Glaucoma is an eye disease that damages the optic nerve over time usually because of the build up of pressure inside the organ. Patients with glaucoma do not experience early symptoms or pain, which is why it is important to visit the doctor for early diagnosis of the disease. It is estimated that around 3 million people in the United States has glaucoma and is the leading cause of blindness.
The pressure inside the eye, known as intraocular pressure, is caused by a build up of the aqueous humor (the fluid inside the eye). When the mesh-like channel of the eye is blocked, the aqueous humor builds up, causing pressure onto the optic nerve and damages it. This nerve is responsible for transmitting images to the brain. Left untreated, glaucoma can lead to total permanent blindness.
The cause of this blockage is still unknown, but research has determined that this disease can be hereditary. Other causes could be a blunt or chemical injury to the eye, severe eye infection, blocked blood vessels in the eye, and inflammatory conditions.
Glaucoma has two main types which are discussed below:
Also called wide-angle glaucoma, this is the most common type of glaucoma. This is caused by the blockage of fluid in the eye’s drain structure despite looking normal.
Also called acute or chronic angle-closure or narrow-angle glaucoma, blockage of the fluid is caused by the angle between the iris and cornea being too narrow. This narrow angle is also linked to farsightedness and cataracts.
Glaucoma does not exhibit early sign symptoms, which is why it is important to have regular eye check ups with your doctor. It is highly advised to seek medical care if you experience seeing halos around lights, vision loss, redness in the eye, hazy looking eyes, nausea, vomiting, eye pain, and narrowed vision.
Glaucoma is treated through prescription eye drops, laser surgery or microsurgery.
In general, these prescription eye drops are used in glaucoma management by decreasing the eye pressure that helps the aqueous humor to drain better and/or decreasing the amount of fluid made by the eye. Below are the types of prescription eye drops for glaucoma:
Prostaglandin analogs work by increasing the outflow of the fluid from the eye. Usage however, might cause systemic side effects which include possible changes in eye color and eyelid skin, stinging, blurred vision, eye redness, itching, and burning.
Beta blockers are the second most used class of prescription eye drops for glaucoma and work by decreasing the production of the eye fluid. However, usage might cause systemic side effects such as low blood pressure, reduced pulse rate, fatigue, and shortness of breath. In rare cases, it might also cause reduced libido and depression.
Alpha agonists work by decreasing the production of eye fluid and increasing the drainage. However, patients might experience side effects such as burning, stinging, fatigue, headache, drowsiness, dry mouth, dry nose, and a relatively higher likelihood of an allergic reaction.
Carbonic anhydrase inhibitors (CAIs)
CAIs are available in eye drop and pill form and work by decreasing the production of intraocular fluid. However, usage might cause side effects. When taken in eye drop form, it might cause stinging, burning, and eye discomfort. When in pill form, this might cause tingling of the hands and feet, fatigue, upset stomach, memory problems, and frequent urination.
This type of medication is usually composed of two types of glaucoma medication. Some examples include Cosopt, which is a combination of a beta blocker and a CAI. These are prescribed to patients who are in need of more than one type of medication for the management of their glaucoma.
Glaucoma and Medical Marijuana
Since the 1970s, studies have shown that when taken orally or via inhalation, medical marijuana can help in lowering intraocular pressure. And according to the statement of the American Academy of Ophthalmology in 2003, some derivatives of medical marijuana lowered intraocular pressure when taken orally, intravenously or by smoking. Despite these interesting findings, research is still very limited when it comes to the potential effects of medical marijuana in various disorders like glaucoma.