What is glaucoma, what are the symptoms, and how is it treated?

In this blog, we’ll look into its causes, symptoms, and most importantly, explore the treatment options available for those with glaucoma.

What is glaucoma?

Glaucoma is a group of eye conditions that causes vision loss due to damage to the optic nerve, responsible for relaying messages from the eye to the brain to create visual images, facilitating the process of sight. One of the leading causes of glaucoma is impaired drainage of the aqueous humour, the fluid that nourishes the eye, resulting in elevated intraocular pressure inside the eye¹.

Damage to the optic nerve can also arise from insufficient blood supply to the crucial optic nerve fibres, structural weaknesses in the nerve, or from issues pertaining to the overall health of the nerve fibres themselves¹.

This can result in gradual vision loss and, if untreated, may lead to irreversible blindness. In fact, glaucoma is the number one cause of irreversible blindness worldwide¹. Glaucoma often develops slowly, and symptoms may not be noticeable until significant damage has occurred².

Types of glaucoma

While there are a number of different kinds of glaucoma, most can fit into two categories:

• Open-angle glaucoma: The most common form of glaucoma, open-angle glaucoma occurs when the drain of the eye is wide open but clogging occurs further along the drainage canal and often develops without early symptoms, progressing slowly over time^{2, 3}.
• Closed-angle glaucoma: While less common than open-angle, closed-angle glaucoma is more severe. Closed-angle glaucoma occurs where the drain of the eye is partially or fully obstructed. It can have a sudden onset with symptoms like severe eye pain and blurred vision^{2, 3}.

Causes and risk factors of glaucoma

Age is a significant risk factor for developing glaucoma, with individuals over 50 being more susceptible. Additionally, genetics play a role, as a family history of glaucoma increases the likelihood of developing the condition. Certain ethnic groups, particularly African and Asian populations, are also at a higher risk⁴.

Other risk factors include pre-existing eye conditions, such as myopia (short-sightedness) or hyperopia (farsightedness), and medical conditions like diabetes and hypertension. Trauma to the eye, corticosteroid use, migraines and sleep apnoea can also contribute to glaucoma development⁴.

Symptoms of glaucoma

Recognising the symptoms of glaucoma is crucial for early detection and intervention to prevent irreversible vision loss. Unfortunately, in the early stages of the disease, glaucoma often presents without noticeable symptoms².

Individuals with open-angle glaucoma may experience peripheral vision loss, leading to tunnel vision¹. However, it’s common for one eye to compensate for the other, meaning sufferers remain unaware until severe, irreversible damage has taken place¹.

Individuals with chronic closed-angle glaucoma can experience blurred vision, difficulty adjusting to low light conditions and experience halos around lights. In acute cases of angle-closure glaucoma, sudden and severe symptoms such as intense eye pain, headache, nausea, and vomiting may occur, warranting immediate medical attention².

Diagnosing glaucoma

Due to glaucoma often progressing with no noticeable symptoms, and with 50% of people in Australia with glaucoma currently being undiagnosed¹, regular eye examinations with an optometrist or ophthalmologist (specialist eye doctor) are paramount for a diagnosis².

During the examination, your optometrist or ophthalmologist will assess your optic nerve fibres and examine the structure of your eyes’ drainage network. Additionally, they will conduct tests to evaluate the field of vision, measure the intraocular pressure and corneal thickness. This examination typically takes between 20 to 45 minutes to complete².

Glaucoma Australia suggests that individuals aged 50 and above should undergo a thorough eye examination with an optometrist every two years. Those with a family history of glaucoma or of Asian or African descent are advised to have check-ups every two years starting from the age of 40⁵.

Glaucoma treatment options

While there is no cure for glaucoma, treatment options are available that can help manage, slow or even stop the progression of vision loss.

The primary approach involves the use of prescription eye drops, which either enhance fluid drainage or reduce fluid production to lower intraocular pressure⁶. Oral medications may also be prescribed in some cases to complement the effects of eye drops⁷.

Laser therapy, specifically selective laser trabeculoplasty, laser peripheral iridotomy, and cyclodiode laser treatment can be utilised to improve fluid drainage from the eye⁸.

In more advanced cases or if other treatments prove ineffective, surgical interventions such as minimally invasive glaucoma surgery (MIGS)⁹ or implants called Glaucoma Drainage Devices (GDDs)¹⁰ may be recommended to create new drainage pathways.

The best treatment will depend on various factors, including the type of glaucoma, its severity, and the patient's overall health.

It’s important to note that while the above treatments can prevent vision loss, they cannot restore sight that has already been lost due to glaucoma¹¹.

Lifestyle changes to help manage glaucoma

Adopting a proactive approach is crucial for preventing or living with glaucoma. As previously mentioned, regular eye check-ups are paramount, allowing for early detection and intervention. If diagnosed, you should strictly adhere to your prescribed treatment plan.

Additionally, maintaining a healthy lifestyle can positively impact eye health. Adopting a healthy diet¹², engaging in regular exercise¹³, not smoking¹⁴, and managing stress¹⁵ can positively impact your eyesight and may help reduce your chances of developing degenerative eye conditions like glaucoma.

For an in-depth look at some ways you can support your eye health through simple lifestyle changes, check out our blog, 7 ways to keep your eyesight stronger for longer.