Dear Mark Foxon,
 
Normally, we take precaution with diabetic patients for a number of reasons, listed below.  I would like to emphasize that LASIK is a corneal refractive procedure.  If you have complications from diabetes that involves the retina (back part of your eye) or the lens, then correcting the cornea, which is the front surface of the eye, will not improve your vision.  Since you had the exam and the doctors told you there is no reason you cannot have LASIK, I am assuming you did not have any ocular complications.  However, do you have the medical reports from them?
 
1.    Patients with diabetes have a high likelihood of experiencing delayed corneal epithelial healing, persistent epithelial defects, neurotrophic changes and persistent erosions after LASIK.   Basically, there is a slower healing of the cornea in diabetic patients.
 
2.   Fluctuation in blood glucose levels might cause shifts in vision for diabetic patients.  Therefore, if the blood sugar is not controlled, vision can alter even after LASIK.
 
3.  If a patient already has preexisting diabetic ocular complications (such as unhealthy ocular surface, cataracts, retinopathy of any sort, fragile retinal vasculature or neovascularization secondary to diabetes, then LASIK is an absolute contraindication.
 
Warm regards,
TRSC International LASIK Center