Optic Nerve Hypoplasia (Includes Septo-Optic Dysplasia)

What is optic nerve hypoplasia?

Optic nerve hypoplasia (ONH) is a present-at-birth (congenital) condition where your optic nerve is small or underdeveloped. Optic nerves help you see by sending messages between your eyes and your brain. ONH can lead to vision problems like vision loss and irregular eye movements.

In addition to an underdeveloped optic nerve, this condition can also affect how other parts of your brain develop, including:

• Midline brain abnormalities: The septum pellucidum and corpus callosum are tissues and nerve fibers that separate the two halves of your brain. They might not develop fully or at all.
• Pituitary gland hypoplasia: Your pituitary gland is at the base of your brain (below the hypothalamus). It regulates many bodily functions, including hormone production. An underdeveloped pituitary gland may not produce enough or any hormones.

Sometimes, ONH is identified as septo-optic dysplasia (SOD or de Morsier syndrome). The reason why is that research shows all cases of SOD affect optic nerve development, but only 5% to 10% of ONH cases affect midline brain (septum pellucidum) development.

How common is optic nerve hypoplasia?

Optic nerve hypoplasia affects an estimated 1 in 10,000 children in the United States. ONH is the leading cause of blindness in children before age 3 in the United States.

Is optic nerve hypoplasia serious?

Yes, optic nerve hypoplasia can be serious. The severity varies from person to person but may affect a child’s ability to see. If it’s accompanied by pituitary problems, it can affect their body’s ability to produce hormones. Symptoms can be life-threatening if they involve the pituitary gland. Let your child’s healthcare provider know right away if you notice any symptoms of ONH or concerning behaviors.

What are the symptoms of optic nerve hypoplasia?

Symptoms of optic nerve hypoplasia that affect one or both eyes may include:

• Visual impairment (mild to severe).
• Rapid eye movements (nystagmus).
• Crossed eyes (strabismus) or eye misalignment (esotropia).
• Difficulty focusing on objects.

Midline and other brain development abnormalities can cause:

• Problems with cognitive development (intellectual disability).
• Seizures.

Pituitary gland hypoplasia affects how your child’s body releases hormones. This can lead to:

• Difficulty regulating body functions like thirst and hunger, sleep and body temperature.
• Slower-than-expected growth (height) and short stature.
• Hypothyroidism.
• Delayed sexual maturation.
• Low blood glucose (hypoglycemia).
• Diabetes insipidus.
• Jaundice.

Does optic nerve hypoplasia cause blindness?

Some cases of optic nerve hypoplasia cause severe visual impairment or blindness. Other cases may only cause mild vision symptoms that may improve slightly as your child gets older. Your child’s healthcare provider will let you know how this condition affects your child’s vision.

What causes optic nerve hypoplasia?

Researchers aren’t sure of exactly what causes optic nerve hypoplasia. Studies suggest it could be a combination of environmental factors and genetics that play a role. Optic nerve hypoplasia can occur in the setting of fetal alcohol syndrome.

Not all cases have a known genetic cause, but some do. Rare genetic changes (mutations) that pass to a child during conception in an autosomal recessive pattern (from both biological parents) that lead to ONH include the following genes:

• HESX1.
• SOX2.
• SOX3.
• OTX2.
• PROKR2.
• Other genes not yet identified.

What are the risk factors for optic nerve hypoplasia?

Risk factors for optic nerve hypoplasia affect the birthing parent during pregnancy and may include:

• The birthing parent being under 19 years of age.
• A first pregnancy.
• A biological family history of the condition.

If you’re planning on expanding your family, visit a pregnancy care provider regularly. They can make sure you and the fetus are in good health.

What are the complications of optic nerve hypoplasia?

Complications of optic nerve hypoplasia vary based on the affected part of the brain and may include:

• Inability to regulate body temperature.
• Hyperphagia (strong hunger and thirst) and obesity.
• Hypophagia (limited food intake) and food aversion.
• Abnormal sleep/wake cycles.
• Developmental delay (motor skills and communication skills).
• Autism spectrum disorder (ASD).

Some complications, especially body temperature regulation and food intake, can be life-threatening in certain situations.

How is optic nerve hypoplasia diagnosed?

A healthcare provider, often an ophthalmologist, will diagnose optic nerve hypoplasia after an eye exam and testing. Usually, the first sign of ONH is abnormal eye movements. This symptom can develop within a child’s first few months, but it might not be apparent until they’re school-aged or an adolescent.

ONH can occur on its own, without any other affected parts of the brain. Your child can receive an ONH diagnosis with one or two additional developmental issues outside of their optic nerve, like midline brain and pituitary gland abnormalities.

To confirm a diagnosis, a healthcare provider will perform an imaging test, like an MRI (magnetic resonance imaging) or a CT scan (computed tomography scan). Imaging tests give your provider a better look at how your child’s brain developed.

Blood tests may also help your child’s provider rule out conditions with similar symptoms. They may perform a blood test to check for serum cortisol and growth hormones. These components may be abnormal with ONH.

Can optic nerve hypoplasia be cured?

There’s no known cure for optic nerve hypoplasia. It’s a malformation or birth defect (congenital condition) and can’t be reversed or restored.

How is optic nerve hypoplasia treated?

Treatment for optic nerve hypoplasia addresses the symptoms that affect your child. This varies and may include:

• Vision therapy (using low-vision aids, such as glasses or magnifiers).
• Hormone replacement therapy (medications).
• Physical, occupational and/or speech therapy.

A healthcare provider will create a treatment plan that addresses your child’s situation. Other symptom-specific treatments may be necessary, depending on how the condition affects your child.

If you child needs to take medications, talk to their provider about when and how often to give your child medications and what side effects to look out for.

Can optic nerve hypoplasia be prevented?

There’s no known way to prevent optic nerve hypoplasia. If you plan on becoming pregnant, talk to a genetic counselor or a pregnancy care provider to learn more about your risk factors and how you can stay healthy.

What’s the outlook for optic nerve hypoplasia?

The severity of optic nerve hypoplasia varies from person to person. Many signs and symptoms are present in babies, while others may happen later during childhood or in adults. Some symptoms can improve slightly with age, like nystagmus. ONH doesn’t progressively get worse over time.

Children with ONH need long-term monitoring by parents, caregivers and healthcare providers to make sure they’re in good health. Your child will need vision exams at least once every year and specialist exams as needed.

Severe pituitary gland problems can be life-threatening, but an early diagnosis and treatment leads to the best outcome.

When should I see a healthcare provider?

Visit a healthcare provider if you notice your child’s eyes don’t follow you, cross or move unexpectedly. Let your child’s provider know if they miss developmental milestones for their age, like sitting up, crawling or grabbing objects.

Contact 911 or your local emergency services number if your child has a seizure.

What questions should I ask my healthcare provider?

Questions you may want to ask your healthcare provider include:

• How can I help my child manage their symptoms?
• What should I do if I notice my child misses developmental milestones?
• Does my child need glasses or visual aids?
• How will ONH affect my child when they start school?
• How often does my child need to schedule vision exams?

A note from Cleveland Clinic

It may be alarming as a parent or caregiver to notice your child’s eyes move around and not follow you. Optic nerve hypoplasia may affect your child’s ability to see you clearly. It can also target other parts of their brain that help their body function as expected, like hormone production or physical development.

A healthcare provider can diagnose your child and offer a treatment plan that addresses their specific symptoms.

It’s normal for children to need a little extra help in school, especially if they need more time to develop than their peers. Let your child’s healthcare providers know if you notice any concerning symptoms that affect their development or growth. Your child’s care team is available to answer any questions you might have.