Glaucoma is a disease of the optic nerve, the part of the brain that carries the images we see to the brain. The optic nerve is made up of many nerve fibers, just like an electric cable conduit containing numerous wires. When damage to the optic nerve occurs, blind spots develop in a person’s vision. These blind spots usually go undetected until the optic nerve is significantly damaged. If the entire nerve is destroyed, then total blindness can result.
Glaucoma is a leading cause of blindness in the United States, especially for older patients. Early detection and treatment by your eye care provider are the keys to preventing optic nerve damage and visual loss from glaucoma.
A clear liquid called the aqueous humor circulates inside the front portion, or anterior chamber, of the eye. To maintain a healthy level of pressure within the eye, a small amount of this fluid is produced constantly while an equal amount flows out of the eye through a microscopic drainage system. In glaucoma, damage to this drainage system occurs at a microscopic level. This leads to elevated pressure because the drain does not remove the aqueous humor as quickly as it should. Prolonged elevated pressure in the eye causes damage to the fibers of the optic nerve at the back of the eye.
There are many different types of glaucoma. The most common type is chronic open-angle glaucoma. Risk factors for open angle glaucoma include age, a family history of glaucoma, African or Hispanic ancestry, and female gender.
Treatment of glaucoma is centers on lowering the pressure inside the eye to prevent damage to the optic nerve. The most common treatment for glaucoma is daily use of eye drops. These drops either decrease the amount of aqueous fluid that is made in the eye, or increase the effectiveness of the drainage system. Laser therapy is as effective as eye drops and is performed on the drainage system to improve the efficacy of the drain. Surgery is performed when other treatments fail. Surgery is used to create an artificial bypass of the drainage system, allowing the fluid inside the eye to drain to a reservoir created under the conjunctiva.
Complete eye examinations conducted every few years by your eye care provider are the best way to detect glaucoma. Early treatment is instrumental in preserving sight. Patients who are being treated for glaucoma undergo special imaging of the optic nerves and testing of visual function on at least a yearly basis.
In 2009, Maine voters approved a law allowing patients with glaucoma to acquire and possess a limited amount of marijuana for medicinal purposes if recommended by their physician. Our practice does not issue the medical certificate required under this law. Because marijuana is not manufactured under FDA (Federal Food and Drug Administration) protocols, the potency (strength), purity, and dosage cannot be assured, whether it is grown by the patient, a caregiver, or purchased at a state-licensed dispensary. This variability makes it impossible to know if the marijuana is effective or how it might interact with other medications. Marijuana is a Schedule I drug under federal law, meaning that it can only be prescribed in connection with a federal-approved research protocol. Furthermore, we are very concerned about the potential abuse of marijuana in Maine, which already suffers from a significant drug problem. Should there be a change in the federal law, scientific evidence of drug effectiveness for the treatment of glaucoma in clinical trials, and FDA approval of that form of marijuana, we would consider changing this policy. At the current time, FDA approved drugs, laser treatments, and surgery have proven themselves to be superior to marijuana for the treatment of glaucoma.