Currently, the treatment for ocular neovascular diseases, including diabetic macular edema (DME) and age-related macular degeneration (AMD), mainly involves repeated intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs. Although it can preserve vision, repeated injections are an invasive treatment modality, leading to serious complications and reducing patient adherence to treatment. To reduce the frequency of administration, prolong the time of drug action, and avoid repeated intravitreal injections, the combination of sustained-release materials with anti-VEGF drug therapy has become an emphasis in ophthalmology. In this review, we highlight the current state of anti-VEGF technology, its challenges, and the sustained-release strategies under investigation or being used in clinical practice. Both continuous release and considerable therapeutic effects can be achieved by encapsulating anti-VEGF drugs in sustained-release materials to minimize the number of intravitreal injections. At present, two sustained-release materials are being tested in clinical research, and although basic research shows the strong therapeutic application prospects of extended-release drugs, its challenges mainly involve the discrepancy between the release rates in vitro and the efficiency of the drugs in vivo. Briefly, sustained release of anti-VEGF agents is an advantageous strategy for treating retinal angiogenesis.

Introduction: The efficacy and influence of steroids for reducing the incidence of proliferative vitreoretinopathy (PVR) after rhegmatogenous retinal detachment (RRD) surgery remains controversial. Systematic review and meta-analysis were conducted to explore the effect of steroids versus placebo on risk of PVR. Methods: We searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2020 for randomized controlled trials (RCTs) assessing the effect of steroids drugs as an adjunct for reducing the incidence of proliferative vitreoretinopathy after RRD surgery. This meta-analysis is performed using the random-effect model. The data were extracted by two reviewers independently, the quality of RCTs was assessed by the Cochrane risk of bias tool. We calculated risk ratio (RR) and the 95% confidence intervals (CIs) of all outcomes and plotted on forest plots. I2 accessed using the chi-square test was applied to quantify the degree of heterogeneity. Results: Four RCTs involving 478 patients (478 eyes) are included in the meta-analysis. There was no significant difference in the incidence of PVR recurrence between steroid groups and control groups (RR 0.87, 95% CI 0.70-1.08, P=0.19). However, the incidence of recurrent PVR was lower in the steroids group (RR 0.67, 95% CI 0.46-0.99, P=0.04) than in the control group when only PVR grade A and B were taken into consideration. Besides, steroids could significantly reduce the incidence of macular edema after surgery (RR 0.64, 95% CI 0.47-0.88, P=0.007). Steroids group and control group had comparable outcomes of retinal reattachment rate and re-operation rate after primary surgery. Additionally, there was no significant difference of incidence of epiretinal membrane, and the incidence of surgery required by epiretinal membrane. Discussion/Conclusion: This meta-analysis reveals that RRD surgery combined with steroid drugs administration could significantly reduce the recurrence in PVR grade A and B subgroup, as well as the incidence of macular edema after surgery.