DRUG-INDUCED GLAUCOMAFind out which medications potentially can place you at risk for developing drug-induced glaucoma, especially if they are taken in high doses and over long periods. Drug-induced glaucoma is an unintended side effect associated with the use of medicines (prescribed or self-administered) to address a health problem, either directly associated with the eye or another area of the body. In the case of prescribed medications, this type of glaucoma most often is caused by a person failing to inform their doctor of all of the medications that they are taking, including those prescribed by another physician, over-the-counter (OTC) medications, and those purchased online or through another source. Without this information, your doctor cannot properly develop a safe and effective treatment plan for you, one that considers potential interactions between medicines and negative side effects.
 It is extremely important that you tell your doctor about all of the medications that you are taking.
Several classes medications have a potential to cause an elevation of intraocular pressure , which can occur by way of an open-angle mechanism or a closed-angle mechanism. Drug-induced glaucoma also can be organized around the class of medication: those that have a steroid component and those that do not.
Steroids are a class of chemical compounds found in nature. They also can be manufactured as an ingredient in prescription medicines. Cholesterol is a steroid compound. Its content in food is talked about a lot because LDL cholesterol is associated with cardiovascular disease. But cholesterol also is a natural compound found in our bodies. It fulfills a structural function in our cells and is the major building block for many of the hormones that circulate in the bloodstream. Steroid-based hormones act as messengers, traveling from one point to another through the blood in order to signal cells to do more work or less work. Medicines containing steroids can produce changes in the trabecular meshwork in the front part (anterior chamber) of the eye. This is the area where a fluid called aqueous humor drains. Changes in the trabecular meshwork cause an increase in intraocular pressure. In turn, elevated intraocular pressure for a prolonged period results in irreversible damage to optic nerve fibers, which signifies the onset of glaucoma. Drug-induced glaucoma caused by the chronic use of steroids is usually is associated with their topical use (eye drops or ointments). This form of open-angle glaucoma also can develop through other modes steroid administration, such as oral, inhaled, intravenous, periocular (surrounding the eyeball but within the orbit), or intravitreal (direct injection into the fluid filling the back part of the eye called vitreous humor).
 I have asthma. My doctor has prescribed me pills and I also use an inhaler. Both contain steroids. Will taking these steroids give me glaucoma?
Steroid-based medications often are an essential component of treatment plans for patients with asthma. Although there is some risk of developing glaucoma with the use of these drugs, the risk is much lower when compared to the use of steroids in eye drops. Nevertheless, to be safe, I recommend having your eye pressure checked regularly. Speak to an ophthalmologist in order to determine how often you should be checked based upon the type of medicine that you are taking. If you have a family history of open-angle glaucoma, you should have your eye pressure checked more frequently. You might also explore with your doctor if you are a good candidate for switching to a treatment regimen that includes leukotriene receptor antagonists (LTRAs). These are a class of non-steroidal medication that have been shown effective in the treatment of asthma for many patients. Examples of LTRA medications include: Singulair® (Montelukast) and Accolate® (Zafirlukast).
Never quit or modify the dose of medications prescribed by your doctor. Doing so can be dangerous. If you are experiencing problems with a particular medication, inform your doctor immediately.
Scientists have found that there is a genetic predisposition to steroid-induced glaucoma. Although the mechanism still is not well understood, you are considered at higher risk if you have relatives diagnosed with glaucoma, especially if they are members of your immediate family (known as first-degree relatives). Others at higher risk are diabetic patients, highly myopic (nearsighted) individuals, and patients with connective tissue disease, specifically rheumatoid arthritis. Patients already diagnosed with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) also are at higher risk. In this case, steroid medications not used properly or not used under a doctor's supervision potentially can accelerate the progression of your glaucoma (make it worse).
I have Cushing's disease and my doctor told me that my cortisol levels are quite high. Am I going to get glaucoma?
Cushing's Disease and Congenital Adrenal Hyperplasia (CAH)represent the first line of evidence for a genetic predisposition to drug-induced glaucoma, because these represent conditions in which the body over-produces corticosteroids. In Cushing's Disease, a non-malignant tumor in the pituitary gland located at the center of the brain produces a hormone called adrenocoticotropic hormone (ACTH) in an exaggerated manner. This, in turn, stimulates the adrenal glands located above the kidneys to increase production of cortisol. Cortisol is a corticosteroid that is involved in the metabolism of carbohydrates, proteins and fats, and in regulating the correct balance of water and electrolytes in the body. Cushing's Disease is one specific cause of elevated cortisol production that falls under the umbrella term Cushing's Syndrome. Cushing's Syndrome includes to other clinical manifestations of elevated cortisol production, such as tumors or other problems in the adrenal gland (adrenal Cushing's) and prescriptions of glucocorticoids by physicians to treat other diseases called iatrogenic (adverse effects) Cushing's. It is important to understand that although Cushing's Syndrome and other conditions, such as congenital adrenal hyperplasia that are associated with elevated cortisol production place you in a higher risk category, this alone does not automatically mean that you will develop glaucoma. However, to be safe, you should have your eye pressure checked regularly. Do not take any medications containing steroids unless under a doctor's supervision and they have been made aware that you have Cushing's Syndrome. The greatest risk for steroid-induced glaucoma is seen with the most potent preparations administered through eye drops or ointments. When it is present, elevated intraocular pressure most commonly is observed 4-6 weeks after administration, but depending on susceptibility it can range from as early as two weeks to even years after the use of corticosteriods is started. The table below lists types of corticosteriod medications and their associated risk for causing drug-induced glaucoma.
My doctor prescribed some eye drops containing dexamethasone, but I am afraid to take them because I heard that they cause glaucoma. What should I do?
I want to make it crystal clear that medicines containing steroids, such as dexamethasone, prednisolone, triamcinolone, and fluoromethalone constitute the mainstay of treatment options for many eye diseases. The effects and benefits of these medications are excellent and far outweigh the risks. But they always must be administered with caution and under a doctor's supervision. Most patients that are prescribed steroid-based medicines do not develop drug-induced glaucoma. In fact, studies have shown that only 5-6% of patients will develop a marked elevation of intraocular pressure 4-6 weeks after regular administration of topical dexamethasone or betamethasone eye drops. The challenge that I face as an ophthalmologist is that science has not yet reached a point where we can identify who these 5-6% of patients will be. Studies also have demonstrated that the percentages of patients that develop elevated intraocular pressure are directly related to the frequency of administration and duration of usage of steroid-based medicines, with increasing usage related to increased risk of elevated intraocular pressure. So . . . does this mean that to be safe you should not use steroid-based drugs at all? ABSOLUTELY NOT! These medicines can be used safely if they are prescribed for use over short periods and if the patient's intraocular pressure is tracked, which is exactly what a responsible physician will do. If intraocular pressure is high, the medication can be discontinued, and it will return back to normal. For example, in my clinical practice I never have seen a single case of drug-induced glaucoma after administration of steroids for a short period (7-10 days).
A diversity of non-steroidal medications have been found to be associated with the development of glaucoma. Medications prescribed for a variety of systemic conditions, such as depression, allergies, and Parkinson's disease can make the pupil of the eye dilate and cause an attack of acute angle-closure glaucoma, especially in patients already diagnosed with primary angle-closure glaucoma (PACG). With respect to open-angle glaucoma, causes of non-steroidal medication-induced elevations in intraocular pressure are wide-ranging. One example is the release of pigment from the iris of the eye during pupillary dilation, resulting in obstructions of the trabecular meshwork (pigmentary glaucoma). Another example, is increases in aqueous humor production because of prolonged dilation of the pupils. It is important to understand that drug-induced glaucoma caused by non-steroidal medicines is relatively rare and usually occurs in patients that are members of one or more of the risk categories for developing glaucoma. Below are classes of medications that have been associated with reported cases of drug-induced glaucoma.
The medicines listed on this page have been linked to drug-induced glaucoma, but they also have undergone extensive scientific testing and have been proven safe and effective. Yes. I have to take certain precautions when prescribing them to patients, but this actually increases the safety of using them. Do not allow fear to prevent you from taking medications that can help you. 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.
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