 |
What is glaucoma?
Glaucoma is an eye disease where the pressure inside the eye becomes too high resulting in progressive damage to the main nerve of the eye (the optic nerve). This progressive damage initially causes a gradual loss of side vision that is not noticeable until it is very advanced. Untreated glaucoma will eventually cause blindness. Most forms of glaucoma produce no noticeable symptoms until major, irreversible nerve damage has already occurred. This is the real danger of the disease. However, if diagnosed early, glaucoma is a very treatable. Therefore, being examined for glaucoma on a regular basis is very important. In addition, if it is determined that you are at high risk for glaucoma or you already have the condition, careful examination, testing, and follow-up care are needed to preserve your sight.
Although glaucoma can occur at any age, the risk of developing the disease increases as we age. being most common after 35 - 40 years of age. It is estimated that glaucoma will affect 1 of every 50 adults. Anyone can get glaucoma, but people at higher risk include:
- Those who are significantly nearsighted (high myopia)
- Those with a family history of glaucoma
- Those with Type I or Type II diabetes
- Those who have had a significant trauma to an eye (even decades earlier)
- Those who have had major eye surgery
- Those of African descent
What is the difference between open angle and narrow angle glaucoma?
Glaucoma is often divided into two major types: open angle glaucoma and closed angle glaucoma. The angle is that part of the eye where the intra-ocular fluid gradually drains out into the blood stream. If the angle is open and yet the pressure in the eye is elevated and causing nerve damage, it is called Open Angle Glaucoma. If the angle is very narrow or closed with the resulting elevated intraocular pressure causing nerve damage, it is called Narrow or Closed Angle Glaucoma. Open angle is by far the most common of the two forms. Only a small percentage of people ever develop narrow or closed angle glaucoma. However, those few that do can experience a sudden elevation in pressure causing a rapid onset of blurred vision, pain, eye redness, and headache. They may also see "rainbows" or "halos" around lights. This sudden closing of the angle with elevated intraocular pressure is called Acute Angle Closure. Immediate treatment is indicated.
If you think you are having an angle closure attack, and do not live in the Lincoln Metro Area, call your local eye doctor or emergency room immediately and advise the doctor on-call of your symptoms and concerns.
What is ocular hypertension?
Some people simply have high eye pressures but no signs of optic nerve damage or side vision loss. These patients are said to have "Ocular Hypertension". Recent studies have indicated that in some instances it is important to start ocular hypertensive patients on glaucoma medications in order to prevent future damage. Deciding which patients to treat or not treat is thus a difficult decision. At the Lincoln Eye & Laser Institute, we pride ourselves on making sure you are making an informed decision on this crucial question.
How is glaucoma diagnosed?
A thorough eye examination that includes careful assessment of a patient's side vision (visual field) and optic nerves is essential to diagnose glaucoma early when it is most treatable. As one the largest and most advanced glaucoma practices in the region, the doctors at the Lincoln Eye & Laser Institute believe it is important for our patients to have access to leading edge technology and expertise to properly manage their glaucoma. Examples of this technology are the GDx Nerve Fiber Analyzer, the Lumenis SLT Laser, and the incorporation of pachymetry corneal thickness analysis into the diagnostic and treatment protocols of our patients.
The GDx Nerve Fiber Analyzer provides a detailed computerized analysis of the amount of nerve fibers in the eye. Since glaucoma, by definition, is gradually destroying optic nerve fibers, the earlier this damage can be detected the better. With the GDx, nerve fiber damage can often be detected at an earlier stage than the doctor can see it. In addition, once a baseline measurement with the GDx has been taken it can be compared to future measurements in order to detect any change for the worse at a much earlier point than ever before imagined. Nerve fiber analysis is truly on the forefront of the diagnosis and management of glaucoma. You will be happy to know that the GDx test does not require dilation of the pupil and only takes a few minutes.
Corneal pachymetry is the measurement of corneal thickness. The accuracy of the measurement of intraocular pressure can be affected by a patient's corneal thickness. People with very thick corneas might have "high pressures" but actually not be at significant risk for glaucoma. Likewise someone with unusually thin corneas might have "normal pressures" but in reality have high pressures and require treatment. At the Lincoln Eye & Laser Institute we measure the corneal thickness of all patients where corneal thickness could have a significant impact on the management of their glaucoma or ocular hypertension.
Other important diagnostic tests for glaucoma include visual field testing, gonioscopy, and careful assessment of the optic nerves by the doctor through a dilated pupil. Even while being treated, glaucoma can sometimes gradually progress. That is why it is so important to gather good baseline information to allow confident future comparison when the testing is periodically repeated.
How is glaucoma treated?
Glaucoma is usually treated by lowering the pressure in the eye to a level that hopefully stops progressive damage to the nerve. The first line of treatment for glaucoma is usually topical eye drop medications. Fortunately many glaucoma drops have been developed over the last few years with several more on the horizon. We are pleased to have participated in numerous clinical research studies proving the efficacy of several new glaucoma medications. Glaucoma medications typically work by either reducing the amount of fluid produced inside the eye or by helping intraocular fluid drain out more efficiently. Some medications may actually do both. It is not uncommon to be on two or more medications at one time to treat glaucoma.
Once a patient is on two or more medications and they still need their intraocular pressures lowered more, it is likely they will need laser or other glaucoma surgery to further reduce the pressure in the eye if it is needed. At the Lincoln Eye & Laser Institute, we are pleased to have the new Lumenis SLT laser for treatment of glaucoma. We are the only facility in Nebraska or Iowa to have this technology. Unlike previous argon lasers which caused significant scarring of the delicate tissues in the angle of the eye, the SLT causes minimal to no damage. The effect of the laser (both argon and SLT) on intraocular pressure often wears off after 1 -3 years. With the old argon lasers there was a limit on being able to do repeat treatments due to the scarring of the laser. With the SLT this problem is resolved and patients can have repeated treatments as needed.
If topical medications and SLT laser treatments fail to lower intraocular pressure effectively, glaucoma surgery is an option. At The Lincoln Eye & Laser Institute we pleased to have one of the few glaucoma fellowship trained ophthalmologists in Nebraska. Dr. Sao J. "John" Liu is very experienced in advanced microsurgical techniques in the treatment of glaucoma including trabeculectomy and Molteno valve implantation. These procedures can be performed in our certified ophthalmic surgery center.