Raising Awareness for CN3 Palsy

Here at Speckles, we're all about raising awareness for the different reasons our Speckles Superstars need to patch. Congenital Third Nerve Palsy is a rare condition that affects the movement of the eye's muscles and how the eye reacts to light. For kids like Violet, this has a huge impact on the development of healthy eyes, as well as their ability to take in and learn from the world around them. Scroll down to find out more about the signs, causes and treatment options of CN3 Palsy.  

What is Congenital Third Nerve Palsy? 

CN3 Palsy is a rare condition that affects the third cranial nerve (CN III), also known as the oculomotor nerve. This nerve controls the movement of four out of six of the eye's muscles, allowing the eye to follow and focus on moving objects. CN3 Palsy also affects the movement and position of the upper eyelid and the reaction of the pupil to light. For kids like Violet, as the eye and upper eyelid cannot move properly and the pupil does not react normally to light, her ability to see the wonderful world around her is affected. When left untreated, CN3 Palsy can lead to Amblyopia, as the brain will rely on the images from the stronger eye, preventing the "curious eye" from developing properly. 

What Causes Congenital Third Nerve Palsy?

CN3 Palsy develops in the womb and often, the precise cause is not clear. It may occur as a result of complications during birth, an infection in the womb, a developmental abnormality, a tumour or an aneurysm. 

What are the signs of Congenital Third Nerve Palsy?

The first signs of CN3 Palsy are usually a droopy eyelid (ptosis) and an enlarged pupil that does not shrink when exposed to light. As the muscles in the eye do not function properly, you may also notice the development of strabismus, where one or both eyes turn inward (esotropia), outward (exotropia), upward (hypertropia), or downward (hypotropia) either sometimes (intermittent) or all of the time. Your child's eyes may also struggle to follow moving objects and they may complain of double vision (diplopia) due to the misalignment of their eyes. If you notice any of these signs, it is essential to pop by your local optometrist where they can perform visual acuity tests and refer you to an ophthalmologist or orthoptist for further treatment.

How is Congenital Third Nerve Palsy Treated?

The treatment of CN3 Palsy is often dependent on the cause and the severity of the condition. In minor cases, an ophthalmologist may recommend patching the stronger eye to help the "curious eye" gain strength and functioning abilities. They may also recommend your child wears prism glasses or contacts that are thicker on one side to alter how light enters the turned eye. This can reduce or eliminate how much the eye must turn to process images clearly.

If the CN3 Palsy does not begin to correct itself, one or multiple eye surgeries may be performed to adjust the length and position of the muscles around the eyes. Following this surgery, your child will have to undergo vision therapies that improve eye coordination and strength, reinforcing the eye-brain connection. These therapies may be completed while patching, allowing the "curious eye" to strengthen and correct itself.

Unfortunately, in some cases of CN3 Palsy, there are no treatment options available to re-establish weak nerve connections. In this scenario, wearing glasses, contacts and patching can help the affected eye gain strength and improve the quality of your child's life. 

Shout out to our Powerhouse Parent Heather Sorrentino Gallo for sharing Violet's story and inspiring us to raise awareness for CN3 Palsy!