May also be called: Optic Glioma; Optic Pathway Glioma; Juvenile Pilocytic Astrocytoma An optic nerve glioma (glee-OH-muh) is a type of brain tumor that forms in or around the optic nerve, which connects the eye to the brain. More to Know The brain and central nervous system are made up of nerve cells and glial cells. Glial cells support and protect the nerve cells. When a glial cell has a defect and grows out of control, the tumor that forms is called a glioma. Optic nerve gliomas form along the pathway of the optic nerve, which sends signals to the brain about what the eye sees. Optic nerve gliomas mostly affect kids under age 10 and those with the genetic condition neurofibromatosis type 1 (which causes tumors to grow on nerve tissue). The most typical symptom is progressive vision loss because of the tumor pressing on the optic nerve. With slow-growing tumors, this may be hard to spot at first — especially in younger children who can't describe what they're seeing. Kids also may start tilting their heads or experiencing what seem like developmental delays, such as clumsiness during walking, speech problems, or behavior changes. A condition called nystagmus (when the eyeballs appear to "jitter" by themselves) also might appear. Sometimes, growth problems can happen if the tumor is pressing on the pituitary gland. Doctors diagnose optic nerve gliomas with imaging tests such as MRI (magnetic resonance imaging) or CT scans and vision testing. Children who have these tumors are watched closely to see if the tumor gets worse or improves on its own. Treatment usually involves chemotherapy, and radiation also can be used. Surgery usually isn't done with this type of tumor. Keep in Mind Although optic nerve gliomas are serious tumors, they usually grow slowly, have a high cure rate, and rarely cause blindness. Most kids do well with treatment, and further vision loss usually is prevented. All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts. Back to Articles Related Articles Eyes The eyes are small compared with most of the body's other organs, but their structure is incredibly complex. Learn more about eyes, vision, and common problems with both. Read More Your Child's Vision It's important for kids to have their eyes examined regularly, as many vision problems and eye diseases can be detected and treated early. Read More Brain Tumors Brain tumors are the second most common group of childhood cancers. Treatment requires a very specialized plan involving a team of medical specialists. Read More Cancer Center From treatments and prevention to coping with the emotional aspects of cancer, the Cancer Center provides comprehensive information that parents need. Read More Childhood Cancer Different kinds of childhood cancer have different signs, symptoms, treatments, and outcomes. But today, most kids with cancer get better. Read More Brain and Nervous System Cancers These cancers are the most common type of cancer in children. When discovered early, they often can be cured. Read More Neurofibromatosis Type 1 Neurofibromatosis type 1 (NF1) is a genetic condition that causes benign tumors in and under the skin, often with bone, hormone, and other problems. Learn more about how it's diagnosed and treated. Read More Retinoblastoma Retinoblastoma is a childhood cancer that affects the retina, the area of the eye responsible for sensing light and sending nerve signals to the brain. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.