Still on Glacuoma, the Sight Thief

SAFE DRIVING

Last week I told you of the risk factors to watch out to save your sight as a driver. According to the WHO reports, Glaucoma is the second leading cause of avoidable blindness in the world. The total number of known cases worldwide is estimated to be about 65 million. As at 2010, about 44.7million has been estimated to have glaucoma. An estimate of 4 million Americans have it but only half know they have it. Though there are no established statistical data on the number of glaucoma sufferers in Nigeria, researchers have shown that there is an alarming increase in prevalence among the old and the young which is risky for driving safety. What then is glaucoma? It is a group of complicated condition in which damage to the optic nerve leads to progressive and irreversible vision loss. It is often referred to as the SILENT THIEF OF SIGHT because in its early stage, there is no pain or any other symptom but can gradually steal your vision.Let me briefly open our minds on what happens in the good eye with a healthy drainage. The front part of the eye is filled with a clear fluid called intraocular fluid or Aqueous Humour (AH) and this is produced by the ciliary body found behind the colored part of the eye (iris). The fluid flows out of the pupil ( a small aperture through which light enters the eyes) and then absorbed into the blood stream through the eye’ s drainage system and the cycle continues. This proper drainage helps keep the eye pressure at a normal level. The production flow and drainage of this fluid is an active continuous process that is needed for the good health of the eye.The inner pressure of the eye, Intraocular Pressure (IOP) depends on the amount of fluid in the eye at each point in time. If your eye’s drainage system is working, then the fluid can drain out and prevent a buildup. A normal IOP can vary at different times of the day but the normal range is 10-21mmHg. In most types of glaucoma, the eye’s drainage system becomes clogged either by papillary blockages, exfoliated fibers, insufficient drainage of the fluid produced due to narrowing /increase in blood flow, the intraocular fluid cannot drain the way it should. As the fluids build up, it results to pressure building up in the eye. High pressure damages the sensitive optic nerve and results to loss of vision. The glaucoma to us eye refers to the bad eye-In most of types of Glaucoma, the eye’ s drainage system becomes clogged either by papillary blockages, exfoliated fibers, insufficient drainage of the fluid produced, due to narrowing/increase in blood flow, the intra ocular fluid cannot drain the way it should. As the fluids build up, pressure builds up in the eye too. Accumulated pressure damages the sensitive optic nerve (nerve that connects the eye to the brain) and results to vision loss.As I explained earlier, this process is usually painless and occurs in such a subtle way that most people do not even realize that something is wrong. In fact most people notice reduction in vision after the damage that has occurred becomes permanent. This condition should be checked and managed as soon as possible or else it could lead to “tunnel vision” where the peripheral or side vision is completely lost and one can only see objects straight ahead. There are many types of glaucoma but I will conveniently and broadly divide it into Primary Glaucoma and Secondary Glaucoma. Primary Glaucoma refers to any case in which the elevation of IOP is not associated with any other ocular disorder which includes the Primary open angle glaucoma, Primary angle closure glaucoma and Congenital glaucoma. Most commonly is the Primary Open Angle Glaucoma (POAG). Painlessly, increase in pressure at the onset occurs slowly overtime and has no symptoms in most people. Once vision is lost, damage has already set in. There is progressively slow and irreversible loss of peripheral (side) vision and optic nerve damage. Its advanced stage ends up in blindness. The Primary Angle Closure Glaucoma (PACG) occurs when exit of AH is suddenly blocked and causes a quick, severe, and painful rise in IOP. Our body mechanisms are quite different so in some individuals there is nausea and vomiting, cloudy and steamy vision. Some others experience rainbow-like haloes especially while looking at a bulb light, red eye, severe eye and head pain and sudden loss of vision. Congenital Glaucomaas the name implies are naturally seen in babies at birth or in few months later. It is caused by abnormal development. Look out for frequent tearing and cloudiness in front of eyes, red eyes high sensitivity to light and unusually large or bulgy eyes. SECONDARY GLAUCOMA is the case where another disease or condition causes or contributes to increase eye pressure which results to optic nerve damage and loss.Eye Trauma (eye injury) is a very common example; a hit by airbag in a crash, a blunt blow in a case of violent conflict between a ‘molue’ conductor and an angry passenger, the list is endless. Other causes can be, pigment granules breaking off at the back of the colored-eye (iris) into the fluid, flaky-dandruff-like materials peels off the outer layer of the lens into the anterior chamber of the eye, drugs (Steroids ), inflammations, hyper mature and advanced cases of cataract, new vessels forming on the colored eye (Iris) blocking the drainage system, systemic diseases such as Hypertension and Diabetes and eye diseases such as Uveatis.