MY EYE DROPS ARE NOT WORKING!Carolina Valdivia, MD answers a question from a woman concerned that eye drops prescribed by her doctor are not adequately controlling her eye pressure problem.  A 49 year-old woman from Belize writes:Hi Dr. Valdivia. I was diagnosed with glaucoma about one month ago. At the time, the doctor told me that the pressure in my eyes was very high. He prescribed two different kinds of eye drops, but they did not help much to control my eye pressure problem. Now I have a third medicine. Why does the pressure in my eyes not want to go down? I can see well from 12 inches and farther out, but closer I do not have good vision. I use reading glasses. I also have to shield my eyes from the sun because it bothers me. I do not have cataracts, diabetes, or high cholesterol. Can you help me understand why I still have an eye pressure problem despite taking glaucoma medications?
The severity of glaucoma in a patient is due to several factors. Important among these are existing damage to the optic nerve and deterioration of the visual field. This determines whether a person's glaucoma is at an early, intermediate, or advanced stage. However, I want to point out that it does not mean that everyone diagnosed with glaucoma is destined to pass through each stage eventually. A person can be diagnosed at an early stage and remain there with proper treatment. Another important factor is a patient's intraocular pressure at the time of diagnosis. A person with an intraocular pressure slightly above normal, for example 23 mmHg, will have a different disease-progression risk profile from a person with an eye pressure problem that is 40 mmHg. Very high intraocular pressures are associated with greater damage to optic nerve fibers and this damage occurs in a shorter period of time. There are many types of glaucoma, but the most common is primary open-angle glaucoma. This could be the type of glaucoma that you have. If this is the case, very high intraocular pressures are associated with abnormalities in a structure in the front part of the eye known as the trabecular meshwork. This serves as a filtering mechanism for a fluid called aqueous humor and represents the fluid's point of exit from the eye. Abnormalities in trabecular meshwork structural components can make it difficult for aqueous humor to leave the eye, creating a back up of the fluid and causing an eye pressure problem that can lead to optic nerve damage. The second most frequent type of the disease is primary angle-closure glaucoma. In this type, increased intraocular pressure results from a narrowing of the anterior chamber angle of the eye formed by the iris and the cornea. Very narrow angles can cause a condition called peripheral anterior synechiae. These are adhesions in the angle between the iris and the trabecular meshwork. This severely restricts the exit of aqueous humor of the eye, which, in turn, can result in an eye pressure problem that leads to optic nerve damage.The goal of eye drops to combat glaucoma is to lower intraocular pressure to a level where damage to the optic nerve is minimized. However, in some cases, outcomes with these medications are not satisfactory and the eye pressure problem continues at levels that remain a threat to the optic nerve. Your ophthalmologist usually will change medications to see if a different type is more effective. If the outcome still is unfavorable, she or he will have you use two or sometimes three different types of anti-glaucoma eye drops. If intraocular pressure still remains at unacceptable levels, it becomes necessary to consider glaucoma surgery. Currently, you are taking your third glaucoma medication. I urge you to schedule the next appointment with your ophthalmologist soon. We can know if eye drops are having their desired effect in a short period of time, usually within a day. It is not a good idea to allow your intraocular pressure to remain at elevated levels for too long. I hope that this third medication functions to lower your intraocular pressure to normal levels. If this is not the case, your ophthalmologist will assess whether further monitoring of your eye pressure using other combinations of medications is warranted or if glaucoma surgery is the best course of action. I understand that you are under a lot of stress and that waiting to find the right medication combination can be very frustrating. You might be wondering, why not just perform the glaucoma surgery and get it over with? This is a question that I am asked routinely by patients. It stems from the common misconception that glaucoma surgery is a cure for disease. It is not. Glaucoma surgery is a treatment and, as such, it is the treatment that carries the greatest risk for complications. While ophthalmologists can employ a number of strategies to manage potential complications associated with glaucoma surgery, the fact still remains that surgery is the treatment that carries the greatest risks. For this reason, ophthalmologists always exhaust other possible solutions for managing intraocular pressure, including combinations of eye drops, before recommending glaucoma surgery to a patient. My advice is to return to your ophthalmologist and have your eye pressure rechecked as soon as possible. Do not hesitate to write again if you have further questions. Carolina Valdivia, MD
REFERENCE:Bendel RE and Juzych MS. Principles and Complications of Medical Therapy of Glaucoma. In: Zimmerman TJ and Kooner KS. Clinical Pathways in Glaucoma. New York:Thieme, 2001:427-456.
A number of visitors have written to me asking for recommendations pertaining to eye-care products and books for obtaining more information. I have joined with Amazon.com to create a dependable resource for books and products. You can find these materials at the Eye-Care Store. My goal in answering your questions is to provide you with information, clear up misconceptions, and to explain options so that you can have an informed conversation with your doctor. However, under no circumstances should my response to your question be considered a substitute for ongoing consultation and examination with your doctor. Since I have not examined you, I only can speak in terms of generalities, whereas your doctor has sufficient clinical details to evaluate your case specifically.
Return from Eye Drops to Answer My Health Question
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A diagnosis of glaucoma can be very frightening and difficult to receive. I am sorry that you are going through this.