Case Summary: A 64-year-old woman visited our clinic complaining of diplopia for 2 days after been undergone 3 cycle radiation therapy with Cyberknife Stereotactic Radiosurgery (800 cGy (Accumulate dose 2,400 cGy)) for treatment a meningioma in the right cavernous sinus. She had a right esotropia of 45 prism diopters in the primary position with a decrease in abduction of the right eye and diplopia in straight, right side gaze. She was diagnosed with right abducens nerve palsy. We observed without special treatment. A diplopia improved after 9 months and only 14 prism diopters was left in the primary position, and she is wearing prism glasses for relief of symptom and on an observation.

Conclusions: Abducens nerve palsy can result from radiation therapy with Cyberknife Stereotactic Radiosurgery.

Ann Optom Contact Lens 2015;14(3):176-180