Can problems with your vision indicate a brain tumour?
Vision problems are often attributed to common eye conditions, but sometimes they can be the first warning sign of something far more serious- a brain tumour.
The most common problem in adults is called ‘bitemporal hemianopia’, the loss of peripheral vision in both eyes. This happens because these tumours press on the spot where your vision nerves cross over in your brain.
Dr Vijay Sankaran, Joint Director and Senior Consultant Neurosurgeon at SIMS Hospitals, Chennai, explains that those who suffer from this kind of vision loss often bump into objects on the fringes of vision. Another sign is a double vision when the individual looks in certain directions. More alarming symptoms include sudden vision loss accompanied by headache, vomiting, and balance problems, which may indicate a dangerous build-up of pressure in the brain.
The patterns of visual loss vary dramatically based on the tumour location. Dr Roopesh Kumar, Director of Neurosurgery at MGM Healthcare, Chennai, notes that symptoms can range from partial vision reduction in one eye to complete blindness in both eyes.
The kinds of tumours that have the greatest impact on vision include:
- Pituitary adenomas - growths in your pituitary gland, a small gland behind your eyes that controls hormones
- Craniopharyngiomas - these are growths near the pituitary gland area
- Hypothalamic and optochiasmatic gliomas - grow in brain areas that control basic body functions and where vision nerves cross
- Germ cell tumors - A type of tumor that can develop in the brain
- Dermoid or epidermoid tumors - Cyst-like growths in the middle of the brain
Thus, early recognition and prompt referral are critical to treating these tumours. Training optometrists and general physicians to identify neurological signs like papilledema or field cuts, combined with public awareness campaigns, can improve early detection rates and ultimately save both vision and lives.
How to diagnose?
The following methods can help in the diagnosis of the tumors.
- MRI brain scans with contrast
- Advanced vision assessment techniques like OCT (Optical Coherence Tomography) help predict visual recovery potential after surgery.
- For children unable to cooperate with formal vision testing, visual evoked potential studies assess the extent of vision damage. These are non-invasive procedures that measure the electrical activity in the brain in response to visual stimuli, specifically the signals generated by the brain's visual cortex when the eyes detect a light pattern.
These modern brain surgery tools can help in protecting your vision:
Intraoperative neuro-navigation: Think of this like a GPS for brain surgery. This technology shows the surgeon exactly where they are inside your brain during the operation and navigates safely around important areas that control vision.
Visual evoked potential monitoring: This is like having a ‘vision alarm system’ during surgery. If the machine detects any problem with your vision during surgery, it immediately alerts the surgeon to stop or change what they’re doing.
Diffusion tractography: This is a special type of brain scan that creates a ‘roadmap’ of all the nerve pathways in your brain. It shows surgeons exactly where the vision pathways run so they can carefully work around them without cutting or damaging them.
Awake brain surgery: The patient stays awake during part of the surgery so they can: look at pictures or read letters on a screen, tell the surgeon immediately if their vision changes, and help the surgeon know in real-time if they’re getting too close to vision areas.
All these technologies work together like a team of bodyguards protecting your vision during brain surgery. They help surgeons remove tumours while keeping your eyesight safe - and sometimes even help restore vision that was lost due to the tumour. For the best treatment outcome, we must remain alert to the changes in vision and seek medical help immediately.
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