Glaucoma

Glaucoma is a group of eye conditions in which the optic nerve progressively becomes damaged. A variety of mechanisms can cause this but a rise in intraocular pressure (IOP) is a common cause. In the UK it is estimated that around 2% of people over the age of 40 have glaucoma. The prevalence increases with age, affecting 10% of those over 75. Approximately 700,000 people in the UK have glaucoma with many cases undiagnosed due to the conditions often asymptomatic nature in the early stages.

If glaucoma treatment is not promptly administered, this damage (neuropathy) can cause loss of field of vision – and ultimately blindness. In this article we will delve into the symptoms of Glaucoma, its types, and of course glaucoma treatment.

What is Glaucoma?

Glaucoma is a family of eye conditions that damage the optic nerve (commonly through pressure that builds up in the eyeball, called intraocular pressure) and is one of the leading causes of blindness in the world for those over the age of 60. This is because the disease progresses without symptoms until vision loss becomes apparent.

There are different types of Glaucoma – open-angle glaucoma and angle-closure glaucoma are the most common forms of the disease and require different treatments.

Is Glaucoma Hereditary?

Twin and population studies have identified Glaucoma can be hereditary, with family history being a significant risk factor, particularly for primary open-angle glaucoma. Regular eye tests are essential for early detection and management of the condition before it leads to irreversible damage.

Types of glaucoma

Glaucoma can be caused by a variety of underlying processes and as there are four major types of glaucoma, it’s important to understand how each type differs before diagnosis and treatment

Primary Open-Angle Glaucoma (POAG)

Chronic open angle glaucoma is a progressive optic neuropathy which damages the optic nerve head. The drainage channel in the eye is open and there is no other cause for the optic nerve damage such as steroid-related glaucoma. POAG affectS 1-2% of the white population in the UK aged 40 and over, increasing to 4-5% of those aged over 80 years. The drainage angle of the eye is damaged, preventing the correct amount of fluid from draining away, leading to a raised IOP and damage to the optic nerve.

It tends to run in families and in those of west African ancestry, with raised intra-ocular pressure as the mechanism of optic nerve damage in POAG.

Glaucoma can also occur in patients with “normal” intra-ocular pressure (normal tension glaucoma).

Other risk factors include age, corneal thickness, myopia (shortsightedness) and diabetes.

Primary Angle-Closure Glaucoma (PACG)

This condition has a lower incidence in the UK, which occurs when the drainage angle between the iris and cornea, through which fluid passes is unusually narrow and can become closed off. When this occurs, the inner eye pressure rises sharply, causing pain, nausea, blurred vision and redness in the eye.

It also tends to run in families, with hyperopic (long-sighted) eyes more at risk.

females are three times more likely to suffer from closed-angle glaucoma attacks. This is down to the anatomical structure of the eye. Since females tend to have smaller eyes with shallower anterior chambers, it makes them prone to a narrower angle between the iris and cornea, making it easier for the drainage angle to be blocked.

Secondary Glaucoma

There are several possible causes including inflammation, trauma, surgery and syndromes such as pigment dispersion and pseudo-exfoliation. This may cause raised IOP and glaucoma.

Pigment dispersion syndrome (PDS) is when the pigment is released from the iris into the anterior chamber (fluid-filled chamber at the front of the eye) which may then lead to a blockage of the drainage canals, a rise in eye pressure and damage to the optic nerve. This is known as pigment dispersion glaucoma.

Pseudo-exfoliation (PXF) is a rare condition caused by a build-up of abnormal protein which may block the outflow of fluid in the eye, causing raised eye pressure and may lead to optic nerve damage.

Congenital Glaucoma

This condition usually results from a genetic mutation or a developmental abnormality in the eye that causes drainage problems during foetal development. One of the most common forms of congenital glaucoma is primary congenital glaucoma, which often occurs in children between birth and early childhood – before the age of three. The condition typically manifests with large eyes (Buphthalmos), excessive tearing, light sensitivity, and cloudy corneas. If left untreated, primary congenital glaucoma can cause irreversible vision loss. Unlike other forms of glaucoma that develop later in life, congenital glaucoma is often something a child is born with, and early treatment is essential for preserving vision.

Learn more about glaucoma in our Video FAQs

Symptoms of glaucoma

Glaucoma is one of the leading causes of blindness in the world, and it’s estimated around 10% of the UK population will go blind due to glaucoma. This is expected to rise due to the ageing population, therefore it’s vital to highlight the need for increased awareness and screening, especially among those with a family history of the condition.

Understanding the symptoms of glaucoma has never been more important for your eye health.

Symptoms of open-angle glaucoma

There are generally no symptoms or early signs of open-angle glaucoma which is why it is known as the “silent thief of sight”.

If untreated, open-angle glaucoma can lead to sight loss so it is critical to see an eye doctor for regular examinations. If this is in one eye only, it may go unnoticed until vision is profoundly affected.

This is the most common type of glaucoma, and if you are diabetic or have cardiovascular disease you are at an increased risk of developing glaucoma.

The risk of developing open-angle glaucoma also increases with age. If you have a family history of glaucoma and are over the age of 40, you should see an eye doctor every one to two years to monitor your eye health.

Symptoms of angle-closure glaucoma

Symptoms to look out for in angle-closure glaucoma include eye and head pain, the appearance of rainbow colour circles in bright lights, and blurry vision. The pain can cause nausea and vomiting and can even lead to sudden sight loss.

These symptoms can develop quickly and are immediately noticeable. If untreated, you are at risk of suffering from repeated closed angle attacks and/or sustained raised intraocular pressure (IOP). This can lead to damage to the optic nerve, known as primary angle-closure glaucoma (PACG).

It is crucial that you monitor the condition of your eyes by having regular eye examinations.

Treatments for Glaucoma

Treatment options for glaucoma include:

Eye Drops – Topical drugs are one of the first line treatements for glaucoma. Treatment involves decreasing fluid production or increasing fluid drainage. Prostaglandin analogues, beta-blockers, alpha agonists and carbonic anhydrase inhibitors are common types. These meds can be effective in many people but need to be taken on a strict schedule, or they become less effective.

iStent Combined Cataract Treatment – The iStent is a tiny device implanted during cataract surgery to treat open-angle glaucoma. It helps to reduce intraocular pressure by improving the outflow of aqueous humor, the fluid in your eye. This combined approach is beneficial for patients needing cataract surgery who also suffer from glaucoma.

Benefits of iStent are as follows:

Reduces the need for glaucoma medications

Performed alongside cataract surgery

Minimally invasive

Procedure:

The iStent is implanted during cataract surgery

It is a quick procedure, often adding only a few minutes to the overall surgery time

Most patients can resume normal activities within a few days

Selective Laser Trabeculoplasty (SLT) – SLT is a laser procedure used to lower intraocular pressure in glaucoma patients. It is considered when medications are insufficient or cause significant side effects. SLT uses a low-level laser to target specific cells in the trabecular meshwork, the eye’s drainage system, increasing fluid outflow.

Benefits of SLT: