A 2010 study suggests that pine bark extract (containing procyanidins) may be helpful to diabetics who have early diabetic retinopathy through improved retinal blood flow and lowering swelling edema.
About 40-50% of Americans who have been diagnosed with diabetes already have some stage of diabetic retinopathy, according to NIH.
Learn more about management of diabetic retinopathy.
Reference: Steigerwalt R, et al. Pycnogenol® improves microcirculation, retinal edema, and visual acuity in early diabetic retinopathy. J Ocular Pharmacol Therap 25:537-40, 2009.