Abstract
Purpose:
The relationship of ocular angiogenesis related factors in vitreous and blood with macular edema and retinopathy severity and their changes before and after intravitreal ranibizumab injection in patients with diabetic patients were aimed to evaluate in our study.
Methods:
Forty-two patients diagnosed with naïve diabetic macular edema undergoing anti-VEGF treatment included in this study. The patients underwent intravitreal ranibizumab injection as needed protocol (PRN) after the first 5 consecutive monthly injections. Vitreous samples were collected during the injection procedure when injection needle is in place at first and fourth injections. Blood samples were also collected at pre and after the first injection and at the day of fourth injection. The levels of vascular endothelial growth factor (VEGF), pigment epithelial derived factor (PEDF) and platelet derived growth factor (PDGF) were measured in both vitreous and blood samples. The levels of eritropoetin (EPO), angiopoetin-1 (ANG-1) and endostatin were also measured in blood samples.
Results:
Thirty-three patients completed the study. Statistically significant improvement in BCVA (p<0.001) at month 3 (0.41±0.23) was obtained when compared to baseline BCVA (0.27±0.16). Baseline central subfield macular thickness was 474.48±103.67μm and improved to 344.39±109.91μm at month 3 (p<0.001). While baseline vitreous VEGF level (1560.67±2470.39pg/mL) significantly decreased to (748.27±498.07pg/mL), PDGF and PEDF levels did not change significantly (p:0.048, 0.254, 0.260, respectively). While serum levels of VEGF, ANG-1, EPO decreased significantly after the 1 day and 3 months after the first injection, PEDF levels showed significant elevation and the levels of PDGF and endostatin did not change significantly (p<0.001 and <0.001, p<0.001 and <0.001, p:0.013 and <0.001, p<0.001 and <0.001, p:0.189 and 0.067, p:0.056 and 0.17, respectively). Vitreous and serum levels of VEGF, PEDF and PDGF did not significant correlation before and after the intravitreal ranibizumab injections.
Conclusions:
Intravitreal ranibizumab injection causes significant alterations in vitreous VEGF and serum VEGF, ANG-1, EPO, PEDF levels after 3 consecutive injections.