Understanding Glaucoma: Causes, Symptoms, and Diagnosis

Glaucoma refers to an assortment of eye conditions that attribute damage to the optic nerve due to the intraocular pressure (IOP) of the eye region. The optic nerve head undergoes pathological changes known as facial changes associated with glaucoma.

If left untreated, peripheral vision loss leads to blindness over time. Glaucoma is unabatedly creeping up as the second most common reason for vision impairment when blended with cataracts. As per WHO, 2.7 million people in America have glaucoma and half of them are undiagnosed.

According to J.G. Hargreaves and part of a cohort collaboration estimates of Australian Eye & Health, 2 million Australians are suffering from ocular hypertension and people suffering from vision disabling glaucoma in Australia are around 1.25-1.5 million. Blindness due to glaucoma results from its advanced or uncontrolled stages, taking 3.12% of the world population.

Glaucoma is asymptomatic for many patients while it is progressing, which is why proactive examinations for patients, especially those more likely to suffer from the condition are essential in identifying glaucoma earlier.

Causes of Glaucoma 

Intraocular pressure (IOP) is the most well-known cause of glaucoma. Nonetheless, there is an endless number of underlying causes for the illness. Two contributing factors are:

• Pressure in the Eyes: The eyeball produces a liquid known as aqueous humor that gets drained through a tissue network. Failure of successful drainage leads to an internal fluid pressure build up, which can impair the optic nerve.
• Hereditary Issues: A family lineage with a history of glaucoma triggers higher chances of contracting the disease. Having a certain chromosome may render the optic nerve more prone to injury from added pressure.
• People of African, Hispanic and Asian lineage may have a higher risk of certain types of open angle glaucoma.
• Diabetes, high blood pressure and heart diseases are just a few other known triggers for developing glaucoma.
• Eye injury: Eye trauma can damage the eye’s drainage system, increasing eye pressure.

Not every case of glaucoma is correlated with high deficient vision eye pressure (dVEP) even though most people associate it with elevated eye pressure. Also, it is known that some individuals with elevated deficient vision eye pressure never experience glaucoma. Therefore, glaucoma cannot solely depend on pressure. It also relies on the condition of the optic nerve for its health.

Also read about how does diabetes affect eyesight

Types of Glaucoma 

There is more than one type of glaucoma, and the stages and symptoms may differ from type to type. The most prevalent forms are:

1. Open Angle Glaucoma: This is a common type of glaucoma known as open-angle glaucoma. It is characterized with gradual and painless progress without any symptoms in its earlier stages. This happens due to a lack of drainage angle that is created by both the cornea and iris, in which the lack of eye’s drainage results in increased pressure in the eye. This leads to slow and gradual damage of optic nerve resulting in reduced vision over time.
2. Angle-Closure Glaucoma: Also called closed-angle glaucoma, angle-closure glaucoma occurs when the space between the iris and the cornea narrows to the point where the fluid in the eye cannot drain properly. This creates the possibility for a sudden elevation of intraocular pressure that requires immediate medical treatment. Severe symptoms may be present, such as intense pain in the eye, headache, nausea, vomiting, and blurring of vision.
3. Normal-tension Glaucoma: In normal tension glaucoma, there is damage to the optic nerve even though the pressure on the intraocular structure is normal. The reason is yet to be determined, but it is likely to be related to the decrease in blood supply to the optic nerve that makes the nerve susceptible to injury.
4. Congenital Glaucoma: Congenital glaucoma is an infrequent disease affecting infants or toddlers and is often the result of a developmental abnormality of the eye’s drainage system. Timely diagnosis and treatment are important in order to avoid serious visual consequences.
5. Secondary Glaucoma: Secondary glaucoma develops due to the existence of other diseases like eye injuries or infections as well as from the use of certain drugs such as steroids. It can also occur in conjunction with other specific eye diseases, such as cataracts or tumors.

Signs of Glaucoma 

Many people suffering from glaucoma, in particular open-angle glaucoma, do not suffer from any symptoms until the disease prognosis is severe. For this reason, it is often referred to it as “silent thief of sight.” However, many symptoms do begin to develop as the disease progresses.

Symptoms of glaucoma are as follows:

1. Vision Loss: One of the first signs of glaucoma is loss of side vision. This occurs rather gradually.
2. Tunnel Vision: These individuals can often focus on areas solely in front of them developing tunnel vision. Tunnel vision can be considered an advanced symptom of glaucoma.
3. Eye Pain: There is severe pain that is suffered in the eye. This pain is more common when there is a spike pain acute angle-closure glaucoma.
4. Headaches: Many people suffering from glaucoma report experiencing pain in their head accompanied by pain in their eye.
5. Vomiting: Nausea and vomiting is reported when there is increased pressure inside the eye due to angle-closure glaucoma.
6. Blurred Vision: People suffering from glaucoma for an extended period of time notice that their vision is increasingly becoming hazy.

Just as vision loss is insidious, symptoms of glaucoma developing in early stages can also be subtle in nature making regular check-ups fils important to avoid major damages.

Diagnosis of Glaucoma 

In diagnosing glaucoma, there are specific tests involving the assessment of intraocular pressure, general health of the optic nerve, and the patient’s visual field.

These specific tests are:

1. Glaucoma Test (Tonometry): The assessment test of choice for glaucoma is tonometry, which is simply the measurement of intraocular pressure. This is usually achieved by means of a puff of air aimed at the eye or by utilizing a small probe that touches the eye and the measuring takes place. Though tonometry effectively indicates intraocular pressure, it is not the only factor that is appreciated while diagnosing glaucoma. High values of intraocular pressure (IOP) is a hallmark sign of glaucoma.
2. Ophthalmoscopy: Optometrists, doctors of osteopathy, and physicians can perform an ophthalmoscopy or fundoscopic exam where they assess the optic nerve for potential damage. The measurement of cupping of the optic nerve is one of the key findings of glaucoma. This method of assessment improves diagnosis of highly suspected optic nerve head damage from increased intracranial pressure.
3. Perimetry (visual field test): The visual field test evaluates the peripheral vision capability of the patient. It helps in diagnosing any loss in vision associated with glaucoma. Finding and diagnosis of glaucoma is usually associated with measurement of peripheral vision and due to the fact that peripheral vision is often the first to go, it makes this test very important and valuable to the diagnostic process.
4. Gonioscopy: Gonioscopy is a procedure that enables the clinician to assess the angle of the anterior chamber of the eye, which is formed by the junction of the cornea and iris. It provides the clinician insight into whether the angle is open or closed, which is very important in the diagnosis of different types of glaucoma.
5. Optical Coherence Tomography (OCT): OCT is an imaging exam where clients receive in-depth images of a cross-section of the optic nerve head area and the retina. This allows physicians to check for the retinal thickness and any changes over time, monitoring for glaucoma progression.

Why Early Diagnosis Is Crucial?

The purpose of glaucoma test is to detect the disease before progressing towards irreversible vision loss. When diagnosed at the early stages, glaucoma is manageable with intraocular pressure lowering medications (eye drops), and in advanced cases, surgical treatments can be considered. Regular eye examinations, specifically for the greater risk populations (those with a family history of glaucoma), is the most effective method of prevention before extensive damage is done.

Conclusion

Glaucoma is a critical eye disorder that can potentially cause blindness if not managed in advance. Knowing the risks, signs, and risk factors of glaucoma is important for every individual in safeguarding their eye health. On World Glaucoma Day, it’s imperative to create awareness regarding this debilitating disease and promote the need for routine eye examinations.

Early detection of glaucoma is important and so are the tests offered at Dr. Lal PathLabs. If you are worried about safeguarding your vision, kindly book an appointment for an eye examination today so you can start protecting your eyesight.