Many patients who have diabetes, think of it as a disease whereby the primary problem is difficulty in properly metabolizing glucose. In fact, this is correct. However, the effects of diabetes are more widespread than simply a “sugar problem”. In fact, diabetes is really a disease that affects the blood vessels throughout the body and damages the normal circulation of the body. That is why diabetics have problems with the circulation to their legs, kidneys, heart, brain and eyes-especially the very small blood vessels of the eye found in the retina. When diabetes begins to affect the small blood vessels in the retina, it is called Diabetic Retinopathy.
About Diabetic Retinopathy
Diabetic Macular Oedema
The first effect of diabetes on the retina is to cause the blood vessels to begin to leak. These “leaky” blood vessels result in a complication called diabetic macular oedema or retinal swelling. Since this swelling occurs in the central visual area of the retina-the macula-macular oedema causes vision loss. To diagnose macular oedema, it may be necessary to have a fluorescein angiogram. A fluorescein angiogram is performed by taking a series of photographs of the retina after a special dye has been injected into a vein in your arm in order to carefully observe the circulation and the integrity of the blood vessels. By using this diagnostic test, it is possible to determine the extent and the location of blood vessel leakage. Fortunately, leaking retinal blood vessels can often be treated by sealing them with a laser. With careful laser treatment it is possible to reduce the swelling and prevent further vision loss. Sometimes, it is possible to have macular edema but still retain normal vision. Nonetheless, a diagnosis of macular oedema indicates the beginning of leaking retinal blood vessels.
Proliferative Diabetic Retinopathy
In the progression of diabetic retinopathy, the normal retinal blood vessels begin to close. The closure of the retinal blood vessels results in a condition called retinal ischemia Retinal ischemia is a condition in which the retina is being deprived of adequate oxygen and nourishment to maintain its normal health. In order to attempt to compensate and overcome this decreased circulation, the retina responds by growing new, but abnormal blood vessels. The response of the retina to grow new blood vessels is called neovascularisation. Unfortunately, new blood vessel growth or neovascularisation is comprised of blood vessels that are very fragile and can break quite easily. The condition whereby retinal neovascularization exists is called proliferative diabetic retinopathy. Since these abnormal vessels are quite fragile, if left untreated, they often lead to a severe loss of vision due to haemorrhaging, scar tissue formation, and finally retinal detachment. Proliferative diabetic retinopathy is treated with either laser treatment or laser treatment combined with a surgical procedure called vitrectomy, which is performed to remove the vitreous that may be filled with blood and /or scar tissue. In some instances, it is possible to have proliferative diabetic retinopathy and neovascularization and still have good vision. However the maintenance of good vision requires treatment of the neovascularisation.
Diabetic Eye Examinations
In order to maintain good vision and avoid the complications of diabetic retinopathy, it is necessary for diabetics to have a comprehensive eye exam at least once a year to detect the presence of diabetic retinopathy in its earliest stages. The use of “screening photographs”, even with a dilated pupil, is not a substitute for a comprehensive eye examination by an optometrist and this is available nationally, at no cost to the patient, to all diabetic patients under the NHS GOS Eye Service.
Photographs alone have the limitation of only capturing a selected number of “fields” or views and even with expert photographic readers may only produce a sensitivity of detection of diabetic retinopathy of 38% as compared to the preferred method of a dilated retina exam by an optometrist. In addition, “photographic screening” will not detect other significant eye problems such as glaucoma and cataracts, which may also be complications of diabetic eye disease.
We recommend yearly eye examinations, available at any registered Optometrist and free of charge to all diabetic patients. This is in addition to the diabetic retinopathy screening programme established in your area and again, available with registered providers and at no cost to the patient.
Early Treatment of Diabetic Retinopathy
It is quite important for all diabetics to obtain regular eye exams because early and aggressive treatment of diabetic retinopathy has been proven to be extremely successful in prolonging vision and preventing severe vision loss. Federally funded, large scale, multi-centre, controlled studies, such as the Early Treatment of Diabetic Retinopathy Study (ETDRS) have given us treatment guidelines indicating which patients may benefit from laser treatments to preserve vision and delay progression of vision loss. The studies have found that with early laser treatment, patients with diabetic retinopathy were only 50% as likely to progress and lose further vision.
Diabetes and Overall Health
It is important for diabetics to maintain their overall health. Staying healthy and controlling your blood glucose helps maintain the circulation in your heart, kidneys and eyes. Lowering the key vascular disease risk factors by controlling high blood pressure, not smoking, exercising regularly, reducing dietary fat intake and lowering cholesterol and triglycerides. Always follow your physician’s instructions carefully.
If you are diabetic or are glucose intolerant, and you wish to have a thorough diabetic eye examination, we invite you to call The Cheshire consulting centre today and arrange an appointment. We will be pleased to provide your examination, consultation and answer all of your questions about diabetic eye problems.