Results of the superior oblique tendon elongation procedure for severe Brown's syndrome

Abstract

Purpose: To evaluate the outcomes of the silicone tendon expander for the treatment of Brown's syndrome.

Methods: This paper consists of 2 parts: a chart review of patients who have under gone the silicone tendon elongation procedure for Brown's syndrome and a survey of the surgical experience of the members of the American Association of Pediatric Ophthalmology and Strabismus. Charts of 15 consecutive Brown's syndrome patients who underwent the superior oblique tendon expander were reviewed by the author from 1987 to 1997. An additional patient referred to the author for management of complications of the silicone tendon expander procedure after surgery elsewhere for Brown's syndrome is reported. The second aspect of the study is a fax survey sent to all 450 members of the American Association of Pediatric Ophthalmology and Strabismus listed in the 1997-1998 directory. Pediatric ophthalmologists were asked to answer questions regarding their experience using the silicone tendon expander for Brown's syndrome.

Results: Of 15 patients operated on by the author, preoperative limitation of elevation in adduction measured -4 in 14 patients and -3 in 1 patient preoperatively. Postoperatively, 14 of the 15 patients showed improved motility, with essentially normal versions in 10 patients (no more than +/- 1 oblique dysfunction); 3 patients were undercorrected (2 mild and 1 severely); and 2 had a consecutive superior oblique paresis (1 mild and 1 requiring an inferior oblique weakening procedure). The 1 patient with a severe undercorrection that did not improve after the silicone tendon elongation procedure showed continued restriction by intraoperative forced ductions after superior oblique tenotomy. Superior oblique tendon was not the cause of Brown's syndrome in this patient. The average final result graded on a scale of 1 to 10 (10 being best) was 8.3. Thirteen of 15 patients (87%) achieved a final result score of 7 or better with a single surgery, and an additional patient was corrected with a second surgery providing an overall success rate of 93%. Ten of the 15 patients had at least 11 months' follow-up, and 6 of the 10 patients showed a delayed improvement over a 4- to 6-month period. Five patients had more than 5 years of follow-up, and 4 (80%) had an excellent long-term outcome (final result, 9 to 10) with a single operations; all 5 had a good final outcome (final result, 7 to 10, mean 9.2) with 1 patient requiring a second surgery. There were no long-term complications, including no extrusions, no restriction of ocular rotations, and no infections. The patient who underwent the procedure elsewhere demonstrated limited movement of the eye to adduction elevation, and there was underaction of the ipsilateral superior oblique muscle. A reoperation performed by the author revealed positive forced ductions up and nasal ward. There were scars and adhesions in the area of the silicone implant, including scar to superior nasal sclera and superior rectus muscle. The silicone implant was removed and scar excised until forced ductions improved. This resulted in improved motility. Thirty-nine AAPOS members reported on 140 patients who had undergone the silicone tendon elongation procedure for Brown's syndrome. Judged by the surgeon on a scale of 1 to 10 (10 being best), 26 surgeons rated 91 patients (65%) as good with a score of 8 to 10, and 14 surgeons rated 18 patients (13%) poor with scores of 1 to 3. Complications were recorded for 9 patients and included scarring and restriction with removal of silicone implant in 4 and spontaneous extrusion in 5. Three of the 5 spontaneous extrusions came from the same surgeon, and in another case a surgeon used a 10 mm length of silicone.

Conclusions: A novel procedure, the silicone tendon expander, is an effective option for correcting Brown's syndrome caused by a stiff or inelastic superior oblique tendon; long-term outcomes are excellent. Proper technique with maintenance of the tendon capsule is critical to the successful outcome of the procedure.