Shifting of the local inflammatory characteristics of diabetic macular edema manifested in SD-OCT after anti-VEGF treatment and associations with system inflammatory bioparameters

Our study aimed to determine the association between baseline system inflammatory bioparameters and the characteristics of spectral domain optical coherence tomography (SD-OCT) and evaluate the efficiency of anti-vascular endothelial growth factor (VEGF) treatment in different stages of diabetic macular edema (DME). A total of 126 patients were enrolled in this prospective study, including 67 males and 59 females who were diagnosed with DME. The patients were initiatively treated with intravitreous anti-VEGF treatment at 1-month intervals for three consecutive months. With respect to the TCED-HFV grading system, ME was classified into early, advanced, severe, and atrophic stages. Best-corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF), and quantities of hyperreflective foci (HRF) of the whole retina were assessed at baseline and three months after the first injection. System inflammatory bioparameters were calculated, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet (PLT)-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and C-reactive protein (CRP). In addition, the association between HRF, SRF, and system inflammatory bioparameters were evaluated, and the efficiency of anti-VEGF treatment in different stages of DME was assessed. There were significant differences in systemic inflammatory bioparameters among the four stages, including CRP, NLR, PLR, MLR, and SII (all p < 0.001), which were significantly higher in the atrophic stage than another three stages. In contrast, the CRP, NLR, PLR, MLR, and SII levels were significantly lower. BCVA and CMT were significantly improved after treatment in the early, advanced, and severe stages except for the atrophic stage (all p < 0.05). The changes in the proportion of SRF and HRF ≥ 30 were most significant in the advanced stage after anti-VEGF therapy (p = 0.030, p = 0.041, respectively). In general, systemic inflammatory bioparameters are closely associated with the characteristics of different stages of DME based on the TCED-HFV grading system, which reflects the local inflammation of DME. The TCED-HFV grading system may be a precise indicator for predicting the efficiency of anti-VEGF treatment of DME and should be tested in further study.