Diabetic retinopathy is a potentially blinding complication of diabetes that damages the eyes retina. It affects half of all patients diagnosed with diabetes.
What action should I take?
First, you may notice no changes in your vision. But don’t let diabetic retinopathy fool you. It could get worse over the years and threaten your good vision. With timely treatment, 90% of those with advanced diabetic retinopathy can be saved from going blind.
It is advisable that everyone with diabetes to has an eye examination through dilated pupils at least once a year.
What is the retina?
The retina is the light- sensitive tissue at the back of the eye. When light enters the eye, the retina changes the light into nerve signals. The retina then sends these signals along the optic nerve to the brain. Without a retina, the eye cannot communicate with the brain, making vision impossible.
A diagram of the eye detailing the postion of the retina
What is the cornea?
The cornea is the clear front window of the eye.
It transmits light to the interior of the eye allowing us to see clearly. Corneal injury, disease or hereditary conditions can cause clouding, distortion and scarring.
Corneal clouding, much like frost on a glass windowpane, blocks the clear passage of light to the back of the eye, reducing sight sometimes even to the point of blindness.
In addition, corneal injury and disease can be painful, sometimes it is the most intense pain we can experience.
What can cause corneal injury?
Knives, pencils, glass and any sharp object can cause severe injury to the cornea. Fireworks, exploding batteries and toxic chemicals (especially alkalis) can result in severe scarring of the cornea.
In fact, protection of the cornea is the reason the emergency washing out of the eye is absolutely necessary when the eye is exposed to toxic chemicals. Most corneal injuries are preventable with protective glasses and proper precautions when dealing with hazardous substances.
What causes corneal disease and degeneration?
Infections; whether bacterial, fungal or viral, frequently result in corneal damage and ulceration.
Abnormal steepening of the cornea (keratoconus), corneal oedema and swelling and some aging processes affect the clarity of the cornea. Some disorders of the cornea are inherited and can lead to corneal clouding and loss of sight.
Age-related macular degeneration
Age-related macular degeneration (AMD) is a disease that affects your central vision. It is a common cause of vision loss among people over age of 60. Because only the centre of your vision is usually affected, people rarely go blind from the disease. However, AMD can sometimes make it difficult to read, drive, or perform other daily activities that require fine, central vision.
What is the macula?
The macula is in the center of the retina, the light-sensitive layer of tissue at the back of the eye. As you read, light is focused onto your macula. There, millions of cells change the light into nerve signals that tell the brain what you are seeing. This is called your central vision. With it, you are able to read, drive, and perform other activities that require fine, sharp, straight-ahead vision.
How does AMD damage vision?
AMD occurs in two forms:
Dry AMD, affects about 90 percent of those with the disease. Its cause is unknown. Slowly, the light sensitive cells in the macula break down. With less of the macula working, you may start to lose central vision in the affected eye as the years go by. Dry AMD often occurs in just one eye at first. You may get the disease later in the other eye. Doctors have no way of knowing if or when both eyes may be affected.
Wet AMD, although only 10 percent of all people with AMD have this type, it accounts for 90 percent of all blindness from the disease. It occurs when new blood vessels behind the retina start to grow toward the macula. Because these new blood vessels tend to be very fragile, they will often leak blood and fluid under the macula.
Glaucoma is a group of diseases that can lead to damage to the eye’s optic nerve and result in blindness. Open-angle glaucoma, the most common form of glaucoma, affects about 3 million Americans (USA statistics); half of whom don’t know they have it. It has no symptoms at first, but over the years it can steal your sight. With early treatment, you can often protect your eyes against serious vision loss and blindness.
What is the optic nerve?
The optic nerve is a bundle of more than 1 million nerve fibres. It connects the retina, the light-sensitive layer of tissue at the back of the eye, with the brain. A healthy optic nerve is necessary for good vision.
How does glaucoma damage the optic nerve?
In many people, increased pressure inside the eye causes glaucoma. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of this space and nourishes nearby tissues. The fluid leaves the anterior chamber at the angle where the cornea and iris meet (see diagram). When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.
Open-angle glaucoma gets its name because the angle that allows fluid to drain out of the anterior chamber is open. However, for unknown reasons, the fluid passes too slowly through the meshwork drain. As the fluid builds up, the pressure inside the eye rises. Unless the pressure at the front of the eye is controlled, it can damage the optic nerve and cause vision loss.
Who is at risk?
A pterygium is a triangular-shaped growth of fleshy tissue on the white of the eye that eventually extends over the cornea. This growth may remain small or grow large enough to interfere with vision. A pterygium can often develop from a pinguecula.
Some pterygia may become red and swollen on occasion, and some may become large or thick, making you feel like you have something in your eye. If a pterygium is large enough, it can actually affect the shape of the cornea’s surface, leading to astigmatism.
It is not entirely clear what causes pterygia and pingueculae to develop. Ultraviolet (UV) light from the sun is believed to be a factor in the development of these growths. Other factors believed to cause pterygia and pingueculae are dry eye and environmental elements such as wind and dust.
If you have a pterygia and it is causing discomfort, has grown over your cornea (the window) of your eye or is bothering you, you should be assessed so that you can decide whether it should be surgically removed. The surgery is done in theatre as a Day case.
Dr Aleksic prefers to use tissue glue to secure the graft over the area where the pterygia was. This technique caused much less discomfort than sutures/ stitches.