One-year outcome of combination therapy with intravitreal aflibercept and photodynamic therapy for polypoidal choroidal vasculopathy

The polyp regression rate and treatment prognosis of different interventions for polypoidal choroidal vasculopathy: a systematic review and meta-analysis

PURPOSE

To estimate the polyp regression rate and treatment prognosis of different interventions for polypoidal choroidal vasculopathy (PCV) and clarify its baseline characteristics.

METHODS

The PubMed, EMBASE, and Ovid were searched up to January 2020 to identify related studies. R software version 3.6.3 was used to perform the statistical analyses. Results in proportion with 95% confidence interval (CI) were calculated by means of the Freeman-Tukey variant of arcsine square transformation. Chi-squared test and I² statistics were used to evaluate the statistical heterogeneity. Sensitivity analysis and subgroup analyses were performed to identify the source of heterogeneity.

RESULTS

This meta-analysis included 104 studies with 5816 patients. The pooling results indicated the general rate of complete polyp regression at post-treatment 12 months was 64% (95% CI [57~71%]), 89% (95% CI [81~95%]) for photodynamic therapy (PDT) monotherapy, 78% (95% CI [68~86%]) for PDT plus anti-vascular endothelial growth factor (anti-VEGF), and 42% (95% CI [35~49%]) for anti-VEGF monotherapy; PDT plus anti-VEGF showed the best efficacy in visual improvement and achieved the highest rate of dry macula (91%, 95% CI [78~99%]), while anti-VEGF monotherapy achieved the lowest polyp recurrence rate (14%, 95% CI [8~20%]); PDT monotherapy showed the best efficacy in pigment epithelial detachment regression (66%, 95% CI [58~83%]). Additionally, the baseline characteristics of PCV were also well described.

CONCLUSION

PDT plus anti-VEGF is still valuable for the management of PCV; it could achieve not only satisfactory anatomical outcomes like dry macula rate and polyp regression rate but also ideal visual prognosis like BCVA improvement.

Pathological Mechanism of Photodynamic Therapy and Photothermal Therapy Based on Nanoparticles

The ultimate goal of phototherapy based on nanoparticles, such as photothermal therapy (PTT) which generates heat and photodynamic therapy (PDT) which not only generates reactive oxygen species (ROS) but also induces a variety of anti-tumor immunity, is to kill tumors. In addition, due to strong efficacy in clinical treatment with minimal invasion and negligible side effects, it has received extensive attention and research in recent years. In this paper, the generations of nanomaterials in PTT and PDT are described separately. In clinical application, according to the different combination pathway of nanoparticles, it can be used to treat different diseases such as tumors, melanoma, rheumatoid and so on. In this paper, the mechanism of pathological treatment is described in detail in terms of inducing apoptosis of cancer cells by ROS produced by PDT, immunogenic cell death to provoke the maturation of dendritic cells, which in turn activate production of CD4+ T cells, CD8+T cells and memory T cells, as well as inhibiting heat shock protein (HSPs), STAT3 signal pathway and so on.