Effects Of Photocoagulation On Retinal New Vessels And Its Factors In Diabetic Retinopathy

Objective To study the effects of photocoagulation on retinal new vessels and its factors vascular endothelium growth factor(VEGF) and pigment epithelium-derived factor(PEDF) in diabetic retinopathy.Methods Forty cases(40eyes) with diabetic retinopathy (from IV stage to V stage) were divided into two groups,namely, the pre-photocoagulation group (20cases) and the post-photocoagulation group (20cases). In the pre-photocoagulation group, all patients suffered from macular edema.Before grid pattern photocoagulation being done, vitreous sample was aspirated at the beginning of vitreous injection of triamcinolone acetonide; meanwhile fast blood sample was gained early in the same morning. Vitreous and blood samples were centrifuged and then stored in low temperature until assay.In the post-photocoagulation group, because the patients had vitreous proliferation, rhegmatogenous retinal detachment and macular hole in 1~3months after photocoagulation, vitreous surgery was performed. Vitreous sample was aspirated at the beginning of vitreous surgery; meanwhile fast blood sample was gained early in the same morning. Vitreous and blood samples were centrifuged and then stored in low temperature until assay.Changes of retinal new vessels were observed before and after...