Papilloedema, also spelled Papilledema by Americans, is one of the causes of a swelling of the optic nerve at the back of the eye, but for us, it is one of the most concerning. Not that most of the other options are all that much better either…
The Central Nervous System (CNS) is comprised of the brain, the spinal cord and the optic nerves, all of which are covered in a protective layer called the meninges. The meninges cover and protect the CNS and bathe the occupants with a fluid called Cerebrospinal Fluid (CSF). This fluid removes waste, as well as cushioning and helping the brain to “float”, and is replaced approximately 4 times per day.
If the pressure of the Cerebro Spinal Fluid increases, for example due to an increase in production or a reduction in drainage, then the brain, spinal cord and optic nerves can begin to be crushed. CSF is produced in the Choriod Plexus found in the ventricles of the brain. Sometimes a tumour here can cause an increased production, other times a blockage or restriction somewhere can cause a reduction in outflow of the fluid, leading to a build up in pressure. Space occupying lesions (things that take up space inside the skull) can also cause a rise in intracranial pressure – because the brain is enclosed in a protective, inelastic box, it has a fixed size, and there is only really room for what is supposed to be there.
This is the reason you might sometimes hear of an Optometrist “detecting a brain tumour”. We cannot definitively detect brain tumours, but we can find signs and symptoms which may lead us to suspect that there is something amiss inside the head – by also checking fields of vision, pupil reactions, how well the eyes move and are controlled, we can have a fair idea when something is going wrong, even if it doesn’t show in the eyes – much of the human brain is sight related.
In the past few years we have had a young girl who had unknowingly gone completely blind in one eye, who was urgently referred because the cause of the blindness appeared to be papilloedema and the other “good” eye had a very swollen optic disc. The uneven appearance of the optic nerves, and the different eye’s function was very worrying, but fortunately it was not a tumour causing the problem. She had brain surgery the following day, but the damage to her left optic nerve is irreparable. I sincerely expected her case to be something else, (more sinister, due to the unevenness of the “damage”) but obviously, was pleased to hear otherwise. Without an MRI scanner, we have to suspect the worst!
I recently referred a young woman who had called for a routine test, with little or no complaints – really I think that she had a Medical Card, had never had an eye test before, and it was therefore “free”- what else to do with a day off! Again she had papilloedema, one of the worst ones I have seen, which I would admit fortunately is few! (I had already chalked up my first one as a probably “never see that again in my career” kind of thing, hopefully). After a trip through casualty she was discharged after 1 week with medicines which alone, hopefully will reduce the pressure inside her head. MRI confirmed that there was no tumour fortunately.
The one thing that “peaked” my attention was that she mentioned that her vision sometimes darkened/blurred/faded on standing up from her computer, though when I further questioned that, she thought that is may do the same when looking away from the screen, but without standing up. Visual obscurations (sight issues on rising) can be a symptom of Papilloedema, but one which I had discounted in her case, until I looked into her eyes!
Idiopathic Intracranial Hypertension (IIH) which used to be called Benign Intracranial Hypertension (BIH), is high pressure inside the skull, without there being a tumour or disease at the root cause. But it is not benign…
I did see a young man with a brain tumour who had very severe papilloedema, with haemorrhaging of his retinas and severely enlarged retinal veins. This resulted in a note to the GP only – he had had all the treatment he could have and had come home to Ireland to be with his parents for his last few weeks. As the husband of a wife living with a brain tumour, that was a difficult one for me.
Not all brain tumours will occupy enough space to cause papilloedema, but the Optometrist can still perhaps pick up issues. Not too long ago, I saw a man who had a very slightly pale optic nerve in one eye, reduced vision in that eye and a weak pupil reaction. He also showed a change in his oculomotor status – we measure where your eyes would tend to point if they were not able to see the same object, and this status should not change much throughout life. This man had a significant change, indicating a weakness of one or more of the muscles which control the eyes, though it was not enough to cause him any symptoms, such as headaches or double vision. He also showed a visual field defect in both eyes.- because of the distribution of the reduction in sensitivity in each eye, there was a suspicion of a “problem” around the optic chiasma, where the optic nerves meet, and then swap fibres (each eye sends information from the left visual field to the right side of the brain, and vice versa).
This gent was later diagnosed with a tumour of his pituitary gland, which for the moment is being treated medically only – no surgery required. Both sexes can develop a Prolactinoma, which was his diagnosis, but men are often late to present, because one of the symptoms often is reduced libido, or impotence. If a middle aged, single man was to have those symptoms, perhaps he would put them down to his age? If we had not seen this man before, and therefore known what to expect his vision and eye control status to be like, possibly these subtle eye changes may have been overlooked. Prolactinomas can rarely cause men to start producing breast milk, which he is unlikely perhaps to mention to his GP, but definitely not likely to mention to his Optometrist! Females may more often complain of leaky nipples, perhaps less often of reduced libido, often with reduced, irregular or absent periods, but either way, this type of tumour usually presents later in men, and often with a loss of the field of vision.
Once again, we would always recommend regular eye checks in the place which knows your eyes. A different optician every time would have picked up the first two cases easily (hopefully!) – there were unmistakable changes, but the man’s changes were extremely subtle and could have been overlooked at first glance, though to be fair he did complain that his sight was poorer in one eye. It was slight enough to dismiss to a natural “unevenness” – many people have one slightly poorer eye, except that there was a previous card to prove otherwise.
This is another reason why everyone should have a regular “eye” examination, regardless of having any symptoms – it should be part of everyone’s healthcare routine. Because Optometrists usually see “normal” people, who have no eye health or other eye affecting issues, it can be more difficult to change into “There is a problem here mode”, as it is so unusual – previous (and detailed) records an invaluable. Another issue is time – how long does an eye exam take where you go??
Fortunately papilloedema and tumours are very rare, but how long would those three cases have gone on for before eventually being referred to the hospital otherwise? How much more damage may have been caused?
To book an “eye” test, call us here. That’s why WE call it a sight test – there is more to seeing than a pair of eyes!
