The Canadian Ophthalmological Society has released Guidelines on Diabetic Retinopathy to provide guidance to ophthalmologists regarding screening and diagnosis of diabetic retinopathy (DR), management of diabetes as it pertains specifically to DR, and surgical and nonsurgical approaches to the treatment of DR. These Guidelines have been published in Canadian Journal of Ophthalmology.
- Screening for diabetic retinopathy (DR) should be initiated 5 years after the diagnosis of diabetes in individuals with type 1 diabetes diagnosed after puberty.
- Screening for DR should be initiated at puberty in individuals diagnosed with type 1 diabetes before puberty, unless there are other considerations that would suggest the need for an earlier exam.
Screening for DR in individuals with type 2 diabetes should be initiated at the time of diagnosis of diabetes.
Subsequent screening for DR in individuals depends on the level of retinopathy. In those who do not show evidence of retinopathy, screening should occur every year in those with type 1 diabetes and every 1–2 years in those with type 2 diabetes depending on anticipated compliance.
Once nonproliferative diabetic retinopathy (NPDR) is detected, examination should be conducted at least annually for mild NPDR, or more frequently (at 3- to 6-month intervals), for moderate or severe NPDR based on the DR severity level.
To prevent the onset and delay the progression of DR, individuals with diabetes should be treated to achieve optimal blood glucose control (ie, A1C ≤7.0%).
As there is a continuous relationship between A1C and microvascular complications with no apparent threshold of benefit, patients should be advised of the incremental benefits associated with incremental reductions in A1C. In patients with type 2 diabetes, the incremental benefits of achieving an A1C ≤6.5% must be balanced against the risks of hypoglycemia or increased cardiovascular mortality in patients at elevated risk of cardiovascular disease.
To reduce the risk of onset or to delay the progression of DR, individuals with diabetes should be treated to achieve optimal control of BP (eg, <130/80 mm Hg).
Eyes that demonstrate clinically significant macular edema by ETDRS (Early Treatment Diabetic Retinopathy Study) criteria without central macular thickening should receive focal laser; however, eyes with central macular thickening should be considered for treatment with a vascular endothelial growth factor (VEGF) inhibitor alone or in conjunction with focal laser.
Eyes that demonstrate evidence of vitreomacular traction and macular edema should be considered for vitrectomy.
In eyes with Diabetic Retinopathy Study (DRS) high-risk characteristics, panretinal photocoagulation (PRP) should be carried out to reduce the risk of severe vision loss.