الفهرس 
Diabetes Mellitus and its ComplicationsOnly 14 pages are availabe for public view
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Abstract
Diabetic retinopathy is one of the microvascular complications leading to macular edema and angiogenesis in the proliferative phase. Advanced proliferative diabetic retinopathy can lead to neovascular glaucoma, vitreous hemorrhage and tractional retinal detachment.
Advanced proliferative diabetic retinopathy occurs secondary to biochemical and cellular alterations which lead to ischemia. Ischemia in turn leads to release of growth factors which result in angiogensis.
Many growth factors are encountered in the pathogenesis of diabetic retinopathy. The most important is VEGF. Other important growth factors are growth hormone, PEDF, IGF and TGF-β.
Vascular endothelial growth factor family consists of seven members, of which VEGF-A has an important role in the microvascular complications of the retina.Vascular endothelial growth factor leads to diabetic macular edema in the non proliferative phase and angiogenesis in the proliferative phase.
Screening and systemic control of glycemia, blood pressure,serum lipid and renal functions are important aspects for prevention and treatment of diabetic retinopathy.
Many therapies are encountered for treatment in various stages of the disease. Both pharmacological therapies and vitrectomy are important lines of treatment.
Protein kinase C, somatostatin, intravitreal drugs as corticosteroids and bevacizumab are examples of pharmacological therapy.
Vitrectomy is done in cases where there is persistent vitreous hemorrhage, subhyaloid hemorrhage, ghost-cell glaucoma, tractional retinal detachment and tractional macular edema.
Complications of vitrectomy include intraoperative bleeding, itraogenic breaks, postoperative vitreous hemorrhage, rubeosis and neovascular complications.
Blocking or decreasing the amount of VEGF is known to play a marked role in regression of ocular angiogenesis. Bevacizumab (avastin) is an antiVEGF which is used to block VEGF and hence decreases bleeding.
In the current study, role of avastin as an adjunct to vitrectomy in diabetic patients is assessed.
Patients undergoing vitrectomy because of diabetic complications were grouped into two groups.One group was injected with avastin preoperatively and the other group didnot receive any injection.
Preoperative injection of bevacizumab decreased intraoperative bleeding and hence facilitated surgery in cases of tractional retinal detachment with vitreous hemorrhage or tractional retinal detachment with active neovascularisation. A number of breaks was in the study group though it was not statistically significant.
Postoperative bleeding in the few days following the surgery was less in patients injected with avastin preoperatively. Bleeding after (1-3) months was not significantly less.
Visual acuity is statistically improved in both groups of patients. This could be attributed to the improved techniques and instrumentation with the new vitrectomy machines.