Proliferative Diabetic Retinopathy (PDR)

PDR demonstrating dot and blot hemorrhages, hard exudates and network of new vessels (NVE) with early fibrovascular proliferation tissue extend over the surface of the retina. 

  • Characterized by growth of new vessels on the surface of the retina.

Clinical features:

  • Symptoms: progressive loss of vision, particularly in those who are not properly followed or treated.
  • Signs:
    • Fine to severe loops of new vessels that may grow on the optic disc: neovascularization of the disc (NVD) or elsewhere (NVE)
    • In the anterior segment, PDR is manifested by neovascularization of the iris (NVI), the angle (NVA) and may eventually complicated with neovascular glaucoma
    • These new vessels may leak and resulting in retinal edema. They are also fragile and prone to bleed
    • Opaque fibrovascular proliferation tissue often appears on the internal limiting membrane (adjacent to the new vessels) and becomes adherent to the vitreous
    • Contraction of this fibrovascular tissue may lead to:
      • Distortion or dragging of the macula
      • Mild to extensive retinal detachment
      • Avulsion of retinal vessels and vitreous hemorrhages

Risk factors:

  • Duration of the diabetes
  • 30-34 years of diabetes increase the risk of retinopathy by 65%
  • Overt albuminuria
  • High level of blood total cholesterol and LDL
  • Others: race, cigarette smoking, alcohol

Management:

  • Strict blood glucose, blood pressure and cholesterol control.
  • Photocoagulation for clinically significant macular edema prior to scatter (panretinal) photocoagulation (PRP).
  • Consider PRP in severe proliferative diabetic retinopathy.
  • Consider additional PRP if incomplete regression is observed, increasing of the extent of vitreous hemorrhage or worsening of overall vitreoretinal condition.
  • Vitrectomy.
  • Experimental treatments; Depo steroid injection for diabetic macular edema, systemic protein kinase-C inhibitor and aldolase reductase inhibitor.