I notice that certain eye conditions come up frequently throughout my career as an optometrist. These eye conditions happen because our population is aging, and most people are approaching middle age and older.
The two eye conditions that pop up the most are Presbyopia and Macular Degeneration. You could assume both of these eye issues are age-related since they occur in older adults. But, it’s interesting to think that eyesight might be genetic as well.
Today, I will discuss Presbyopia and Macular Degeneration and see if there is a genetic component to both, or if they are purely age-related.
Presbyopia
When you think of Presbyopia, the phrase that comes up more often is, “When I read something up close, my arms don’t seem to be long enough to get it into focus.”
The reason for this curious anomaly is that there is a lens inside each of your eyes that bends and stretches with the help of tiny muscles. This provides you with the magnification to focus on near objects.
Over time, especially after a person is forty years old, that lens becomes less flexible and less elastic. The lens is no longer able to give the focusing power you need to see up-close objects such as your texts, computer screen, and paperwork.
Reading glasses, bifocals, and progressive lenses are needed to supplement the eyes’ diminished ability to see up close. More power in your favorite eyewear is required to compensate for the lens getting stiffer and less elastic as time passes.
Because of this process, Presbyopia is essentially an eye condition that is progressive as the person ages.
There is minimal evidence to support the idea that genetics play a small role in determining at which age you will need reading glasses, bifocals, or progressives.
Still, other factors such as diet, stress, work environment, and medications also play a hand in when you would need supplemental eyewear.
Macular Degeneration
Age-Related Macular Degeneration (AMD) is the leading cause of blindness in the elderly. Changes in the macula in the back of the eye (retina) lead to a gradual loss of central vision. There is also a “washed out” effect on colors because the macula contains a concentration of color vision receptors that are also affected.
There are two stages of Macular Degeneration – Dry and Wet.
Dry Macular Degeneration:
- Vision is only mildly compromised
- Build-up of yellow deposits called Drusen
- Mild scarring and thinning of the macula and surrounding retina
- Vitamins and supplements are helpful
Wet Macular Degeneration:
- Rapid and severe loss of central vision
- Abnormal, leaky blood vessels growing in the macular area
- Moderate to severe scarring and thinning of the macular area
- Injectable medications may slow the progression of Wet AMD
Several factors lead to the development of AMD. Among them are age, smoking, diet, lifestyle, and genetic susceptibility.
Oxidative stress and inflammation cause AMD to progress from Dry to Wet. Free radicals are produced from oxidative stress, and they can disrupt the natural processes that help maintain macular health. Poor diet, smoking, and poor lifestyle choices contribute to creating free radicals and make a person more likely to develop and worsen AMD.
Antioxidants in healthy foods such as leafy green vegetables and vitamin supplements can combat free radicals and help fight against AMD.
There is also a genetic component to AMD. People can inherit specific genes that influence an immune response called the “complement cascade.”
Because of increased inflammation through free radicals created by smoking, poor diet, and lifestyle choices, the complement cascade is triggered to destroy pathogenic organisms and cellular debris. However, the complement cascade can go overboard and destroy healthy cells—specifically, the retinal pigment epithelium (retina).
Those with specific genetic variants are at a higher risk of the complement cascade going haywire and damaging healthy cells without having the ability to stop it or regulate the immune response.
Because of genetic factors, people who have a relative with AMD stand a greater risk of acquiring AMD themselves. This susceptibility only means they have a higher risk of developing AMD, but the other factors (smoking, diet, age, etc.) also come into play. So it is not a guarantee that they will get AMD for sure.
Based on this information, AMD is a combination of genetic, environmental, and habits/lifestyle factors, which add up to pose a higher or lower risk of getting AMD.
Final Thoughts
AMD and Presbyopia become more significant the older someone gets. Both eye conditions have a substantial age component, especially with Presbyopia where it is primarily age-dependent. On the other hand, AMD is a complicated mix of genetics, lifestyle, eating habits, and environment.
The Presbyopia solution for most people is to get the proper eyewear that suits their needs and lifestyle. AMD is more severe and may require medical intervention and an adjustment in a person’s lifestyle and habits. Knowing this information can help you make an informed decision on the best ways to prevent or treat each condition.
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