Glaucoma Treatment and Laser Surgery
Glaucoma is a family of diseases that damage the optic nerve. The optic nerve is the nerve that connects the eye and the brain.
Often the pressure in the eye with glaucoma is elevated. The eye is filled with fluid that is made and drained in the eye. A mis-match between fluid production and fluid drainage causes the pressure to be elevated.
Not all cases of glaucoma are caused by elevated pressure. There is a large percentage of glaucoma cases–perhaps up to 40%– where the pressure is not elevated.
On the other hand, having elevated pressure does not necessarily mean you have glaucoma, just high eye pressure or ocular hypertension. Sometimes an eye with a thick wall or cornea can fool the pressure measuring device into reading higher than the real pressure. Often when the pressure is high, we measure the corneal thickness to be sure that we aren’t being fooled. A thick cornea will give falsely high pressures and often a factdor against having glaucoma. The opposite is true for thin corneas. Here the pressure will read falsely low and the risk of having glaucoma is well known to be higher.
Often the first signs of glaucoma are visible by looking at the optic nerve. The changes –called optic nerve cupping– are often seen years before a patient looses vision.
A normal optic nerve ( the round white structure) seen to the left) has blood vessels coming from the middle. It has a small dimple in the middle. That is the optic cup. Imagine it as a belly button.
The optic nerve cup on the left is quite large. The “belly button” is abnormally big. The finding results from loss of the nerve fibers. There are usually about 1.2 million nerve fibers here. This one has less. A nerve that looks like this would make the doctor suspicious of glaucoma. The patient may be seeing well this point. But further tests should be done.
A note of caution, if the eye is not dilated, seeing this finding might be missed. That is one reason why dilation should not be skipped at your eye exam.
The vision loss is measured by a computerized test called a visual field. A visual field test measures how dim a light needs to be before you don’t see it anymore. It measures this at several points in your field of vision and compares it to your prior tests and to normal person’s results of the same age, sex, and glasses prescription. The field loss is usually subtle and not something you can see by waving a hand on the side of your head–at least early in the disease. The changes actually occur in the nose side of the vision first. This is often the same area served by the center vision of the other eye. So it is easily missed. Some computerized visual field tests are faster than others. Some pick up early disease better–like the Short Wave or SWAP testing stategy which tests with blue colored dots on a yellow background instead of the usual white dots. This is done because glaucoma tends to affect the nerves that see the color blue first.
Their are other tests like OCT or HRT that measure thinning of the optic nerve layers. These can often help follow the disease early on.
Glaucoma tTreatment usually consists of lowering the pressure whether the initial pressure is high or not. Many different eye drops can do this. Glaucoma laser surgery improves fluid drainage from the eye –like Argon or Selective Laser Trabeculoplasty. There are lasers that can be used tat the time of cataract surgery ( called ECP) that can decrease fluid production, Finally, there is traditional Glaucoma surgery that can help fluid get out of the eye and lower the pressure. We usually reserve that for the most difficult of cases.
Glaucoma is a lifelong disease. Different Glaucoma treatments often work well at first but need to changed later. So follow up is key.
Family history dramatically increases your risk of having the disease but doesn’t mean you will definitely get it. Black people do worse than white people. Smokers in my experience really have tough time with the disease.
Vision loss is common but is often preventable. Early Glaucoma treatment is key because what vision you lose doesn’t come back. It is often said it’s like running toward a cliff. It doesn’t actually hurt until you fall off. Glaucoma treatment slows you down so hopefully your vision doesn’t fall off that cliff!
Contact The Eye Clinic of Florida for more information on our Glaucoma treatment and Laser Surgery services.