purpose of this technique is to identify preoperative characteristics that are predictive of reoperation and evaluate outcomes."

The retrospective study included 58 patients with thyroid eye disease who met inclusion criteria for surgery between 1999 and 2009. Forty-five patients underwent one strabismus surgery, 10 patients had two surgeries and three patients underwent three surgeries.

The mean follow-up interval was 12.1 months (range: 1.5 months to 11.5 years).

Outcomes were rated excellent (no diplopia), good (diplopia requiring low correction) and poor (chronic diplopia despite correction).

Study results showed excellent outcomes in 48 patients (83%), good outcomes in four patients (7%) and poor outcomes in six patients (10%). Data showed a significantly increased likelihood of reoperation in patients with multiple treatment modalities for Graves' disease (P = .03) and larger horizontal deviations (P = .03), the authors said.

Nicholson et al present an alternative surgical procedure for these normally difficult thyroid eye disease patients where they allow the disinserted muscle to be operated on to relax back to the point where they will do a planned recession instead of predetermining the amount. They have had excellent results with their technique and those of us who perform these surgeries should strongly consider its merit when presented with their next thyroid eye disease case. In addition, the authors identified those cases that should be recognized to cause the need for probable reoperation. This included a large angle esotropia that can mask a vertical deviation requiring further surgery and those with three restricted muscles in one eye, which would require additional surgery to prevent anterior segment ischemia. They mention other predictive factors including multiple treatment modalities for Graves’, diplopia before orbital decompression, primary horizontal strabismus, and large angles of horizontal plane strabismus. The authors are to be commended for this paper and contribution to our treatment of thyroid eye disease patients.

– Robert S. Gold, MD
OSN Pediatrics/Strabismus Section Editor
Disclosure: Dr. Gold has no relevant financial disclosures.