Clinical features

Proliferative disease:

• neovascularisation:
  • from the venous side of the circulation on the optic disc and the surface of the retina adjacent to the temporal vessels
  • the fragile new vessels leak serum and protein
    
    
• vitreous haemorrhage with sudden visual loss:
  • associated with proliferation of the new vessels onto the posterior surface of the vitreous

Advanced disease:

• advanced stage, proliferative diabetic retinopathy, is characterized by (1):
  • neovascularization on the inner surface of the retina
    • new vessels at the optic disc and
    • new vessels elsewhere in the retina
      • prone to bleed, resulting in vitreous hemorrhage
      • new vessels may undergo fibrosis and contraction
    • may result in epiretinal membrane formation,
    • vitreoretinal traction bands,
    • retinal tears, and
    • traction or rhegmatogenous retinal detachments
• retinal detachment:
  • fibrovascular bands may form around the new vessels which tug on the retina as the vitreous contracts
• neovascular glaucoma:
  • occurs secondary to iris neovascularisation - rubeosis iridis - and obstruction of the drainage angle
  • results from new vessels growing on the iris and anterior chamber angle structures.

Notes (1)

• high-risk proliferative diabetic retinopathy
  • new vessels are accompanied by vitreous hemorrhage, or
  • new vessels at the optic disc occupy greater than or equal to about 1/4 to 1/3 disc area, even in the absence of vitreous hemorrhage

Reference:

1. American Academy of Ophthalmology Retina Panel (2003). Diabetic Retinopathy,Preferred Practice Pattern® Guideline