Several factors influence DR viz., long duration of the disease, age, level of hyperglycemia control, hyperlipidemia, hyperviscosity, renal failure etc. Most
important is the contribution of the biochemical changes associated with hyperglycemia
(Abdulrahman, 2011). The exact mechanism by which hyperglycemia causes vascular disruption in
retinopathy is not clear. Probably the intraocular formation of reactive oxygen species lead to pathological and biochemical changes seen in DR