Age-related macular degeneration (AMD) is a common eye condition that affects millions of people worldwide, particularly those over the age of 50. Among the two primary forms of AMD, wet AMD, also known as neovascular AMD, is a more severe and rapidly progressing variant. In this blog post, we will explore the causes, symptoms, and treatment options available for wet AMD.

Understanding Wet AMD

What is wet AMD?

Wet AMD, or neovascular AMD, is a progressive eye disease characterized by the growth of abnormal blood vessels beneath the macula, the central part of the retina responsible for sharp central vision. These blood vessels leak fluid and blood, leading to macular scarring and damage, which can result in severe vision loss.

How does wet AMD differ from dry AMD?

Dry AMD is the more common form of AMD, accounting for about 80-90% of cases. It involves the breakdown and thinning of the macula over time. In contrast, wet AMD is characterized by the abnormal growth of blood vessels, which can cause rapid and severe vision loss.

Causes of Wet AMD

Age as a risk factor:

Wet AMD is primarily an age-related condition, with the risk increasing significantly after the age of 50. The exact reasons behind this age-related susceptibility are not fully understood, but it is believed to be a combination of genetic and environmental factors.

Genetic predisposition:

Family history and genetic factors play a role in the development of wet AMD. Specific genes, such as variants in the complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) genes, have been associated with an increased risk of developing AMD.

Lifestyle factors:

Certain lifestyle choices may contribute to the development or progression of wet AMD. These include smoking, poor diet, obesity, and sedentary behavior. Smoking, in particular, has been strongly linked to an increased risk of AMD.

Other risk factors:

Other factors that may increase the risk of wet AMD include hypertension, cardiovascular disease, and prolonged exposure to ultraviolet (UV) light.

Symptoms of Wet AMD

Blurred or distorted central vision:

One of the most common symptoms of wet AMD is a decline in central visual acuity. This can manifest as blurred or hazy vision, making it difficult to see fine details or read small print.

Decreased color perception:

Individuals with wet AMD may experience changes in color vision, with colors appearing less vibrant or faded.

Increased difficulty in reading or recognizing faces:

Reading becomes challenging due to the loss of central vision. Additionally, identifying faces may become more difficult, as facial features may appear distorted or blurred.

Straight lines appearing wavy or distorted:

A classic symptom of wet AMD is the perception of straight lines as wavy, bent, or distorted, a phenomenon known as metamorphopsia.

Diagnosis of Wet AMD

Comprehensive eye examination:

A comprehensive eye examination is crucial for diagnosing wet AMD. It involves a review of medical history, visual acuity testing, and the evaluation of the retina using various instruments.

Visual acuity test:

Visual acuity is assessed using an eye chart to determine the sharpness of central vision.

Optical coherence tomography (OCT):

OCT is a non-invasive imaging technique that provides detailed cross-sectional images of the retina. It helps in identifying abnormalities and fluid accumulation beneath the macula.

Fluorescein angiography:

This diagnostic test involves injecting a dye into a vein in the arm, which travels to the blood vessels in the eye. Photographs are taken as the dye circulates, highlighting any leakage or abnormal blood vessel growth.

Treatment Options for Wet AMD

Anti-VEGF therapy

Anti-vascular endothelial growth factor (VEGF) therapy is the most common and effective treatment for wet AMD. Medications such as ranibizumab, aflibercept, and bevacizumab are injected into the eye to block the action of VEGF and reduce the growth of abnormal blood vessels.

Mechanism of action

VEGF promotes the growth of new blood vessels. By inhibiting VEGF, anti-VEGF drugs help prevent the formation of abnormal vessels, reduce leakage, and preserve vision.

Commonly used medications

Ranibizumab (Lucentis), aflibercept (Eylea), and off-label use of bevacizumab (Avastin) are approved for the treatment of wet AMD.

Administration and frequency

Anti-VEGF drugs are administered through injections into the vitreous gel of the eye. The treatment requires regular follow-up injections, typically on a monthly or as-needed basis.

Possible side effects and risks

Side effects of anti-VEGF therapy are generally rare but can include eye infections, increased intraocular pressure, and retinal detachment. Patients should discuss potential risks with their eye care professional.

Photodynamic therapy (PDT)

PDT involves the intravenous administration of a light-sensitive drug called verteporfin, followed by the activation of the drug with laser light. This therapy helps to selectively destroy abnormal blood vessels in the retina.

Procedure and mechanism of action

The light-sensitive drug is absorbed by the abnormal blood vessels in the retina. When activated by laser light, it damages these vessels while minimizing damage to the surrounding healthy tissue.

Limitations and considerations

PDT is less commonly used nowadays due to the widespread adoption of anti-VEGF therapy. It is primarily reserved for certain cases where anti-VEGF therapy may not be appropriate or as a supplementary treatment.

Laser photocoagulation

Laser photocoagulation was one of the earliest treatment options for wet AMD. It uses a laser to seal and destroy abnormal blood vessels in the retina.

Procedure and application

Laser photocoagulation involves the application of laser energy to abnormal blood vessels, which causes them to coagulate and shrink, reducing the leakage and preventing further growth.

Limitations and potential risks

Laser photocoagulation is less commonly used today due to the development of more effective treatments. It can cause some damage to the surrounding healthy tissue, leading to potential visual field defects.

Combination therapy

Combining different treatment modalities can sometimes yield better outcomes in specific cases of wet AMD.

Anti-VEGF therapy with laser photocoagulation

In some situations, combining anti-VEGF therapy with laser photocoagulation may be recommended to achieve better control over abnormal blood vessels while minimizing the frequency of injections.

Pros and cons of combination therapy

Combination therapy can provide additional benefits in specific cases, but it also carries some risks and may not be suitable for everyone. A healthcare professional can assess the individual’s condition and determine the most appropriate treatment approach.

Investigational Treatments and Emerging therapies

Ongoing research is exploring novel treatment options for wet AMD, including gene therapy, stem cell therapy, and artificial retinal implants. These treatments are still in the experimental stage and not widely available.

Lifestyle Modifications and Prevention

Nutritional supplements

Certain vitamins and minerals, such as vitamin C, vitamin E, zinc, copper, and antioxidants, have been studied for their potential benefits in slowing the progression of AMD. Dietary supplements, such as the Age-Related Eye Disease Study (AREDS) formulation, may be recommended in specific cases.

Smoking cessation

Smoking is a significant risk factor for the development and progression of wet AMD. Quitting smoking can help reduce the risk and slow down the disease’s advancement.

Regular exercise and maintaining a healthy weight

Engaging in regular physical activity and maintaining a healthy weight can contribute to overall well-being and potentially reduce the risk of AMD progression.

Regular eye examinations

Regular comprehensive eye examinations, especially for individuals over the age of 50, are essential for early detection and timely treatment of wet AMD. Routine check-ups allow eye care professionals to monitor any changes in vision and provide appropriate interventions.

Coping with Wet AMD

Assistive devices and low vision aids

Various low vision aids, such as magnifiers, specialized glasses, and electronic visual aids, can help individuals with wet AMD make the most of their remaining vision and carry out daily tasks.

Support groups and counseling

Joining support groups or seeking counseling services can provide emotional support and practical tips for managing the challenges associated with wet AMD. Connecting with others who are going through similar experiences can be helpful in coping with the condition.

Maintaining mental and emotional well-being

Living with wet AMD can be emotionally challenging. Engaging in activities that promote mental and emotional well-being, such as practicing relaxation techniques, pursuing hobbies, and seeking support from loved ones, can be beneficial.

Conclusion

Wet AMD is a complex eye condition that requires early diagnosis and prompt treatment to optimize visual outcomes. The advent of anti-VEGF therapy has revolutionized the management of wet AMD, offering significant improvements in preserving vision. However, lifestyle modifications, regular eye examinations, and preventive measures remain crucial in reducing the risk of developing wet AMD and slowing its progression. By staying informed, seeking professional care, and adopting a proactive approach, individuals with wet AMD can navigate the challenges associated with the condition and maintain a good quality of life.

FAQ’s

Will wet AMD cause blindness?

Wet AMD is more likely to result in sudden blindness, although dry AMD can cause more gradual visual loss. Wet AMD can permanently impair vision if left untreated within a few weeks or months.

Is it possible to halt the spread of wet macular degeneration?

Anti-VEGF, or anti-vascular endothelial growth factor, medications must be injected into the eye on a monthly or bimonthly basis to treat wet AMD. Anti-VEGF medications can, in most circumstances, successfully halt further vision loss while slowing or stopping the growth of blood vessel leaks.

Which foods should people who have macular degeneration avoid?

Foods to stay away from if you have macular degeneration

• Trans-fat-containing processed foods.
• Tropical oils, like palm oil (use vitamin E–rich safflower and corn oil instead)
• Margarine, shortening made from vegetables, and lard.
• Dairy products high in fat (moderate consumption of eggs is a beneficial source of nutrients for the eyes)
• Fatty pork, lamb, and beef.

How soon will blindness result from wet macular degeneration?

From diagnosis to legal blindness, it typically takes around 10 years, however, some types of macular degeneration can result in vision loss within a matter of days.