If you get that uncomfortable feeling or even a full blown panic attack coming on when you hear “eyesight “and “diabetes” in the same sentence then perhaps you should just pull the covers over your head and stay in bed tomorrow. Thursday 10th of October is World Sight Day and the merchants of doom and fear mongering are at it again. There’s a “dim outlook for future generations of Australians” according to the Baker IDI and Centre for Eye Research Australia and no doubt there’ll be lots more headlines like that.
Sure there are horror stories of people losing their eye sight from diabetes but fortunately this is actually quite rare in Australia and rates of vision impairment amongst people with type 1 diabetes are declining as we’re lucky to have excellent healthcare. So I’ve dug out some facts about diabetes and eyesight. I’ve got a bit technical with the evidence as I want to show that the story with diabetes and eyes is no longer scary but really cause to celebrate (really!).
So first off, let’s get the hysteria out of the way! The single biggest risk factor for developing diabetic retinopathy is how long you’ve had diabetes.
“The duration of diabetes is probably the strongest predictor for development and progression of retinopathy. Among younger-onset patients with diabetes in the WESDR, the prevalence of any retinopathy was 8% at 3 years, 25% at 5 years, 60% at 10 years, and 80% at 15 years.” (Fong, D.S. Aiello, L. Gardner, T.W., King, G.L, Blankenship, G. Cavallerano, J.D. Ferris, F.L., Klein, R. 2004)
If you’ve had diabetes for 30 years or more, then you will have some evidence of retinopathy. So don’t panic about it. I actually think it’s a little liberating to hear this. How often have I heard people really distraught and fearful about their eye doctor finding some evidence of retinopathy and blaming themselves for not having perfect control. It’s not the end of the world, and it happens to virtually everyone with type 1. In most cases it won’t need treatment and if you know it’s there you can be careful about getting your eyes checked regularly.
As with almost everything with diabetes, the DCCT showed that statistically, the onset and progression of retinopathy was slowed with a lower a1c. Other studies have shown that blood pressure control and keeping your cholesterol in the healthy range will also slow the progression or onset of retinopathy. (Wisconsin Study, UK Prospective Diabetes Study) An Australian study has shown the decreasing incidence of retinopathy in adolescents with type 1 which is really encouraging.(Downie et al 2011)
Laser Photocoagulation is extremely effective in preserving vision if your retinopathy advances beyond the benign background kind, just ask 100s of diabetics who’ve had it or look at the Study of Diabetic Retinopathy (1984) referenced below. As I mentioned last week your eye doctor can actually fix you, unlike your endo and other doctors who help you manage diabetes in hopes things don’t get any worse. This is extremely good news and reason not to be afraid of a retinopathy diagnosis but to beat a path to your ophtho’s door. Laser is done in the eye doctors rooms and isn’t too much worse than just the normal dilated pupil eye exam. The success of laser isn’t dependent on your HbA1c, blood pressure or lipids either!
So stay calm and follow the ADA recommendations and all should be well
“Patients with type 1 diabetes should have an initial dilated and comprehensive eye examination by an ophthalmologist or optometrist within 3–5 years after the onset of diabetes…..Patients with type 2 diabetes should have an initial dilated and comprehensive eye examination by an ophthalmologist or optometrist shortly after diabetes diagnosis. …… Subsequent examinations for both type 1 and type 2 diabetic patients should be repeated annually by an ophthalmologist or optometrist who is knowledgeable and experienced in diagnosing the presence of diabetic retinopathy and is aware of its management. “ (http://care.diabetesjournals.org/content/27/suppl_1/s84.full last accessed 8th October 2013)
Despite the gloomy way in which they present their views, I do support the Baker IDI and Centre for Eye Research’s call for a national screening program for diabetic retinopathy. It seems amazing to me that the risk of retinopathy for people with type 1 is 100% and yet there is no co-ordinated system or incentives to manage screening reminders and recalls and surveillance of background retinopathy. I’ll also add a call to remove the financial disincentive for ophthalmologists to accept permanent referrals for type 1 diabetic patients.
PS Smoking greatly increases your risk of severe retinopathy so in case you’ve been living under a rock for while, here’s a reminder. Don’t Smoke!
Donald S. Fong, Lloyd Aiello, Thomas W. Gardner, George L. King, George Blankenship, Jerry D. Cavallerano, Fredrick L. Ferris III, and Ronald Klein Retinopathy in Diabetes Diabetes Care January 2004 27:s84-s87; doi:10.2337/diacare.27.2007.S8
Elizabeth Downie, Maria E. Craig, Stephen Hing, Janine Cusumano, Albert K.F. Chan, and Kim C. Donaghue Continued Reduction in the Prevalence of Retinopathy in Adolescents With Type 1 Diabetes: Role of insulin therapy and glycemic control Diabetes Care November 2011 34:2368-2373; doi:10.2337/dc11-0102
Klein R, Klein BE, Moss SE, Davis MD, DeMets DL: The Wisconsin Epidemiologic Study of Diabetic Retinopathy. II. Prevalence and risk of diabetic retinopathy when age at diagnosis is less than 30 years. Arch Ophthalmol 102: 520–526, 1984
UK Prospective Diabetes Study (UKPDS) Group: Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). Lancet 12:352: 854–865, 1998