ABSTRACT
PURPOSE: We report an example of successful operation of rare convergent strabismus fixus, which had previously been mistaken for orbital tumor in private clinics because of severe adduction with unseen cornea. METHODS: A 57-year-old woman had convergent strabismus fixus with inward deviation of the left eye that had gradually progressed since she was around 40. Her cornea was buried in the intraorbital rim. An eye movement examination revealed that the eyeball was fixed to the internal part and that eyeball movement was impossible in all directions. When the forced duction test was performed, strong resistance was shown in all directions when abducted. During surgery, the medial rectus muscle was disinserted after resection of 3.0 mm for the left eye, and lateral rectus muscle tucking of 11.0 mm for the left eye was conducted. Since there was resistance in the inferior oblique muscle by the forced duction test during the operation, inferior oblique muscle myectomy of 4.0 mm was simultaneously performed. RESULTS: In the forced duction test implemented immediately after the operation, resistance subsided considerably and eye movement was shown in all directions, with cosmetically satisfactory results. Optic atrophy was found in the fundus examination after the operation. CONCLUSIONS: Convergent strabismus fixus, which recurs frequently and causes severe limitation of eye movement, was changed from the primary position to orthophoria by medial rectus muscle resection with disinsertion and lateral rectus muscle tucking. The eye movement disorder was improved and a satisfactory result was obtained.