What common misconceptions exist about ageing eyes?

What common misconceptions exist about ageing eyes?

Take Home Message:

We hope that by debunking the following misconceptions, we will enable you to appreciate why it is essential to have your eyesight checked regularly. We recommend a Glaucoma Safe Assessment if you have any concerns.

Misconception 1: There Is Only One Type Of Glaucoma

There are several types of glaucoma which all induce damage to the optic nerve head structure, usually (but not always) associated with elevated intraocular pressure, which if left untreated, can result in permanent impairment to vision.

There are two main subtypes of glaucoma: open angle, in which the drainage area is not blocked and angle closure when the internal anatomy of the eye changes resulting in the drainage area becoming blocked (described as the iris blocking the drainage angle).

Primary Open Angle Glaucoma is the commonest type of glaucoma. Research has estimated that almost 80 million people will be affected by glaucoma by 2020, of which 75% will have this type of glaucoma. Primary Angle Closure Glaucoma is the second most common form of glaucoma, affecting over 16 million people worldwide. It is more likely (but not exclusively) to affect people of East Asian (or Oriental) ethnicity.

There are also other uncommon types of glaucoma, sometimes affecting younger age groups &/or associated with general health illnesses.

Misconception 2: Glaucoma Only Affects The Elderly

While it is true that glaucoma is more common in people over the age of 60 years, you can potentially develop this disease at any age depending on the type of glaucoma. It has been reported that the commonest type of glaucoma (Primary Open Angle Glaucoma) can affect up to 2% of 40-year-olds of Caucasian ethnicity and up to 4% of 80-year-olds.

Also, there is a rare form of glaucoma where babies are born with glaucoma called congenital glaucoma. Children with an inflammatory condition of their joints called juvenile idiopathic arthritis can also develop glaucoma if their eyes are predisposed to becoming inflamed (called uveitis).

Misconception 3: Glaucoma Only Affects People With A Family History Of Glaucoma

Although people with a family history of glaucoma in a first-degree relative (mother, father, brother or sister) have a higher risk of developing glaucoma, other people can also develop this disease. This is because there are different types of glaucoma and also because glaucoma is a disease in anyone of older age. For those with a family history of glaucoma, we recommend an annual sight test from your 40s onwards.

Misconception 4: Elevated Eye Pressure Is The Only Thing That Causes Glaucoma

This is not true because there is a subtype within Primary Open Angle Glaucoma called Normal Pressure Glaucoma when the optic nerve is damaged even though the eye pressure is not very high. We still do not understand why some eyes are predisposed to this type of damage even though they have normal eye pressures.

Research has reported that there is no specific level of elevated eye pressure that leads to glaucoma although very high eye pressures are more likely to lead to optic nerve head damage; conversely, there is no lower level of IOP that will eliminate a person’s risk of developing glaucoma.

As indicated in misconception 1, the term “glaucoma” encompasses a range of diseases, and therefore the causes are multi-factorial including changes to the anatomy of the eye as well as specific ageing processes within the eye. Research has shown that genetic factors are considered to play a key role in all major forms of glaucoma. Some people from specific ethnic groups are more predisposed to certain types of glaucoma.

What is important about eye pressure is that reducing the eye pressure (compared to the baseline eye pressure before treatment was commenced) can slow down or stop further glaucoma damage. At present, reducing eye pressure is the mainstay of all glaucoma treatments.

Misconception 5: If You Have Developed Glaucoma, You Will Have Symptoms

Mostly, this is not true. When developing Primary Open Angle Glaucoma, there are usually no early warning symptoms, i.e. there are no visual or sensation symptoms. It typically develops slowly and sometimes without noticeable sight loss for many years. Sometimes the condition can affect one eye more than the other, which can mean that some people still get diagnosed with advanced disease because the visual loss in one eye has gone unnoticed.

Even when the disease has affected your peripheral vision, symptoms are uncommon, because you have two eyes which means that the good vision of one eye can compensate for the loss of vision in the other. Also, the brain does not highlight the glaucoma patient the areas of missing vision. Research into driving and visual hazards have shown that glaucoma patients miss things since their brains have filled in their visual field defects with plausible visual data. 

By the time a patient is aware of vision loss, the disease is usually quite advanced. This is why it is essential to have your eyesight checked regularly since with early detection, and treatment, you can preserve your vision.

Misconception 6: Glaucoma Is A Curable Condition

Currently, there is no cure for glaucoma. Although there is no cure, glaucoma is an eminently treatable condition, and the prognosis is very good for most people. If your doctor has recommended treatment to lower your eye pressure, then this usually means that you will need to take this treatment for the rest of your life.

The mainstay of all glaucoma treatments is to reduce eye pressure, and research has shown that reducing the eye pressure can slow down or stop further glaucoma damage.

Take Home Message:

It is essential to have your eyesight checked regularly throughout your life to identify any features that might flag up risk factors for glaucoma. We recommend a Glaucoma VisionSafe Assessment if you have any concerns.