While many types of Glaucoma exist, the two main types are Primary Open Angle Glaucoma (POAG) and Angle Closure Glaucoma.
Primary Open Angle Glaucoma
The most common type of Glaucoma is Primary Open Angle Glaucoma (POAG). In a normal eye, there is a continuous production and drainage of a clear fluid called the Aqueous Humor. This production and drainage is balanced to maintain an equilibrium. As a result of this equilibrium, the Intraocular Pressure (IOP) remains normal. Patients with POAG usually have an increase in IOP, called Tonometry.
When there is either too much Aqueous Humor being produced, or too little being drained, there is a rise in pressure inside the eye. Any elevation of IOP is abnormal. This elevation in IOP causes the circulation in the optic nerve to become compromised, depriving it of oxygen and nutrients. As a result, the optic nerve can become permanently damaged. Any damage to the optic nerve can result in a loss of vision. The optic nerve is the connection responsible for communicating visual images between the retina and the brain. Once the optic nerve is damaged, it cannot carry visual images. This results in vision loss. This is why it is so important to monitor, detect and control IOP. If left untreated, an elevated IOP will cause progressive and permanent damage to the optic nerve.
Angle Closure Glaucoma
Primary Angle Closure Glaucoma and Acute Angle Closure Glaucoma are the two main types of Angle Closure Glaucoma. Although Angle Closure Glaucoma occurs much less frequently than POAG, it is important to understand because it can produce considerable vision loss in a short period of time.
Primary Angle Closure Glaucoma and Acute Angle Closure Glaucoma
Primary Angle Closure Glaucoma accounts for approximately 10% of all cases of Glaucoma. About two-thirds of these cases produce no symptoms for patients. In fact, Acute Angle Closure Glaucoma is one of the only types of Glaucoma that produce distinct symptoms. These include pain, light sensitivity, redness, blurred vision, colored halos around lights, and nausea or vomiting.
Angle Closure Glaucoma occurs when the drainage structure of the eye, the Trabecular Meshwork, becomes blocked or closed. The Trabecular Meshwork is a fine filter, so if it becomes blocked or obstructed, it will cause the Intraocular Pressure to elevate. In instances where the meshwork becomes blocked abruptly, it will cause a sudden rise in the IOP, resulting in Acute Angle Closure Glaucoma. This sudden rise in pressure which will cause pain, redness, light sensitivity, colored haloes around lights, nausea or vomiting and blurred vision. If left untreated, it will lead to permanent loss of vision.
Acute Angle Closure Glaucoma is a medical emergency. If you experience a sudden onset of pain, redness, blurred vision, light sensitivity, halos around lights, nausea and vomiting, please call The Eye Center at 303-777-5455. Relay these symptoms to the receptionist so you can get an immediate appointment.
Causes of Angle Closure Glaucoma
Angle Closure Glaucoma is caused when there are anatomical changes in the internal structures of the eye. It is more common in smaller, farsighted eyes, and in patients between the ages of 45 to 60.
If your doctor observes a narrowed angle, they will perform an additional examination called Gonioscopy. This will allow the doctor to directly examine the Trabecular Meshwork angle in order to carefully assess your predisposition to Angle Closure Glaucoma. By placing a special contact lens on your eye and using a slit lamp bio-microscope, the doctor will be able to make a thorough evaluation.
In the event that you are at risk for Angle Closure Glaucoma or that you have Acute Angle Closure Glaucoma, the doctor will prescribe some medication to lower the pressure. They will also recommend performing a Glaucoma Laser procedure to produce a small opening in the Iris so that Aqueous Humor can drain from the eye more effectively. This procedure, called a Laser Iridotomy. It is quite successful in treating Angle Closure Glaucoma and preventing recurrences.
Glaucoma is a very complex eye disease and not simply an elevated IOP. Nonetheless, when detected early, it can be successfully treated. The Eye Center provides diagnosis and treatment of all types of Glaucoma.
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If you, a family member or friend, would like to schedule an eye examination for Glaucoma, please call The Eye Center at 303-777-5455.