Glaucoma is a condition that damages the optic nerve and causes vision loss. Increased eye pressure often causes glaucoma and occurs due to a buildup of fluid in the eye which damages the optic nerve fibers over time. Normally the fluid, or aqueous humor, inside of the eye circulates and drains from the eye at the same rate that it is produced. This maintains a healthy eye pressure. People with glaucoma often experience a blockage of the drainage channels in the eye which results in the increase of fluid. Optic nerve damage happens slowly, but continuously in most forms of glaucoma. This makes it difficult for you to know if you are losing your vision without the help of a doctor. There are close to three million people in the United States with glaucoma, and many do not even know they have this condition. Without treatment, glaucoma can cause blindness. Glaucoma can be slowed in 90% of patients through early detection and treatment before the optic nerve is severely damaged.
Are your eyes under pressure?
There are several types of glaucoma but the similarity between each kind is that they cause damage to the optic nerve. Different types of glaucoma vary in frequency and characteristics and are classified as primary, where glaucoma occurs naturally, or secondary, where there is something identifiable causing increased pressure in the eye.
Open-angle glaucoma is the most common form of the disease. It occurs when the fluid in the eye drains too slowly through tissues in the eye. This type of glaucoma rarely has symptoms in its early stages but in later stages is characterized by blank spots in your vision that are a result of the optic nerve becoming damaged. Open-angle glaucoma is associated with increased eye pressure. Normal eye pressure can vary from person to person so it is important to speak with your eye doctor about what your target eye pressure is.
Closed-angle glaucoma is a result of the iris being closer than normal to the drainage angle in the eye. There is an increased risk in people with hyperopia developing this type of glaucoma because they have smaller eyes and narrower angles. Acute angle-closure glaucoma occurs if the angle becomes completely closed, while subacute angle-closure glaucoma can occur intermittently and can sometimes resolve naturally. With the acute form, there is a sudden increase in the pressure inside the eye and symptoms can include extreme eye pain, headaches, blurred vision, excess tearing and nausea or vomiting. It is important to see an ophthalmologist immediately if you experience these symptoms in order to prevent optic nerve damage and vision loss. For either type, your ophthalmologist may decide to perform a procedure called a laser iridotomy, during which a hole is made in the iris to allow for normal drainage of the fluid in the eye.
Unlike all other types of glaucoma, normal-tension glaucoma is not characterized by an increase in eye pressure. Damage to the optic nerve still occurs and gradual vision loss is often noted but the pressure in the eyes will stay within normal ranges. There is no known cause of this condition and it can be diagnosed by an examination of the optic nerve.
Let’s get this under control
Most forms of glaucoma are chronic, which means that they develop slowly and last for an extended amount of time. Glaucoma can be treated with both medication and surgery. Through treatment, glaucoma cannot be cured and lost vision cannot be restored, but further vision loss may be prevented.
At this time, the best way to treat glaucoma is to lessen the intraocular pressure (IOP) which causes optic nerve damage and most cases of glaucoma can be controlled with eye drops. Miotics and prostaglandin analogs are two classes of drugs that increase the outflow of aqueous fluid, and help lessen pressure in the eyes. Beta-blockers and carbonic anhydrase inhibitors are drug classes that lessen pressure by decreasing the amount of aqueous fluid made in the eye. Adrengic agonists lessen pressure by both decreasing how much fluid is made, and helping its outflow. Oral medications may also be prescribed but are generally only used in extreme cases because they can have serious side effects.
Laser surgery is another method to lessening pressure in your eye. Surgery can open the drainage channels of your eye to lessen pressure. Laser surgery works in lessening pressure immediately; however, in more than 50% of patients, the pressure increases again two years after surgery.
In what is known as conventional surgery, the surgeon creates a new channel for fluid to drain from the eye. Conventional surgery is usually done if medicine and laser surgery do not work in controlling eye pressure.