Glaucoma is a group of eye diseases that cause damage to the optic nerve. The optic nerve carries images of the retina, which is the specialized tissue of the light it detects, to the brain making us able to see.
In glaucoma, ocular pressure plays a role in damaging the delicate nerve fibers of the optic nerve.
When a significant number of nerve fibers are damaged, blind spots develop in the field of vision. Once nerve damage and visual loss occur, it is permanent.
Most people do not notice these blind areas until much of the optic nerve damage has already occurred.
If the entire nerve is destroyed, blindness occurs. Glaucoma is one of the leading causes of blindness in the world, especially in the elderly.
Early detection and treatment by your ophthalmologist are the keys to preventing optic nerve damage and loss of glaucoma vision.
The exact causes of glaucoma optic nerve damage are not fully understood, but involve mechanical compression and / or decreased optic nerve blood flow.
Although high eye pressure sometimes leads to glaucoma, many people can also develop glaucoma with “normal” eye pressure.
What are the different types of glaucoma?
- Open-angle glaucoma
Chronic open-angle glaucoma is the most common form of glaucoma. The “open” drainage angle of the eye can be blocked, which leads to a gradual increase in eye pressure.
If this increase in pressure results in damage to the optic nerve, it is known as chronic open-angle glaucoma.
Optic nerve injury and loss of vision usually occur gradually and painlessly, so that those who suffer from it are not aware of problems until the optic nerve is already severely damaged.
- Closed angle glaucoma
Closed angle glaucoma results when the drainage angle of the eye narrows and becomes completely blocked. In the eye, the iris can close the drainage angle and cause dangerously high eye pressure.
When the drainage angle of the eye is completely blocked, the pressure builds up rapidly, and this is called acute angle-closure glaucoma.
Symptoms include severe pain in the eyes, blurred vision, headache, rainbow halos around the lights, nausea and vomiting.
Unless an ophthalmologist deals quickly with angle-closure glaucoma, blindness can occur.
When the drainage angle of the eye is closing and completely blocked, the pressure builds up gradually, and this is called chronic angle-closure glaucoma.
Also, this form of glaucoma occurs most often in people of African and Asian descent, and in certain eye conditions.
Other types of glaucoma
Not all types of glaucoma are characterized by eye pressures.
- In normal tension or low tension glaucoma, the optic nerve suffers damage with the resulting visual field loss, although normal eye pressures are maintained.
Eyes afflicted with this condition are much more susceptible to damage of the optic nerve with any increase in intraocular pressure compared to other eyes.
- Exfoliation syndrome is a common form of open-angle glaucoma that results when there is an accumulation of abnormal, whitish material in the lens and drainage angle of the eye.
This material and the pigment of the posterior part of the iris can obstruct the drainage system of the eye, causing an increase in ocular pressure. This form of glaucoma responds well to laser treatment.
- Pigmentary glaucoma is a condition that typically affects young Caucasian men, mypes.
This condition is characterized by the iris bending backwards and coming into contact with the supporting structures that hold the lens in place.
This position disrupts the cells lining the posterior surface of the pigment containing the iris and results in a release of pigment particles in the drainage system of the eye.
This pigment can clog drainage and can lead to an increase in eye pressure. This form of glaucoma responds well to laser treatment.
Other types of glaucoma can be caused by eye injuries, tumors and other eye diseases. A rare type of glaucoma may even be present in children at birth.
What are the warning signs indicated by this disease?
Unfortunately, most cases of glaucoma do not occur with easily discernible symptoms that warn of irreversible damage to the optic nerve.
However, the presence of the following warning signs indicates that you need a thorough examination by an ophthalmologist:
- Unusual problems to focus the sight inside dark rooms
- Difficulty focusing on near or distant objects
- Blinking or flickering due to unusual sensitivity to light or glare
- Change of iris color
- Caps with red, encrusted or swollen edges
- Recurrent pain in or around the eyes
- Double vision
- Dark spot in the center of visualization
- Lines and edges appear distorted or wavy
- Excessive tearing or “watery eyes”
- Dry eyes with itching or burning
The following may be indications of potentially serious problems that may require emergency medical attention:
- Sudden loss of vision in one eye
- Blurred or sudden cloudy view
- Flashes of light or black spots
- Halos or rainbow around the light.
The symptoms mentioned above may not necessarily mean that you have glaucoma.
However, if you experience one or more of these symptoms, contact your ophthalmologist for a complete examination.
How is glaucoma detected?
Regular eye exams by your ophthalmologist are the best way to detect glaucoma.
Your ophthalmologist will measure your eye pressure (tonometry); inspect the drainage angle of your eye (gonioscopy); evaluate your optic nerve (ophthalmoscopy); and test the visual field of each eye (perimetry).
Optic nerve evaluation and visual field tests are performed at regular intervals to monitor the effects of glaucoma.
The information obtained from these tests provides an indication of the effectiveness of the treatment being used and whether additional treatments may be necessary.
Not all of these tests are necessary for each person, nor at each visit. The goal is to determine if glaucoma damage has progressed over time.
Who is at risk of developing glaucoma? High eye pressure alone does not mean you have glaucoma, but it is an important risk factor that your ophthalmologist will use to determine your risk of developing the disease.
Most of the risk factors include a history of severe anemia, and this is why your ophthalmologist should analyze all of these factors before deciding if you need treatment for glaucoma; or if it should be checked regularly as a glaucoma suspect to detect the first signs of damage to the optic nerve.
Treatment for glaucoma
The treatment for glaucoma depends on the nature and severity of each case.
In general, glaucoma can not be cured, but it can be controlled. Eye drops, pills, laser procedures, and surgical operations are used to prevent or delay further damage.
With any type of glaucoma, regular eye exams are very important to detect progression and to prevent vision loss.
Because glaucoma can get worse without you being aware of it, it is likely that your treatment needs to be changed over time to achieve a lower “target eye pressure”.
Medications for glaucoma
Glaucoma is often treated with eye drops administered several times a day, sometimes in combination with pills.
These medications will alter the circulation of the eye fluid and decrease eye pressure, either by decreasing the production of fluid inside the eye or by increasing the flow leaving the drainage angle.
It is important to tell all your doctors about the eye medications you are using because glaucoma medications can have side effects.
You should notify your ophthalmologist immediately if you think you may be experiencing side effects. The side effects of some eye drops may include a stinging sensation, red eyes, blurred vision, headaches, changes in the pulse, heartbeat or breathing.
Side effects of the pills may include tingling of the fingers and toes, drowsiness, loss of appetite, intestinal irregularities, kidney stones, anemia or bleeding disorders.
Laser surgery and glaucoma
Laser surgery is also effective for the treatment of glaucoma.
Trabeculoplasty is a laser treatment to improve the function of eye drainage age to control eye pressure within the eye when treating open-angle glaucoma.
Iridotomy is a laser treatment to create small holes in the iris to improve the flow of eye fluid to the drain when treating narrow-angle glaucoma.
Operative surgery: When surgical surgery is needed to treat glaucoma, your ophthalmologist will use a microscope and specialized instruments to create a new bypass drainage channel for the eye fluid to leave the eye.
The new channel helps lower eye pressure. Surgery is recommended only if your ophthalmologist feels that the benefit of lower eye pressure achieved with an operation outweighs possible complications and / or increased progression of optic nerve damage.