RETINA
The retina is a delicate film in back of the eye that converts light into nerve signals that are sent to the brain. The retina is like the film in the back of a camera, and it is essential for vision.
Many conditions can damage the retina including macular degeneration, diabetes and retinal detachments. If you see flashes and floaters you may have a tear in the retina which needs a simple office laser treatment to prevent a blinding retinal detachment. If you see distortion in straight lines you may have active macular degeneration requiring treatment. Any changes in your vision should be reported to your eye doctor for evaluation.
Diabetes is a leading cause of vision loss and blindness among adults in the United States. Diabetic eye disease can include blurred vision, early development of cataract, Diabetic retinopathy, and macular edema.
Diabetic retinopathy
The persistently high blood sugar levels that occur with diabetes can damage the retina’s small blood vessels (capillaries), which deliver oxygen and nutrients. Diabetic retinopathy affects around 15% of people with diabetes and there are three main types:
Non-proliferative diabetic retinopathy is the early stage in which capillary damage results in blood and fluid leaking into the retina, causing it to swell. Depending on the number of vessels affected, there is usually minimal or no effect on vision.
Diabetic macular oedema occurs if swelling extends to the macula, which is the part of the retina responsible for central vision. Diabetic macular oedema (swelling) is the usual cause of vision loss related to diabetes and the level of impairment can be significant.
OCT Diabetic macular oedema
is the advanced stage of the disease. In an attempt to supply the retina with more oxygenated blood, abnormal blood vessels start to grow but these are fragile and bleed easily. This can lead to the formation of scar tissue. If these new vessels bleed, the person may see ‘floaters’ or even lose all vision. This requires emergency treatment.
Treatment of diabetic retinopathy is mainly with anti-VEGF eye injections.
Macular degeneration
Macular degeneration (also called age-related macular degeneration or AMD) refers to a group of degenerative diseases of the retina – in particular the macula, which is responsible for central and fine-detail vision.Tthis is a painless condition and peripheral vision is not affected, many people are not aware that they have AMD until the disease is in the advanced stages. Once advanced, AMD can be classified into wet and dry forms. Most people have the dry form of AMD.
People aged over 50 years or those with a family history of macular degeneration face the greatest risk. This eye disease causes people to lose the ability to distinguish faces, read, drive and see fine detail. Early detection and treatment offers the best hope of minimising significant damage.
If you have difficulty reading, distinguishing faces, or start to see dark or empty patches in your central vision, have your eyes checked immediately
Diagnosing macular degeneration
1. Regular eye examinations 2. Home screening An Amsler Grid may be recommended for people at high risk of developing macular degeneration, this grid contains a series of horizontal and vertical lines with a dot in the middle. If the lines appear wavy or any are missing, have your eyes checked immediately. 3. Fluorescein angiography 4. Optical coherence tomography (OCT)
OCT Normal Macula Treating wet macular degeneration
There is no cure for wet macular degeneration, although some treatments can slow or stop progression of the disease and vision can be maintained (or even improved) for many people.
Anti-VEGF eye injections
For wet macular degeneration, early detection is vital because eye (intravitreal) injections can be used to stop abnormal blood vessels leaking and dry up the abnormal macular fluid (oedema). Repeated injections and regular monitoring can prevent further vision loss in 95% of sufferers. Vision is significantly improved in up to 40% of those treated.
Treating dry macular degeneration
Unfortunately, there is no approved treatment for patients with the dry form.
Research studies investigating disease progression and potential therapies, are currently ongoing.
Preventing macular degeneration
Quit smoking
Smokers are three times more likely to develop macular degeneration (in addition to a number of other serious health-related issues), so now is the time to quit.
Eat fish, green and gold
Research has shown eating foods rich in carotenoids are particularly beneficial. These include dark green leafy vegetables (e.g. spinach and kale) and coloured vegetables (particularly gold-coloured ones, e.g. corn, yellow capsicum, sweet potato). Foods rich in vitamin C, omega-3 fatty acids (e.g. oily fish such as salmon) and zinc are also good for eye health.
This is a picture of a normal retina, the delicate film in back of the eye. The dark spot in the center is the macula and is required for clear vision. Any problem with the retina reduces vision.
This patient has diabetic retinopathy. This macula has bleeding and leakage that must be treated. All diabetics must be followed by an ophthalmologist to prevent loss of vision
This patient has macular degeneration and if there is leaking, then treatment is required to prevent blindness (wet macular degeneration). Dry macular degeneration patients must take special nutritional supplements to preserve vision.
This patient has a retinal detachment of the upper retina and needs surgery to prevent blindness. Patients may initially see floaters and flashes and need an office laser to treat the retina before it gets to stage of detachment.
Retinitis pigmentosa is the name for a range of genetic diseases that damage the retinal rod and/or cone cells (photoreceptors), causing vision loss. Unfortunately, there is no known treatment. An ophthalmologist can give you advice on what to expect and how to manage the disease.
Epiretinal membrane, also known as macular pucker, epiretinal membrane occurs when a thin sheet of scar-like tissue grows on the surface of the macula and interferes with central vision. Your doctor will monitor progression using an OCT scan and fluorescein angiogram. Vitrectomy may be recommended.
Eye floaters are specks or smudges that float around your field of vision, caused by the degeneration of the clear, jelly-like fluid that fills your eye (the vitreous). Most floaters are harmless, but they may also be a sign of more serious retinal conditions. New floaters should always be checked by an eye specialist. Laser treatment or vitrectomy surgery can be performed for severe floaters if they are affecting your quality of life.
Diagnosing retinal conditions
- Retinal examination (dilated ophthalmoscopy).
- Digital retinal photography: State-of-the-art equipment is used to produce high-resolution photographs of your retina, optic nerve and blood vessel.
- Fluorescein angiography: A fluorescein angiogram uses a fluorescent dye (injected into a vein in the arm) to show any blockages or leaks in the blood vessels supplying the retina. or leaks and will use a special camera to take photographs. Your vision will be blurred for up to 12 hours after the test.
- Optical coherence tomography (OCT) the retina and the optic nerve.
