Geographic Atrophy - Types, Symptoms, Risk Factors, Diagnosis, and Treatment

Introduction:

Geography atrophy is one of the age-related eye disorders seen in elder individuals above 50 years of age. It is also referred to as age-related maculopathy or age-related macular degeneration. This causes loss of vision due to the thinning or degeneration of the macula-the inner retinal layer which plays an essential role in eyesight. Initially, this disorder may affect only one eye then gradually it may affect both eyes and lead to progressive and irreversible vision loss.

What Are the Different Forms of Geographic Atrophy?

1. Dry Geographic Atrophy - Dry geographic atrophy is the most common variant of geographic atrophy. It is formed by small, yellow deposits known as drusen, that develop behind the retina. They can enlarge and obstruct the retina's access to nutrition. As a result, the macula's retinal cells start to degenerate and die, which will obscure the vision.

2. Wet Geographic Atrophy - Wet geographic atrophy typically results in faster and, perhaps, more severe vision loss. The loss of vision is related to bleeding, therefore the word is termed "wet." Tiny new blood vessels develop beneath into the retina in wet geographic atrophy. These blood vessels frequently burst and leak, accumulating fluid under the retina and impairing vision.

What Are the Symptoms of Geographic Atrophy?

There may be no symptoms in the early stages, until the disease advances or affects both the eyes. Symptoms may include:

• Sharper and clearer vision.

• Faded or dull colors.

• Need more light to read.

• Difficulty seeing in dim light.

• A shadowy area in central or nearby central vision.

• Some numbers or letters may disappear while reading.

• Difficult to identify faces.

What Are the Risk Factors of Geographic Atrophy?

• Age - The disease is more common in older individuals above 50 years of age.

• Race - Geographic atrophy is most common in the caucasians seen in North America.

• Light Colored Eyes - Geographic atrophy is more likely to develop in people with blue or green eyes.

• Smoking - The risk of geographic atrophy is considerably increased by smoking cigarettes or being frequently exposed to smoke.

• Cardiovascular Diseases - The risk of geographic atrophy is more to those who have heart or blood vessel disorders.

• Obesity - According to the studies, obesity may raise the likelihood of advancement of geographic atrophy to a more severe type of condition.

• Genetics - Several genes that transfer from the mother to the child may increase the risk of developing the condition.

• Poor Diet - A low intake of fruits and vegetables (specifically dark green leafy vegetables) may increase the risk of geographic atrophy.

How is Geographic Atrophy Diagnosed?

• Visual Acuity - The results of this test indicate how well each eye can see through the center of the retina. This test involves reading an eye chart to assess the vision.

• Fluorescein Angiography - A dye is injected into the patient's arm during this test that goes to the eye. Then, to check for blockages or leaks, a special camera is used to capture images of the interior of the eye.

• Fundus Autofluorescence -This technique makes use of a unique camera that reveals the areas of damage as small points of light in a photograph.

• Optical Coherence Tomography - This imaging technique may produce highly detailed pictures of the inside of the eye.

• Visual Function Tests - An eye doctor may provide additional exams to detect visual impairment.

• Dilated Eye Examination - Eye drops is used by the doctor to enlarge (dilate) the pupils during the dilated eye examination so that they can see the back of the eyes more clearly (retina and macula). The doctor examine the macula for any changes.

What Are the Complications of Geographic Atrophy?

• Depression and social isolation are more likely to affect people with dry geographic atrophy that has advanced to the point of central vision loss.

• Visual hallucinations may occur in patients who have severe vision loss (Charles Bonnet syndrome). Additionally, if neglected, dry geographic atrophy may turn into wet geographic atrophy, which can quickly impair eyesight.

• In some cases, geographic atrophy may also increase the risk of developing other eye conditions such as cataracts (clouding of the eye's natural lens), glaucoma (damage to the optic nerve), or choroidal neovascularization (an abnormal growth of blood vessels in the choroid layer of the eye that can lead to vision loss).

What Are the Treatments of Geographic Atrophy?

Currently, there is no cure for geographic atrophy, but some treatments may slow its progression or manage its symptoms, including high-dose antioxidant vitamins, zinc supplements, dietary modifications, low-vision aids, and investigational therapies such as stem cell transplantation or gene therapy.

How To Prevent Geographic Atrophy?

• Manage Additional Medical Conditions - For instance, if any patient has a heart disease or high blood pressure, they should take medicine and adhere to the doctor's advice for controlling the illness.

• Avoid Smoking - Geographic atrophy is more likely to affect smokers than non-smokers. Ask a doctor for advice on quitting smoking.

• Amsler Grid - This test aids in the identification of central vision issues. Every day, it's crucial to run this test with both eyes. Lines that are both horizontally and vertically straight make up an amsler grid. Inform the eye doctor in case of any changes, such as difficulty reading, or straight lines that seem wavy or broken while reading.

• Keep a Healthy Weight and Exercise Frequently - Reduce calorie intake and up your daily workout to lose weight. Opt for a fruit and vegetable-rich diet.

• Choose a Balanced Diet Rich in a range of Fruits and Vegetables - These foods provide antioxidant vitamins that lower the risk of getting geographic atrophy Include fish in the diet, fish contains omega-3 fatty acids, which may lessen the risk of developing geographic atrophy.

Conclusion -

Geographic atrophy is a progressive and irreversible form of age-related macular degeneration that leads to a loss of central vision and independence. Although there is no cure for this condition, early diagnosis and regular monitoring can help identify and manage its associated risk factors and symptoms. With ongoing research and innovation, there is hope for the development of more effective treatments and interventions that can slow or prevent the progression of geographic atrophy and improve the quality of life for those affected by this challenging condition.