Glaucoma - the thief of sight
Glaucoma: the thief of sight
Glaucoma is usually associated with the build-up of fluid pressure inside the eye. If left untreated it can cause vision loss by damaging the optic nerve (the wire that connects the eye to the brain).
Glaucoma is commonly referred to as “the silent thief of sight,” because in most cases it progresses gradually and quietly. Vision can be damaged without any noticeable symptoms. It may begin with loss of peripheral vision and then progress to central vision loss and blindness. It affects nearly 2 out of every 100 people over the age of 35. Half of those are at risk for blindness because they may not even know that they have the disease. With early detection and careful management, significant damage to eyesight from glaucoma is nearly always preventable, although treatment cannot restore vision that has already been lost.
Glaucoma is a complex disease associated with the build-up of fluid pressure inside the eye that can damage the optic nerve. The optic nerve, a bundle of over a million nerve fibers, transmits the message of sight from the eye to the brain. In glaucoma, the nerve fibers carrying peripheral vision are affected first. This reduction in side vision can be gradual and is usually asymptomatic. By the time it affects central or reading vision, tremendous damage to the nerve has already occurred.
To understand what’s happening with glaucoma, imagine the eye as a sink filled with water. The clear fluid inside the eye is always flowing into and out of the eye, just like a sink with an open faucet and drain. As long as the drain is open, a sink won’t overflow. But if anything happens to block the drain, the water level rises and spills over the edge. Since the eye is a closed ball, blockage to its drain and pipe doesn’t cause the aqueous to overflow or leak out. It has nowhere to overflow. Rather, the eye’s fluid pressure increases and damages the optic nerve.
Although there are many different causes of glaucoma, there are two broad categories: open angle and narrow angle. The most common type is the chronic open angle glaucoma. In this condition, the opening into the trabecular meshwork is working, but is internally clogged, causing the pressure to painlessly and gradually increase.
The other major type of glaucoma is narrow (closed) angle glaucoma. With narrow angles the iris (the colored part of the eye) blocks the trabecular meshwork’s opening, causing a sudden severe rise in eye pressure. This can cause halos around lights, severe pain, and rapid vision loss.
Both of these types of glaucoma can be inherited. If someone in your family has glaucoma, your risk of developing it is increased. Likewise, if you have glaucoma, others in your family need to be made aware that their risk is increased.
The diagnosis is not always clear-cut since each eye varies in its susceptibility to eye pressure. Successful diagnosis and treatment begin with a careful ocular evaluation. First, we measure the fluid pressure within the eye. Corneal thickness may affect this pressure reading and can be checked with an ultrasonic pachymeter. We examine your eyes thoroughly and look for optic nerve damage. Using our OCT machine, we can measure the nerve fiber layer thickness around your optic nerve. This test may determine if you have glaucoma even before you experience any vision loss.
How is glaucoma treated?
1. Eye drops
In most cases, open-angle glaucoma can be treated with eye drops used once or twice daily. These drops help lower eye pressure and reduce the risk of further vision loss. Sometimes more than one drop is needed. If drops do not adequately control eye pressure, laser or surgery may be needed. There are many types of glaucoma drops.
2. Minimally invasive laser procedures
Selective Laser Trabeculoplasty (SLT)
SLT is a safe, painless, 5-minute office procedure that uses a laser to lower eye pressure and reduce the need for eye drops. It uses an extremely short burst of laser energy to selectively treat and remove pigmented cells that may clog the trabecular meshwork. Compared to traditional argon laser trabeculoplasty, SLT does not cause any structural changes or scarring so it can be repeated as needed. Patients whose pressures are not controlled by eye drops, who cannot afford eye drops, or who have poor compliance with eye drops are good candidates for SLT.
Will I go blind from glaucoma?
Virtually no one should be blinded by glaucoma. Treatments are highly effective and, while vision already lost cannot be restored, significant further loss can be avoided. The most important ingredient in successful glaucoma management is patient compliance. Continuous pressure control is possible only by strictly following your treatment plan…and that is primarily up to you. In most cases, the only people who become blind from glaucoma are those who do so before their condition is diagnosed or who do not follow their doctor’s advice and treatment regimen.
For more information on glaucoma or a complete eye exam, contact us at Fuerste Eye Clinic, conveniently located inside Grant Regional Health Center in Lancaster. For appointments, call (888) 582-0769.
Dr. Tyler Risma
Luke Ploessl, OD