Glaucoma

Overview

Glaucoma refers to a group of eye disorders that damage the optic nerve. This nerve is crucial for transmitting visual information from the eye to the brain. Damage to the optic nerve is frequently linked to elevated intraocular pressure (IOP) within the eye. However, glaucoma can also develop with normal eye pressure. Glaucoma is the leading cause of optic nerve damage and associated vision loss. It is more prevalent in older adults and can occur at any age. For people over 60, it is a leading cause of blindness.

In the majority of cases, fluid accumulates in the front portion of the eye, increasing pressure and causing gradual optic nerve damage. Untreated or poorly controlled glaucoma can lead to permanent and irreversible vision loss, including blindness. Glaucoma typically affects both eyes, but it may initially be more severe in one. Open-angle glaucoma can cause moderate or severe damage in one eye while only mildly affecting the other. People with closed-angle glaucoma in one eye have a 40% to 80% probability of developing the same condition in the other eye within five to ten years.

Symptoms

The symptoms of glaucoma can vary depending on the type and stage of the condition:

• Open-angle glaucoma: In the early stages of open-angle glaucoma, symptoms may not be evident. As the condition progresses, individuals may experience a gradual emergence of patchy blind spots in their peripheral vision. In more advanced stages, difficulties in seeing objects within the central vision may become apparent.
• Acute angle-closure glaucoma: Acute angle-closure glaucoma is characterized by severe symptoms, including intense headache, eye pain, nausea or vomiting, blurred vision, the perception of halos or colored rings around lights, and eye redness. These symptoms collectively indicate a critical condition that requires immediate medical attention to prevent further complications.
• Normal-tension glaucoma: In the initial phases of normal-tension glaucoma, individuals may not experience any noticeable symptoms. As the condition progresses, a gradual onset of blurred vision may occur. In more advanced stages, there is a potential for the loss of peripheral vision, underscoring the importance of regular eye examinations for early detection and intervention.
• Glaucoma in children: Glaucoma in children may manifest with various signs, including a dull or cloudy appearance in the eyes of infants, increased blinking, tearing without accompanying crying, blurred vision, worsening nearsightedness, and headaches. Recognizing these symptoms in a timely manner is crucial for ensuring proper pediatric eye care and addressing potential vision-related concerns. Regular eye check-ups are advisable to monitor and address any emerging issues in a child’s visual health.
• Pigmentary glaucoma: Pigmentary glaucoma is characterized by distinct symptoms, such as the perception of halos around lights, blurred vision, especially during physical exercise, and a gradual decline in peripheral vision over time. These indicators highlight the importance of ongoing monitoring and early intervention to manage the progression of the condition and preserve visual health. Regular eye examinations are recommended to detect and address these symptoms promptly.

If symptoms of acute angle-closure glaucoma, such as sudden severe headache and eye pain, arise, prompt medical attention is crucial. Immediate treatment is necessary, and individuals should either go to an emergency room or contact an ophthalmologist’s office without delay.

Causes

Glaucoma develops when damage occurs to the optic nerve, resulting in the emergence of blind spots in one’s vision. The cause of this nerve damage is often associated with increased pressure in the eye, though the exact reasons remain unclear to medical professionals.

Elevated eye pressure is the consequence of a fluid buildup, known as aqueous humor, circulating within the eye. Normally, this fluid drains through the trabecular meshwork, a tissue located at the angle where the iris and cornea meet. The cornea, crucial for vision, allows light to enter the eye. When there is an excess production of fluid or a malfunction in the drainage system, eye pressure may rise.

There are several types of glaucoma:

• Open-angle glaucoma: Common, with an open drainage angle but impaired drainage causing a gradual pressure increase.
• Angle-closure glaucoma: Iris bulging blocks drainage, leading to sudden or gradual pressure rise.
• Normal-tension glaucoma: Optic nerve damage with normal eye pressure; reasons may include optic nerve sensitivity or reduced blood flow (atherosclerosis).
• Glaucoma in children: Present at birth or early years due to blocked drainage, injury, or underlying medical conditions.
• Pigmentary glaucoma: Pigment granules from the iris obstruct drainage, causing pressure increase, sometimes triggered by activities like jogging.

Risk factors

Glaucoma can affect anyone, and it can develop without early warning symptoms. Nevertheless, certain factors can elevate an individual’s risk of developing glaucoma, including:

• Being above the age of 55
• Black, Asian, or Latino ancestry
• Medical history of glaucoma in the family
• High intraocular pressure, or internal eye pressure
• Long-term use of corticosteroids
• Medical disorders, including high blood pressure, diabetes, migraines, and sickle cell anemia
• Hyperopia or farsightedness (for closed-angle glaucoma)
• Myopia or nearsightedness (for open-angle glaucoma)
• Prior eye surgery or damage
• Corneas with a narrow central layer
• Narrow drainage angles (for angle-closure glaucoma)