The increased risk of cataracts in patients with diabetes
In this post, I continue my interview with Jaheed Khan, where we began by discussing how he treats diabetic retinopathy. Now we turn our discussion towards the incidence of cataracts among patients with diabetic retinopathy.
Jane: Are patients with diabetic retinopathy more likely to get cataracts?
Jaheed: Yes, one consequence of high glucose in your blood is that it can make the lenses inside your eye mistier. It is usually quite clear when you are young, but if you have uncontrolled diabetes your lens becomes misty, and that is another description of cataract, so we have a higher rate of cataract surgery in diabetic patients.
Jane: Their symptoms of mistiness, is that a constant mistiness or does it vary?
Jaheed: Well there are two types: Uncontrolled diabetics can have blurry vision that is intermittent, and that is usually due to the lens swelling of high glucose.
Jane: Is that then called a cataract or not?
Jaheed: It is not technically a cataract, it is more related to poor sugar control, and then a cataract is when there are structural abnormalities in the lens that you can see. So, if you look at the lens and it looks misty and it does not change then that is a permanent cataract from diabetic complications, and that happens gradually, and most patients notice a gradual blur rather than a transient blur.
Jane: And then you also are also dealing with their cataracts?
Jaheed: Yes, so a large majority of my patients need cataract surgery to improve their vision as well as treatment for their diabetic retinopathy and diabetic cataracts are the same as age-related cataracts so they are the same technical challenge and they have the same surgical treatment as normal cataracts.
Jane: What would you do for the diabetic retinopathy or the cataract and what does it depend on?
Jaheed: It does depend on the patient and usually we would treat the condition which is at most risk to the sight. So, if there were any bleeding within the retina, we would apply laser treatment first to stabilise the vision before we did a cataract. But if the cataract was very dense and we could not see a very good view at the back of the eye it would be sensible to do cataract surgery soon, so we have an idea of what complications are happening at the back.
Jane: Is cataract surgery higher risk in patients who have diabetes?
Jaheed: It can be more challenging partly because patients are a little bit younger and they are a bit more nervous, and sometimes they need more sort of anaesthetic to do the cataract surgery. Also, pupils tend to dilate a little bit slowly, and sometimes we need to stretch the iris when we do a cataract operation in diabetic patients. But on the whole, the complication rates are pretty similar.
Jane: What about infection? Is that a higher risk?
Jaheed: The infection risk with cataract surgery has gone right down partly because we give antibiotics inside the eye at the end of the operation. So there may be a slightly higher risk with uncontrolled diabetics with infections, but they are usually well controlled by the time they have cataract surgery to ensure that they do not have any concurrent infections, they do not have any foot ulcers or any other things going on before we do cataract surgery just to…
Jane: So no active infection on board.
Jaheed: It is sensible for any patient undergoing surgery at any time
Jane: At any time whether a diabetic or not. Thank you very much for talking about patients with diabetes. Can we go on and talk about cataracts in general now? How does a patient know when they are ready for cataract surgery?
To continue reading this interview, read our next post.