Neuro-ophthalmology is the unique branch of Ophthalmology that addresses conditions related to the connection between our brain and eyes. These conditions can manifest with visual symptoms such as blurring, loss of vision, double vision, or shaky vision. Individuals may also notice a difference in their appearance, for example, deviation of an eye, droopy eyelid(s), change in shape or size of the iris (brown portion of the eye) and even spasms of facial muscles.
The optic nerve is a structure which connects our eyes to the brain for processing of visual information. The optic nerve can be injured by conditions within the eye or the brain.
A normal and healthy optic nerve is very essential for us to enjoy clear vision, vibrant colours and sharp contrast.
The appearance of the optic nerve can give an ophthalmologist a clue to problems affecting your vision. The image below shows a swollen optic nerve due to high brain pressure from a brain tumour. The patient was experiencing intermittent blurring of vision.
Thinning, or cupping of the optic nerve is a characteristic sign in patients who have Glaucoma. Glaucoma can be without symptoms till much later where it typically causes loss of visual field (constriction) over time.
A pale disc represents a nerve that was previously damaged either primarily, or secondarily from retina or brain issues.
Visual field defects or a loss of a portion of vision can result from diseases in the optic nerve, retina or brain. This can affect vision in one or both eyes.
Central visual loss of a patient who unfortunately had severe inflammation of his optic nerve.
Left hemianopia (loss of left half of vision of each eye) due to a stroke. This can be easily mistaken as loss of vision over the left eye.
At ERS, we are able to help our patients with visual rehabilitation with our low vision service.
Ptosis, or drooping of the eyelid(s) can be congenital or develop later in life due to a variety of causes.
Aponeurotic ptosis is the most common cause of droopy eyelid and usually occurs with age as our skin and muscles lose tone over time. This can also occur in younger individuals with chronic contact lens use.
While most ptosis is benign, it can be a sign of a more serious condition affecting nerves, muscles, or the connection between nerves and muscles (neuro-muscular junction). Your doctor will evaluate your eyelids, together with other nerve functions of your eyes and face before recommending suitable tests and treatment.
Squint and eye movement abnormalities result in the eyes looking misaligned.
The most common symptoms arising from misaligned eyes is double vision, which is very debilitating for the individual.
Nystagmus is the to and from movement of the eyes which can be observed in some individuals. Some individuals can be born with nystagmus and remain symptom free throughout life. It can arise later in life, in association with strokes, tumours, medications and even ear problems!
The pupil is the opening in the iris, which allows light to enter the eye. Pupillary disorders can cause visual symptoms of glare and blurring at various distances. At times, there are no symptoms, but an abnormal pupil can be a sign of disease elsewhere in the body.
Keyhole pupil, or coloboma which is a congenital deformity of the iris and can be associated with poor vision, if there is a corresponding defect in the retina.
Difference in pupil size, which can be normal in up to 20% of individuals, can be a sign of disease elsewhere in the body. The image shows a smaller right pupil due to compression of nerve fibres in the neck of a patient with a tumour. This was incidentally noted by a family member.
Face and eyelid spasms, otherwise known as hemifacial or blepharospasm can arise in individuals of all ages. A common cause is dry eyes, although spasms can arise in cases of previous facial nerve injury or aberrant vessels in contact with the facial nerve. In older individuals, primary blepharospasm can develop.
Botox injections can temporarily reduce the amount of eyelid and facial twitching, which provides the individual with symptomatic relief. It is a useful temporising measure, while your doctor investigates and treats the underlying cause of your spasms.
Headaches occur commonly in the general population. While most headaches are benign, this can be a symptom of underlying neurological disease. There are a variety of different headaches, from the common tension headache to migraine spectrum disease and cluster headaches.
Migraine spectrum
Migraine spectrum disease is a combination of headaches which can be accompanied by visual phenomenon such as flashing lights, zig zag lines and even missing areas in your vision. These attacks can be severe in intensity and debilitating for the individual.
Simulated image of a migraine aura, which a patient with migraine spectrum disease experiences.
What to expect?
Neuro-ophthalmic consultations typically require more time for evaluation as compared to a routine ophthalmological review. You are advised to have ample rest prior to your appointment, avoid driving and to bring along any of your past medical records or previous tests done.
Following evaluation, you might be advised to undergo further testing in the form of scans like magnetic resonance imaging (MRI), blood tests and/or electrodiagnostic studies.
