AMSLER RECORDING CHART
|1. Look at the square (grid).|
2. Wear your reading glasses (if you use one) and cover one eye.
3. Focus on the center dot for one full minute.
4. While looking directly at the center, be sure that all the lines are straight and clear, and all the small squares are the same size.
5. Repeat the test in the other eye.
6. If any lines or squares appear distorted, wavy, blurred, discolored, or otherwise abnormal, call your eye doctor right away.
7. In healthy eyes the lines are straight.
|The Amsler's chart is very useful for early detection of macular problems and thus is very important as this may be an early sign of macular problems and lead to a loss of central vision! But one must know its limitations.The Amsler grid will NOT detect proliferative diabetic retinopathy, most preproliferative changes and other types of damage that may threaten vision, nor is it useful for detecting any of the early changes. Remember: a normal Amsler grid test does not rule out the presence of retinopathy that can threaten your vision.It cannot replace routine eye exams. Only regular eye exams can do this. |
What can be done to prevent serious eye problems?
Meticulous management of the risk factors and an early diagnosis would go a long way towards averting diabetic retinopathy or retarding the progression of the retinal changes even if one is not able, to revert the changes that have occurred.
The risk of retinopathy is directly related to the degree and duration of hyperglycemia.
The prevalence of proliferative retinopathy - and of blindness related to this condition - is directly associated with the duration of diabetes and the degree to which blood glucose concentrations have been elevated
Thus, all efforts must be made to keep a "tight" control on the blood glucose levels. Many studies have shown the importance of a good glycemic control. If one does not have diabetic retinopathy but does not keep the blood glucose under optimal control, one would have FOUR times the chances of getting retinopathy as compared to someone who does keep the blood glucose well controlled! Moreover, in people who already have retinopathy, the condition progresses in those with good control only half as often as those not well controlled.
In fact, it has been shown that for each 1% rise in the HbA1c, the retinopathy gets worse at the rate of 32%. So if one's HbA1c is 9%, the retina is getting damaged twice as fast as someone with a level of 6% (3 x 32% = 92% additional deterioration).
High blood pressure is fairly common in people with diabetes. Again one should aim for a good control of the blood pressure 130/80 or less (lower still if there is protein in your urine). With blood pressure, for each 10mmHg rise, the retinopathy gets 11% worse. So if one's blood pressure is 150/90, their retina is getting 22% worse that someone whose pressure is 130/80.
Patients with diabetes who have high serum lipid concentrations have an increased risk of both proliferative retinopathy and vision loss from macular edema and associated retinal hard exudates. Reducing the hyperlipidemia may lower this risk.
Similarly Smoking literally doubles the rate of damage that diabetes causes to the bodies larger arteries, making amputations and heart disease far more likely. Smoking triples the rate of retinopathy progression
These impressive results show that we can do a tremendous amount to prevent serious deterioration of the diabetic retinopathy.
To sum up,
Specific Management of Diabetic Retinopathy
|lifestyle ||30-60 minutes exercise a day, moderate alcohol consumption only, avoid obesity if possible, balanced diet including 5 portions of vegetables or fruit a day, with the minimal of animal or 'hard' vegetable fats, and very low salt. |
|blood pressure||130/80 or less125/75 or less if protein in urine present|
|HbA1c||6.5% or less with very few or preferably no hypos.If hypos develop, see expert advice.ACE inhibitors or AT11 unless young/pregnant/very low blood pressure/poorly tolerated|
|Cholesterol||<5.0mmol/l, and statins recommended for most adult patients
|Smoking||smoking 20 a day triples retinopathy (passive smoking: room-mates inhale at least 25%)|
Prevention of retinopathy is the best approach to reducing the risk of blindness among patients with diabetes, but this is not yet possible in many patients.
At the outset it should be made clear that there are no drugs available to treat diabetic retinopathy. Hopes raised previously by a group of drugs called the Aldose reductase Inhibitors have not been borne out and neither has antioxidant treatment. Treatment with aspirin did not affect the progression of retinopathy, the risk of visual loss
The two treatments are laser surgery and vitrectomy. They are very effective in reducing vision loss from this disease. In fact, even people with advanced retinopathy have a 70-80% chance of keeping their vision when they get treatment before the retina is severely damaged.
Which again brings into focus the importance of regularly examining the retina of the patients!
Laser photocoagulation therapy is effective in reducing the risk of further visual loss and is generally useful in preventing blindness in diabetics with high risk proliferative retinopathy and macular edema. There is now evidence that early treatment with laser photocoagulation, without waiting for the development of severe changes, may lead to a better prognosis in preventing vision loss.
Vitrectomy may restore vision in some patients with recent traction retinal detachment or vitreous hemorrhage
It is important to note that although these treatments are successful, they do not cure diabetic retinopathy.