Glaucoma is a disease that can gradually and silently steal your vision without you noticing, resulting in severe loss of sight. Glaucoma is usually seen in the elder population over the age of 50, but it can occur earlier. This is why it’s recommended to be tested every two years during adulthood. The symptoms that are associated with glaucoma vary depending on the type of glaucoma.
Glaucoma is a disease that relates to a build of intraocular pressure. The pressure in the eye is dictated by the volume of aqueous humor found in the anterior chamber. This aqueous humor is produced by the ciliary body and then travels into the anterior chamber where it drains into the angle/faucet. If this drainage system is impaired at all then there will be a build up of pressure inside the eye which will then start to damage the optic nerve head. The optic nerve head is the cable that connects the eye to the brain, thus allowing visual information to travel through this nerve to the brain. In glaucoma patients central vision is fine but peripheral vision slowly deteriorates as time progresses, until it ends up affecting their central vision near the end stage of the disease.
The optic nerve is the cable that connects the brain to the eye. As the retina becomes stimulated by light, it will transmit and carry visual information through the optic nerve to the brain. Fibers that make up the nerve become damaged by increased pressure, decreasing the amount of visual information sent to the brain. In turn, this would result in permanent loss of vision.
The goal in the treatment of glaucoma is to prevent vision loss by lowering the intraocular pressure. Glaucoma is treated with therapeutic eye drops or laser. Occasionally, additional drops or multiple laser procedures may be needed to sustain a low intraocular pressure. If these modalities fail then surgery is crucial in order to improve drainage and reduce pressure.
Unfortunately, any vision loss from glaucoma is permanent and cannot be restored. This is why early detection is a necessity in preventing permanent visual loss.
The cause differs depending on the type of glaucoma; it can be either primary or secondary. Primary indicates that glaucoma is the main culprit, while secondary indicates another disease that has lead to glaucoma. Primary glaucoma can occur from either an open or closed angle. In primary open-angle glaucoma the drainage angle (faucet) formed by the cornea and iris remain open, but the trabecular meshwork (drainage channels) in the angle may be partially blocked, causing the fluid to drain out of the eye slowly. Therefore, fluid gets backed up and causes the intraocular pressure to increase. In closed-angle glaucoma, the iris is either pushed forward or anatomically situated forward. This causes the drainage angle to be narrow or even blocked, thus increasing the intraocular pressure. Trauma, infection, tumor, dense cataract or certain eye conditions like diabetes can lead to the development of secondary glaucoma. This disease can also occur from a number of pharmaceutical agents that are used for certain health conditions.
Glaucoma is commonly seen with aging but can be evident in younger individuals as well. This disease is more prevalent in certain ethnic groups; people of African and Hispanic ethnicities are more likely to develop open-angle glaucoma, whereas people of Asian ethnicity are more likely to develop narrow-angle glaucoma. Additionally, there is a higher risk for developing glaucoma when there is a history of the disease in the family. Diabetes and hypertension may also lead to the development of normal tension glaucoma due to the poor perfusion of blood getting to the optic nerve.
Glaucoma is detected through measuring the intraocular pressure of the eye. Another key element to diagnosing glaucoma is to examine the optic nerve head as well as performing a visual field test. A visual field is a sensitive test that checks for the development of abnormal scotomas. The best way to diagnose this disease is to assess all of these tests and correlate them with one another.