What Is Optic Nerve Glioma?
An optic nerve glioma (also called an optic pathway glioma) is a slow-growing brain tumor in or around the optic nerve. The optic nerve connects the eye to the brain. As the tumor progresses, it presses on the optic nerve, causing vision problems. While these are serious tumors, they have a high cure rate.
- Optic nerve glioma accounts for five percent of all childhood brain tumors.
- Nearly 75 percent of optic nerve gliomas, which may affect one or both eyes, occur in children younger than ten years old. Most children are younger than five years old at the time of diagnosis.
- The optic system is located near the brain’s hormone center. Therefore, an optic nerve glioma can sometimes affect the body's endocrine functions, such as hormone production, salt and water balance, appetite, and sleep.
- Blindness occurs in approximately five percent of cases.
At Dana-Farber/Boston Children's Cancer and Blood Disorders Center, specialists across disciplines come together to provide children with the best possible care and treatment. We bring together pediatric oncologists and ophthalmologists through our Childhood Glioma Program, part of our comprehensive Brain Tumor Center to treat the tumor and care for all aspects of the eye, including visual system development.
Causes and Symptoms of Childhood Optic Nerve Glioma
As a parent, you undoubtedly want to know what may have caused your child’s tumor. In most cases, the cause of optic nerve glioma is unknown. There’s nothing that you could have done or avoided doing that would have prevented the tumor from developing.
Optic nerve glioma is more common in children with a genetic condition called neurofibromatosis 1 (NF1). NF1 can cause tumors to form, and optic pathway glioma appears in about 15 percent of children with the disease. In a majority of these cases, the tumor stops growing and disappears forever on its own without treatment.
Brain tumors can cause various symptoms in children based on their age and the tumor’s location. Optic nerve glioma symptoms may resemble other more common conditions or medical problems, such as needing glasses to correct poor vision. It is important to consult your child's physician for a diagnosis.
The most common symptoms are:
- Vision problems such as squinting, difficulty reading, or turning to see things out of the corner of the eye.
- Proptosis (eyeball protrusion) occurs when the tumor has grown to the extent that it pushes the eye outward from the socket (an eye with proptosis has very little vision).
- Hormonal problems, including abnormal growth, weight gain or loss, endocrine dysfunction (such as having to urinate frequently), or early puberty.
How We Diagnose Childhood Optic Nerve Glioma
A complete and accurate diagnosis is the first step in treating your child. Your child’s physician will review their medical history and perform vision exams. The doctor will also order various diagnostic tests, including comprehensive imaging studies.
After all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and outline the best possible treatment options.
How We Treat Childhood Optic Nerve Glioma
We personalize each child’s treatment based on many factors, including their age, overall health and medical history, as well as the tumor’s characteristics and disease extent.
Most often, we treat optic nerve glioma with chemotherapy. Chemotherapy is a drug treatment that interferes with the cancer cell's ability to grow or reproduce, thus shrinking the tumor and stabilizing or improving vision.
Chemotherapy can stop the progression of optic pathway glioma in most cases. But if your child's tumor is resistant to chemotherapy, radiation therapy may also be an option. Radiation therapy uses high-energy rays (radiation) from a specialized machine to damage or destroy cancer cells and shrink tumors.
While we don’t commonly perform surgery to treat optic nerve glioma, it can sometimes relieve symptoms and improve vision. Our expert pediatric neural surgeons have extensive experience determining whether surgery is the right option for your child.
If the tumor has affected your child's endocrine system (a network of gland controlling hormones), they may also need hormone replacement therapy, possibly for the rest of their life.
Once treatment is complete, your child will receive continued care and support through our pediatric cancer survivorship programs, including the Stop & Shop Family Pediatric Neuro-Oncology Outcomes Clinic for pediatric brain tumor survivors. These services address health and social issues, ranging from motor function evaluation and physical therapy to return-to-school and learning programs.
We also provide specific resources for children with vision challenges, including Boston Children’s Hospital’s Low Vision Service and Vision Therapy Service.
Children will typically have a follow-up MRI every three months for a year, then every six months for another year, and then yearly after that. Throughout, your child will have a vision exam every three months.