PON1 activity was significantly decreased in patients with diabetic retinopathy (227.66 +/- 123.57 U/l) when compared with control (312.04 +/- 129.77 U/l).
The results also indicated that PON2 gene polymorphisms, as well as PON1‑Q192R, may not confer major genetic risk to DN or DR. Additional studies are required to enrich the understanding of PON genes, particularly for its functional role in DR.