Glaucoma – ‘The Silent Thief of Sight’

A glaucoma attack is a sudden and severe condition due to a surge of high eye pressure affecting the eye, and it can lead to permanent damage if left untreated.

Glaucoma encompasses a range of eye diseases usually marked by increased eye pressure, loss of field of vision, and characteristic damage to the optic nerve, observable only through an examination of the back of the eye. The concept of the field of vision, which may need clarification for some, refers to the area each eye can see individually. Together, both eyes provide a complete visual field, enabling us to navigate our surroundings effectively.

Glaucoma is a complex condition with various subtypes originating from different causes. It can result from genetic factors, manifesting as one ages, or from anatomical predispositions. Glaucoma can also be associated with systemic diseases like diabetes or be a side effect of long-term steroid use. Additionally, it can develop due to other eye conditions such as ischemia (lack of oxygen), inflammation, or injury.

What unifies these various subtypes of glaucoma is the eventual thinning and loss of nerve cells in the optic nerve, often due to eye pressure that can appear normal but is actually high for that specific eye. If left untreated, glaucoma can quietly cause irreversible blindness. As the leading cause of permanent blindness, educating the public about glaucoma is a major priority in ophthalmology. However, mandatory glaucoma screening is not considered cost-effective in public health policies globally. As a result, opportunistic eye screening is the common practice.

Glaucoma is generally categorized into two main types based on the shape of the eye’s drainage system: open-angle and closed-angle glaucoma. While open-angle glaucoma is more common, closed-angle glaucoma occurs relatively more frequently among East Asians and Caucasians, compared to Africans, due to racial and anatomical differences. Both types are typically silent in the early stages, with few early warning signs of vision loss.

However, closed-angle glaucoma is known for sudden, acute attacks where eye pressure spikes dramatically due to blocked drainage. During such attacks, individuals may experience a red, painful, and blurry eye, often accompanied by severe headaches, nausea, and vomiting. These symptoms can be so intense that patients are sometimes mistakenly referred to gastroenterology for what appears to be stomach flu.

While managing an acute glaucoma attack might seem straightforward in eye specialty board exams, real-life cases are much more complex. After stabilizing an attack, further steps are required to prevent recurrence, restore vision, and protect the other eye. The high pressure during an attack can severely affect both the front part and the nerve of the eye, and needs careful follow-ups to prevent further damages.

The open angle variety of glaucoma is also linked to vascular diseases and is more common in individuals with poor circulation in their extremities, such as cold hands and feet. Additionally, significant drops in nighttime blood pressure, snoring, and sleep apnoea may also contribute to the condition.

In general, glaucoma treatment options include topical eye drops, laser treatments, and surgical therapies, with recent advancements in minimally invasive glaucoma surgery. All these approaches aim to lower eye pressure to prevent further vision loss. Opportunistic screening and regular monitoring are highly recommended, especially for those with a family history or significant risk factors. Once glaucoma is suspected, tailored management strategies for each subtype are implemented.

Preventive treatments, such as laser procedures and early cataract extraction, are also advised for closed-angle glaucoma. This recent shift in management, supported by recent large-scale multinational studies, is considered a more cost-effective approach to reduce the risk of acute attacks. Indeed, as the saying goes, “Prevention is the best medicine”!