Don't Lose Sight. Glaucoma is a Silent Disease That You Should Keep An Eye On
Photo by Daniil Kuželev on Unsplash
Glaucoma is a disease that damages the optic nerve. It has
been described for many years as the “silent thief of sight.” This name was
coined because the damage to one’s vision often occurs very slowly over a long period
of time. By the time a decrease in vision has been noticed, considerable damage
has already been done. The damage is almost always permanent and cannot be
Since there is no “cure” for glaucoma, treatment is aimed at halting the development of the disease and preventing further vision loss. Therefore, early detection through annual eye examinations is vitally important.
Who is Most at Risk?
The World Health Organization has listed glaucoma as the second leading cause of blindness in the world today. It is also the leading cause of blindness among African Americans. The population groups who should be checked regularly for glaucoma are African Americans, Hispanics, anyone with a family history of glaucoma and those over the age of 60.
How Does Glaucoma Develop?
The eye is a marvelous organ that acts like a camera to give us our sight and sense of the world around us. Like a camera, it has a “lens” in the front (the cornea), and “aperture” (the iris), “photographic film” in the back (the retina), and “wiring” to transmit the pictures to the brain (the optic nerve).
The eye’s enclosed sphere is filled with its own special clear fluid, the aqueous. Throughout our lifetime, this fluid is continually produced inside the eye and is drained away through special channels. In doing so, it creates its own fluid pressure (intra-ocular pressure) that for the most part is separate from our blood pressure. If the “drain” were to become constricted or blocked, the pressure inside would rise. In other cases, some medications, other eye disorders, or event some injuries can cause the aqueous to be produced faster than it can be drained off, which will also cause an increase in pressure.
This increased intra-ocular pressure can set the state for glaucoma to develop. If left untreated, glaucoma will begin to destroy the nerve cells that make up the retina and optic nerve.
Because of the way the damage occurs, the nerves furthest from our visual center are destroyed first. Therefore, the vision loss due to glaucoma tends to start at the outer edges of our peripheral visual field. The loss is so gradual that most people do not notice anything different about their vision. Over time the loss of the peripheral vision will lead to a progressively worsening form of tunnel vision. Without treatment to slow down or arrest the progression, total blindness can occur.
There are several different types of glaucoma, including some forms in which the intra-ocular pressure is not elevated. However, pressure is one of the best modifiable factors in glaucoma management. That’s why most therapies are aimed at reducing the intra-ocular pressure. For most people, this can be accomplished by using one or more prescription eye drops. There are several different classes od rugs in eye drop form that are very good at reducing pressure. Some patients may have to use a combination of two or three eye drops to accomplish the necessary reduction in their pressure.
There are also surgeries to help in the reduction of pressure, either in opening the existing drains or in creating new channels to allow for more aqueous to drain away. Surgical methods are usually performed when the use of eye drops no longer reduces the pressure as needed, or when the patient cannot remain compliant in using the eye drops as prescribed by their optometrist or ophthalmologist. Some of these surgeries are conventional while others use a laser.
Categories of Glaucoma
Glaucoma can be classified into two main categories, “open-angle” and “closed-angle” (also called “angle closure” or “narrow-angle”. The angle is a name given to the junction between the cornea and the iris, where the drain for the aqueous is located.
An “open-angle” is one that appears wide open and unobstructed. This type progresses at a slower rate and tends to be a chronic condition that lasts throughout the patient’s lifetime. Unless this insidious form is discovered in a regular eye exam, most people will not notice any difference in their vision until significant damage has been done. There is also a sub-type of glaucoma within this group in which the pressure appears to be normal, but damage to the retina and optic nerve is ongoing. Most of the “open-angle” types are managed with prescription eye drops or oral medication.
A “closed-angle” is one in which the drain appears very narrow and constricted. This type is on in which the drain can become completely sealed off. A sudden high-pressure attack occurs often causing a painful, red eye. Internal damage and vision loss can progress quickly. Due to the pain, however, most people seek immediate medical care before any significant damage has occurred. While many of these cases are managed with eye drops or oral medications, surgeries and laser procedures are sometimes more helpful among this group of patients.
A third category can also be noted in which glaucoma is induced to develop due to use of certain types of medications (usually steroids), from injuries to the ye which damage one of its internal components or from debris which plus up the draining.
Early Detection is Key
Early detection through annual eye exams is vitally important. A comprehensive eye exam by an optometrist or ophthalmologist includes a test to measure the intra-ocular pressure as well as examination of the retina and optic nerve to assess their health.
If you are being treated for glaucoma, take your medication and use your eye drops as prescribed. Consistency and regularity are very important controlling the ye pressure, expecially with eye drops. In addition, follow up appointments with your doctor to monitor your eye pressure every few months to ensure that your glaucoma is being controlled.
Cameron Smith, D.O. at Texas State Optical in Mansfield. The team of eye care professionals at Texas State Optical - Mansfield, TX is available to handle your eye care needs. Texas State Optical is located at 1650 Hwy 287 N. in Mansfield.