What is geographic atrophy (GA)?
How it’s related to dry AMD and who’s the most at risk
For those with dry age-related macular degeneration (dry AMD), there’s always a risk that this condition could develop into geographic atrophy (GA), a condition where retinal pigment epithelial (RPE) cells start to die off. Research estimates that there are approximately 180,000 new cases of GA in Canada each year.
When cells begin to die or deteriorate, they cannot regenerate, and their loss can result in a decline in visual sharpness and detail resolution. As such, it’s important to know what it is and what the risk factors are so it can be identified and hopefully prevented.
What is GA and how is it related to dry AMD?
Dry AMD is when parts of the macula at the back of the retina start to thin. It can also be marked by an accumulation of clumps of protein called drusen1.
GA is an advanced form of dry AMD that occurs when cells on the back of the retina start to atrophy or die2. Most of the time, this change is irreversible and can cause a dimming or loss of vision in the affected area, causing people to lose their ability to see fine details2.
“Dry AMD is a big spectrum of diseases. It could be just drusen which is basically the deposits under your retina, and these usually would not directly affect the vision,” says ophthalmologist Dr. Ghassan Cordahi. “But it can go from just the deposits to the disease being more progressive and then you can start losing some of these cells. And by losing these cells, the RPE gets to advanced AMD which is basically geographic atrophy.”
Symptoms of GA
Dr. Cordahi says that the development of GA from dry AMD is a slow progression that could take many years. In its early stages, it may be completely asymptomatic and only able to be detected by an eye care professional.
“We can detect it by doing the autofluorescence test which can show us the loss of RPE,” says Dr. Cordahi. RPE stands for retinal pigment epithelium, a critical layer of cells located in the retina. The RPE plays a vital role in maintaining the health and function of the retina, particularly the photoreceptors (rods and cones), which are responsible for capturing light and enabling vision.
As GA progresses it starts to affect the central vision and you may start to experience symptoms2 like:
- Difficulty seeing in your central field of vision
- Numbers or letters disappearing or missing when you’re reading
- A dark or dim spot in the center or side of your vision
Since the early stages can be asymptomatic, it’s important to attend regular appointments with your ophthalmologist so they can monitor your eyes and catch any signs of GA or other eye conditions early before there are any permanent and irreversible changes to your vision2.
What are the typical risk factors of developing GA?
Dr. Cordahi says two of the biggest risk factors for developing GA are having dry AMD and a family history of GA.
Other risk factors include2:
- Age
- Smoking
- Diabetes
- Heart disease
- High blood pressure
- Obesity
- Low diet intake of fruits and vegetables
- Having light-coloured eyes
- High cholesterol
Impacts on quality of life
Dr. Cordahi says that depending on the severity of vision loss associated with a person’s GA and the area of the retina that it affects, they may have trouble with daily activities like reading. Further, if the disease is significantly progressed, they may no longer be able to drive or do things by themselves, which could lead to feelings of a loss of independence.
Patients also report that with the progression of GA they often feel depression, anxiety and a change in their desire to socialize with others.
Are there any promising treatments available for GA?
Dr. Cordahi says that taking daily multivitamins reduce the risk of dry AMD becoming more severe, but as of now, there are no proven ways to reduce your risk of developing GA.
Taking daily multivitamins and other treatments such as MacuMira Vision Therapy for dry AMD can improve visual acuity and quality of life for patients.
Dr. Cordahi says there is a medication for slowing the progression of GA that was approved in the United States and could make its way to Canada.
He says there are currently no proven ways for remediating the retinal cells that have died because of GA
But while there’s no way to regain cells that have atrophied, treatments like MacuMira available in Canada help treat dry AMD by stimulating RPE cells in your retina to clear toxins like drusen and lipofuscin using a patented microcurrent. MacuMira Vision Therapy has been a clinically proven treatment to help dry AMD patients improve their vision on an average of eight letters on the ETDRS chart.
Take control of your vision today – with MacuMira‘s treatment for dry AMD, you can restore your eyesight and improve your quality of life. Book a consultation with your local eye care professional to get started with MacuMira Vision Therapy!
Disclaimer: Always speak to your primary health care provider and/or eye care provider before making any changes to your lifestyle, activities or diet.