Dr Ojum Ekeoma Ogwo
Last week alone I received about five texts requesting that I discuss “glaucoma” and “cataracts”, and these were mostly from people suffering from diabetes mellitus. So I am republishing my last year’s article on glaucoma.
Before you begin to read me. Wait a second. Think back. Was any of your grandparents blind? Or was your mother, father or relative, blind as they clocked 60 years? Was the blindness the type we call “open-eye-blindness”. That is the eyes are open, appear normal, yet the person is stone-blind. Yes such blindness is usually caused by glaucoma, and it runs in the family.
● So now let us attempt to change history, by breaking the blindness-history-jinx. So if you are above 40, and had relatives who became blind in their late 50s, please in the name of God visit an ophthalmologist now.
● Yes, glaucoma, which is medically known as “ocular hypertension “, but which my Chief Nursing Officer(CNO), insist on calling “hypertension of the eyes”, is like essential hypertension – if management starts early and properly, you will live to be a hundred, with your sights intact.
● Let me repeat, please I said if you are above 40, and had, or still have a relative, who became blind due to glaucoma. I am urging you to check mate it immediately, by consulting an ophthalmologist, who will control the glaucoma now.
● You do not deserve to be blind for a very simple preventable illness. Research has shown that 90% of the people who became blind due to glaucoma after 50, would have had their sights intact if they had bothered to consult their ophthalmologist at the first signs of blurred vision. Now back to brass tacks.
What is glaucoma?
The word glaucoma is from ancient Greek – “glaukos”, which means blue, green or gray in English.
● Glaucoma has been called “the silent thief of sight” – because the loss of vision usually occurs slowly, over a long period of time. Glaucoma is the 2nd-leading cause of blindness after cataracts.
● Glaucoma occurs most frequently after the age of 50 years. It is caused by a build up of the fluid pressure in the eye. The fluid that fills the eye(aqueous humor) is normally being continually drained away and replaced by fresh fluid.
● Glaucoma is a disorder in which the pressure in the eyeball increases, damaging the optic nerve and causing a loss of vision.
●If the out flow channels are open, the disorder is called “open-angle-glaucoma”. If the channels are blocked by the iris, the disorder is called “ closed-angle-glaucoma”.
What are the associated causes of glaucoma?
a) Usually glaucoma has no known cause, however it runs in families.
b) Ocular hypertension – increased
pressure within the eye is the most important risk factor in most glaucoma. It damages the optic nerve thereby causing blindness.
c) Open-angle-glaucoma accounts for 90%, and closed-angle-glaucoma accounts for less than 10%.
d) Caffeine increases intraocular pressure in those with glaucoma, but does not appear to affect normal individuals.
e) Positive family history is a risk factor for glaucoma – possibility of developing glaucoma increases by 2 to 4 folds if any our relatives had glaucoma.
f) Prolonged use of steroids could lead to steriod-induced-glaucoma. Severe diabetic retinopathy also predisposes to glaucoma.
What are the signs and symptoms of glaucoma?
1) Glaucoma is usually painless, especially open-eye-glaucoma. Later symptoms may include narrowing peripheral vision, mild headache and vague visual disturbances, such as seeing halos around electric lights or having difficulty adapting to darkness.
2) Eventually tunnel vision – an extreme narrowing of the visual fields that makes it difficult to see anything on either side, when looking straight ahead, may develop. Open- angle-glaucoma may not cause any symptoms until irreversible damage has developed.
3) There is progressive visual field loss and optic nerve damage that eventually results in blindness.
4) In closed-angle-glaucoma, there is sudden attacks of ocular pain,due to increased pressure, usually in one eye. With redness of the eye, severe throbbing pain in the eye. Nausea and vomiting are common. The eye lid swells, and the eye gets watery and red. The pupil dilated and doesn’t close normally in response to bright light.
Usually, the diagnosis is made by checking intra-ocular-pressure. Therefore every routine eye examination should include a test of intra- ocular-pressure, but if you are above 45, with hereditary history, please do this annually.
How do we treat glaucoma?
I) Treatment of glaucoma is more likely to be successful if started early. Once vision is greatly impaired, treatment may prevent further deterioration, but it usually can’t restore vision completely.
II) Medicated eye drops can usually control open-angle-glaucoma. Typically the first eye drop medication prescribed is a beta- blocker – such as timolol, betaxolol, carteolol, levobunolol, or metipranolol – which probably decreases the production of fluid in the eye.
III) If medication can’t control eye pressure or if side effects are intolerable, an eye Surgeon can increase drainage from the anterior chamber, by using laser therapy to create a hole in the iris, or using surgery to cut out part of the iris. Always be medically guided.
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