Glaucoma Explained: Causes, Symptoms, And Treatments

According to the experts at Vision Source, the eye is a complex organ made up of delicate, intricate parts which work in sync in order for us to transfer the information we see to the brain and convert it into an image. The optic nerve is the only communication pathway we have — and once it's damaged, there is no known way to reverse it. 

Defined as a group of complex eye diseases which damage the optic nerve, glaucoma is a serious condition that if left untreated, can lead to irreversible vision loss (via the Glaucoma Research Foundation). In fact, glaucoma is the second on the list of the most common causes of blindness, per the Centers for Disease Control and Prevention (CDC). 

There are different types of glaucoma, and while some groups of people are at a higher risk of developing this disease, anyone can start experiencing symptoms as they age. The danger with glaucoma lies in its gradual progression, often with no warning signs and a slow process of development that doesn't produce noticeable changes in vision before it's already too late. Here's everything you need to know about glaucoma, including its causes, symptoms, and treatment.

Secondary glaucoma is caused by another medical condition or disease that affects the intraocular pressure and results in optic nerve damage (per the Glaucoma Research Foundation). Most of the other types of glaucoma are considered to be variants of either open-angle glaucoma or angle-closure glaucoma, and they can affect both or only one eye. 

Exfoliative glaucoma is characterized by a build-up of flaky material that peels off the outer layer of the eye lens, causing the blockage of the drainage canals. Meanwhile, pigmentary glaucoma is developed when the pigment granules at the back of the iris break into the eye fluid and clog the drainage canals. Neovascular glaucoma is caused when new blood vessels form over the eye's drainage canals and the iris, causing blockage. 

Traumatic glaucoma happens after an injury that either penetrates the eye or bruises it. Uveitic glaucoma involves the swelling of the eye's middle layer (uvea). Last but not least, an infant may suffer from congenital glaucoma as a result of abnormal development of the eye drainage system prior to the child's birth. 

Even though everyone can be diagnosed with glaucoma in their lifetime and the exact causes of glaucoma aren't completely clear, there are certain groups of people and factors which can make them at higher risk of developing this complex disease (via John Hopkins Medicine). People over 60 years of age are the most likely group to develop glaucoma. It's 6 to 8 times more likely to occur in African Americans than white Americans (per the CDC). Meanwhile, findings from a paper in Opthalmology show that Asians are more likely to experience angle-closure glaucoma. Moreover, people with thinner corneas are also at higher risk of developing glaucoma.

Research published in Archives of Opthalmology shows that family history may play a role in one's risk of developing open-angle glaucoma, which may be hereditary. Therefore, having a family member diagnosed with glaucoma puts you at a greater risk of developing it yourself. Eye injury or trauma which cause bruises and injuries penetrating the eye can damage the eye drainage system. This can occur immediately after the injury or even several years later. Additionally, a paper published by StatPearls establishes a connection between steroid use and glaucoma development.

Glaucoma is usually diagnosed through a regular eye exam, which is recommended for those at an increased risk of developing this disease. 

The Glaucoma Research Foundation thoroughly explains the procedure for a regular eye exam, which consists of five common tests that can detect glaucoma. Tonometry is a test that measures the intraocular pressure using a device called a tonometer. The normal eye pressure falls within the 12-22 mm Hg (millimeters of mercury) range, so when the test result exceeds it, it's usually a sign of glaucoma. However, in the case of normal-tension glaucoma, the eye pressure does not exceed the optimal range. 

Ophthalmoscopy is a diagnostic procedure that checks for optic nerve damage. If there are abnormalities in the way your optic nerve looks (especially if it's accompanied by high IOP), more tests will be required. Meanwhile, perimetry analyzes your complete field of vision and checks for any blind spots or light delays. Gonioscopy is a test that helps detect whether the angle between the cornea and the iris is wide and open or closed and blocked, while pachymetry is a diagnostic procedure that measures your corneal thickness.

The most common treatments for glaucoma include medications and surgery. Medications are supposed to help drain the liquid from your eyes (via the Glaucoma Research Foundation), thus reducing the eye pressure and preventing the optic nerve damage. These medications are usually in the form of eye drops or pills, but they come with a myriad of potential side effects. As a result, your doctor may prescribe a specific combination of medications (or even switch them up throughout your therapy) in order to address the side effects. 

Surgery, on the other hand, is the more invasive option, and it's used when the medications simply aren't effective. There are two main types of glaucoma surgery, selective laser trabeculoplasty or SLT (via the Journal of Current Glaucoma Practice) and incisional surgery. SLT is a laser treatment that helps improve eye fluid drainage due to chemical and biological changes in the laser-affected tissue. Meanwhile, incisional surgery is typically the last option when it comes to treating glaucoma, recommended when neither medications nor laser treatments suffice. During the procedure, a tiny hole is made in the sclera (the white part of the eye), basically creating a new drainage canal through which the fluid can flow without restriction (per the Glaucoma Research Foundation). 

Since signs of glaucoma aren't usually detected before the damage is irreversible, prevention is key. It's wise to have regular eye exams, because seeing your ophthalmologist consistently is one of the most important tips to prevent glaucoma and nerve damage, especially if you're at a higher risk of developing glaucoma (via the Glaucoma Research Foundation). That way, your doctor will be able to detect early signs and start you on a treatment plan that can help prevent any further damage or complications. 

Additionally, be careful when it comes to steroid medications, as they're known to increase IOP. Talk to your doctor about performing regular eye exams while you're on steroid medications. It's also important to implement healthy lifestyle habits: a nutritious diet, regular exercise, adequate sleep, and stress-reducing techniques. These will all help reduce inflammation in your body and improve your health in general. Keeping your blood pressure, cholesterol, and blood sugar at normal levels will also help prevent a plethora of diseases that you may become increasingly at risk of developing as you age. 

Lastly, do your best to protect your eyes from trauma and injury — and when you notice any possible signs of irregularities in your eyes, have your ophthalmologist run diagnostic tests as soon as possible.

Another important lifestyle habit you should focus on is sleep. Sleep is extremely important when it comes to your overall health and longevity, helping your body recover and successfully complete all repair processes. Unfortunately, according to the experts at Sleep Health, 50 to 70 million Americans are experiencing sleep-related problems, resulting in insufficient or poor-quality sleep. A lack of good sleep is one of the major factors that contribute to the development of obesity, diabetes, and other metabolic diseases. 

Meanwhile, a 2019 study cited by Healio affirmed that sleep duration and latency also matter. According to the study, when compared to participants who slept an average of seven hours per night, those who slept for 10 hours or more were three times more likely to be diagnosed with disc-defined glaucoma. Although long sleep time and daytime fatigue aren't surefire symptoms of glaucoma, it's important to discuss your sleep and sleep quality with your ophthalmologist. 

Along with the evolution of medicine, many existing procedures for diagnosis and treatment have improved over the years. There has also been an increase in potential new options for treating serious diseases, and while many of them are still in the experimental phase, they've managed to show promising results. 

For instance, experts at the Glaucoma Research Foundation have talked about retinal ganglion cell replacement, which uses stem cell therapy to regenerate sick cells and replace the ones that have already been lost. While much research still has to be conducted on this type of treatment, it does have noteworthy potential in terms of protecting or perhaps even restoring vision in patients with glaucoma. 

Meanwhile, the National Institutes of Health has funded research on gene therapy, exploring its potential to protect optic nerve cells and prevent vision loss. Tests have so far only been conducted on mice, though.