There is no quick and easy answer as to whether or not diabetics can have laser eye surgery as it really does depends on the individual circumstances. The aim of the article is to explain the different issues surrounding diabetes and laser eye surgery to give you a better understanding of where you stand.
The 2 main types of diabetes are type 1 and type 2 and their main features are as follows:

• Type 1 diabetes is the condition you generally get when you are young (below the age of 20) and people with this type of diabetes will typically need to use insulin to control their blood sugar levels.
• Type 2 diabetes normally affects people as they get older and can sometimes (not always) be associated with obesity. People with type 2 diabetes can be diet controlled diabetics (e.g. control their blood sugar levels by watching what they eat), medication controlled (e.g. metformin) or if they are struggling to control their blood sugar levels they may need Insulin.

People with diabetes are normally assessed annually by an eye specialist to check that they do not have any diabetic retinopathy. Diabetic retinopathy is caused by a weakening of the blood vessels of the retina which can lead to a whole range of complications such as leaking blood vessels and retinal haemorrhages.
During your diabetic screening, your pupils will normally be dilated which ensures a detailed photograph of your retina can be taken. If you are found to have significant retinopathy you will be referred to an ophthalmologist who may consider treating your retinopathy with a laser. This is not the same type of laser that is used in laser eye surgery.
What is the problem with performing laser eye surgery on diabetics?

• Fluctuating prescription: Poorly controlled blood sugar levels can cause the prescription in your glasses to fluctuate as a result of a change in the hydration of the lens within your eye. The lens is responsible for focusing the light entering your eye, so any change to this can lead to a change in your vision. The reason this is a problem is that it is essential that the prescription that is measured during a laser eye surgery consultation is 100% accurate as this is the information that will be used when lasering your eye.  If for example, your blood sugars were high on the day of your consultation then the readings may not be accurate. This is likely to mean that the visual correction would not be long lasting as once your blood sugar levels are back under control, your prescription is likely to change again and your vision become blurred.
• Slower healing: Diabetics generally have slower and less efficient healing of the cornea following laser eye surgery. Some surgeons will insist that you have Intralase as opposed to standard Lasik as the healing time is generally quicker with this procedure.
• Pre-existing diabetic retinopathy. If you already have diabetic retinopathy your vision may well be slightly impaired. Laser eye surgery will not improve your diabetic retinopathy or any visual impairment that it has caused.

Every clinic and surgeon will have slightly different guidelines on who they will consider being suitable for laser eye surgery. The following lists what is generally required for diabetics to be considered safe for surgery:

• Well-controlled blood sugar levels: This is to ensure an accurate and long-lasting laser vision correction. Most surgeons will insist on a letter from your general practitioner stating that your blood sugar levels are stable.
• Minimal diabetic retinopathy: What constitutes minimal retinopathy will vary from one surgeon to the next. Most surgeons will be happy to carry out laser eye surgery if you have mild background retinopathy which is not affecting the central part of your vision.

In summary, laser eye surgery has been carried out successfully on thousands of diabetics and most surgeons are happy to carry out the procedure. If you have well-controlled blood sugar levels and minimal diabetic retinopathy you are unlikely to have any issues. Insulin-dependent diabetics (type 1) and those who have had the condition for many years are less likely to be suitable as there is a higher chance of them having significant retinopathy.
The only way you will know for certain if you are suitable for surgery is by having a consultation. You should ask your GP for a letter stating how well controlled your blood sugar levels are and take this along with you.  Attending aftercare appointments and sticking diligently to the post-surgery instructions is especially important if you suffer from diabetes.