AGE-RELATED MACULAR DEGENERATION (AMD)
- AMD is a leading cause of vision loss in older adults (>50) around the world. It may advance slowly or progress rapidly.
- AMD gradually affects the macula, the central part of the retina that provides sharp, central vision needed for seeing objects clearly and to see colour.
- The vision loss makes it difficult to recognize faces, drive a car, read, or do close work, such as sewing or fixing things around the house.
- AMD does not cause complete blindness. Patients will still be able to see using their side (peripheral) vision.
Figure 1: Structure of eye
Types of AMD
- Early AMD is often called ‘dry’ AMD, while late or more severe disease progression is often referred to as ‘wet’ AMD. Either form can advance & cause vision loss.
- Dry AMD:
- More common (80% of all cases), and (typically) milder form of AMD.
- It is important for individuals with dry AMD to have their eyes examined regularly because it may eventually develop into the more severe wet form.
Figure 2: Drusen accumulate in the tissue beneath the macula
- Wet AMD:
- Late, or wet, AMD is characterized by rapid loss of central vision caused by bleeding under the macula by abnormal new blood vessels.
- Although the wet form of AMD accounts for only 20% of all AMD, the risk of severe sight loss is much greater, being responsible for 90% of severe vision loss caused by AMD.
- In Asian populations, the prevalence of early AMD is 6.8% & late AMD is 0.56%.
- Age Smoking
- Poor nutrition Hypertension
- Obesity and inactivity Sun exposure
- In its early stages, AMD may not have symptoms.
- Straight lines start to appear distorted (usually the first sign)
- Dark, blurry areas or white out appears in the centre of vision.
- Scotoma (a dark spot in the centre of a visual field surrounded by a distorted image).
Figure 3: Normal vision and the same scene as viewed by a person with AMD
- Annual eye checks for AMD for those over 60 so early symptoms can be recognised.
- Eye exams include the following tests:
- Visual Acuity Test
- Dilated ophthalmoscopy
- Amsler Grid
- Optical coherence tomography (OCT)
Figure 4: Amsler Grid and what it might look like to someone with AMD
- The goal of treatment is to stop further vision loss. Unfortunately, in most cases, damage that has already occurred cannot be reversed, making early detection important for vision preservation.
- While there is currently no cure for dry AMD, taking a specific formulation of antioxidants and zinc may slow the progression of the disease.
- For wet AMD, medical treatments are available that can stop deterioration or even restore some lost vision.
- Anti-VEGF Treatments
- The drugs are injected into the eye every month and inhibit the growth of new blood vessels.
- Photodynamic Therapy with laser
- Submacular haemorrhage Displacement Surgery
- Anti-VEGF Treatments
- The following suggestions will help protect vision, improve overall health, and potentially lower the risk of developing AMD:
- Eating a varied and nutritious diet that includes leafy green vegetables, fruit, fish, and food containing vitamin D, E, and C, beta carotene, lutein, and omega-3 fatty acids.
- Getting regular exercise.
- Maintaining a healthy weight.
- Keeping blood pressure at a normal level and controlling other medical conditions.
- Not smoking.
- Preventing overexposure to sunlight (wide brimmed hats & sunglasses)
- Regularly visiting an eye care professional for comprehensive eye exams.
- Performing an Amsler Grid test at home.