Age-Related Macular Degeneration (ARMD) is the most prevalent cause of visual impairment in people over the age of 50 in the Western world, and the leading cause of blind registration in this age range. It affects 10% of adults over the age of 65 and 30% of those over the age of 80. Numerous mutations have been found in numerous genes, including fibulin 5, complement factor H, and the Arg 80 Gly variation of complement C3. Although the etiology is uncertain, risk factors include growing older, smoking, hypertension, hypercholesterolemia, and UV radiation.
Risk factors
ï‚· Age: most patients are over 60 years of age
ï‚· Female sex
ï‚· Smoking
ï‚· Family history
ï‚· More common in Caucasians
ï‚· High cumulative sunlight exposure
Dry ARMD
It is characterised by Drusen – yellow round spots in Bruch’s membrane.
Dry AMD is a progressive degeneration of the macula cells that occurs over time when the retinal cells die off and are not replaced. The word ‘dry’ does not imply that the individual has dry eyes; rather, it indicates that the condition is not wet AMD.
While the course of dry AMD varies, patients may continue to function normally for some time.
Symptoms of dry ARMD
- Gaps or dark patches in your eyesight (similar to a smear on glasses) may emerge, especially first thing in the morning.
- The objects in front of you may change shape, size, or color, as well as appear to move or vanish.
- Colors might fade over time.
- You may find bright light blinding and uncomfortable, or you may have difficulty adjusting to changing surroundings from dark to light.
- When you are reading, words may vanish.
- Straight lines, such as those found on door frames and lampposts, might look deformed or curved.
Wet ARMD
It is characterized by choroidal neovascularisation. Leakage of serous fluid and blood can subsequently result in a rapid loss of vision. It carries the worst prognosis.
Patients with nonexudative AMD may develop wet, or exudative, AMD, in which pathologic choroidal neovascular membranes (CNVM) grow underneath the retina. If left untreated, the CNVM can leak fluid and blood and eventually result in a centrally blinding disciform scar. Around 10%–20% of people with nonexudative AMD eventually develop exudative AMD, which accounts for the vast majority of the estimated 1.75 million instances of advanced AMD in the United States.
Symptoms of wet ARMD
At first, you may notice that your eyesight is hazy or distorted. The features of your impaired vision may include a blind spot in the middle of your field of vision if you have wet AMD. This empty space may be gray, red, or black. For instance, if you stare directly at the face of a clock with hands, the numbers around the perimeter may appear normal, but you may be unable to see the clock’s hands if you have this disease.
Another indicator is that objects appear twisted or warped as if viewed through a distorted mirror.
Additional symptoms may include the following:
- Straight lines might appear to be wavy.
- Incapacity to perceive minute details clearly.
- In low light, it’s difficult to read or discern details.
- Glare may irritate your eyes.
- The size or color of an item may appear to be different when viewed through one eye vs the other.
Diagnosing ARMD
- Fundoscopy shows drusen, neovascularization, and pigmentary changes in the retina.
- Optical coherence tomography: cross-sectional views of the macula.
- If neovascularization is present then fluorescein angiography is performed.
Treatment
- Although no dietary alteration has been demonstrated to prevent the development of age-related maculopathy, oral therapy with antioxidants (vitamins C and E), zinc, copper, and carotenoids may slow its progression (lutein and zeaxanthin, rather than vitamin A). Omega-3 fatty acids taken orally have no added benefit.
- Ranibizumab (Lucentis), pegaptanib, bevacizumab (Avastin), and aflibercept are VEGF inhibitors that reverse choroidal neovascularization. As a result, vision is stabilized in people with wet degeneration (or even, albeit less frequently, improved). The VEGF inhibitors must be repeated intraocularly, perhaps for an extended period of time. Although the procedure is generally well tolerated with few side effects, there is a risk of intraocular complications. Long-term outcome studies indicate that up to one-third of eyes have a poor outcome, even when treated over an extended period of time.
- Macular surgery may be therapeutic in cases with bilateral severe illness. Gene therapy using a VEGF inhibitor in combination with a viral vector as a subretinal injection may be a viable option for long-term treatment.
- Treatment for dry ARMD is vision correction by eye glasses, and contact lenses.Â
