Sixth nerve palsy is the most common optic nerve palsy. The sixth nerve mainly sends signals to the muscle that makes the eye move outward. In sixth nerve palsy, the eye cannot move outwards, and strabismus, blurring, and double vision occur inward.
Sixth nerve palsy can occur as a result of a direct blow to the head, or sometimes it can occur suddenly for an unknown reason. The sixth nerve is also known as the Abducens nerve. When the abducens nerve does not work, the inability to function properly in eye movements and double vision occurs.
Internal strabismus is observed in sixth nerve palsy. If the right eye is affected, the right eye cannot look to the right, if the left eye is affected, the left eye cannot look to the left. Rarely, both eyes may be affected.
Causes of Sixth Nerve Palsy
Severe head trauma such as a fall or traffic accident
Paralysis seen in the elderly, people with hypertension or arterial stiffness
Infection (such as Lyme disease or from a virus)
Glioma
Inflammation of the nerve, for example, after vaccination
Sclerosis
High pressure in the brain (eg, meningitis)
Congenital
It is a very rare problem. It can also be seen with birth trauma or neurological diseases. For example, in Möbius syndrome, sixth and seventh nerve palsies occur together.
Later Acquired Sixth Nerve Palsy
Childhood trauma, viral infections, post-vaccination, tumors, and unexplained conditions can cause sixth nerve palsy.
Traumas that cause a sudden increase in pressure, tumors that cause compression of the sixth nerve, neurological diseases such as Lupus and Multiple Sclerosis, hemorrhages can cause sixth nerve palsy.
Myopia due to Sixth Nerve Palsy in Adults
The most common cause of sixth nerve palsy in adults is the narrowing of capillaries and sudden starvation of the optic nerve due to hypertension and diabetes.
Our patients complain of sudden onset of double vision or having to turn their head to the side to see single and clearly.
Symptoms of Sixth Nerve Palsy
1. Inward turning of the eye (Esotropia):
- The damaged eye turns inward, toward the nose, instead of looking straight.
2. Double vision (Diplopia):
3. Restriction in eye movements:
- The affected eye cannot move outward (to the appropriate side) or this movement is limited.
- Asymmetry is observed in eye movements.
4. Compensatory posture of the head:
- The patient tilts or turns his head to one side to prevent double vision and correct vision.
- This compensator is used to make the head posture and eyes more suitable.
5. Decreased vision:
- Vision may be impaired in the damaged eye because the eye cannot move or focus properly.
- This can have a negative effect on the overall quality of vision.
6. Headaches and restlessness:
Symptoms of sixth nerve palsy can vary from person to person and depend on the degree of nerve damage. If any of these symptoms are observed, it is important to see an eye doctor immediately. Early diagnosis and treatment are very important to minimize the effects of sixth nerve palsy and to restore the patient's vision.
Diagnosis of Sixth Nerve Palsy
The diagnosis of sixth nerve palsy is made by clinical examination.
If the sixth nerve palsy is a sudden problem and the patient is younger than 55, we prefer to evaluate with MRI and CT. In addition to imaging, we investigate metabolic problems with blood tests.
Purpose of Botox Treatment in Sixth Nerve Palsy
In sixth nerve palsy, the outer rectus muscle of the eye weakens or does not work, causing the eye to turn inward. To correct this condition, Botox is injected into the strong muscle in front of the weak muscle. This weakens that muscle, allowing the eye to turn more correctly and helping to reduce double vision.
How is the Procedure Performed?
Anesthesia: Pre-procedure local anesthesia (eye drops) may be used to reduce pain and discomfort.
Injection: Botox is injected with a fine needle into the strong muscle that causes the eye to turn inward. This causes the eye to turn more correctly by weakening that muscle. The procedure is usually completed in a short period of time, within a few minutes.
Effectiveness of Botox Treatment
Temporary effect: The effect of Botox lasts temporarily for 3-4 months. If nerve regeneration occurs during this time, normal eye function may return.
Reduction of double vision: Botox treatment helps reduce double vision problems and helps the eyes function more properly.
