Glaucoma: Symptoms, Causes and Prevention

What is Glaucoma? 

Glaucoma represents a set of eye disorders characterised by damage to the optic nerve, which is crucial for transmitting visual information from the eye to the brain and is essential for clear vision. This damage is frequently associated with elevated pressure within the eye, although glaucoma can also develop with normal eye pressure levels.

This condition can develop at any age, but is more prevalent in older adults. It stands as one of the primary causes of blindness in individuals over 60 years of age.

Symptoms of Glaucoma

The symptoms of glaucoma vary based on the specific type and progression of the condition.

Open-angle Glaucoma

• Early stages typically show no symptoms.
• Over time, individuals may notice patchy blind spots in their peripheral or side vision.
• In advanced stages, central vision may become impaired.

Acute Angle-closure Glaucoma

• Intense headaches.
• Severe pain in the eye.
• Nausea or vomiting.
• Blurry vision.
• Halos or coloured rings around lights.
• Redness in the eye.

Normal-tension Glaucoma 

• Initially, it presents no symptoms.
• Progressively, vision may become blurry.
• Eventually, there may be a loss of peripheral vision.

Glaucoma in Children 

• A hazy or cloudy eye in infants.
• Increased blinking in infants.
• Tearfulness without actual crying in infants.
• Blurred vision.
• Worsening near-sightedness.
• Headaches.

Pigmentary Glaucoma 

• Rings or halos around lights.
• Blurred vision when exercising.
• Slow loss of peripheral vision.

Causes of Glaucoma

Glaucoma occurs due to damage to the optic nerve, which leads to the development of blind spots in one's vision. The exact cause of this nerve damage is not entirely understood by ophthalmologists, but is often associated with increased ocular pressure.

This heightened pressure within the eye is due to an accumulation of aqueous humour, a fluid present inside the eye. Normally, this fluid drains through the trabecular meshwork, a tissue located at the angle where the iris and cornea meet. The cornea plays a crucial role in vision by allowing light into the eye. An overproduction of this fluid or a malfunction in the drainage system can lead to increased eye pressure.

Open-angle Glaucoma

In this most prevalent type of glaucoma, the drainage angle created by the iris and cornea stays open, but other components of the drainage system fail, leading to a slow and gradual rise in eye pressure.

Angle-closure Glaucoma

This type occurs when the iris bulges, partially or completely blocking the drainage angle, preventing fluid circulation within the eye and raising pressure. Angle-closure glaucoma can develop suddenly or over time.

Normal-tension Glaucoma

The precise cause of optic nerve damage in cases of normal eye pressure is unknown. The nerve might be naturally sensitive or suffer from reduced blood flow, potentially due to arterial fatty deposits or other circulatory issues.

Glaucoma in Children

Children can be born with glaucoma or develop it early in life, typically due to blocked drainage, injuries, or underlying medical issues causing optic nerve damage.

Pigmentary Glaucoma 

In this condition, pigment granules from the iris detach and hinder fluid drainage from the eye. Physical activities like jogging can agitate these granules, leading to their accumulation in the tissue at the angle where the iris and cornea meet, consequently increasing pressure.

Glaucoma Diagnosis

To diagnose glaucoma, an ophthalmologist conducts a thorough eye examination to detect signs of nerve tissue degradation. Various tests and procedures are utilised for this purpose, including:

Comprehensive Medical History

The doctor will inquire about any symptoms experienced, along with a personal or family history of glaucoma. A broader health evaluation is also conducted to identify any conditions, such as diabetes or hypertension, that might affect eye health.

Tonometry

This set of tests is used to measure the internal pressure of the eye.

Pachymetry

Given that individuals with thinner corneas are at a higher risk for glaucoma, this test assesses whether the corneas are thinner than normal.

Perimetry

Also known as a visual field test, this evaluates the impact of glaucoma on vision by measuring both peripheral (side) and central vision.

Optic Nerve Monitoring

For ongoing observation of optic nerve changes, the doctor might take optic nerve photographs for comparative analysis over time.

Glaucoma Treatment

Glaucoma treatment aims to lower intraocular pressure through a range of methods, including eye drops, oral medications, laser treatments, and surgeries.

Eye Drops

Glaucoma often starts with prescription eye drops to either improve fluid drainage or decrease fluid production in the eye. Multiple drops may be prescribed based on the required level of pressure reduction. These include prostaglandins, beta blockers, alpha-adrenergic agonists, carbonic anhydrase inhibitors, Rho kinase inhibitors, and miotic or cholinergic agents. Side effects can range from eye redness and stinging to more systemic effects like breathing difficulties or fatigue.

Oral Medications

In cases where eye drops are insufficient, oral medications, usually carbonic anhydrase inhibitors, may be used. They can have side effects like frequent urination or tingling sensations.

Surgical Treatments

For more advanced cases, options include:

• Laser Therapy: Laser trabeculoplasty to improve drainage.
• Filtering Surgery: Trabeculectomy creates an opening in the eye for fluid drainage.
• Drainage Tubes: Inserted to help drain excess fluid.
• Minimally Invasive Glaucoma Surgery (MIGS): Less invasive procedures are often combined with cataract surgery.

Regular follow-up exams are necessary after these procedures.

Acute Angle-closure Glaucoma Treatment

This emergency condition requires immediate treatment to lower eye pressure, usually through medication and procedures like laser peripheral iridotomy, which creates a small hole in the iris to facilitate fluid flow.

Glaucoma Disease Complications

Here are the key complications associated with glaucoma:

• Loss of vision: Glaucoma can cause partial vision loss, often starting with peripheral or side vision. If left untreated, it can lead to complete blindness. Typically, the damage to vision is irreversible.
• Blindness: Glaucoma is one of the leading causes of blindness, particularly in older adults. Without treatment, glaucoma can lead to permanent blindness within a few years.
• Eye pain: Certain types of glaucoma, particularly acute angle-closure glaucoma, can cause severe eye pain due to rapid increases in intraocular pressure.
• Headaches: Associated with the increase in intraocular pressure, particularly in acute angle-closure glaucoma, leading to severe headaches.
• Nausea and vomiting: These are often associated with acute angle-closure glaucoma and can accompany severe eye pain and headaches.

Glaucoma Disease Prevention 

To detect and manage glaucoma in its early stages, which can help prevent or slow down vision loss, the following steps are recommended:

• Regular eye examinations: It's advised that individuals undergo regular comprehensive eye exams. The American Academy of Ophthalmology suggests these exams every 5 to 10 years for those under 40 years old; every 2 to 4 years for ages 40 to 54; every 1 to 3 years for ages 55 to 64; and every 1 to 2 years for those over 65. Early detection of glaucoma can prevent significant damage.
• Frequent screening for high-risk individuals: Those at risk of glaucoma, possibly due to family history, should have more frequent screenings. They need to consult their healthcare providers for an appropriate screening schedule.
• Awareness of family eye health history: Since glaucoma can be hereditary, knowing one's family eye health history is crucial. Increased-risk individuals may need more frequent screenings.
• Use of eye protection: Serious eye injuries can lead to glaucoma. Wearing eye protection while using power tools or participating in sports can help prevent such injuries.
• Adherence to prescribed eye drops: Regular use of prescribed glaucoma eye drops can greatly reduce the risk of high eye pressure developing into glaucoma. Even in the absence of symptoms, it's important to use these drops as directed by a healthcare provider.

Conclusion

Glaucoma is a serious eye condition characterised by optic nerve damage and vision loss. Early detection and consistent treatment are crucial in managing its progression. For comprehensive care and expert guidance on preventing and managing glaucoma, consult the specialists at Max Healthcare, one of the best eye care hospitals. Book your appointment today to safeguard your vision and ensure the health of your eyes for years to come.