Age related macular degeneration is a chronic, progressive disease affecting the macula of the eye resulting in the deterioration of central vision. This may affect your ability to see smaller prints. see face faces and drive.
Age related macular degeneration (AMD) is the primary contributor of moderate to severe vision loss in adults above 50-55 years, causing about 9% of the total blindness globally. A systematic review in 2014 predicted the number of AMD cases to reach 196 milion in 2020, increasing to 288 million by 2040 worldwide.
Types of AMD
- Early age related macular degeneration: Described by the presence of numerous small drusen. It’s important to note that small drusen are commonly observed in individuals aged 50 and above and may simply be indicative of the aging process.
- Intermediate age related macular degeneration: At this stage, drusen can be either small and extensive or intermediate in size, or there may be any drusen of large size (125 microns or larger).
- Advanced age related macular degeneration
1- Advanced Dry AMD: makes upto 80-90 % cases of AMD. It is characterized by
Geographic atrophy involving the central macula or fovea
2-Advanced Wet AMD: the remaining 10-20% is contributed by the wet form of
AMD. It is characterized by neo-vascularization within the macula.
Risk Factors
Age-related macular degeneration (AMD) has several known risk factors, including:
- Advancing Age: AMD is more common in individuals over the age of 50, and the risk increases with age.
- Genetics: Family history plays a significant role in AMD risk. If you have a close relative with AMD, you are at a higher risk of developing the condition yourself.
- Smoking: Smoking tobacco significantly increases the risk of developing AMD and can accelerate its progression. Smokers are more likely to develop both early and late stages of AMD compared to nonsmokers.
- Race/Ethnicity: AMD is more common in Caucasians than in other racial or ethnic groups. However, individuals of all races can develop the condition.
- Gender: Women appear to be at a slightly higher risk of developing AMD compared to men.
- Hypertension (High Blood Pressure): High blood pressure is associated with an increased risk of AMD.
- Cardiovascular Disease: Conditions such as heart disease and high cholesterol may increase the risk of AMD.
- Obesity: Being overweight or obese is a risk factor for AMD, particularly for the more advanced forms of the disease.
- Sunlight Exposure: Prolonged exposure to ultraviolet (UV) light may contribute to the development and progression of AMD.
- Dietary Factors: A diet high in saturated fats and low in fruits, vegetables, and omega-3 fatty acids may increase the risk of AMD.
- Low Macular Pigment Density: Macular pigment consists of carotenoids like lutein and zeaxanthin, which help protect the retina from damage. Low macular pigment density is associated with an increased risk of AMD.
Symptoms
Individuals with AMD may experience various changes in vision, including:
- Blurred or distorted central vision
- Difficulty reading or performing tasks that require sharp central vision
- Metamorphopsia (perceived distortion of straight lines)
- Scotomas (areas of reduced or missing vision)
- Decreased contrast sensitivity
Amslers Grid
- Place the Amsler grid in a location where you can easily view it every day. Many individuals choose to affix an Amsler grid to their refrigerator door or bathroom mirror for convenient access.
- In well-lit surroundings, position yourself approximately 12 to 15 inches away from the grid. Ensure you are wearing your reading glasses if they are part of your regular vision correction.
- Cover one eye and focus your gaze directly on the central dot within the grid using your uncovered eye. Take note of any distortion or waviness in the lines of the grid. Check for any areas of blurriness, dimness, or irregular shape within the grid.
- Next, cover your other eye and repeat the same process to assess your vision.
If you observe any wavy, blurry, or dim lines or sections within the grid, it is important to contact your ophthalmologist promptly for further evaluation and guidance. Early detection of such changes can be crucial in managing potential issues with your vision.
Management
General
- In every stage, it is strongly recommended to mitigate risk factors, with particular emphasis on quitting smoking.
- Dietary supplementation including Vitamin C (500 mg), Vitamin E (400 IU), Lutein (10 mg), Zeaxanthin (2 mg), Zinc (80 mg) and Copper (2 mg).
The effectiveness of this particular dietary supplementation, as administered in AREDS-2, was only demonstrated in individuals already diagnosed with intermediate or advanced stages of AMD.
- Low vision aids, including yellow-tinted glasses, bioptic telescope, prismatic lenses, magnifiers, text to speech softwares, audiobooks, canes etc.
Dry AMD
There is no cure or specfici treatment options available for dry AMD.
Wet AMD
Treatment options include
- Anti-VEGF Therapy: Anti-VEGF (vascular endothelial growth factor) injections are the primary treatment for wet AMD.
- Photodynamic Therapy (PDT): PDT may be used in some cases of wet AMD, particularly when the abnormal blood vessels are located away from the center of the macula.
- Laser Therapy
- Combination therapy
What Does Future Holds For AMD?
Several potential treatment options for age-related macular degeneration (AMD) are being investigated for the future. These include:
Gene Therapy: This approach could potentially slow or halt the progression of the disease by addressing underlying genetic factors.
Stem Cell Therapy:. This approach holds promise for restoring vision in individuals with advanced AMD.
Retinal Prostheses: Retinal prostheses, also known as bionic eyes or retinal implants, are electronic devices that stimulate the remaining retinal cells to generate visual signals.
Complement Inhibition: Drugs that target complement proteins or pathways are being investigated as potential treatments for AMD. The DERBY and OAKS trials are phase 3 studies assessing intravitreal pegcetacoplan, a complement component 3 inhibitor, for efficacy and safety.
Drug Delivery Systems: Improved drug delivery systems, such as sustained-release implants or nanoparticles, could enhance the effectiveness of existing AMD treatments by delivering drugs directly to the retina and prolonging their therapeutic effects.
Metformin: the role of metformin in preventing AMD in diabetics is being studied and investigated.
While these potential treatments show promise for the future management of AMD, further research and clinical trials are needed to evaluate their safety and efficacy. It’s essential to continue monitoring advancements in AMD research and treatment and to work closely with eye care professionals to explore all available options for managing the condition.
