Glaucoma can steal your vision gradually without you ever noticing, until it is too late.
What is Glaucoma?
Glaucoma is a complicated disease in which damage to the optic nerve leads to progressive, irreversible vision loss. It is the second leading cause of blindness.
There are several types of glaucoma. The two main types are open-angle and angle-closure. These are marked by an increase in intraocular presssure.
Primary open-angle glaucoma
By far the most common type (90%) primary open-angle glaucoma develops gradually and painlessly. The inner eye pressure (IOP) rises because the correct amount of fluid cannot drain out of the eye. The entrances to the drainage canals are clear and working but the clogging problem occurs further inside the drainage canals. Most people have no symptoms until they have lost a lot of vision. This type of glaucoma if detected early usually responds well to medication.
Acute angle-closure glaucoma
This results from a sudden blockage of the drainage channels within your eye. With angle closure, the iris is not as wide and open as it should be and it bunches up over the drainage canals and the pressure rises very high. Symptoms of angle closure may include headache,eye pain, nausea, rainbows around lights at night and blurred vision. Treatment of angle closure needs to be done immediately or significant vision loss can occur. Treatment usually involves either a laser or surgery to remove a small portion of the bunched up iris.
During our comprehensive eye examinations, we look at this part of the eye to ensure you are not at risk of developing this emergency event and can send you to an ophthalmologist for preventive treatment to avoid this occurring.
Normal Tension Glaucoma(NTG)
This is also called low tension or normal pressure glaucoma. In this glaucoma the optic nerve is damaged even though the pressure is not very high. It is unknown why this damage occurs. For some reason the optic nerve is susceptible to damage from even the normal amount of eye pressure. Those at highest risk for this type of glaucoma are: people with a family history of normal-tension glaucoma, people of Japanese ancestry, people with a history of systemic heart disease. Since little is known about why normal pressure damages some eyes, most doctors lower eye pressure as much as possible using drops and laser or conventional surgery.
This type of glaucoma occurs in babies when there is incorrect or incomplete development of the eye’s drainage canals during the prenatal period. This is a rare condition that may be inherited. Microsurgery is usually performed to correct the structural defects.
Other Types of Glaucoma
- Pigmentary Glaucoma (pigment from the iris blocks the drainage of the fluid and IOP rises)
- Pseudoexfoliation Glaucoma
- Traumatic Glaucoma
- Neovascular Glaucoma (uncontrolled diabetes)
- Irido Corneal Endothelial Syndrome (ICE)
Why is glaucoma harmful to vision?
The optic nerve, located at the back of the eye, carries visual information to the brain. As the fibers that make up the optic nerve are damaged by glaucoma, the amount and quality of information sent to the brain decreases and a loss of vision occurs. This could be loss of visual clarity and brightness, gaps in vision, loss of a section of your vision or eventually if not detected and treated complete loss of vision.
Will I go blind from glaucoma?
If diagnosed at an early stage, glaucoma can be controlled and little or no further vision loss should occur. If left untreated, side awareness (peripheral vision) and central vision will be destroyed and blindness may occur.
How is glaucoma detected?
Tests for glaucoma are part of a comprehensive eye examination. A simple and painless procedure called tonometry measures the internal pressure of your eye. Ophthalmoscopy examines the back of the eye to observe the health of the optic nerve. Biomicroscopy of the front structures of the eye are evaluated for possible risk factors for glaucoma. A visual field test, a very sensitive test that checks for the development of abnormal blind spots, may also be completed. Imaging of the optic nerve with photography and OCT also provides additional information to confirm a diagnosis.
How is glaucoma treated?
Glaucoma is usually treated with prescription eye drops and medicines. In some cases, surgery may be required to improve drainage. The goal of the treatment is to prevent loss of vision by lowering the pressure in the eye.
Will my vision be restored after treatment?
Unfortunately, any vision loss as a result of glaucoma is permanent and cannot be restored. This is why regular eye examinations are important.
Glaucoma cannot be prevented, but early detection and treatment can control glaucoma and reduce the chances of damage to the eye and a loss of sight.