Anti-VEGF Therapy for Wet AMD.

What Is AMD?

Age-related macular degeneration (AMD) reduces vision-related function, and it is a serious health concern. AMD comes in two main types: exudative (wet), which causes severe vision issues with abnormal blood vessel growth, and atrophic (dry), which is less severe but involves gradual retinal cell loss. Treatments for wet AMD include photodynamic therapy (PDT), which can have complications, and anti-VEGF (vascular endothelial growth factor) drugs, which are now preferred but require repeated injections. New drug delivery methods are being developed to reduce treatment frequency.

What Is Vascular Endothelial Growth Factor (VEGF) Treatment and Its Importance for Eye Health?

VEGF is a protein in the body that helps create new blood vessels when needed. Sometimes, too much VEGF leads to abnormal blood vessel growth in the eye, which can damage vision and potentially cause blindness.

Conditions Treated with Anti-VEGF Injections:

Anti-VEGF medicines block VEGF to slow or stop abnormal blood vessel growth in the eye, which can help prevent further vision loss and sometimes even improve vision.

They are used to treat:

• Wet age-related macular degeneration (AMD).

• Swelling in the retina (macular edema).

• Diabetic retinopathy (a serious eye problem leading to vision loss for people with diabetes).

• Retinal vein occlusion (vein blockage that drains blood from the retina, leading to vision loss).

Types of Anti-VEGF Medicines:

There are three main anti-VEGF drugs:

• Bevacizumab.

• Ranibizumab.

• Aflibercept.

All three are generally safe and effective but differ in cost, packaging, and potential risks. New anti-VEGF drugs are expected soon, offering more options.

How Do They Work?

During the treatment:

• The eye is cleaned to avoid infection.

• The eye is numbed to reduce discomfort.

• A small device may hold the eyelids open.

• The medicine is injected into the eye with a very thin needle, which is quick and not usually visible.

• The doctor will determine how many injections a person will need and may suggest other treatments as well.

What Are the Ant-VEGF Treatments for Wet AMD ?

Wet age-related macular degeneration (AMD) is where the eyes are affected, and due to this,

There is a loss of central vision. It mainly happens when blood vessels grow abnormally into the retina and leak fluid, leading to vision problems. Treatment should be done to avoid permanent vision loss. Researchers found that in people with wet AMD, the retina produces too much of a protein called VEGF, which leads to the growth and leaking of these abnormal blood vessels. To counter this, doctors use special drugs that block VEGF and stop the growth of these blood vessels.

Current Treatments:

There are six main drugs used to treat wet AMD:

• Brolucizumab.

• Aflibercept.

• Ranibizumab.

• Faricimab.

• Ranibizumab injection via ocular implant.

• Bevacizumab - Originally for cancer, it was used off-label for AMD.

Most people need these injections every four to 12 weeks. The frequency depends on how well the drug works for them. For example, Faricimab can last up to four months between injections for some patients. Doctors use a special imaging tool to check how much fluid is in the retina and adjust treatment as needed.

Comparing the Drug:

• Avastin: It is the cheapest and works similarly to Lucentis, based on a large study.

What Is Age-Related Macular Degeneration (AMD)?

Age-related macular degeneration (AMD) is seen in the elderly, affecting the eyes, and can lead to permanent loss of central vision. It happens when the central part of the retina, known as the macula, gets damaged due to aging and other risk factors. AMD can start in one eye and often affects both eyes over time. Key risk factors include old age, smoking, high body weight, high cholesterol, high blood pressure, family history, and genetic issues.

AMD is of two types:

• Dry AMD: This the most common type of AMD.

• Wet AMD: It involves blood vessel growth that is abnormal under the macula, which can lead to bleeding, fluid leakage, and scar tissue formation.

Doctors diagnose AMD through various tests:

• Visual Acuity Tests: To check how well one sees.

• Amsler Grid: To detect vision distortions.

• Eye Exam: Using special tools to look inside one’s eye.

• Imaging: The retina can be seen with the help of optical coherence tomography (OCT) or fluorescein angiography.

In the early stages, AMD might not cause noticeable symptoms. As it progresses, symptoms may include blurry vision, distorted images, loss of central vision, or difficulty seeing contrasts. Wet AMD usually causes more sudden and severe vision problems.

There is no cure for AMD, but several treatments can help manage it:

• Lifestyle Changes: Quitting smoking, exercising, and eating an antioxidant-rich diet.

• Nutritional Supplements: Vitamins and minerals that may slow progression.

• Laser Therapy: To target abnormal blood vessels.

• Anti-VEGF Injections: Drugs injected into the eye block will promote abnormal blood vessel growth.

How Is AMD Related to VEGF?

The risk factors of AMD are age, race, and smoking, which increase the risk. AMD is more common in Caucasians and less so in Black people, with no significant difference between men and women. One key factor in AMD development is the VEGF/VEGFR pathway. It was first discovered in the 1980s, and several types of VEGF proteins, including VEGF-A, are the most important for encouraging new blood vessel growth. VEGF binds to specific receptors (VEGFR1 and VEGFR2) on cell surfaces. VEGF-A is known for promoting blood vessel growth and increasing permeability. It also helps new blood vessels invade tissues and attract immune cells. In the early stages of exudative AMD, VEGF can be detected at higher levels in the retina.

What Are the Side Effects of Anti-VEGF Therapy?

The side effects of anti-VEGF therapy are:

• Infection.

• Sensitivity to light.

• The feeling of something is in the eye.

• Blurred vision.

• Eye pain or redness.

• Increased pressure in the eye.

What Precautions Should Be Taken After the Treatment?

Antibiotic eye drops should be used after the treatment. Painkillers, such as acetaminophen and ibuprofen, are given to relieve postoperative pain. After the treatment, symptoms such as floaters, soreness, and blurred vision might be present, which should disappear in one or two days. It is better to avoid driving for at least a day after surgery.

Newer Advancements:

RGX-314 is a gene therapy. It is an anti-VEGF treatment. This gene can block VEGF for years following a surgical procedure. Here, a harmless adeno-associated virus is injected under the retina. Regarding safety and efficacy, this clinical trial looks promising.

Conclusion

Anti-VEGF treatments are one of the best choices to prevent further sight loss. They help stabilize vision and prevent it from getting worse. Anti-VEGF drugs are used in adults with wet AMD. They help slow the progression of the disease. The main concern of these drugs is that they are expensive and also require a medical professional who is trained to administer and monitor the treatment response.

Keynotes From iCliniq:

Anti-VEGF drugs help treat the eyes by providing vision and preventing further damage. Bevacizumab, Ranibizumab, and Aflibercept are three main anti-VEGF drugs that are safe and effective but differ in cost, packaging, and potential risks. Let the doctors at iCliniq help you find the cause of this symptom and provide further treatment.