A 13-year-old girl with a right intraorbital optic nerve glioma (ONG) was referred to our glaucoma clinic because of uncontrolled intraocular pressure (IOP) in her right eye. The IOP reached as high as 80 mmHg. Several months earlier, she had undergone stereotactic image-guided robotic radiosurgery using the CyberKnife for her ONG; the mass had become smaller after treatment. Her visual acuity was no light perception. Slit lamp examination revealed rubeosis iridis, a swollen pale optic disc, and vitreous hemorrhage. After medical treatment, the IOP decreased to 34 mmHg, and no pain was reported. Although the mass effect of an ONG can cause neovascular glaucoma (NVG), this case shows that stereotactic radiosurgery may also cause NVG, even after reducing the mass of the tumor. Patients who undergo radiosurgery targeting the periocular area should be followed carefully for complications.
Keywords: Neovascular glaucoma; Optic nerve glioma; Radiosurgery.