Abstract
Purpose: :
Superior oblique myokymia (SOM) is an eye movement disorder in which patients experience oscillopsia and/or vertical or torsional diplopia. The chronic condition often responds poorly to medical therapy. We investigated clinical features and long-term outcome of patients with SOM who underwent a reverse Harada-Ito (recession or resection of the anterior aspect of the superior oblique tendon) procedure.
Methods: :
After obtaining IRB approval, we evaluated the medical records of all 16 patients with the diagnosis of SOM who underwent the reverse Harada-Ito procedure between 1992 and 2007 at the Cole Eye Institute in Cleveland, Ohio. At time of follow-up, we contacted patients regarding symptom frequency and change compared to pre-surgery symptoms.
Results: :
Sixteen patients underwent surgical treatment for their SOM utilizing the reverse Harada-Ito procedure between 1992 and 2007. There were 3 males (19%) and 13 females (81%). The mean age of onset was 40 years (range, 19 - 56 years of age). Average time between presentation and surgical treatment was 13 months (range, 1 day - 10.4 years). The right eye (63%) was more frequently affected than the left eye (37%). There were no bilateral cases. Oscillopsia presented in 7 patients (44%), diplopia in 5 patients (31%), and both in 4 patients (25%). 11/16 patients (69%) had received prior medical therapy (the others had declined medical therapy). Of the 11 patients on medical treatments for the SOM, 6 (55%) had been on multiple medications prior to surgery. Follow-up for 11 patients (69%) was obtained. Average post-operative follow-up was 6.4 years (range, 1 month - 11 years). Postoperative symptomatic improvement was none in 2/11 patients (18%), 90% in 2/11 patients (18%), and 100 % in 4/11 patients (36%). Three patients reported improvement in symptoms of 50%, 75% and <10%, respectively. Overall, 8/11 patients (73%) reported ≥ 50% improvement in symptoms at time of follow-up. No patients reported worsening of symptoms following surgery. Anatomic abnormalities of the superior oblique muscle were noted in 5/16 patients at surgery. Follow-up for 3/5 of these patients was obtained, and showed improved symptoms of 0%, 50%, and 75%, respectively.
Conclusions: :
The reverse Harada-Ito procedure appears to be a viable treatment for the treatment of SOM. 73% of patients reported ≥ 50% improvement in symptoms. Anatomic abnormalities involving the superior oblique muscle may be associated with SOM.
Keywords: eye movements • ocular motor control