DETECTION OF VASCULAR ENDOTHELIAL GROWTH-FACTOR MESSENGER-RNA AND VASCULAR ENDOTHELIAL GROWTH FACTOR-LIKE ACTIVITY IN PROLIFERATIVE DIABETIC-RETINOPATHY

Objective: To study the involvement of eight angiogenic growth factors that have been identified so far in the literature, especially vascular endothelial growth factor, in proliferative diabetic retinopathy. Methods: Samples of neovascular membranes were obtained from diabetic patients; these samples, excised at vitrectomy, were used to study the expression of messenger RNA of the angiogenic factors by using the method of the reverse transcription-polymerase chain reaction. Vitreous aspirates that were taken from diabetic and control patients were used to quantify vascular endothelial growth factor-like activity with a competitive radioreceptor assay. Results: Of the eight angiogenic factors studied, vascular endothelial growth factor was the only one that was always expressed in the samples of neovascular membranes. Furthermore, vascular endothelial growth factorreceptor-binding activity was greater in vitreous aspirates that were obtained from diabetic patients than in samples that were taken from control patients (P<.01). Conclusion: Vascular endothelial growth factor seems to be an appropriate candidate for mediating retinal diabetic neovascularization.