Serum pro-inflammatory factors as predictors of persistent diabetic macular oedema with limited anatomic response to anti-VEGF: association with intravitreal injection treatment profiles in real-world setting

The Impact of Laboratory Findings and Optical Coherence Tomography Biomarkers on Response to Intravitreal Anti-VEGF Treatment in Patients with Diabetic Macular Edema

PURPOSE

To investigate potential laboratory and imaging biomarkers as treatment response predictors to intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents in patients with diabetic macular edema (DME).

METHODS

The study included 36 treatment naïve patients with DME, treated with intravitreal anti-VEGF agents and followed-up for 12 months. At baseline, all participants underwent best-corrected visual acuity (BCVA) measurement, dilated fundoscopy, optical coherence tomography, color fundus photography and fluorescein angiography, while full blood count and biochemical analysis of various parameters was also performed. At month 12, treatment response was examined and classified as "favorable" or "non-response". Potential associations between laboratory/imaging biomarkers and treatment response were assessed.

RESULTS

Univariate analysis showed that favorable response at month 12 after initiation of anti-VEGF treatment was correlated with baseline central subfield thickness (CST)≤405 μm (p < .001), absence of subretinal fluid (p = .034), absence of exudates (p = .041), absence of disorganization of the inner retinal layers (p = .037), intact ellipsoid zone (EZ) and external limiting membrane (ELM) (p < .001 and p = .002, respectively), absence of epiretinal membrane (ERM) (p = .040) and absence of macular ischemia (p = .042), while increased lipoprotein(a) was associated with no treatment response (p = .025). At the multivariate analysis, CST was found to be independent predictor of treatment response, while EZ, ELM and ERM were found to predict treatment response perfectly and they could not be entered in the model.

CONCLUSION

Intact EZ and ELM, absence of ERM and CST≤405 μm at baseline can predict favorable treatment response in patients with treatment naïve DME, while no correlation with baseline laboratory parameters was found.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.