On pituitary tumours causing blindness


The baseline

When patients complain of headaches, progressive loss of vision and pain behind the eyes, I think of a pituitary tumour. But, then I am a neurosurgeon and I know about pituitary tumours. When patients with similar complaints talk to an optician, some think of prescription glasses as a solution. When patients speak to a general practitioner, some diagnose the same problem as Malaria and Typhoid.

The stories

The story is that she has been having progressive visual failure for years and diagnosed with all sorts, by opticians and ophthalmologists before the penny dropped. After a long period of prescription glasses and treatments for glaucoma, Malaria and Typhoid, she finally got a brain scan performed which unfortunately revealed a massive pituitary tumour: the cause of all her previous complaints of headaches, pain behind the eyes, tiredness, irritability, head fullness and of course, blindness.

In another patient, the story is that she suddenly went blind in childhood. She had tests done at various hospitals and nothing was found to be amiss. Her eyes looked normal. Since hospitals could not make a diagnosis, they took her to countless prayer houses. Alas, the penny dropped when she started having seizures which led to a brain scan. Scan revealed a huge tumour, the likely cause of her long years of blindness.

Blind spots

There are so many stories of patients with brain tumours going blind while wearing beautiful designer glasses.The point? Fancy spectacles do not help blind people. Opticians, optometrists and Ophthalmologists must have a low threshold for obtaining imaging especially if there are symptoms and signs of blindness. When a patient is complaining of progressive visual failure and especially if the examination of the eyes does not show evidence of cataracts or glaucoma, a brain scan should be mandatory.

But, I appreciate the poor level of eye care delivered is because opticians, especially, make their living from prescription glasses. However, if we continue this way, we might soon have a nation of the blind leading the blind!

Pituitary tumours

Pituitary gland is a small endocrine gland in the brain. It produces many hormones that we need for life. Hormones such as cortisol, thyroxine, growth hormone and the sex hormones too. The pituitary gland can develop a tumour just like any other tissue in the body. However, because of its unique position in the brain, an increase in the size of the gland can lead to blindness. The tumor compresses the optic chiasma leading to visual field defect initially and then blindness.

Careful history taking, detailed optic nerve assessment with visual field test will help in the diagnosis. Other important parts of the patient’s story such as headaches, weight gain, hyperactivity or poor sexual performance (impotence or infertility in women) will help in directing attention to the pituitary gland. It beholds on the clinician to be open minded while managing patients.

In truth, examination for glaucoma and cataracts are important as these can and do cause blindness. Good history, good clinical examination and even limited investigation can make all the difference.However, and especially if the eye is seen to be normal, then a brain scan in important to rule out a brain tumour. Even before this state of the art tools was available in Nigeria, diagnosis of pituitary lesions was possible.

Poverty rules

One may ask, how many of our Nigerian patients can afford a brain MRI in such a resource poor setting? Secondly, are brain scans widely available and accessible? However, that should not be the major concern of the clinician or the reason for not ordering the test.

Some doctors still say, ‘The patient cannot afford an MRI scan’. But, the same patient will travel from pillar to post spending the little money they have looking for solution in the wrong place. The money wasted could have helped in making a firm diagnosis. It is not the doctors business to determine the poverty level of the patient and allow that to cloud their judgment. Ask for the scan. Tell the patient it is very important. No more!

We must be seen to be doing or have done the right thing. Clinicians need to have a low threshold for brain scan. The cost of the scan is perhaps as much as the prescription lenses and drugs often prescribed. But, a scan can be the difference between life and death.

If the scan does not show a brain tumour, all well and good. But, if the scan does show a pituitary tumour, then immediate referral to a brain surgeon is indicated. Operating on patients with some vision is better than operating on patients who are already blind because the sight will not return. This is pretty devastating for patients. So, when you are in the position to help, get it right.

Get a scan.



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