During precision radiotherapy to treat optic nerve sheath meningioma, early improvement in visual function has been seen. This has been difficult to explain biologically. In the present study, we aimed to investigate this rapid improvement in visual function. To this end, we prospectively tested a single patient's visual field (VF) using Humphrey automated perimetry at weekly intervals. The patient exhibited significant stepwise improvement in VF during an intensity-modulated radiotherapy course.
Keywords: Humphrey automated perimetry; Intensity-modulated radiotherapy (IMRT); Optic nerve sheath meningioma (ONSM); Rapid improvement of visual field defect.