Age-related eye diseases that can lead to vision impairment or blindness
A high percentage of elderly who were admitted to hospitals with falls had vision impairment. And their sight problem may be compounding or causing falls.
Studies also indicated that a vast majority of elderly people with poor vision could have been successfully treated but failed to seek help from eye specialists. This problem was particularly acute in deprived areas.
Globally, the most common age-related eye diseases which can cause low vision are:
- age-related macular degeneration
- diabetic retinopathy
Cataracts occur when the lens of the eye becomes cloudy or opaque. Vision is decreased because the amount of light passing through the lens is reduced.
Cataracts can be treated by removing the opaque lens and replacing it with an artificial lens implant. This safe and effective operation can be done as an outpatient procedure. The improvement in vision is immediate.
However, if cataract surgery is delayed for too long, the lens can become harden and more difficult to remove, and may lead to other complications such as glaucoma. Cataracts can cause blindness if untreated.
Age-Related Macular Degeneration (AMD)
Macula is the small central area of the retina, the light-sensitive tissue that lines the back of the eye. It is responsible for seeing fine details so that we can read, recognize faces, drive, use a computer etc.
Macular degeneration causes “blind spots” in the central vision; the straight-ahead vision becomes distorted or missing.
There are two types of AMD. Dry AMD develops when there is ageing or thinning of the macula tissue or a build-up of waste material in there. The vision loss with this condition is relatively mild and presently there is no treatment.
The more serious type is Wet AMD which occurs when abnormal blood vessels grow underneath the retina. These vessels leak blood and fluid which can cause permanent damage to retinal cells. Treatment is by injecting a medicine called ranibizumab (Lucentis) into the eye regularly to stop the abnormal blood vessels from growing.
AMD affects only the central vision. It will not cause complete blindness because there is still peripheral vision. A person with AMD should get help from a low vision specialist to maximize the use of the remaining useful vision.
There are many useful assistive devices and aids which help people with low vision to continue living an independent life.
Glaucoma is a disease in which rising fluid pressure in the eyeball causes irreversible damage to the optic nerve.
Peripheral vision is lost at the beginning, progressing to tunnel vision if left untreated. Globally, glaucoma is one of the leading causes of blindness.
Glaucoma may be hereditary and more prevalent in certain ethnic groups. It is also more common among people with diabetes and those who have had previous eye injuries. Since there are little warning signs, it is important to have regular eye tests to detect it early. You should also see doctor immediately if there is a sudden pain in the eye.
Any vision that has been lost cannot be recovered. But early diagnosis, careful monitoring and getting appropriate treatment can prevent further damage and limit vision loss.
Glaucoma can be treated with eye drops, oral medicines, laser therapy and eye surgery, or a combination of these methods.
Diabetic retinopathy, a condition caused by damaged blood vessels in the retina, is a complication of diabetes. It is especially prevalent in patients with uncontrolled blood sugar level over a long period of time. It affects up to 80% of people who have had diabetes, both type 1 and 2, for 10 years or more
The damaged blood vessels in diabetic retinopathy become leaky or close.
In diabetic macular oedema (DMO), fluid leaks out of the damaged blood vessels and accumulates in the macula, leading to swelling of the tissue and poor central vision. Usually the peripheral vision remains normal.
In proliferative diabetic retinopathy (PDR), the close blood vessels cause abnormal and very fragile blood vessels to grow on the surface of the retina. This can lead to permanent loss of vision from bleeding into the eye, retinal scarring and retinal detachment.
There is no cure for diabetic retinopathy. However, laser photocoagulation can be used to seal off leaking points and reduce swelling. Vitrectomy, surgical removal of the vitreous gel containing the bleeding vessels, may help improve vision in advanced PDR. Anti-VEGF, which inhibit the vascular endothelial growth factor, have been found to be effective in preventing further growth of abnormal blood vessels.
Regular eye checks are essential for all diabetics so that signs of diabetic retinopathy can be detected as early as possible.
Just like the rest of the body, ageing brings about changes to our eyes and vision. By late 40s, most of us would experience problem seeing well in dim light, more sensitive to glare and bright light, presbyopia and so on.
Although these changes are a bit of a nuisance, they are normal part of aging and can be fixed by prescription glasses, sunglasses and light adjustment in the house. However, to prevent vision impairment as described above, we have to be more proactive about eye care.
Start with a yearly appointment with the eye specialist.
- Bourne RRA, Flaxman SR, Braithwaite T, Cicinelli MV, Das A, Jonas JB, et al.; Vision Loss Expert Group. Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis. Lancet Glob Health. 2017 Sep;5(9): e888–97.