Health Corner

Understand about Macular degeneration

Among common eye diseases, most people may have heard of cataracts and glaucoma, but are less familiar with age-related macular degeneration (AMD). “Macular degeneration,” “glaucoma,” and “cataracts” are the world’s three leading causes of blindness. With an aging population, the number of people suffering from AMD continues to rise, and in many countries, it has even become the leading cause of blindness among people aged 55 and above. As the saying goes, “Prevention is better than cure.” Let’s learn more about this condition to better protect our “windows to the soul.”

What is Macular Degeneration?

The structure of the eyeball is similar to that of a camera. The pupil at the front of the eye works like a camera aperture, allowing light to enter. The lens focuses the light and projects it onto the retina. The retina functions like film—it receives light and converts it into images sent to the brain. Because the macula is located at the center of the retina, where photoreceptor cells are densest, it plays a vital role in vision. Many daily activities depend on central vision, such as reading, writing, recognizing faces, and driving.

What is Age-related Macular Degeneration (AMD)?

Age-related macular degeneration (AMD) is a degenerative disease of the central retina (macula) caused by aging, damaging the macula’s photoreceptor cells and impairing central vision.
AMD can be classified into two types: dry and wet.

• Dry AMD
  In dry AMD, yellowish deposits called drusen accumulate under the retina in the retinal pigment epithelium (RPE). These deposits are waste materials excreted by photoreceptor cells and can disrupt their function, leading to gradual degeneration. Most early-stage patients have few or no noticeable symptoms, and vision loss tends to progress slowly. However, the condition should not be ignored, as it can develop into the more severe wet AMD.

• Wet AMD
  In wet AMD, abnormal blood vessels grow under the retina in the macula. If these vessels rupture, they can cause bleeding and scarring, damaging photoreceptor cells. This form progresses quickly and can severely impair central vision—sometimes permanently destroying sight in the center of the field.
  Wet AMD can cause marked vision loss within as little as three months, or even within days in extreme cases. If sudden changes in vision occur, one should consult an ophthalmologist immediately without delay.

Why Do I Have AMD?

Multiple factors contribute to AMD development, but age is the strongest link—the older you are, the higher your risk. Studies show that smoking is associated with AMD progression, while quitting smoking can reduce risk. Genetics also play a role; those with close family members suffering from AMD are at higher risk. Other potential risk factors include diets high in saturated fats and cholesterol, hypertension, cardiovascular disease, and excessive sunlight exposure.

How Can I Check If I Have AMD?

To diagnose AMD, in addition to routine vision and anterior segment checks, doctors will dilate the pupils to examine the back of the eye with an ophthalmoscope to assess the location, extent, and type of lesions.
For precise classification, patients may undergo Fundus Fluorescence Angiography (FFA) or Indocyanine Green Angiography (ICGA), both of which involve injecting a dye into the bloodstream to observe retinal blood vessels.
Another non-invasive test is Optical Coherence Tomography (OCT), which uses laser and light imaging to analyze the retinal and macular layers in detail.
Besides professional exams, the Amsler grid test is a quick and simple self-assessment tool for detecting macular changes.

What Are the Treatment Options for AMD?

• Photodynamic Therapy (PDT)
  PDT combines medication with laser treatment. The patient receives an injection of a light-sensitive drug into the arm. This drug circulates through the bloodstream and binds to the abnormal blood vessels under the retina. The ophthalmologist then uses a low-energy (cold) laser to activate the drug, destroying the abnormal vessels and slowing vision loss. Studies show PDT can reduce the risk of significant vision decline and, unlike laser coagulation therapy, does not harm surrounding healthy tissue.

• Intravitreal Injection of Anti-VEGF Drugs
  This is the current gold-standard treatment for wet AMD. Anti-VEGF (vascular endothelial growth factor) drugs block factors that promote abnormal blood vessel growth, reducing leakage and bleeding. Studies have shown that over 90% of patients receiving anti-VEGF injections maintain stable vision, and nearly one-third experience improvement. Because abnormal vessels may regrow, repeated monthly treatments are often needed until vision, macular thickness, and leakage are controlled.

• Intravitreal Injection of Steroids
  Steroid injections can reduce damage to the blood-retinal barrier (BRB). The procedure must be carried out under sterile conditions with topical anesthesia and infection prevention measures in place.

• Laser Photocoagulation Therapy
  Using laser heat, this treatment destroys abnormal fragile blood vessels under the retina, sealing and preventing further leakage, bleeding, or swelling. Because the laser can also damage nearby cells, it is only suitable for cases where the abnormal vessels are located away from the macular center. Otherwise, treatment could harm central tissues and cause vision loss.