What Is Geographic Atrophy?

Have you ever come across the term "geographic atrophy"? It's quite fascinating because the name itself draws inspiration from real maps. To grasp its meaning, let's delve into the key components. "Atrophy" refers to the shrinking or wasting away of cells due to their death. Now, imagine this happening in specific regions of the retina (part of your eye which detects incoming light and signals to the brain to create an image). These regions, marked by branching capillaries (tiny blood vessels), actually resemble a map, and that's why it's called "geographic atrophy." So, in a nutshell, geographic atrophy involves certain parts of the retina wasting away due to cell degeneration, forming a unique and map-like pattern. But that is not all to the question, ‘What is geographic atrophy?’

In this article, we will delve deeper into the topic of geographic atrophy, exploring what it is, its underlying causes, and the available treatment options. By the end, you will have a comprehensive understanding of this condition, as we will also cover other important facts to paint a complete picture of geographic atrophy.

Overview

Geographic atrophy (GA) is a chronic and progressive condition that affects the macula (the centre of your retina, which forms a key part of your eye). GA is part of advanced-stage age-related macular degeneration (AMD). GA leads to specific areas of the macula deteriorating and wasting away, causing vision loss, central blind spots in your vision, and decreased visual acuity (clarity and sharpness).

Until recently, no effective treatment was available for GA. However, there is hope as the FDA recently approved Pegcetacoplan (SYOFOVRE™), a groundbreaking medication that involves eye injections given monthly or every other month. This treatment has shown promising results in slowing down the progression of the disease. In addition to Pegcetacoplan, other management strategies include visual rehabilitation with specialised glasses and aids. 

Early diagnosis through comprehensive eye examinations and specific diagnostic tests is crucial for accurate management. While GA leads to irreversible vision loss, prompt medical attention can help preserve the remaining vision and improve the patient's quality of life. As research continues to advance, there is renewed hope for better treatments and improved outcomes for individuals affected by geographic atrophy, offering a brighter future for those living with this vision-threatening condition.

Causes of geographic atrophy

Geographic atrophy (GA) is a progressive and chronic condition that affects the macula. GA often occurs as part of advanced-stage age-related macular degeneration (AMD). In GA, there is a specific area of the macula where the cells degenerate and waste away, leading to vision loss. This condition usually starts around the centre of the vision and gradually expands, affecting the central part of the vision over time. As a result, people with GA may experience dark spots or blank areas in their sight and a permanent decrease in their ability to see clearly.¹

GA commonly affects both eyes and is found in about 20% of individuals with AMD, affecting more than 8 million people worldwide. The number of people with GA is expected to increase as the population ages in developed countries.

The exact cause of geographic atrophy is not fully understood, but researchers believe that the immune system, specifically a process called the complement cascade, may be involved. Genetic factors and the environment also likely play a role in the development of this condition.²

It's important to know that geographic atrophy is not a contagious condition - you cannot pass it on to others like you would with a contagious disease. It is a non-infectious eye condition.

Other types of retinal atrophy

Geographic atrophy, characterised by retinal atrophy, is just one piece of the puzzle. Let's explore other potential causes that share similar features:

• Atrophy secondary to anti-VEGF treatment - sometimes, when people undergo anti-VEGF therapy (used to treat another eye disease), their retinas may experience atrophy as a side effect.
• Genetic conditions and dystrophies - there are various genetic conditions that can also lead to retinal atrophy resembling geographic atrophy,³ including pattern dystrophy, maternally inherited diabetes and deafness (MIDD), central areolar choroidal dystrophy, Stargardt disease, and Best macular dystrophy.
• After macular surgeries - interestingly, certain surgical procedures involving the macula can sometimes result in retinal atrophy.
• Chronic central serous chorioretinopathy - when central serous chorioretinopathy persists for a long time, it may also lead to retinal atrophy.
• Congenital infections - some congenital infections, such as the Zika virus, could also cause retinal atrophy resembling geographic atrophy.
• Basal laminar drusen with pseudovitelli form detachment - this condition can also present with retinal atrophy resembling geographic atrophy.

By considering these various possibilities, healthcare professionals can better understand and manage the different conditions that share similarities with geographic atrophy. It's like exploring different paths that may lead to the same destination.

Signs and symptoms of geographic atrophy

Geographic atrophy may not display noticeable symptoms during its early phases or when affecting only one eye. However, when symptoms do manifest, they can include:

• Decline in visual acuity - your vision's sharpness may decrease.
• Challenges with activities - tasks heavily reliant on central vision, like reading, driving, or crafts, may become difficult.
• Presence of dark or blind spots - you might experience empty or dark areas in the centre of your vision.
• Difficulty seeing in low light - your ability to see in dim lighting conditions may be impaired.
• Fading colours - colours may appear less vibrant or more dull.

If you observe any of these symptoms or suspect you may have geographic atrophy, seeking prompt medical attention is crucial for accurate diagnosis and appropriate management. Detecting and treating it early can significantly impact preserving your vision and maintaining a good quality of life.

Management and treatment for geographic atrophy

Geographic atrophy is a condition that causes vision loss as the retina deteriorates. Until recently, no effective treatment existed. However, there's exciting news, the FDA has approved a groundbreaking medication called Pegcetacoplan (SYOFOVRE™).^4,5 This treatment involves eye injections given monthly or every other month, effectively slowing down the disease's progression.

In addition to Pegcetacoplan, there are other management strategies for geographic atrophy. Visual rehabilitation plays a crucial role, even if vision seems satisfactory. It includes using specialised glasses and aids, such as magnifying glasses, to enhance contrast sensitivity and improve reading ability.

While some supplements have shown potential in treating related eye conditions, they haven't proven effective in slowing down geographic atrophy. But hope remains! Ongoing studies are testing various medications that target specific factors contributing to the disease's progression.

The approval of Pegcetacoplan marks a significant advancement, and researchers continue to explore new approaches, like neuroprotective agents and visual cycle inhibitors. Stem cell research is also being investigated for its potential to halt the advancement of geographic atrophy.

With ongoing research and these promising developments, there's renewed hope for better treatments and improved outcomes for those affected by this condition. As science continues to progress, patients with geographic atrophy can look forward to a brighter future with increased possibilities for improved vision and quality of life.

Diagnosis

To diagnose geographic atrophy, your eye care provider will employ a comprehensive eye examination along with specific diagnostic tests. Additionally, they will inquire about your symptoms, medical history, and family medical history to gain a comprehensive understanding. The diagnostic tests used to identify geographic atrophy may include:

• Fundus autofluorescence - this retinal imaging technique utilises the inherent fluorescence of specific retinal substances, such as lipofuscin. The procedure does not require the use of injected dyes, making it a non-invasive and comfortable option for patients.
• Optical coherence tomography (OCT) - this non-invasive retinal imaging method employs reflected light to generate highly detailed cross-sectional images of the retina. It enables eye care professionals to visualise the intricate layers of the retina, aiding in the detection of abnormalities.
• Microperimetry - combining visual field examination with retinal imaging, microperimetry allows for the assessment of the sensitivity and functionality of specific areas on the retina. This comprehensive analysis helps in understanding the visual capabilities of different regions of the retina.
• Multifocal electroretinography (mfERG) - this advanced test involves exposing the retina to light and recording its electrical activity. The data obtained from mfERG offers valuable insights into the functional integrity of various retinal areas, contributing to the evaluation of geographic atrophy.

By utilising these sophisticated diagnostic tests, eye care providers can achieve accurate and detailed diagnoses of geographic atrophy, leading to the development of tailored and effective management plans for their patients' ocular health.

Risk factors

Geographic atrophy (GA) is a form of age-related macular degeneration (AMD) that can have several risk factors associated with its development. Let's explore these factors:

• Age and family history: One of the most significant risk factors for GA is simply getting older. Additionally, if you have a family history of age-related macular degeneration, your risk of developing GA may be higher.
• Smoking: Smoking is a major culprit that significantly increases the risk of GA. Both current smokers and those who used to smoke are at a greater risk of experiencing geographic atrophy.⁶
• Differences in populations - interesting findings from the Asian Eye Epidemiology Consortium show that GA is relatively less common in Asian populations compared to those of European ancestry. Also, the ratio of GA to neovascular AMD, another complication of advanced AMD, is different in these populations.⁷
• Gender - studies conducted in the United States did not find any gender differences in GA prevalence, but the Asian Eye Epidemiology Consortium discovered a higher prevalence of GA in men.⁸
• Other factors - some studies suggest that using thyroid hormones or antacids might increase the risk of GA. On the other hand, having a higher level of education appears to be associated with a lower risk of developing this condition.
• Health conditions - certain health conditions seem to be linked to a higher risk of GA, including coronary heart disease and issues related to the lens of the eye, like lens opacities (cataracts) or previous cataract surgery.⁹

By understanding these risk factors, we can better grasp the complexities of geographic atrophy and take steps towards prevention and management. Remember, it's essential to protect our eyes and maintain a healthy lifestyle to reduce the risk of age-related vision problems like GA.

Complications

As of the present, vision loss caused by geographic atrophy is irreversible. The loss of central vision can significantly impact the ability to perform various daily activities such as reading, driving and facial recognition.

FAQS

How can I prevent geographic atrophy?

Regrettably, there is currently no known method to prevent geographic atrophy. However, as it commonly follows age-related macular degeneration, it would be beneficial to ensure you get your eyes checked regularly, as well as maintain good eye health and an overall healthy lifestyle

How common is geographic atrophy?

Geographic atrophy affects over 8 million individuals globally, accounting for approximately 20% of all age-related macular degeneration cases.

When should I see A doctor?

Follow the guidelines and advice provided by your eye care provider concerning the regularity of your eye examinations. It's important to keep a vigilant eye on any alterations in your vision.

In case of abrupt vision loss or eye discomfort, seek immediate medical assistance from your eye care professional. Prompt action is crucial in such situations to ensure proper care and treatment.

Summary

In conclusion, geographic atrophy (GA) is a progressive condition affecting the macula and leading to vision loss. While there is currently no known prevention, early detection through regular eye exams is crucial. Recent advancements, such as Pegcetacoplan treatment, offer hope for slowing the disease's progression. Visual rehabilitation and ongoing research hold promise for better management in the future. Remember to prioritise eye health, maintain regular check-ups, and adopt a healthy lifestyle to reduce the risk of age-related vision problems like GA.