Glaucoma, a leading cause of vision loss worldwide, is a serious eye condition influenced by various factors, including family history.
Research shows that those with a family history of glaucoma are up to 4 times more likely to develop the condition themselves.
However, a genetic predisposition doesn’t guarantee you’ll develop glaucoma, but it does make regular screenings more important.
What Is Glaucoma?
Often referred to as the “silent thief of sight” glaucoma is a group of eye conditions–each with its unique characteristics and risk factors–that damage the optic nerve, a structure that, transfers visual information to the brain.
This damage is generally caused by abnormally high eye pressure inside the eye, although it can also develop when eye pressure is within its normal range.
How Glaucoma Affects the Eye
Eye fluid, known as the aqueous humor, is responsible for maintaining the shape of the eye and nourishing the tissues within. This fluid is continuously produced and drained out of the eye through a specialized drainage system between the iris and the cornea.
When the production or drainage of the aqueous humor is destabilized, it can lead to an increase in intraocular pressure (IOP). This elevated IOP is a major risk factor for developing glaucoma, as it places stress on the optic nerve.
It disrupts vision and, if left unmanaged, can result in permanent vision loss, emphasizing how severely glaucoma can affect vision and overall ocular health.
Types of Glaucoma
This condition can be categorized into 5 main types:
- Open-angle glaucoma: The eye’s drainage angle remains open but fluid doesn’t drain properly, leading to pressure buildup.
- Angle-closure glaucoma: A more acute condition that develops by a sudden blockage of the drainage angle.
- Normal-tension glaucoma: This develops when eye pressure is within its normal range.
- Congenital glaucoma: Develops in infants because of abnormal eye development
- Secondary glaucoma: May be caused by an eye injury, inflammation, certain drugs such as steroids and advanced cases of cataract or diabetes.
Each type progresses in distinct ways, requiring its own unique approach to slow its progression and preserve vision.
Symptoms
One of the challenges with glaucoma is its lack of early symptoms. It progresses slowly and can cause significant damage before symptoms manifest. However, some patients may experience:
- Severe eye pain
- Sudden onset of vision loss or blurred vision
- Halos around lights
- Nausea or vomiting
Risk Factors for Glaucoma: Genetics?
Anyone can develop glaucoma, but certain factors can increase the risk, by affecting the balance within the eye that regulates pressure, including:
- Age, particularly after the age of 60, where glaucoma is the leading cause of vision loss in this age range.
- Certain chronic medical conditions like diabetes, high blood pressure, and heart disease.
- History of high intraocular pressure.
- Certain eye injuries or surgeries.
- Some medications.
- Certain refractive (visual) prescriptions.
Genetics is also a significant risk factor.
Studies show that those with a family history of glaucoma are up to 4 times more likely to develop the condition themselves. This is especially true for open-angle glaucoma, the most common form of this condition.
Understanding the hereditary link to glaucoma is important. Knowing your family history can help identify your risk for eye conditions like glaucoma earlier, allowing for proactive, preventative care to preserve your eye health.
During a visit with your optometrist, it’s beneficial to inform them if any close relative has been affected by glaucoma.
Despite this hereditary link, a genetic predisposition doesn’t guarantee you’ll develop glaucoma. But, it does make regular screenings more essential.
Testing for Glaucoma: Is that the Pressure Test?
We use several methods to screen for glaucoma, and the tried and true “air-puff” test is one of them.
It’s far from anyone’s favourite part of the eye exam, but measuring eye pressure using a non-contact tonometry (NCT) device, is one of the most common ways to screen for glaucoma.
It’s non-invasive and works by releasing a quick puff of air onto the eye’s surface. The device measures how the cornea flattens in response to the air, calculating IOP.
IOP is quantified in millimetres of mercury (mmHg). Typically, a normal range for eye pressure falls between 10 and 21 mmHg. Anything over 21 mmHg is considered “high” IOP.
It’s worth noting that while a single high reading can signify a risk for glaucoma, it doesn’t confirm a diagnosis. Individual variation and corneal thickness are factors that can influence the results of the reading.
Ultimately, this test helps identify patients who may require further evaluation.
Other Methods of Detecting Glaucoma
If you find the NCT screening slightly uncomfortable, you’re not alone. The discomfort is only temporary and a small price to pay for preserving eye health, but there are other ways we screen for glaucoma. MEye Health offers a more comfortable way to measure eye pressures, iCare Tonometer.
These methods focus on assessing the structural health of the optic nerve to look for signs of damage or any abnormalities, like cupping or thinning, that may indicate glaucoma:
- Retinal images: Provides a snapshot of the eye’s internal structures, including the optic nerve.
- Visual field test: Assesses the sharpness of a patient’s peripheral vision, helping to detect any vision loss that may not yet be noticeable.
- Optical coherence tomography (OCT) scans: Provide layered, and retailed cross-sectional views of the retina, allowing optometrists to assess for changes in retinal thickness, which may indicate glaucoma.
- Ophthalmoscopy: A direct examination of the optic nerve using a specialized lens and light.
- Slit lamp exam: Give a magnified stereoscopic view of the eye’s structures, aiding in the detection of abnormalities related to glaucoma.
- Goldmann Tonometry: Is considered the gold standard of measuring eye pressures.
Along with tonometry testing, these tools provide a comprehensive approach to accurately diagnosing and monitoring the progression and allow for the treatment of eye conditions, like glaucoma.
Schedule a Visit
Glaucoma’s silent nature highlights the importance of visiting your optometrist for annual eye exams. These visits are key to preserving vision and ocular health and are encouraged for everyone, regardless of age or health status.
Connect with our team at MEye Health to schedule an appointment for your routine eye exam and to screen and detect glaucoma.
