Age-related macular degeneration (AMD) initially shows no significant symptoms but gradually leads to decreased central vision or distorted lines. If left untreated, it can result in blindness. It is the leading cause of blindness for individuals over 60. Factors such as genetics, smoking, diet, hypertension, and obesity are known contributors. We spoke with Professor Ju Kwang-sik of the Department of Ophthalmology at Bundang Seoul National University Hospital. Professor Ju said, "Age-related macular degeneration can affect anyone, so regular retinal (fundus) exams are recommended for those over 50. Numerous treatments for the most common cause of blindness, wet macular degeneration, have been developed, allowing timely treatment to preserve vision."
What is Age-Related Macular Degeneration?
The macula is the central part of the retina that lines the inside of our eye and is essential for sharp vision. When problems arise in this area, objects may appear distorted, or blind spots (scotomas) may develop, causing parts of the field of vision to disappear. The most common disease affecting the macula is age-related macular degeneration. It begins as dry macular degeneration (the early stage), which typically shows few symptoms. Around 6% of people over 40 are affected. If dry macular degeneration worsens, it can progress to wet or atrophic macular degeneration. Approximately 10% of people over 50 with macular degeneration develop the wet form, leading to visual distortions and reduced vision. As the disease advances, objects may become misshapen, and blind spots may appear and enlarge, eventually causing a loss of central vision. Atrophic macular degeneration is also a more severe form of dry macular degeneration, where retinal photoreceptors, retinal pigment epithelium, and choroidal capillaries are lost. This causes blurry vision, and vision or color perception worsens, especially in low-light conditions. Although atrophic macular degeneration progresses more slowly than the wet form, by the time symptoms are noticeable, significant damage has often already occurred.
How is it Diagnosed?
The main risk factor for age-related macular degeneration is age. The prevalence rate increases with age, from 3.4% in the 40s to 24.8% in those over 70. Other contributing factors include smoking, hypertension, dyslipidemia, obesity, and genetic mutations such as CFH and ARMS2.
Macular degeneration can be diagnosed through a retinal (fundus) exam or optical coherence tomography (OCT). A fundus exam involves dilating the pupils to examine or photograph the retina. Recently, wide-angle, non-mydriatic fundus photography has also been introduced. OCT uses harmless light interference to capture cross-sectional images of the macula. This can also detect new blood vessel growth (choroidal neovascularization) associated with wet macular degeneration or identify atrophic lesions. While contrast agents were once used for more detailed diagnoses, OCT angiography has been developed to visualize these new blood vessels. For atrophic macular degeneration, autofluorescence fundus imaging can be used to monitor the extent and progression of the disease.
How is it Treated?
For early-to-mid-stage dry macular degeneration, lifestyle changes that eliminate risk factors are essential. Regular exercise can lower biological age, and a diet rich in green and yellow vegetables and fish is recommended. Smoking cessation and hypertension treatment are also helpful. Antioxidants such as lutein complex supplements, omega-3 fatty acids, vitamins C and E, copper, zinc, and zeaxanthin are beneficial. In mid-stage dry macular degeneration, antioxidant supplements can reduce the risk of progression to wet or atrophic macular degeneration by half. Regular check-ups every six months are recommended. For wet macular degeneration, treatment involves injections into the sclera (the white part of the eye) every 1-4 months. Currently, five main drugs, including Avastin, are commonly used. The U.S. FDA has also approved the "Port Delivery System," which is undergoing clinical trials in South Korea. This system involves implanting a rice-sized port in the eye that slowly releases medication, requiring refills every six months. Additionally, the expiration of patents on various drugs and the development of biosimilar medications allow patients without insurance to receive affordable treatment.
No Symptoms in the Early Stages
Age-related macular degeneration can affect anyone. Therefore, regular annual retinal exams are recommended for those over 50. These exams can help detect macular degeneration early, along with other retinal diseases such as diabetic retinopathy, retinal vein occlusion, and epiretinal membrane, as well as conditions like glaucoma and optic nerve abnormalities. The Amsler grid, a checkerboard-like tool, can also help individuals self-diagnose macular degeneration. By periodically focusing on the center of the grid, any sudden distortion, line breaks, or blind spots should prompt a visit to an ophthalmologist.
By Kwon Dae-ik, Medical Journalist
