Glaucoma- Causes, Symptoms, Treatment

What is Glaucoma?

Glaucoma is a collective term for a set of eye disorders that primarily damage the optic nerve—an essential component of our visual system that transmits visual information from the eye to the brain. Glaucoma often stems from increased intraocular pressure (IOP), which essentially means higher pressure within the eye. However, glaucoma can also occur even with normal eye pressure levels.

In India, glaucoma is one of the leading causes of irreversible blindness, especially prevalent among individuals aged 60 and above. It tends to develop slowly over time and is often dubbed the ‘silent thief of sight’ as there are no noticeable symptoms until considerable vision loss has occurred.

The perilous nature of glaucoma underlines the need for regular eye examinations for early detection and treatment. With proper management and care, it’s possible to slow or halt the progression of this disease, preserving your vision for a lifetime.

What Causes Glaucoma?

Glaucoma usually occurs due to certain factors that contribute to an increase in intraocular pressure. Let’s delve into the various causes of glaucoma:

• Intraocular Pressure Increase: The most significant factor contributing to glaucoma is elevated eye pressure due to fluid accumulation in the front part of the eye.
• Genetic Factors: Having a family history of glaucoma increases the risk, suggesting that genetics play a vital role.
• Age: People aged 40 and above have a higher risk of developing glaucoma due to age-related physiological changes.
• Ethnicity: Certain ethnic groups, such as African Americans, Hispanics, and Asians, are more prone to developing glaucoma.
• Other Medical Conditions: Certain health conditions like diabetes, high blood pressure, and previous eye injuries can up the chances of developing glaucoma.
• Eye Anatomy: If you have thinner corneas or specific structural abnormalities in your eyes, you could be more susceptible to glaucoma.
• Secondary Glaucoma: This type results from other medical conditions affecting the eye, including inflammation and trauma.
• Normal-Tension Glaucoma: Here, optic nerve damage occurs despite normal intraocular pressure; the exact cause is not yet fully understood but it may involve reduced blood flow to the optic nerve.

Types of Glaucoma

Various types of glaucoma can detrimentally affect your eyesight. Let’s look at the major ones:

• Open-Angle Glaucoma: In this most common form, drainage canals in the eye slowly clog, leading to a rise in eye pressure. Damage may have significantly progressed before symptoms become evident.
• Angle-Closure Glaucoma: Here, the drainage angle between the iris and cornea gets blocked, causing an abrupt increase in eye pressure. This can be acute (sudden) or chronic (long-term).
• Normal-Tension Glaucoma: Despite normal intraocular pressure (IOP) levels, optic nerve damage occurs. Reduced blood flow to the optic nerve could be the cause, though this is still unclear.
• Secondary Glaucoma: This is caused by other medical conditions or injuries that affect the eye, such as inflammation, trauma, or certain medicines.
• Congenital Glaucoma: Amongst infants and young children, this rare type occurs due to abnormal development of the eye’s drainage system.
• Pigmentary Glaucoma: Here pigment granules from the iris dislodge and obstruct the drainage canals, resulting in elevated pressure.
• Neovascular Glaucoma: New blood vessels form on the iris and block fluid drainage, often linked with conditions like diabetes.

Symptoms of Glaucoma

Glaucoma often silently progresses and by the time symptoms occur, significant damage may have taken place:

• Open-Angle Glaucoma: This usually does not cause symptoms in early stages but may eventually lead to peripheral vision loss.
• Angle-Closure Glaucoma: This includes sudden vision loss, severe eye pain, headache, nausea, vomiting, and seeing halos around lights.
• Normal-Tension Glaucoma: Similar to open-angle glaucoma but without elevated pressure; this may lead to gradual vision loss.
• Congenital Glaucoma: In infants, sensitivity to light, excessive tearing, and cloudy corneas are typical symptoms.
• Pigmentary Glaucoma: This may cause blurred vision during physical activity and gradual peripheral vision loss.

Diagnosis and Evaluation of Glaucoma

Identifying glaucoma often involves an extensive eye examination incorporating:

• Tonometry: This measures intraocular pressure.
• Visual Field Test: This assesses peripheral vision for any loss.
• Optic Nerve Assessment: Doctors examine the optic nerve for signs of damage.
• Pachymetry: The thickness of the cornea is measured, as this can influence glaucoma risk. Regular eye examinations are essential for early detection, particularly for individuals at higher risk due to age, family history, or other health conditions.

How is Glaucoma Treated?

Though glaucoma does not have a cure, treatments aim to lower IOP and prevent further vision loss:

• Medications: Eye drops are often prescribed to reduce IOP by improving fluid drainage or decreasing fluid production.
• Laser Treatment: For open-angle glaucoma, laser trabeculoplasty helps improve drainage, whereas laser iridotomy creates a new drainage pathway for angle-closure glaucoma.
• Surgery: If medications and laser treatments are ineffective, surgical options may include creating a new drainage channel or implanting devices to facilitate fluid outflow.

Regular monitoring and follow-up appointments are essential to assess treatment effectiveness and make necessary adjustments.

When is Glaucoma Considered Serious?

Glaucoma is a critical eye condition characterised by damage to the optic nerve. It becomes serious when it leads to substantial vision loss. Specific situations include:

• Acute Angle-Closure Glaucoma: This is a medical emergency due to a sudden increase in intraocular pressure. Symptoms such as severe eye pain, headache, nausea, and blurred vision can appear swiftly, leading to blindness if not addressed immediately.
• Progressive Vision Loss: In chronic cases like open-angle glaucoma, the condition may slowly worsen over years, leading to irreversible peripheral vision loss before noticeable symptoms appear. Regular monitoring is essential to prevent severe damage.

Prevention of Glaucoma

While there is no certain way to prevent glaucoma, there are measures you can take to reduce your risk. These include regular eye check-ups, especially as you age, and more frequently if you have health conditions like diabetes or have a family history of the disease. Maintaining a healthy lifestyle, which includes regular exercise and a balanced diet, can also contribute towards overall eye health. If you’re at higher risk for glaucoma, consult your eye doctor regularly so that glaucoma treatment can start as early as possible.

Myths & Facts About Glaucoma

Misinformation about glaucoma can lead to delayed diagnosis and treatment. Here are some common myths and facts:

• Myth: Glaucoma only affects older adults.
  Fact: Although it’s more common among the elderly, glaucoma can occur at any age.
• Myth: I don’t have symptoms, so I don’t have glaucoma.
  Fact: Many forms of glaucoma, particularly open-angle glaucoma, don’t show symptoms in the early stages.
• Myth: Eye drops are the only treatment for glaucoma.
  Fact: While eye drops are commonly used, other treatments include laser procedures and surgery.

When to Consult a Doctor for Glaucoma?

It’s crucial to consult your family doctor or ophthalmologist if you experience symptoms like blurred vision, severe eye pain, headaches, and nausea. These could be signs of acute angle-closure glaucoma, a medical emergency. If you’re above 40 or have a family history of glaucoma, regular eye check-ups are crucial for early detection and management of the disease.

Questions to Ask Your Doctor About Glaucoma

It’s important to understand your condition and treatment options. Consider asking your doctor these questions:

• What type of glaucoma do I have?
• How often should I have eye examinations?
• Can you inform me about potential side effects of my medications?
• What lifestyle changes can enhance my eye health?
• How will glaucoma affect my vision in the long run?
• Are there other treatment options apart from eye drops?
• Will I go blind from glaucoma?
• What should I do if I experience sudden symptoms like severe pain or blurred vision?