Every day, 27 Canadians are sat down by their doctor and told the devastating news that they have a brain tumour.
With more than 120 different types of brain tumours in existence, it is estimated that 55,000 people nationwide are living with one right now. FYidoctors takes a closer look at those that can affect the overall health of your eyes and vision.
How an eye exam can save your life
There are many indications that a brain tumour is affecting your vision. Symptoms can include blurred, double, or cloudy vision, partial or total blindness, loss of peripheral viewing capabilities, and loss of colour perception. These visual disturbances can indicate there may be damage to the visual pathway.
Brain tumours can manifest in many ways and can be diagnosed during routine eye exams. While in an examination, your eye doctor will check visual acuity, pupil function and optic nerve health. FYidoctors also uses Optomap ultra-widefield retinal imaging technology to monitor changes on the retina and optic nerve. Linking images from one year to the next helps your doctor spot abnormalities more easily. If irregularities are noticed, you’ll likely receive a referral to a neurologist for further investigation.
Brain tumours fall into two categories: primary (originating from the brain) and metastatic (a cancer that spread from other areas of the body). In Canada, those categorized as primary occur in eight out of 100,000 people, while 32 out of every 100,000 cases are diagnosed as metastatic masses.
Routine eye exams can also determine if there are dangerous amounts of pressure building up in your brain due to idiopathic intracranial hypertension, as well as signs of unnoticed aneurysms (when a blood vessel in your brain weakens or breaks).
Your eyes at risk
Amongst the array of brain tumours that exist, there are a few that affect the eye and optic nerve. As it grows, depending on the location, it presses on the surrounding tissue and affects the function controlled by that part of the brain.
Tumours that develop in the hindbrain (cerebellum area) can instigate uncontrolled movement of the eyes. If it begins pressing against your brain stem it can cause double vision or drooping of the eyelid or mouth to one side. When tension occurs on the frontal lobe, occipital lobe, or against any nerves that control sight or hearing, it will create problems such as blurry vision and potential loss of vision. In general, brain tumours compressing optic pathway nerve fibre affect the functionality of your eyes.
Masses inside the eye commonly develop in the middle and inner layers of the eye. Here are some of the most common types:
Uveal tract tumours
Uveal melanomas develop in the middle layer of the eye between the retina and sclera (the white area of your eyeball). Melanoma can grow in the eye’s choroid (the blood-vessel layer beneath the retina), iris, or ciliary body (the coloured portion). Treatment options include radiotherapy, transpupillary thermotherapy, or enucleation (removal of the eye).
Although extremely rare, these are often benign. They are located at the retina and optic nerve head. If diagnosed early enough, laser photocoagulation, cryotherapy, or radiotherapy can control the growth and prevent any complications.
Optic nerve tumours
Optic nerve melanocytoma is a benign tumour made up of melanocytes and melanin cells. If not diagnosed, this can create blind spots in your vision. Surgery and radiation therapy are two possible treatments.
Officially called primary intraocular lymphoma, this cancer can affect your eye because it develops in the retina, vitreous inside the eye, and optic nerve at the back of the eye. Most often, it grows in both eyes of those who are elderly or have poor immune systems. It causes blurry vision, a decrease in or loss of sight, floaters, redness, swelling, light sensitivity, and pain. Chemotherapy and external radiation therapy (or sometimes a combination of both) are the recommended treatments.
Post-op eye issues
The most common method of treatment is removal via surgery. The type of operation and recovery time is greatly dependent on the type, size, and location of the tumour, coupled with the patient’s state of health. A neurosurgeon works to remove all traces of the tumour or cancerous tissue. Sometimes, partial removal is the best option for the health of the individual when combined with radiation and chemotherapy.
Following surgery, your eyes can be impacted permanently. Risks differ for every type of operation and patient’s unique situation. In general, it can take anywhere from one to four months for vision to repair itself. However, results can range vastly. Although some patients experience nerve damage in the skin around the eye and face, many survivors live problem free post-surgery.
If you have concerns about your vision, please contact a Visique clinic near you to book an exam.