Magnetic resonance imaging of the extraocular muscle path before and after strabismus surgery for a large degree of cyclotorsion induced by macular translocation surgery.

PURPOSE: To evaluate the changes in the location of the extraocular muscles (EOMs) following strabismus surgery to treat a large degree of torsional diplopia induced by macular translocation surgery. METHODS: Six consecutive patients who underwent macular translocation surgery with 360 degrees of retinotomy and subsequent strabismus surgery were studied. Magnetic resonance imaging (MRI) was performed before and after the surgery. The angle made by the line connecting the center of the orbit and the center of each rectus muscle and the horizontal was measured. The changes in these angles before and after strabismus surgery were studied. RESULTS: The average rotation of the globe after strabismus surgery was 28 degrees (SD = 7.21; range, 17 degrees -39 degrees ). The average measured EOM shift was -0.3 degrees (SD = 8.04; range, -20.4 degrees to 20.2 degrees ). CONCLUSIONS: Despite large torsional rotation of the globe, there was no corresponding torsional repositioning of the deep paths of the rectus muscles. The paths of the operated muscles were essentially unchanged.

Superior oblique palsy with class III tendon anomaly.

PURPOSE: To describe the clinical findings and surgical results of superior oblique palsy with class III tendon anomaly. DESIGN: Observational case series. METHODS: One hundred and forty-one cases of congenital and idiopathic superior oblique palsy were operated on by one surgeon (M.S.) between September 1, 1995 and August 31, 2007. The superior oblique tendons were explored in 26 cases. Among these, five cases were found to have the distal end of the tendon inserted into the Tenon capsule. Preoperative eye alignment, visual acuity, stereopsis measured with Titmus stereo acuity tests (Stereo Fly SO-001; Stereo Optical Co, Chicago, Illinois, USA), and magnetic resonance imaging findings were collected from the patients' records. Main outcome measures included preoperative eye position, surgical results, and stereoscopic acuity. Stereopsis and the amount of vertical deviation were compared in cases with class I, II, and IV tendon anomalies. RESULTS: A total of eight surgeries were performed on five patients with class III superior oblique tendon anomaly. Three muscles were operated on for each patient. The amount of vertical deviation was not significantly different from other types of tendon anomaly. Patients with class I to III tendon anomalies obtained good stereopsis after strabismus surgery, whereas cases with class IV anomaly achieved only limited stereopsis. The number of surgeries performed was significantly higher in cases with class IV anomaly. CONCLUSIONS: Without careful search of the Tenon capsule, the condition can be misdiagnosed as an absent tendon. Strengthening the superior oblique tendon in the Tenon capsule can improve the alignment significantly.