Long-term results of rescue photodynamic therapy for type 1 neovascularization refractory to anti-vascular endothelial growth factor

A novel active mitochondrion-selective fluorescent probe for the NIR fluorescence imaging and targeted photodynamic therapy of gastric cancer

The annual morbidity and mortality due to gastric cancer are still high across the world, posing a serious threat to public health. Improving the diagnosis rate of gastric cancer and exploring new treatments are urgent issues in the clinical field. In recent years, photosensitizer (PS)-based photodynamic therapy (PDT) has proven to be an effective cancer treatment strategy and can be used to treat a variety of cancers. Developing PSs with tumor-targeting ability and high singlet oxygen yield (Φ(¹O₂)) is the key to improving the PDT effect. Herein, we developed a novel diagnosis and treatment system (Cy₁₃₉₅-NPs). Our active thio-photosensitizer is based on the sulfur substitution strategy as it can reduce the S1-T1 energy gap, which can promote the process of intersystem crossing (ISC), thus resulting in high ROS generation efficiency. Cy₁₃₉₅-NPs exhibited stable spectral characteristics, satisfactory biocompatibility and high ¹O₂ yield under laser irradiation due to the introduction of the sulfur atom. In cellular studies, Cy₁₃₉₅-NPs could specifically target MKN45 cells via integrin α_vβ₃-mediated cRGD endocytosis and selectively aggregate in the mitochondria. Cy₁₃₉₅-NPs had no obvious cytotoxicity for MKN45 cells and exerted obvious phototoxicity due to the production of ¹O₂ under laser irradiation. The in vivo results showed that the fluorescence signal from the tumor site was obviously enhanced in 16-48 h, and Cy₁₃₉₅-NPs could selectively target solid tumors with a retention time of about 32 h. Under laser irradiation, Cy₁₃₉₅-NPs significantly inhibited tumor growth and led to significant tumor suppression and apoptosis. In summary, the developed Cy₁₃₉₅-NPs could actively target tumors and exert mitochondrial selectivity, showing an excellent fluorescence imaging effect. Under the irradiation of an 808 nm laser, Cy₁₃₉₅-NPs achieved good inhibition of gastric cancer cells both in vitro and in vivo, thus displaying the functions of tumor targeting, mitochondrial selectivity, fluorescence imaging and tumor inhibition. Our strategy provides a new diagnostic and treatment method for gastric cancers in clinical settings.

One-year efficacy of "rescue photodynamic therapy" for patients with typical age-related macular degeneration, polypoidal choroidal vasculopathy, and pachychoroid neovasculopathy refractory to anti-vascular endothelial growth factor therapy

PURPOSE

This study aimed to evaluate the one-year outcomes of photodynamic therapy (PDT) as a rescue treatment for age-related macular degeneration (AMD) refractory to anti-vascular endothelial growth factor (VEGF) therapy.

METHODS

Patients with AMD refractory to anti-VEGF therapy, treated with "rescue-PDT" were retrospectively investigated. The time of PDT was defined as the baseline value. Baseline characteristics including sex, age, best-corrected visual acuity (BCVA), central macular thickness (CMT), and foveal choroidal thickness (FCT) were examined. The changes in BCVA, CMT, and recurrence were also assessed at the 1-year follow-up. The logMAR VA change of 0.3 or more was defined as "improved" or "declined."

RESULTS

Twenty-three consecutive eyes (typical AMD: 10 eyes, polypoidal choroidal vasculopathy: 10 eyes, and pachychoroid neovasculopathy: 3 eyes), which underwent "rescue-PDT," were analyzed in this study. The BCVA was improved in three patients and maintained in 20 patients at 12 months after PDT (mean BCVA change: 0.11 ± 0.19). The CMT improved in 19 patients (82.6%), and the mean CMT changed from 318.5 ± 93.7 μm to 225.9 ± 51.6 μm (p < 0.01) 12 months after PDT. "Retreatment" of anti-VEGF drug injections was considered if the retinal fluid or retinal hemorrhage recurred after PDT. The baseline FCT of the "retreatment group (15 eyes)" was significantly lower than that of the "no retreatment group (8 eyes)" (206.3 ± 50.7 μm vs 293.9 ± 85.7 μm: p = 0.033).

CONCLUSIONS

PDT could be an effective treatment option for anti-VEGF refractory AMD to maintain visual acuity and control retinal fluid for up to 12 months.

Short-Term Outcomes of Switching to Ranibizumab in Polypoidal Choroidal Vasculopathy Resistant to Aflibercept Therapy

Background: To evaluate the short-term outcomes of switching to ranibizumab in aflibercept-resistant polypoidal choroidal vasculopathy (PCV). Methods: This retrospective study included 18 eyes diagnosed with aflibercept-resistant PCV. All patients were treated with two to four consecutive ranibizumab injections at 4–5-week intervals. The best-corrected visual acuity (BCVA), and central retinal thickness (CRT) values before and after switching to ranibizumab were compared. The proportion of eyes showing ≥100 µm decrease in retinal thickness and/or complete resolution of fluid after switching was identified. Results: The mean number of aflibercept injections before switching was 5.7 ± 3.3. After switching, a mean of 2.8 ± 0.6 consecutive ranibizumab injections was performed. The mean logarithm of minimal angle of resolution (logMAR) BCVA was 0.41 ± 0.26 (Snellen equivalents = 20/51) before switching, and 0.40 ± 0.30 (20/50) after switching (p = 0.574). The mean CRT was 422.2 ± 152.4 µm before switching, and 400.7 ± 182.0 µm after switching (p = 0.236). A decrease in CRT of ≥100 µm, and/or complete resolution of fluid was noted in three eyes (16.7%). Conclusions: Switching to ranibizumab in aflibercept-resistant polypoidal choroidal vasculopathy was not effective in most patients, suggesting the need for further investigation to seek more effective treatment options for this condition.

Anti-VEGF-Resistant Retinal Diseases: A Review of the Latest Treatment Options

Anti-vascular endothelial growth factor (anti-VEGF) therapy currently plays a central role in the treatment of numerous retinal diseases, most notably exudative age-related macular degeneration (eAMD), diabetic retinopathy and retinal vein occlusions. While offering significant functional and anatomic benefits in most patients, there exists a subset of 15–40% of eyes that fail to respond or only partially respond. For these cases, various treatment options have been explored with a range of outcomes. These options include steroid injections, laser treatment (both thermal therapy for retinal vascular diseases and photodynamic therapy for eAMD), abbreviated anti-VEGF treatment intervals, switching anti-VEGF agents and topical medications. In this article, we review the effectiveness of these treatment options along with a discussion of the current research into future directions for anti-VEGF-resistant eyes.