Management of proliferative diabetic retinopathy

Principal goal is prevention with

• systemic and local measures (1)
  • good glycaemic control
  • control of hypertension

Treatment is directed at regressing neovascularisation using Argon laser pan-retinal photocoagulation

• the new vessels themselves are not targeted but photocoagulation is spread over a wide area in order to destroy ischaemic retina and remove the vasoproliferative stimulus
• there is variable visual loss and night blindness.

Vitrectomy is indicated if a vitreous haemorrhage has not resolved spontaneously within 6 months or retinal detachment is suspected.

• vitrectomy (2)
  • a surgical technique
    • approached from the pars plana,
    • vitreous excised
    • suctioning the gel done
    • replaced with aqueous fluid.
    • fibrous tissue removed
    • areas of retinal detachment flattened

Patients with neovascular glaucoma or high-risk proliferative diabetic retinopathy should receive prompt scatter photocoagulation (3)

Gene therapy for ocular neovascularization is still under study (4)

Future treatment prospects under trial include (5)

• protein kinase C inhibitors,
• intravitreal steroid,
• anti-vascular endothelial growth factor agents,
• angiotensin converting enzyme inhibitors,
• growth hormone

Pan-retinal photocoagulation may prevent thrombotic glaucoma but once developed, this may be difficult to treat.

Untreated eyes with severe disease have about 40% risk of severe visual loss within two years.

Reference:

1. American Academy of Ophthalmology, basic and clinical science course,2005-2006, retina and vitreous, section12, 99-119
2. Ferris FL et al. Treatment of Diabetic Retinopathy.N Engl J Med 1999;341:667.
3. Campochiaro PA.Gene therapy for ocular neovascularization. Curr Gene Ther. 2007 Feb;7(1):25-33.
4. American Academy of Ophthalmology Retina Panel (2003). Diabetic Retinopathy,Preferred Practice Pattern® Guideline
5. Yam JC et al. Update on the treatment of diabetic retinopathy.Hong Kong Med J. 2007 Feb;13(1):46-60.