Vitreous and Retina

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.