March 12 was World Glaucoma Day , a disease which is the second leading cause of blindness in the world, even despite the availability of modern analytical systems to prevent their onset and evolution. The problem is that no warning , which suffers no pains to note that the loss of vision stage where we can no longer back away starts.
What is glaucoma?
It is a disease that is defined as ischemic optic neuropathy , ie an optic nerve involvement ( neuropathy ) by lack of blood flow ( ischemic ) that causes loss of vision ( optical ) . The optic nerve is responsible for driving the electrical stimulation that occurs in the retina ( by encoding the light coming from outside) , to the brain , how to recode it and the feeling of seeing .
In glaucoma, the optic nerve is damaged , so the signal to the brain is deficient , generating an altered vision. The optic nerve is very sensitive to oxygen levels , thus any disorder that results in a reduction in oxygenation produce atrophy of fibers that compose the peripheral field of view is reduced. The most frequent cause of glaucoma is raised intraocular pressure .
Is it the same ocular hypertension glaucoma?
Not exactly, ocular hypertension can occur for multiple reasons and stay for varying lengths of time. If the pressure is high enough ocular remain for an extended time, will result in the compression of blood vessels within the eye and a reduction in oxygen arrival . The optic nerve , the beginning, the papilla , is one of the most sensitive structures to this phenomenon (Figure ) . Ischemia at this level causes atrophy of nerve fibers and nerve is at this stage when it comes to glaucoma.
Based on this , we differentiate between the phase of ocular hypertension, without injury to the optic nerve and injury phase , then we speak of glaucoma.
Do all glaucoma due to high eye pressure?
Again the answer is no. 85 % of cases of glaucoma are caused by ocular hypertension , values above 20 mmHg , but a 15 % of cases in which death of optic nerve fibers due to other causes is produced , it is that normotensional known as glaucoma .
What are the most common causes of glaucoma?
In most cases it is due to a blockage in the outlet area ( trabecular ) , the fluid inside the eye, the aqueous humor. It builds up inside the eye and intraocular pressure rises .
Alteration of trabecular can occur from birth (congenital glaucoma), by degenerative changes that occur with age (primary glaucoma) , secondary to other diseases ( pigmentary glaucoma, pseudoexfoliation ) for secondary anatomical changes ( angle closure glaucoma ) or the presence of cataracts , or taking certain medications such as corticosteroids antidepressants.
What are the symptoms glaucoma?
Except in cases of acute angle-closure glaucoma , the rest of glaucoma usually give no discomfort. In acute forms a sharp pain in the eye appears as if you drive a nail , so also known as " sore spot" , very intense , causing the patient to seek medical attention.
In most glaucomas , non- acute form , the disease not only causes discomfort and we realize his presence at the time already has killed 60 % of the fibers of the optic nerve , too late. To avoid this situation ophthalmologists emphasize the need for routine scans once a year to detect before vision loss begins.
Who is more likely to have glaucoma ?
The presence of glaucoma is increased in people with a family history of glaucoma, especially after age 40 in individuals of Black or Asian . Patients suffering from vascular disorders such as diabetes, blood pressure and vasospastic conditions, such as Raynaud 's disease or migraine headaches , patients are characteristically have cold hands and feet are also more likely . An abnormal diet and stress can also influence the development of glaucoma.
How is it diagnosed ?
You must perform a review in which we take into account the presence of risk factors, which we have quoted above, and a series of explorations that basically include taking eye pressure , visual field and especially , the study of nerve fibers of the retina and optic nerve ( optic disc and macula OCT and GDx ) .
The study of nerve fibers is a breakthrough in early diagnosis . When we only had the outlet pressure and visual field glaucoma is detected when it had already produced significant atrophy, a decline of 60% of the fibers , whereas now , with these new systems is detected when a minimal deterioration of 20% , which allows viewing safeguard these patients very efficient .
How is glaucoma treated?
Treatment aims to reduce eye pressure , improve aqueous outflow and protect the fibers of the optic nerve. In most cases, drug therapy is initiated, usually in the form of eye drops and if this is not enough or the patient is not constant drug administration , surgery, alternative treatments , laser or recommended .
Today more and more frequently performed surgery because it is very effective, safe and prevents pressure fluctuations by poor compliance in drug delivery and tissue alterations that induce these drops , usually the presence of dry eye impairment ocular surface . The Deep sclerectomy or new drainage systems that are implanted with minimally invasive surgery, is being imposed in the treatment of glaucoma.
With this article we want to raise awareness of the importance of regular eye tests once a year, for early diagnosis of diseases that can cause irreversible vision loss , such as glaucoma , especially now that we have technology help very effectively and safely.