Optic Nerve Sheath Meningioma (Kennerdell Case 34, PPT)

History: A 54-year-old woman who presented with progressive painless right visual loss for several years. Visual acuity at presentation was counting fingers at one foot in the right eye and 20/20 in the left eye. She had a right Afferent Pupillary Defect, but full motility. Anatomy: Optic Nerve Sheath. Clinical: Diagram of marked loss of visual field with only a small island of vision remaining in the right eye. Diagram showing the slight recovery of visual field following 5,000 cGy radiation therapy in divided doses. Disease Diagnosis: Meningioma. Neuroimaging: The enhancing lesion on an axial MRI scan of the right Optic Nerve from the globe to the apex of the orbit. A non-enhanced scan of the lesion shows the enlarged right Optic Nerve. Presenting Symptom: Progressive painless right visual loss, right Afferent Pupillary Defect. Treatment: Radiation therapy: 5,000 rads in divided doses.