Changes of vascular endothelial growth factor after vitrectomy for macular edema secondary to retinal vein occlusion

Purpose. To examine whether vitrectomy combined with retinal photocoagulation reduces the vitreous level of vascular endothelial growth factor (VEGF) in patients with macular edema associated with retinal vein occlusion (RVO). Methods. The authors measured VEGF levels in vitreous samples from four eyes of four patients with RVO during vitrectomy and fluid samples obtained during revitrectomy 3 to 9 months postoperatively for complications: an epiretinal membrane in two patients, macular holes in one patient, and vitreous hemorrhage in one patient. During vitrectomy, retinal photocoagulation was performed on the ischemic region of the retina in all cases (mean of 510 shots). Results. In four eyes with RVO, there was a difference in the vitreous VEGF levels between the vitreous samples obtained during vitrectomy (mean of 2692 pg/mL, range of 15.6-9040 pg/mL) and the fluid samples obtained at the time of revitrectomy (mean of 947 pg/mL, range of 15.6-3430 pg/mL). Conclusions. The results suggest that the vitreous levels of VEGF may be reduced by vitrectomy combined with retinal photocoagulation for macular edema with RVO. It may be important to reduce the vitreous levels of VEGF by vitrectomy and retinal photocoagulation for ischemic retina in macular edema with RVO.