Discover What is chronic glaucoma Means?
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glaucoma |
1-What are the signs of glaucoma?2-What makes the severity of glaucoma?3-How to detect glaucoma?4-Are there subjects more prone to glaucoma?5-How to avoid this evolution of glaucoma?6-CAUSES AND RISK FACTORS about glaucoma:
Intro:
Dr. Marc Timsit - Chronic glaucoma is a disease of the optic nerve (optical neuropathy). If glaucoma is not detected and treated, glaucoma evolves insidiously over years without the patient's knowledge, gradually narrowing the visual field and causing the destruction of the nerve fibers of the optic nerve to the point of blindness.
Glaucoma is linked to several factors, the most common of which is elevated eye tension. But it is not the only one: patients can develop glaucoma without elevated eye pressure (glaucoma with normal eye tension). Similarly, other patients may have high eye tension without destruction of the optic nerve: they are considered to be at risk for glaucoma.
Glaucoma is a common condition after 40 years, affecting 2% of the population. An estimated one million French people have glaucoma and half the number of those who ignore or neglect it.
What are the signs of glaucoma?
In chronic glaucoma, there are no symptoms and this is what makes it all gravity. All the danger of glaucoma comes from its extreme insidiousness: there is no perceptible sign, no pain, no loss of vision and the eye is normal. When a patient with glaucoma realizes a decrease in vision, it is already very late.
Glaucoma is a disease of the optic nerve where one can lose one's vision without knowing it. Whether the treatment is medicated, laser or surgical, it only stops the evolution of glaucoma on the date it is applied. In no case does it make it possible to go back as soon as the fibers of the optic nerve are destroyed, they are definitively destroyed.
Are more prone to glaucoma subjects who have an elevated eye strain.
There are other risk factors for glaucoma: heredity, myopia, diabetes, tobacco, hypercholesterolemia and hypertriglyceridemia, high blood pressure, low blood pressure. The incidence of glaucoma is higher in blacks.
What makes the severity of glaucoma?
Glaucoma is severe because in the absence of screening and treatment the patient will consult at a late stage for visual defect or vision loss alas irreversible. If it is not treated or if it is detected too late, it can even lead to blindness. Glaucoma is the leading cause of blindness in industrialized countries. Both eyes are usually affected. This is all the more distressing because it is a blindness easily avoided with current therapies.
How to detect glaucoma?
To screen glaucoma, it is necessary at the age of 40 years to carry out a thorough ophthalmological examination which begins with the taking of the tension of the eyes. Recognition of whether an eye is prone to glaucoma is within the scope of the specialist provided that the subject over 40 years of age is submitted to an examination and that the examination is complete on the occasion of any consultation, Reasons as banal as the prescription of a pair of glasses. This is one of the main reasons why the prescription of spectacles belongs to the ophthalmologist and not the optician.
The increase in the frequency of glaucoma with age obviously implies that this examination of the tension of the eyes is repeated over time. An eye tension test every 2 to 3 years can be advocated in normal subjects after 40 years. It should be more frequent in case of glaucoma risk factor (eye disease, family history, diabetes, vascular pathology, diabetes).
This comprehensive examination should include not only eye tension, but also the examination of the optic nerve (papilla and optical fibers) with a 3-mirror glass and better still a Frequency Doubling Technology (FDT) Glaucoma very early a few years before the first signs and glaucoma without tension, the eye tension being in this normal case.
Are there subjects more prone to glaucoma?
Increased eye pressure is a major risk factor for glaucoma. The higher the eye pressure, the greater the risk of developing glaucoma. There is no normal figure in theory and a figure for glaucoma but an individual figure for each person (eye-to-target). This figure is to be appraised imperatively according to the thickness of the cornea by a pachymetry. A high thickness tends to increase the eye tension figure. Conversely, a tension in the lower eye diminishes the eye tension. In fact only 10% of people with high eye pressure have glaucoma and conversely, a low eye tension is not a certainty that there is no glaucoma.
The risks of glaucoma are greater among the parents of affected individuals; Glaucoma can, therefore, be hereditary. It is, therefore, imperative that all members of a family be monitored as soon as possible when there is a case of glaucoma, without waiting for the age of forty.
There are other risk factors for glaucoma than eye strain: myopia, diabetes, tobacco, hypercholesterolemia and hypertriglyceridemia, vascular antecedents, high blood pressure (indirectly by the arteriosclerosis it causes ), Or the opposite hypotension arterial. It is important to emphasize that in a person with high blood pressure, blood pressure should be lowered as slowly as possible, smoothly and not too low, a sudden drop that can be responsible for the deterioration of the field Visual in a subject with glaucoma. It is, therefore, necessary to always inform his general practitioner that one is carrying glaucoma.
Ethnic origin is also a risk factor: glaucoma is 4 times more common in black than in white people.
At present, a consensus is reached to treat all subjects with more than 22 eye strain if there are risk factors, reducing the number of cases evolving towards glaucoma.
In rare cases (one in 20,000 newborns), glaucoma can occur at birth: congenital glaucoma, caused by ocular malformation or secondary to a disease contracted during pregnancy (eg, rubella ). However, these rare forms are serious because they account for 10% of blind young people.
How does glaucoma develop?
The eyeball contains a liquid, the aqueous humor which gives it the ocular tension necessary for the preservation of its spherical shape. This fluid is secreted into the eye by a "tap" the ciliary body, and evacuated in the angle between the iris and the cornea through an "evacuation grid", the trabeculae. Vision is directed from the visual retinal fibers to the brain by the optic nerve irrigated by the ophthalmic artery.
The following is easy to understand: chronic glaucoma is due to the alteration of the trabeculae which no longer plays its role of an evacuation of the aqueous humor the ocular tension increases and will cause a suffering of the optic nerve at its starting point called The papilla.
This suffering may also be due to a second mechanism, the drop in blood pressure in the ophthalmic artery.
How to avoid this evolution of glaucoma?
Glaucoma is severe because in the absence of screening and treatment the patient will consult at a late stage for visual defect or vision loss alas irreversible. If eye tension is not treated or if it is detected too late, it may even lead to blindness. Glaucoma is the leading cause of blindness in industrialized countries. Both eyes are usually affected. This is all the more distressing because it is a blindness that is easy to avoid with the current therapies that make it possible to lower the tension of the eyes.
This evolution of glaucoma is perfectly preventable by early detection by taking eye tension (eye tension) at a stage where glaucoma is easy to control with a simple treatment. It may seem surprising that such a serious and frequent eye disease is so little known to the public. The general public, the media, public authorities, general practitioners, and opticians must, therefore, be made aware and informed.
It should be noted that glaucoma, if not cured, is controlled very well, like other conditions such as diabetes or high blood pressure and that by different treatments, it can be stabilized, stopped. A patient with glaucoma, screened in time, well monitored and monitored regularly by a specialist leads an absolutely normal life.
The eye is a spherical organ filled with liquid: the aqueous humor.
This is secreted permanently by the ciliary body and then normally evacuated at the angle between the iris and the cornea (iridocorneal angle). This angle has a variable width depending on the individual and allows the regulation of intraocular pressure.
WHAT IS IT?
The second cause of blindness in Western countries after diabetes, glaucoma is defined as an increase in pressure inside the eye.
This increase in pressure results in damage to the retina, which in turn causes visual impairment, ranging from a moderate decrease in visual acuity to loss of vision.
Primary glaucoma is distinguished from secondary glaucoma by cause:
Primary glaucoma occurs spontaneously. They include:
Congenital glaucoma, which appears at about 3 or 4 months of age and is surgically treated from the outset;
Primary adult glaucoma (see below).
Primary adult glaucoma
Two forms exist angle closure glaucoma (acute glaucoma) and chronic wide-angle or open angle glaucoma.
Secondary glaucoma is a complication of other ophthalmic diseases (uveitis, ocular trauma, lens abnormalities, diabetes, obstruction of the central retinal vein, tumors of the eye, etc.). Some drugs such as local corticosteroids may be responsible for an increase in eye strain; Their judgment is imperative.
These glaucomas are also distinguished according to their mode of development:
Acute glaucoma that occurs suddenly;
Chronic glaucoma that settles gradually and may go unnoticed before the signs appear.
Acute glaucoma
CAUSES AND RISK FACTORS about glaucoma:
In acute glaucoma, the already narrow iridocorneal angle closes abruptly: the aqueous humor, unable to escape by this route, accumulates rapidly in the posterior chamber of the eye and causes an increase Of the intraocular pressure.
This hyper-pressure, rapid and painful, leads to impaired vision by compression of the optic nerve.
Factors favoring the occurrence of acute glaucoma include hyperopia, cataracts, and familial predisposition.
Triggering circumstances are often found: stress, emotions, drugs, prolonged stay in the darkness or the darkness (cinema, etc ...). Any dilation of the pupils (mydriasis) is a risk factor.
Many drugs are contraindicated: atropine, neo-synephrine associated with antiseptics in certain eye drops, psychotropic drugs (neuroleptics, tricyclic antidepressants, MAOIs, amphetamines, etc ...), antispasmodics, antiparkinsonians, antihistamines, and bronchodilators, Etc ...
SIGNS OF SICKNESS
An emergency consultation of an ophthalmologist is necessary at the first signs.
These symptoms are colored halos around light sources, fog or fog printing, eye pain and headache, sometimes accompanied by vomiting.
A great crisis of glaucoma is possible with a brutal and dramatic beginning. Most of the time, the crisis affects only one eye and occurs in a patient over 50 years of age.
The eye is red, painful with a significant drop in visual acuity (the eye barely perceives light). The pains are violent, paroxysmal on a permanent painful background. They sit above and around the orbit and often spread to the back of the skull. Tearing and fear of light are constant. Other less specific signs such as nausea and vomiting are frequently associated.
CONSULTATION
On examination the doctor regains a "glaucous appearance" of the cornea (hence the name of this disease): it is cloudy, edematous and has lost its polish ("aspect in the eye of dead fish"). The pupil is dilated and the photometer reflex disappears (no shrinkage of the pupil in the illumination).
On palpation of the eyeball, eyes closed, the doctor perceives a very hard eye in relation to the healthy eye ("like wood or like a glass ball").
Measurement of ocular tension shows a pressure greater than 40 mmHg for normals of 10 to 20 mmHg as a function of age.
TREATMENT
It is a therapeutic emergency to reduce the pressure of the eye: stop the production of the aqueous humor and/or promote its evacuation of the eye.
Secondly, surgical management may be necessary to limit recurrences.
The doctor administers emergency acetazolamide, a drug promoting the elimination of aqueous humor.
A myopic eye drop (which shrinks the pupil) is then installed every ten minutes to attempt an opening of the iridocorneal angle and restore the flow of the aqueous humor out of the eye. These eye drops are mainly composed of anticholinergics (pilocarpine and acridine).
Analgesics and sedatives are often prescribed to reduce pain and improve the comfort of the patient. In addition, anti-inflammatory eye drops will reduce local inflammation.
A transfer in specialized service allows the subsequent management with the discussion of surgery or laser (iridectomy or laser iridotomy). These interventions make it possible to prevent recurrences and are usually performed on both eyes.
Chronic Glaucoma
WHAT IS IT?
A decrease in the circulation of the aqueous humor increases the ocular pressure. The iridocorneal angle remains open.
The disease often affects both eyes and is responsible for more than two-thirds of the diagnosed glaucoma.
This affection alters the visual functions silently for about fifteen years, without pain or symptom. When the first signs appear, it is often too late; Systematic screening for glaucoma is, therefore, fundamental.
No cause is found; This disease is often hereditary, bilateral and reaches the adult after 60 years.
CAUSES AND RISK FACTORS
Type pressure of the eyeball is due to changes in the secretion, circulation or evacuation of the aqueous humor but the exact cause remains unknown.
Chronic glaucoma gradually destroys the eye in about fifteen years with the progressive involvement of the fibers of the optic nerve. Since the ocular hyper pressure is relatively limited (25 to 35 mmHg) it causes no symptoms.
SIGNS OF SICKNESS
Early signs are inconstant: visual fog, colored halos around the lights, episodic headaches often attributed by the patient to nervous tension or sinus problems, refractive changes, lacrimation, the obligation to change corrective lenses, etc. ..
It is the systematic examination of ocular pressure in adults over 40 years that reveals the existence of ocular hypertension.
The discovery of an ocular tension greater than 20 mmHg requires a careful ophthalmological assessment:
Taking eye pressure several times during 24 hours and establishing a curve;Study of the visual field;Background;Visual field.
In the absence of treatment, the development takes place in a variable time towards aggravation and blindness by destruction of the optic nerve.
TREATMENT
It is always medical at first:
The treatment is first local, with a college whose objective is either to promote the elimination of the aqueous humor or to reduce its production.
First-generation eye drops (based on pilocarpine, beta-blocker, sympathomimetics or enzyme inhibitors) and second-generation eye drops (based on prostaglandin derivatives) are distinguished.
If the local treatment fails, oral acetazolamide may be used and the aqueous humor of the ocular globe may be released. An osmotic antiglaucoma based on glycerol may optionally be associated with it.
In the event of failure of these medical treatments, laser or surgical treatment can be performed at the iridocorneal angle (trabeculoplasty or trabeculectomy).
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