You can’t have clear vision without a healthy retina. Located in the back of the eyes, the retina are thin tissue that has the amazing ability to transform light waves received from the lenses into complex neural signals. Under normal circumstances, the data produced in the retina are immediately transported via the optic nerve to the brain’s visual cortex.
Since the retina plays such a crucial role in healthy vision, it’s no wonder that retinal disease and injuries often result in permanent visual impairment. Everyone should take extra care of their retina if they want to increase the odds of enjoying healthy vision for life.
In this article, we’ll explore the anatomy of the retina in closer detail and explain a few of the major conditions related to these eye tissues. You’ll also find a few prevention strategies in this piece that you could use to boost your retinal health.
How Does The Retina Work?
To find the retina on an eye diagram, simply look for the thin layer that wraps around the inner surface at the back of the eye. You should notice that the retina is attached to the optic nerve via a raised spot known as the optic disk.
To understand how the retina transforms light waves into visual data, it’s essential to briefly mention photoreceptors. A well-functioning retina will have millions of these light-sensitive cells busily sending messages through the optic nerve.
There are two major kinds of photoreceptors with different tasks: rods and cones. Rods are most often associated with night vision because they are better able to pick up visual cues in dim settings. Cones, on the other hand, are essential for sight during the daytime as well as distinguishing between different colours.
You can find rods throughout the retina, but cones tend to be concentrated in two central areas known as the macula and the fovea. While the macula has a few rod photoreceptors, the fovea only contains cones. For this reason, the fovea is most often associated with concentrated daytime vision.
Interestingly, new research out of Germany suggests rods might have more to do with daylight vision than scientists previously assumed. Researchers at the University of Tübingen observed rod levels in the eyes of a group of mice as they increased light brightness. They found that rods actually increased in the retina as they exposed the mice to more light. This new study suggests the functions of rods and cones might be more complicated than previously imagined. Anyone interested in this study could read the full paper on this website.
A Few Common Retinal Disorders
As the name suggests, a retinal detachment occurs when the retinal tissue starts to tear away from its proper place in the back of the eye. Since the retina can’t obtain essential nutrients and oxygen in this state, it’s critical to seek medical attention as soon as possible to avoid permanent vision loss.
Typical warning signs of a retinal detachment include
- Sudden flashes of light
- A loss of peripheral vision
- Increased eye floaters
- Blurry vision
Patients usually don’t report eye pain symptoms when they are experiencing a retinal detachment.
There are many potential causes of retinal detachments, but one of the most common reasons for this issue has to do with fluid leakage in the eyes. A few obvious reasons for retinal tears and detachment include direct trauma to the eye or eye surgery. People who are short-sighted, over 50, or have a genetic link with a retinal detachment patient are at a higher risk of developing this disorder.
The NHS recommends anyone who experiences symptoms of retinal detachment to immediately call 111. Once you arrive in the hospital, doctors will most likely scan your retina to see if it’s torn or detached. For a retinal tear, ophthalmologists will usually use laser surgery or a freezing procedure to produce a scar on the retinal tissue. If the retina is actually detached, then doctors might have to inject gas into your eyes to prevent eye fluid from leaking.
According to the World Health Organization (WHO), glaucoma is second only to cataracts as the leading cause of blindness worldwide. Scientists believe there will be at least 80 million glaucoma patients around the world in 2020.
There are many forms of glaucoma, but most are caused by an unnatural buildup of eye fluid that puts pressure on the retinas and optic nerves. Over time, the retinal nerves can become damaged, which could lead to permanent visual impairment.
Unfortunately, visual symptoms of glaucoma don’t usually appear until the disease has progressed a great deal. Optometrists can, however, monitor a patient’s risk for this disorder at a standard vision exam.
Although there’s no treatment for glaucoma, doctors can slow the disease’s progression with drug therapies and laser surgery. Eye doctors might also recommend diet changes and supplements to improve glaucoma symptoms.
Moorfields Eye Hospital reports that at least 480,000 people living in England have glaucoma. UK doctors point out that people of African or Caribbean ethnicity have a greater risk of developing glaucoma compared with white Europeans and Asians.
Age-Related Macular Degeneration
One of the most prevalent retinal diseases for people over 40-years-old is appropriately known as age-related macular degeneration (AMD). The non-profit organisation Macular Society currently estimates there are about 600,000 citizens in the UK with some degree of AMD.
There are two major forms of AMD: dry and wet. About 9 out of 10 AMD patients suffer from the dry form of this disease, which causes the retina to deteriorate over time. Although wet AMD is somewhat rare, it’s far more serious than dry AMD because it’s caused by leaky retinal blood vessels.
There’s no cure for AMD, but doctors can slow the progression of sight loss if they catch the disease early. Typical treatment methods include vitamin supplements, eye injections, and laser eye surgery.
Like glaucoma, you won’t experience obvious symptoms when AMD is in its early stages. For this reason, health professionals advise patients over the age of 40 to get at least one visual screening per year.
Diabetic patients need to be extra careful about their visual health because elevated blood sugar levels can adversely affect the retina. This breakdown of the retina over time could eventually lead to a potentially blinding disorder known as diabetic retinopathy.
Recent statistics out of the UK suggest almost 100 percent of people who have type 1 diabetes will end up with diabetic retinopathy within 20 years of their initial diagnosis. Type 2 diabetic sufferers have a 60 percent risk of developing this eye condition within the same timeframe.
As with many of the other conditions listed above, the visual symptoms associated with diabetic retinopathy don’t occur until the disease has progressed a great deal. The NHS now recommends all diabetics 12 and older get an eye screening at least once per year.
There’s no cure for diabetic retinopathy, but doctors can improve symptoms using laser surgery, diet modifications, and medication.
Ways To Improve Retinal Health
The chemicals lutein and zeaxanthin have been getting a great deal of press in the eye care field recently. These healthy nutrients are mostly found in dark green vegetables, and work like antioxidants in the retina and prevent the tissues from damage. For this reason, people who get more lutein and zeaxanthin into their diet often have a decreased risk of developing diseases like AMD.
While you can take lutein and zeaxanthin in supplement form, most doctors recommend working these nutrients into your daily diet. The best food sources of lutein and zeaxanthin are as follows:
• Swiss Chard
• Collard Greens
Although these greens are the absolute best sources of lutein and zeaxanthin, you could also find trace amounts of these compounds in corn, eggs, and squash.
The stats are clear: smokers are far more likely to develop a disease like AMD or glaucoma than non-smokers. Indeed, recent research suggests smokers have at least a three-times greater risk of developing AMD compared with non-smokers. The sooner you ditch your smoking habit, the greater chance you’ll have of enjoying a clear vision for life.
UK residents who are struggling to quit smoking should know that the NHS now offers a “Smokefree” program. People interested in taking part in this program should visit this official portal.
The Retina: Key To Great Visual Health
The retina might not be center stage, but they are central to healthy functioning vision. While there are actionable steps you could take to strengthen your retina, the best thing you could do is schedule a regular visual screening with a certified eye doctor. Optometrists can spot warning signs of retinal issues long before they cause problems with your vision.
Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 11 May 2023, Last modified: 18 May 2023