What is Glaucoma?
Glaucoma occurs when fluid builds up in the front part of your eye, increasing the pressure in your eye and damaging the optic nerve. It's called "the silent thief of sight" because you may not notice any vision problems until it's already advanced.
Fortunately, there are medicines and surgeries that can control eye pressure and slow down the progression of glaucoma, but the treatment depends on what type of glaucoma you have and its severity.
Different Types of Glaucoma
There are various kinds of glaucoma, and below are the most common forms:
Primary Open-Angle Glaucoma
Primary open-angle glaucoma (POAG) is the most common type of glaucoma and occurs when the eye does not drain fluid properly. This slowly worsens over time and, if left untreated, will lead to complete loss of peripheral vision (also known as tunnel vision) and eventually complete blindness. However, starting treatment early can help prevent further vision deterioration.
Normal, or Low-Tension Glaucoma
People with this type of glaucoma still show symptoms of glaucoma despite the pressure in the eye being within the normal range. The cause is thought to be related to inadequate blood flow to the optic nerve.
Here, a sudden rise in eye pressure results in intense pain, blurry vision, halos around lights, nausea, and headaches. The increased pressure is due to a blockage in the fluid at the front of the eye. If the blockage is not promptly resolved, it can result in permanent vision loss and therefore requires immediate treatment.
This is a genetic type of glaucoma that is present from birth. Babies with this form of the disease have a defect that hinders the regular flow of fluid out of the eye. Typically, they receive a diagnosis before their first birthday. Some noticeable symptoms may include excessive tearing, cloudy or hazy eyes, enlarged or bulging eyes, or sensitivity to light. Surgery is commonly conducted to restore complete vision, which has a high success rate.
Secondary glaucoma occurs as a side-effect of various factors including eye surgeries, injuries, or certain medical conditions such as cataracts, tumors, or uveitis (inflammation of the middle layer of the eye).
Secondary glaucomas include:
- Neovascular glaucoma: This is characterized by the formation of new blood vessels over the iris and the angle of the anterior chamber.
- Pigmentary glaucoma: This occurs when pigment from the iris sheds and obstructs the drainage of fluid from the eye. As a result, it can cause inflammation and harm to the eye and its drainage system.
Glaucoma Risk Factors
It's often extremely difficult to detect glaucoma because you might not have any symptoms until the disease has progressed. This is why regular eye exams, including glaucoma screenings, are absolutely crucial, especially if you:
- Are over 60
- Are of Hispanic, African-American, Asian, or Latino descent
- Have a family history of glaucoma
- Suffer from diabetes
- Have severe nearsightedness
- Use certain medications like steroids
- Had a serious eye injury (even if it occurred in childhood)
During a regular and thorough eye examination conducted by one of our eye doctors, your eyes will be dilated to allow for an examination of the optic nerve for any indications of glaucoma. Additionally, the following tests will be performed:
Intraocular pressure (IOP) will be measured using a tonometer. The procedure involves the application of numbing eye drops followed by gentle pressure on the surface of the eye to determine the pressure inside. It is important to note that since IOP can vary throughout the day and glaucoma can exist even without elevated IOP, this measurement alone is not sufficient to rule out the presence of the disease. If any signs of glaucoma are observed, further tests will be conducted.
Visual Field Test
To identify any blind spots in your peripheral or side vision, a visual field test will be performed. During this test, you will be instructed to position your head in front of a machine while looking straight ahead. You will then be prompted to indicate when you detect signals appearing in your peripheral field of view.
As part of the examination, your doctor may also assess the thickness of your cornea using an ultrasonic wave instrument in a procedure called pachymetry. Alternatively, they may employ imaging techniques such as digital retina scanning or optical coherence tomography (OCT) to generate an image of your optic nerve and evaluate any potential damage caused by glaucoma.
Treatment for glaucoma is determined based on the type and severity of the disease. It can involve various approaches, including:
Medication and eye drops are commonly prescribed as an initial treatment to control inner-eye pressure. Although these drops may have some uncomfortable side effects, it is crucial to comply with the treatment plan to preserve vision and halt the progression of the disease.
Surgical procedures aim to regulate the fluid flow within the eye by either reducing fluid production or improving drainage. In many cases, a combination of surgery and medication is deemed the most effective approach by your doctor.
Emphasizing the significance of early detection and treatment, it cannot be overstated that the most effective treatment for glaucoma occurs before substantial vision loss transpires. Once vision is lost, it cannot be restored. Therefore, the best prevention strategy involves being aware of your risks and taking responsibility by regularly undergoing comprehensive eye examinations.