Diabetic Retinopathy
Diabetic retinopathy is an eye condition that affects people who have had diabetes for some years. However, as current statistics show that about half of the diabetics in Canada are, as yet, undiagnosed, the incidence is probably more prevalent than the statistics show. Certainly, the number of cases of diabetic retinopathy is increasing significantly.
According to the World Health Organization, the incidence of diabetes is rising at an alarming rate. During this decade alone, the number of diabetics will increase by almost 25%, rising from 177 million cases worldwide in 2000 to 221 million cases by 2010. By 2030, it is estimated that the number will have reached 370 million.
In Canada, the growth rate is even more dramatic, with an anticipation that this decade will see the combined diagnosed and undiagnosed diabetics increasing from 1 million to 3 million people.
Significantly, this is also the eye problem that generally affects the younger — working — generation. While many of the other retinal diseases are associated with people over the age of 60, diabetic retinopathy is seen among people from late teens to mid 50s.
Two Forms of Diabetic Retinopathy
There are two forms of this condition - background retinopathy and the more serious proliferative retinopathy. Essentially, both are caused over a period of time by poorly controlled blood sugar levels, which damage the blood vessels in the retina.
Vision is not normally affected with background retinopathy. When vision is affected it is the result of macular edema and/or macular ischemia. Macular edema, the most common cause of loss of vision in diabetes, is a result of the swelling, or thickening of the macula, the central part of the retina that enables people to see fine details. Macular ischemia, in turn, is the result of the closure of blood vessels supplying the macula.
Proliferative retinopathy is the result of new, fragile blood vessels growing over the surface of the retina. Their fragility usually leads to them bursting and bleeding into the vitreous in the eye, resulting in clouding or loss of vision, and often necessitating intraocular surgery. There is also the potential of developing a retinal detachment.
Patients with diabetic retinopathy visiting Dr. Uniat will initially have their pupils dilated, to have their retinas more effectively visualized through special lenses and the ophthalmoscope or microscope. A detailed analysis of the extent of damage will then be carried out — with the Centre's OCT (optical coherence tomography) unit and/or fluorescein angiography .
Treatment
Background retinopathy, if mild and not threatening central vision, usually requires only periodic monitoring. However should the damaged blood vessels create swelling or edema within the central macula, treatment is indicated and usually takes the form of injecting medication (anti-VEGF) to heal the damaged blood vessels. Occasionally, laser may be applied.
When the stage of proliferative retinopathy develops, laser treatment is necessary, and the procedure is performed in the office as an outpatient.
In severe cases, where the abnormal blood vessels have bled into the vitreous cavity, or a retinal detachment has developed, a hospital surgery called vitrectomy is required.
Background retinopathy – secondary to diabetic retinopathy
Proliferative diabetic retinopathy