Photodynamic therapy for polypoidal choroidal vasculopathy

Current developments of gene therapy in human diseases

Gene therapy has witnessed substantial advancements in recent years, becoming a constructive tactic for treating various human diseases. This review presents a comprehensive overview of these developments, with a focus on their diverse applications in different disease contexts. It explores the evolution of gene delivery systems, encompassing viral (like adeno-associated virus; AAV) and nonviral approaches, and evaluates their inherent strengths and limitations. Moreover, the review delves into the progress made in targeting specific tissues and cell types, spanning the eye, liver, muscles, and central nervous system, among others, using these gene technologies. This targeted approach is crucial in addressing a broad spectrum of genetic disorders, such as inherited lysosomal storage diseases, neurodegenerative disorders, and cardiovascular diseases. Recent clinical trials and successful outcomes in gene therapy, particularly those involving AAV and the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated proteins, are highlighted, illuminating the transformative potentials of this approach in disease treatment. The review summarizes the current status of gene therapy, its prospects, and its capacity to significantly ameliorate patient outcomes and quality of life. By offering comprehensive analysis, this review provides invaluable insights for researchers, clinicians, and stakeholders, enriching the ongoing discourse on the trajectory of disease treatment.

Macular neovascularization

Neovascularization of the macula, a common complication of many chorioretinal diseases such as neovascular age-related macular degeneration, polypoidal choroidal vasculopathy, and pathologic myopia results from increased synthesis of vascular endothelial growth factor (VEGF) by the retinal pigment epithelium and/or Müller cells because of localized ischemia and inflammation. The Consensus on Neovascular AMD Nomenclature (CONAN) study group acknowledged that these vessels may originate from either the choriocapillaris or the retinal microvasculature, prompting them to propose the term 'macular neovascularization' (MNV) to include intraretinal, subretinal, and sub-pigment epithelial neovascularization localized to the macula. MNV frequently appears as a grey-green macular lesion with overlying intraretinal thickening and/or subretinal exudation, causing metamorphopsia, reduced central vision, relative central scotoma, decreased reading speed, and problems with color recognition. Multimodal imaging with optical coherence tomography (OCT), OCT angiography, dye-based angiographies, fundus autofluorescence, and multiwavelength photography help establish the diagnosis and aid in selecting an appropriate treatment. The standard of care for MNV is usually intravitreal anti-VEGF injections, though thermal laser photocoagulation, verteporfin photodynamic therapy, and vitreoretinal surgery are occasionally used. This current review discusses the etiology and clinical features of MNV, the role of multimodal imaging in establishing the diagnosis, and the available therapeutic options.

Real world treatment outcomes in polypoidal choroidal vasculopathy in a Caucasian population of British ethnicity

PURPOSE

To assess treatment response of Polypoidal choroidal vasculopathy (PCV) in a Caucasian population of British ethnicity with intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections alone and with a combination of anti-VEGF injections and photodynamic therapy (PDT).

SETTING/VENUE

Department of Ophthalmology, University Hospital Southampton NHS Foundation Trust, United Kingdom.

METHODS

Retrospective review of 95 Caucasian patients in a single centre with diagnosis of PCV between 2013 and 2018 were included. Best corrected visual acuity (BCVA), central retinal thickness (CRT), indocyanine green angiography (ICGA) characteristics, numbers and type of treatment were analysed at baseline and at 1 year.

RESULTS

One hundred and one eyes included from 95 patients received either anti-VEGF injections (n = 79, 78.2%) alone or combination therapy with anti-VEGF and PDT (n = 6, 6%). A third untreated group was also observed (n = 16, 15.8%). Five eyes were excluded from the study due to structural retinal damage. Mean number of injections was 7.3 in the monotherapy group and 6.5 in the combination group. Both treatment groups showed improvement in BCVA at 1 year and this was statistically significant in the monotherapy group with a mean gain of 8.3 letters (p < 0.001). Mean CRT decreased in all treatment groups at twelve months and this change was significant (p < 0.01). In the observation group, vision and CRT remained stable.

CONCLUSIONS

This study demonstrates significant improvements in BCVA at one year in our Caucasian cohort of British ethnicity with PCV in the treatment group.

Encapsulated cell technology: Delivering cytokines to treat posterior ocular diseases

Encapsulated cell technology (ECT) is a targeted delivery method that uses the genetically engineered cells in semipermeable polymer capsules to deliver cytokines. Thus far, ECT has been extensively utilized in pharmacologic research, and shows enormous potentials in the treatment of posterior segment diseases. Due to the biological barriers within the eyeball, it is difficult to attain effective therapeutic concentration in the posterior segment through topical administration of drug molecules. Encouragingly, therapeutic cytokines provided by ECT can cross these biological barriers and achieve sustained release at the desired location. The encapsulation system uses permeable materials that allow growth factors and cytokines to diffuse efficiently into retinal tissue. Moreover, the ECT based treatment can be terminated timely when we need to retrieve the implant, which makes the therapy reversible and provides a safer alternative for intraocular gene therapy. Meanwhile, we also place special emphasis on optimizing encapsulation materials and enhancing preservation techniques to achieve the stable release of growth factors and cytokines in the eyeball. This technology holds great promise for the treatment of patients with dry AMD, RP, glaucoma and MacTel. These findings would enrich our understandings of ECT and promote its future applications in treatment of degenerative retinopathy. This review comprises articles evaluating the exactness of artificial intelligence-based formulas published from 2000 to March 2024. The papers were identified by a literature search of various databases (PubMed/MEDLINE, Google Scholar, Cochrane Library and Web of Science).

A study of the relationship between cytokine levels and the response to anti-VEGF therapy in polypoid choroidal vasculopathy with different choroidal thicknesses

Purpose

Polypoidal choroidal vasculopathy (PCV) is an irreversible retinal choroidal disease. Individuals with PCV exhibit diverse baseline characteristics, including systemic characteristics, ocular traits, metabolic factor levels, and different responses to intravitreal anti-VEGF therapy. This study aims to investigate the pathogenesis of PCV by analyzing the systemic characteristics, ocular traits, and cytokine levels at baseline within a cohort of patients who exhibit different responses to anti-VEGF treatment.

Methods

We conducted a retrospective analysis involving 80 eyes diagnosed with PCV. Patients were categorized into two groups based on responses to suboptimal intravitreal ranibizumab injection therapy: those with suboptimal responses and optimal responses. Aqueous humor samples were collected from the experimental eyes, and cytokine expression levels were assessed using cytometric bead array analysis. All subjects were further stratified into two groups according to the median choroidal thickness. Subsequently, logistic regression analysis and the ROC curve were employed to examine the relationship between cytokine expression levels, choroidal thickness, and anti-VEGF response.

Results

The results revealed that compared to the group of optimal anti-VEGF response, the choroid in the suboptimal response group exhibited a significantly greater thickness. Additionally, compared to the suboptimal anti-VEGF response group, the expression levels of VEGF and VCAM-1 were markedly lower observed in the optimal anti-VEGF response group, while TNF-α showed the opposite trend. Logistic regression analysis indicated that VEGF, VCAM-1, and TNF-α in the aqueous humor were independent risk factors for a suboptimal anti-VEGF response. After adjusting other risk factors, the risk of suboptimal anti-VEGF response decreased to 0.998-fold, 0.997-fold, and 1.294-fold. The AUC values for VEGF, VCAM-1, and TNF-α were determined to be 0.805, 0.846, and 0.897, respectively. Furthermore, the risk of VEGF, VCAM-1, and TNF-α were significantly associated with an increased risk of suboptimal anti-VEGF response after correction for risk factors in the thick choroid group.

Conclusions

Our study demonstrated that PCV exhibits systemic and ocular characteristics variations based on different anti-VEGF responses. The levels of cytokines in aqueous humor were found to have a significant correlation with the anti-VEGF response in PCV. VEGF, VCAM-1, and TNF-α are potential targets for assessing treatment response in thick choroidal PCV.

The Interplay between Meningeal Lymphatic Vessels and Neuroinflammation in Neurodegenerative Diseases

Meningeal lymphatic vessels (MLVs) are essential for the drainage of cerebrospinal fluid, macromolecules, and immune cells in the central nervous system. They play critical roles in modulating neuroinflammation in neurodegenerative diseases. Dysfunctional MLVs have been demonstrated to increase neuroinflammation by horizontally blocking the drainage of neurotoxic proteins to the peripheral lymph nodes. Conversely, MLVs protect against neuroinflammation by preventing immune cells from becoming fully encephalitogenic. Furthermore, evidence suggests that neuroinflammation affects the structure and function of MLVs, causing vascular anomalies and angiogenesis. Although this field is still in its infancy, the strong link between MLVs and neuroinflammation has emerged as a potential target for slowing the progression of neurodegenerative diseases. This review provides a brief history of the discovery of MLVs, introduces in vivo and in vitro MLV models, highlights the molecular mechanisms through which MLVs contribute to and protect against neuroinflammation, and discusses the potential impact of neuroinflammation on MLVs, focusing on recent progress in neurodegenerative diseases.

Examining the efficacy of verteporfin photo-dynamic therapy (PDT) at different dose & fluence levels

OBJECTIVES

Photodynamic therapy (PDT) is a vaso-occlusive treatment for a number of chorioretinal vascular pathologies. We aimed to retrospectively analyse efficiency and safety of PDT for different conditions (central serous retinopathy (CSR), age-related macular degeneration (AMD), macular telangiectasia type 2 and choroidal hemangioma) and with different verteporfin parameters.

METHODS

Clinical parameters were ascertained from the medical records of patients undergoing PDT over a 6-year period. This included indications for PDT, dosing regimens of verteporfin PDT (which includes treatment dose of verteporfin and fluence). Response to treatment was measured by best corrected visual acuity (BCVA) and central foveal thickness (CFT) on ocular coherence tomography. Complications and side effects were recorded.

RESULTS

67.4 % (31/46) of PDT treatments performed over the last six years were for CSR. In the CSR cohort, there were significant improvements in BCVA (0.47 ± 0.24 to 0.29 ± 0.27, p < 0.05) and CFT (350.2μm ± 66.9 μm to 286.1μm ± 60.6 μm. In the AMD cohort, there was no change in BCVA (1.08 ± 0.52 to 1.07 ± 0.53, p = 0.96) but significant improvement in CFT (488.2μm ± 164.6 μm to 348.7μm ± 65.7 μm, p < 0.05). There was no significant difference in BCVA or CFT for macular telangiectasia type 2 and choroidal hemangioma.

CONCLUSIONS

PDT continues to have a role in the management of medical retina conditions. Our results show PDT is most effective in improving and stabilizing visual acuity in CSR, with earlier intervention resulting in better outcomes.

Systemic Risk Factors for Vitreous Hemorrhage Secondary to Polypoidal Choroidal Vasculopathy

INTRODUCTION

It remains unclear whether systemic factors are associated with an increased risk of vitreous hemorrhage (VH) secondary to polypoidal choroidal vasculopathy (PCV), and there is no method to predict the possibility of VH occurrence in patients with PCV. This study aimed to investigate and visualize systemic risk factors for VH in patients with PCV.

METHODS

Data on the sex, age, history of systematic diseases, best-corrected visual acuity, intraocular pressure, and laboratory data of patients with PCV were collected from the medical record system. Univariate and multivariate binary logistic regression analyses were applied to investigate independent risk factors for VH in patients with PCV. Receiver operating characteristic analysis and nomograms were used to visualize the independent risk factors.

RESULTS

The patient population comprised 115 patients with VH secondary to PCV and 181 patients with PCV without VH. Binary logistic regression analyses showed that higher white blood cell count [WBC; odds ratios (OR) 1.247], higher aspartate aminotransferase/alanine aminotransferase ratio (AST/ALT; OR 2.339), and longer activated partial thromboplastin time (APTT; OR 1.196) were independent risk factors of VH in patients with PCV. Integrated application of APTT, AST/ALT, and WBC as markers showed the best performance for distinguishing patients with VH, with an area under the curve of 0.723. The nomogram was created for doctors to calculate the possibility of VH in a patient with PCV.

CONCLUSIONS

Higher WBC, higher AST/ALT, and longer APTT are independent serum risk factors of VH secondary to PCV, which may shed light on VH prevention in patients with PCV.

Pathological angiogenesis: mechanisms and therapeutic strategies

In multicellular organisms, angiogenesis, the formation of new blood vessels from pre-existing ones, is an essential process for growth and development. Different mechanisms such as vasculogenesis, sprouting, intussusceptive, and coalescent angiogenesis, as well as vessel co-option, vasculogenic mimicry and lymphangiogenesis, underlie the formation of new vasculature. In many pathological conditions, such as cancer, atherosclerosis, arthritis, psoriasis, endometriosis, obesity and SARS-CoV-2(COVID-19), developmental angiogenic processes are recapitulated, but are often done so without the normal feedback mechanisms that regulate the ordinary spatial and temporal patterns of blood vessel formation. Thus, pathological angiogenesis presents new challenges yet new opportunities for the design of vascular-directed therapies. Here, we provide an overview of recent insights into blood vessel development and highlight novel therapeutic strategies that promote or inhibit the process of angiogenesis to stabilize, reverse, or even halt disease progression. In our review, we will also explore several additional aspects (the angiogenic switch, hypoxia, angiocrine signals, endothelial plasticity, vessel normalization, and endothelial cell anergy) that operate in parallel to canonical angiogenesis mechanisms and speculate how these processes may also be targeted with anti-angiogenic or vascular-directed therapies.

Progression of Polypoidal Lesions Associated with Exudative Recurrence in Polypoidal Choroidal Vasculopathy

PURPOSE

To investigate the characteristics of the branching vascular network (BVN) and polypoidal lesions in polypoidal choroidal vasculopathy (PCV) to determine near-term indicators that may predict exudative recurrence.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients with PCV receiving anti-vascular endothelial growth factor (VEGF) monotherapy or anti-VEGF plus photodynamic therapy were followed for at least 1 year using swept-source OCT angiography (SS-OCTA) imaging.

METHODS

Patients were divided into 2 groups based on whether exudative recurrence occurred during follow-up. Multiple parameters were collected and compared between the 2 groups, such as age, gender, visual acuity, number of polypoidal lesions, lesion area at the first SS-OCTA visit, and total lesion area change from the first SS-OCTA visit to the last SS-OCTA visit. To evaluate the association between SS-OCTA imaging-based risk factors and the exudative recurrences, imaging features associated with PCV such as BVN growth and polypoidal lesion progression (enlargement, new appearance, and reappearance) at each follow-up visit were analyzed. The time intervals from the nonexudative visit with lesion progression to the corresponding exudative recurrence visit were documented to explore their association with exudative recurrences. Cox regression and logistic regression analyses were used.

MAIN OUTCOME MEASURES

Association between BVN growth and polypoidal lesion progression with exudative recurrence.

RESULTS

Thirty-one eyes of 31 patients (61% men) were included. Sixteen eyes had no recurrence of exudation, and 15 eyes had recurrence during follow-up. The average follow-up duration was 20.55 ± 6.86 months (range, 12-36 months). Overall, the recurrence group had worse best-corrected visual acuity (P = 0.019) and a greater increase in lesion area (P = 0.010). Logistical regression analysis showed that polypoidal lesion progression, including new appearance, enlargement, and reappearance of polypoidal lesions, was associated with exudative recurrences within 3 months (odds ratio, 26.67, 95% confidence interval, 3.77-188.54, P = 0.001).

CONCLUSIONS

Growth of nonexudative BVN and progression of polypoidal lesions were found to be lesion characteristics associated with exudative recurrences, and progression of polypoidal lesions might serve as a stand-alone indicator for the near-term onset of exudation. In PCV, more frequent follow-up visits are recommended when polypoidal lesions show progression.

Membrane Attack Complex Mediates Retinal Pigment Epithelium Cell Death in Stargardt Macular Degeneration

Recessive Stargardt disease (STGD1) is an inherited retinopathy caused by mutations in the ABCA4 gene. The ABCA4 protein is a phospholipid-retinoid flippase in the outer segments of photoreceptors and the internal membranes of retinal pigment epithelial (RPE) cells. Here, we show that RPE cells derived via induced pluripotent stem-cell from a molecularly and clinically diagnosed STGD1 patient exhibited reduced ABCA4 protein and diminished activity compared to a normal subject. Consequently, STGD1 RPE cells accumulated intracellular autofluorescence-lipofuscin and displayed increased complement C3 activity. The level of C3 inversely correlated with the level of CD46, an early negative regulator of the complement cascade. Persistent complement dysregulation led to deposition of the membrane attack complex on the surface of RPE cells, decrease in transepithelial resistance, and subsequent cell death. These findings are strong evidence of complement-mediated RPE cell damage in STGD1, in the absence of photoreceptors, caused by reduced CD46 regulatory protein.

Comparison of 3-year outcomes of photodynamic therapy combined with intravitreal ranibizumab or aflibercept for polypoidal choroidal vasculopathy in a European cohort

PURPOSE

Combined use of photodynamic therapy (PDT) with intravitreal anti-vascular endothelial growth factors (anti-VEGF) agents, such as ranibizumab (IVR) or aflibercept (IVA), has been shown to be effective for treating polypoidal choroidal vasculopathy (PCV). However, it is currently not well established which anti-VEGF agent provides superior outcomes for performing combination therapy. The present study compares the visual outcomes and re-treatment burden of combination therapy of PDT with either IVR or IVA in a European cohort of patients with PCV.

METHODS

A retrospective analysis was done on PCV patients who had received combination therapy of PDT with either IVR or IVA. The demographic characteristics, visual outcome, and anti-VEGF re-treatment exposures were analysed and compared.

RESULTS

A total of forty-four eyes (n = 11 male, 25%) were included in the analysis: 7 patients received IVR, 19 started with IVR but switched to IVA (IVS), and 18 received IVA, in combination with PDT. The BCVA improved in all three groups at 6-, 12-, 18-, 24-, 30-, and 36-month follow-ups after PDT, although the improvement was not statistically significant in the IVR group. The number of intravitreal anti-VEGF injections required/year after PDT was significantly fewer than before PDT. Significantly less eyes in the IVS group attained a good visual acuity of more than 70 ETDRS letters at the final visit.

CONCLUSION

Both IVR and IVA combined with PDT were effective treatments for the European cohort of patients with PCV. In eyes refractory to IVR, performing PDT promptly may be more beneficial than switching to IVA.

Real-world outcomes of combined therapy of photodynamic therapy with anti-vascular endothelial growth factor for polypoidal choroidal vasculopathy

OBJECTIVES

To describe the real-world outcomes of photodynamic therapy (PDT) as a rescue therapy in eyes with polypoidal choroidal vasculopathy (PCV) refractory to anti-vascular endothelial growth factor (VEGF) monotherapy in a British cohort of patients.

METHODS

This is a retrospective chart review of 53 eyes with PCV. Based on the timing of PDT, the eyes were stratified into two groups (9 in the Initial-PDT group, 44 in the Deferred group). The number of anti-VEGF injections/year and the best corrected visual acuity (BCVA) before and after PDT were analysed. Multivariate regression model was created to identify factors predictive of visual outcome and treatment burden after PDT.

RESULTS

The Deferred group received a mean of 9.4 injections/year but significantly reduced to 7.2 after PDT (p < 0.001). The Initial-PDT group required significantly fewer injections after PDT compared to the Deferred group (p = 0.004). The Deferred group experienced improvement in BCVA from 58.7 letters at baseline to 63.8 at 18-months follow-up (p < 0.001), but no significant increase was observed in the Initial-PDT group (p = 0.310). Better baseline BCVA is associated with higher likelihood of achieving good BCVA ≥ 70 letters after PDT (Odd Ratio=1.12, 95% CI: 1.03-1.21, p = 0.006), while increased number of anti-VEGF injections/year before PDT reduces the likelihood of easing treatment burden to ≥12 weeks apart between each injection after PDT (Odd Ratio=0.724, 95% CI: 0.58-0.91, p = 0.006).

CONCLUSIONS

PDT as a rescue therapy is beneficial in the long-term management of PCV, particularly in eyes that had experienced a significant period of prior exposure to anti-VEGF monotherapy.

Updated guidelines for the management of polypoidal choroidal vasculopathy: Recommendations from the Indian Polypoidal Choroidal Vasculopathy Panel and the Vitreoretinal Society of India

In Asians, polypoidal choroidal vasculopathy (PCV) is becoming more widely recognized as a significant cause of exudative maculopathy. The previous set of Indian guidelines on the management of PCV were published in 2018, with a literature search updated up to November 2015. As the treatment of PCV evolves, retinal physicians must constantly modify their current practice. The current guidelines are based on the most up-to-date information on PCV and are an update to the previous set of guidelines. These guidelines were developed by a panel of Indian retinal experts under the aegis of the Vitreoretinal Society of India (VRSI), based on a comprehensive search and assessment of literature up to September 2021. The final guidelines i) provide the updated nomenclature in PCV; ii) discusses the newer diagnostic imaging features of PCV, especially in the absence of indocyanine green angiography (ICGA); and iii) recommends the best possible therapeutic approach in the management of PCV, including the choice of anti-vascular endothelial growth factor (anti-VEGF) agents, treatment regimen, and the role of switching between the anti-VEGF agents. In the face of non-availability of photodynamic therapy (PDT) in India, we constructed practical recommendations on anti-VEGF monotherapy in PCV. The current updated recommendations would provide a broader framework to the treating retinal physician for the diagnosis and management of PCV for optimal therapeutic outcomes.

Intravitreal injection of EV11, a novel aryl ketone amide, inhibits choroidal neovascularization via AKT/ERK1/2 pathway

PURPOSE

Choroidal neovascularization (CNV) is the major cause of irreversible vision loss associated with age-related macular disease (AMD). The currently clinical chemical therapeutic strategies are of high cost and facing supply chain shortage. In our study, we aim to investigate EV11, a novel derivative from Sorafenib, as a new approach to inhibit the formation of CNV.

METHODS

Cell viability assay, wound healing assay, transwell assay and tube formation assay were applied to explore the effects of EV11 on human vascular endothelial cells (HUVECs). Western blotting analysis was performed to investigate the pathways when EV11 acts on HUVECs. Laser-induced CNV in mice and intravitreal injection of EV11 were applied to find out the efficacy of the drug in vivo. Histological examination and electroretinogram (ERG) evaluated the retinal morphology and visual function after drug application.

RESULTS

EV11 influenced the HUVECs cell viability as the concentration increasing after 24 hour incubation. It influenced HUVECs through suppressing AKT and ERK1/2 pathway. EV11 reduced CNV area with the optimal concentration of 200uM in mice eyes and compared with Bevacizumab, it had the same effect. The retinal thickness around the optic in each group was not influenced. The amplitudes of the a- and b-waves on scotopic and photopic ERG were not reduced after intravitreal injection.

CONCLUSION

The present study indicated that EV11 affected the proliferation, migration and tube formation of HUVECs, inhibited the area of neovascular of laser induced choroidal neovascularization in mice eyes with no toxicity. EV11 could block the AKT/ERK1/2 signaling pathway in effects of HUVECs. This study unveiled a novel perspective drug EV11 to be a potential candidate for neovascularization.

[Effects of systemic drugs on the development of drug-induced retinopathy]

This article reviews information on possible adverse events occurring in the organ of vision - in particular, the retina - after using systemic drugs, discusses the drugs that lead to drug-induced retinopathy most often, and describes histomorphological changes and modern understanding of the pathogenesis of damage to retinal structures.

Short-Term Efficacy in Polypoidal Choroidal Vasculopathy Patients Treated With Intravitreal Aflibercept or Conbercept

Purpose

To compare the short-term efficacy in patients with polypoidal choroidal vasculopathy (PCV) treated using either aflibercept or conbercept.

Methods

This prospective study included 41 patients with treatment-naive PCV (42 eyes). All the patients were treated with either aflibercept or conbercept using an initial series of 3 monthly loading injections. Changes in the best-corrected logMAR visual acuity (BCVA) and anatomic outcomes were evaluated at 3 months.

Results

BCVA was improved with reduction in central choroidal thickness (CCT), central foveal thickness (CFT), and subretinal fluid (SRF) after 3 monthly loading injections in both aflibercept (IVA) and conbercept (IVC) groups. There was no significant difference in either visual or anatomic outcomes between the two groups after 3 months of treatment. However, compared with the IVC group, significantly higher BCVA improvement was observed in the patients in the IVA group with baseline BCVA better than 1. A visual outcome improved ≥3 lines in 13 patients in the IVA group (59%), and 9 patients in the IVC group (45%). A relatively high proportion of polyp regression was observed in the IVA group (63%) compared with the IVC group (55%) via OCTA.

Conclusions

Visual and anatomic outcomes were significantly improved in both IVA and IVC groups, but the results suggest a potentially superior short-term response in the IVA group.

Quantitative analysis of branching neovascular networks in polypoidal choroidal vasculopathy by optical coherence tomography angiography after photodynamic therapy and anti-vascular endothelial growth factor combination therapy

PURPOSE

To study serial changes in branching neovascular networks (BNN) by using optical coherence tomography angiography (OCTA) in patients with polypoidal choroidal vasculopathy (PCV) who underwent combined photodynamic therapy (PDT) and anti-vascular endothelial growth factor (anti-VEGF) therapy.

METHODS

In this retrospective study of 30 PCV patients who underwent combined therapy, OCTA images obtained at baseline and 1, 3, and 6 months after treatment were collected. The vessel area, vessel percentage area, average vessel length, and presence of polypoidal lesions on OCTA images as well as best-corrected visual acuity (BCVA), central retinal thickness (CRT), and central choroidal thickness (CCT) were recorded at each time point.

RESULTS

The BNN- and polypoidal lesion-detection rates on baseline OCTA images were 100% and 71%, respectively. The vessel area decreased during the first 3 months, and increased 6 months post-treatment, showing significant differences from baseline (p = 0.031). The vessel percentage area also reduced 1 and 3 months post-treatment (p = 0.025) and increased 6 months post-treatment. Continuous polypoidal lesion regression was observed from 1 to 3 and 6 months post-treatment (p = 0.031, p = 0.004, p = 0.002, respectively, in comparison with baseline). Patients with a decreasing vessel area over 6 months showed greater choroidal thickness than those with increasing vessel area (p = 0.004).

CONCLUSIONS

The BNN showed initial regression but were enlarged at 6 months after therapy. Patients showing continuous BNN regression showed a thicker choroid at baseline. This difference should be considered during treatment for PCV, and OCTA could be used for follow-up evaluations of PCV patients.

Publication Trends of Research on Polypoidal Choroidal Vasculopathy During 2001–2020: A 20-Year Bibliometric Study

Introduction

Polypoidal choroidal vasculopathy (PCV) is a special subtype of AMD, which is one of the leading threats to vision health worldwide. At this time, many aspects of PCV, from how it works to potential treatments, remain a mystery. In this study, we explored the frontier researches and revealed the study trends within the study of PCV.

Methods

We collected all the publications in this field from 2001 to 2020, analyzed trends within them, and defined the contributions of various countries/regions, institutions, authors, and journals. Additionally, VOSviewer software was used to define the hot keywords in this field.

Results

A total of 1,190 publications were ultimately examined; We found that PCV is becoming an increasingly relevant topic of research, and that Japan has contributed the most publications (428), the most citations (14,504 in total), and the highest H-index value (62) to the field. Our keywords analysis was classified into four clusters to show the hotspots within the study of PCV, namely mechanism-related, imaging-related, prognosis-related, and therapy-related topics. The average years in which the keywords appeared the most were also calculated, and we identified anti-VEGF therapy, anti-complement therapy and angiography as having been the main focus in recent years.

Conclusions

These results helped clarify the comprehensive research progress that has been made as well as the future trends in the study of PCV, which can assist and guide future research.

Could Photodynamic Therapy Be a Promising Therapeutic Modality in Hepatocellular Carcinoma Patients? A Critical Review of Experimental and Clinical Studies

Simple Summary

Hepatocellular Carcinoma (HCC) is one of the leading causes of cancer-associated mortality worldwide. With a limited number of therapeutic options available and a lack of effective anti-tumoral immune responses by the therapies, there is a dire need to search for new translational treatment options. Photodynamic Therapy (PDT), in recent years, has proven itself as an effective anti-cancer therapy. In this review, we discuss the mechanism of PDT, its evolution as an anti-cancer modality, with a special focus on HCC. We also highlight the immune response generated by PDT and how it could be essential in HCC treatment. Finally, we proposed an intraoperative procedure for the treatment of HCC by combining hepatectomy with PDT.

Abstract

Photodynamic Therapy (PDT) relies on local or systemic administration of a light-sensitive dye, called photosensitizer, to accumulate into the target site followed by excitation with light of appropriate wavelength and fluence. This photo-activated molecule reacts with the intracellular oxygen to induce selective cytotoxicity of targeted cells by the generation of reactive oxygen species. Hepatocellular carcinoma (HCC), one of the leading causes of cancer-associated mortality worldwide, has insufficient treatment options available. In this review, we discuss the mechanism and merits of PDT along with its recent developments as an anti-cancerous therapy. We also highlight the application of this novel therapy for diagnosis, visualization, and treatment of HCC. We examine the underlying challenges, some pre-clinical and clinical studies, and possibilities of future studies associated with PDT. Finally, we discuss the mechanism of an active immune response by PDT and thereafter explored the role of PDT in the generation of anti-tumor immune response in the context of HCC, with an emphasis on checkpoint inhibitor-based immunotherapy. The objective of this review is to propose PDT as a plausible adjuvant to existing therapies for HCC, highlighting a feasible combinatorial approach for HCC treatment.

Activation of quiescent polypoidal choroidal vasculopathy after membrane peeling vitrectomy for epiretinal membrane: a case report

BACKGROUND

Regular membrane peeling vitrectomy for epiretinal membrane (ERM) patients seldom causes large pigment epithelial detachment (PED). We presented an unusual case of the activation of quiescent polypoidal choroidal vasculopathy (PCV) after membrane peeling vitrectomy for ERM, with an uneven therapeutic process.

CASE PRESENTATION

A 75-year-old female patient complained of metamorphopsia in her left eye for 2 years. Her best-corrected visual acuity was 20/160 with a moderate nuclear cataract. An irregular ERM and slight PED were shown in optical coherence tomography (OCT). No obvious orange-red lesion was detected. The patient underwent vitrectomy + ERM peeling + cataract surgery. After the operation, large PED emerged, and indocyanine green angiography (ICGA) confirmed PCV. Four monthly injections of intravitreal ranibizumab were administered, but PED persisted. After focal laser therapy targeted to the polyps combined with ranibizumab treatment, PED was absorbed.

CONCLUSIONS

Careful evaluation for PCV before membrane peeling vitrectomy for ERM is important, as indolent PCV may be activated postoperatively. Anti-VEGF therapy accompanied by laser photocoagulation may be more effective for PCV polyps located away from the fovea.

Discovery of new vascular disrupting agents based on evolutionarily conserved drug action, pesticide resistance mutations, and humanized yeast

Thiabendazole (TBZ) is an FDA-approved benzimidazole widely used for its antifungal and antihelminthic properties. We showed previously that TBZ is also a potent vascular disrupting agent and inhibits angiogenesis at the tissue level by dissociating vascular endothelial cells in newly formed blood vessels. Here, we uncover TBZ's molecular target and mechanism of action. Using human cell culture, molecular modeling, and humanized yeast, we find that TBZ selectively targets only 1 of 9 human β-tubulin isotypes (TUBB8) to specifically disrupt endothelial cell microtubules. By leveraging epidemiological pesticide resistance data and mining chemical features of commercially used benzimidazoles, we discover that a broader class of benzimidazole compounds, in extensive use for 50 years, also potently disrupt immature blood vessels and inhibit angiogenesis. Thus, besides identifying the molecular mechanism of benzimidazole-mediated vascular disruption, this study presents evidence relevant to the widespread use of these compounds while offering potential new clinical applications.

Multicentre, randomised clinical trial comparing intravitreal aflibercept monotherapy versus aflibercept combined with reduced-fluence photodynamic therapy (RF-PDT) for the treatment of polypoidal choroidal vasculopathy

PURPOSE

To compare the efficacy and safety of intravitreal aflibercept (IVA) monotherapy versus aflibercept combined with reduced-fluence photodynamic therapy (RF-PDT) (IVA+RF-PDT) for the treatment of polypoidal choroidal vasculopathy (PCV).

METHODS AND ANALYSIS

Multicentred, double-masked, randomised controlled trial to compare the two treatment modalities. The primary outcome of the study is to compare the 52-week visual outcome of IVA versus IVA+RF PDT. One hundred and sixty treatment-naïve patients with macular PCV confirmed on indocyanine green angiography will be recruited from three centres in Singapore. Eligible patients will be randomised (1:1 ratio) into one of the following groups: IVA monotherapy group-aflibercept monotherapy with sham photodynamic therapy (n=80); combination group-aflibercept with RF-PDT (n=80). Following baseline visit, all patients will be monitored at 4 weekly intervals during which disease activity will be assessed based on best-corrected visual acuity (BCVA), ophthalmic examination findings, optical coherence tomography (OCT) and angiography where indicated. Eyes that meet protocol-specified retreatment criteria will receive IVA and sham/RF-PDT according to their randomisation group. Primary endpoint will be assessed as change in BCVA at week 52 from baseline. Secondary endpoints will include anatomical changes based on OCT and dye angiography as well as safety assessment. Additionally, we will be collecting optical coherence tomography angiography data prospectively for exploratory analysis.

ETHICS AND DISSEMINATION

This study will be conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki and that are consistent with the ICH E6 guidelines of Good Clinical Practice and the applicable regulatory requirements. Approval from the SingHealth Centralised Institutional Review Board has been sought prior to commencement of the study.

TRIAL REGISTRATION NUMBER

NCT03941587.

The role of oral steroids in the treatment of photodynamic therapy-associated exudative maculopathy, a case report and review of the literature

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment of pachychoroid spectrum disease. PDT can cause a rare complication known as PDT-associated exudative maculopathy (PAEM). Treatments including intravitreal anti-vascular endothelial growth factor (anti-VEGF) medications, local or systemic steroids, and observation have been attempted with variable success to address this complication.

METHODS

A thorough literature review was performed using the PubMed database on search terms aimed at treatments of PAEM. These cases were compared with each other and a novel case of PAEM in polypoidal choroidal vasculopathy (PCV) treated with oral prednisone by the authors.

RESULTS

Fifteen patients were compared; 11 were treated with anti-VEGF alone or in combination with intravitreal steroid and/or vitrectomy, one was treated with topical steroid, one was observed, one was treated with intravenous methylprednisolone, and one was treated with oral prednisone. The two cases treated with systemic steroids were given adjunctive sub-tenon's triamcinolone acetonide (STTA) after a favorable response was observed. Most cases had anatomic resolution of serous retinal detachment with stability of vision between 16 days and 2 months, with the most rapid resolution occurring in a patient with PCV treated with oral prednisone and STTA.

CONCLUSIONS

Reported treatment of PAEM includes intravitreal anti-VEGF agents with or without local or systemic steroids. Oral steroids may be advantageous in cases where there is concern regarding the risk profile of periocular steroids, intravitreal steroids or anti-VEGF agents. However, data describing the various treatments of this rare complication is limited, precluding firm conclusions regarding relative safety and efficacy.

Transient accumulation of subretinal fluid after half-fluence photodynamic therapy in neovascular age-related macular degeneration

Background

Photodynamic therapy (PDT) is known to occlude choroidal neovascularisation selectively, and there have been several reports on its adverse effects on the normal choroid and retinal pigment epithelium, resulting in decreased vision.

Methods

This retrospective interventional case series aimed to investigate the changes in visual acuity and retinal thickness in the immediate post-treatment period after half-fluence PDT, administered alone or with anti-vascular endothelial growth factor and steroids, in 29 eyes (26 patients) with neovascular age-related macular degeneration. The patients’ best-corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography images were measured 1 day, 1 week, and 1 month post-treatment.

Results

Compared to the pre-treatment CFT (270.38 μm), the mean CFT was significantly increased 1 day post-treatment (387.07 μm, P = 0.001), which then started to decrease, with a mean CFT of 269.32 μm (P = 0.516) at 1 week, and of 240.66 μm (P = 0.066) at 1 month post-treatment. All CFT increases were due to the accumulation of subretinal fluid (SRF), rather than the intraretinal or subretinal pigment epithelium fluid. Relative to the pre-treatment BCVA (0.59 logMAR), the mean BCVA at 1 day (0.74 logMAR, P = 0.005) and 1 week (0.75 logMAR, P = 0.002) post-treatment was significantly deteriorated; however, it recovered to 0.62 logMAR at 1 month. The patterns of change in CFT and BCVA did not differ according to treatment modality.

Conclusions

Half-fluence PDT resulted in accumulation of SRF in the immediate post-treatment period; this damage mostly recovered within a week, and the BCVA was restored within a month.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01867-w.

Systematic review with network meta-analysis of antivascular endothelial growth factor use in managing polypoidal choroidal vasculopathy

Polypoidal choroidal vasculopathy (PCV) is a vision-threatening disease common in Asian populations. However, the optimal treatment for PCV remains under debate. We searched the databases with optimal searching strategy. The study included randomized clinical trials and prospective studies that recruited patients with active PCV who had received interventions, including PDT, anti-VEGF, or a combination of PDT and anti-VEGF. The Grading of Recommendations Assessment, Development, and Evaluation methodology was used for rating the quality of evidence. Our study included 11 studies involving 1277 patients. The network meta-analysis of RCTs revealed the anti-VEGF group, early combination group, and late combination group had significant BCVA changes compared with the PDT group. Early combination therapy led to a significant decrease in CRT compared with PDT, anti-VEGF, and late combination therapy. Additionally, the early combination group had a significantly higher complete polyp regression rate than the anti-VEGF group. No significant differences were detected in the analysis of the number of anti-VEGF injections and safety profile. This network meta-analysis revealed that early combination therapy exhibited better efficacy related to anatomical outcomes than other therapies. Nonetheless, no significant differences related to BCVA change could be detected between anti-VEGF and late combination therapy.

One-year Results of Aflibercept Treatment for Polypoidal Choroidal Vasculopathy with Good Visual Acuity

PURPOSE

To evaluate the one-year efficacy of intravitreal aflibercept injection in polypoidal choroidal vasculopathy (PCV) with best-corrected visual acuity (BCVA) of 20 / 40 or better.

METHODS

This was a multicenter retrospective study. The medical records of patients diagnosed with treatment-naïve PCV were retrospectively reviewed. Patients with an initial BCVA of 20 / 40 or better and who had undergone intravitreal aflibercept injection were included. Patients were treated with three consecutive monthly injections, followed by pro re nata regimen according to the clinician's discretion at variable interval visits. The proportions of eyes for which BCVA was maintained (≤ 0.2 logarithm of the minimum angle of resolution change) or improved at 12 months were evaluated. The changes of BCVA, central subfield macular thickness (CSMT), pigment epithelial detachment, and subretinal fluid also were assessed.

RESULTS

A total of 86 eyes were included. The mean number of injections for 12 months of treatment was 5.4 ± 1.7. BCVA was maintained or improved in 94.2% (81 / 86) of cases. Mean BCVA (logarithm of the minimum angle of resolution) had changed from the baseline (0.23 ± 0.09) at 3 months (0.21 ± 0.14), 6 months (0.24 ± 0.22), and 12 months (0.20 ± 0.18), but with no statistical significance. CSMT had improved significantly from the baseline (336.1 ± 97.3 μm) at 3 months (223.6 ± 47.22 μm), 6 months (239.6 ± 64.2 μm), and 12 months (223.8 ± 47.9 μm). Pigment epithelial detachment was observed in 93% of cases at the baseline, 72.1% at 3 months, and 69.8% at 12 months, showing a significant decrease at all observation points. Subretinal fluid was observed in 91.9% of cases at the baseline, 20.9% at 3 months, and 29.1% at 12 months, showing a significant decrease at all observation points.

CONCLUSIONS

In cases of PCV with good visual acuity, intravitreal aflibercept injections decreased CSMT and were effective in maintaining visual acuity.

Efficacy and Safety of Intravitreal Aflibercept for Polypoidal Choroidal Vasculopathy: Two-Year Results of the Aflibercept in Polypoidal Choroidal Vasculopathy Study

PURPOSE

We sought to evaluate longer-term efficacy and safety of intravitreal aflibercept monotherapy (IAI) vs IAI plus rescue photodynamic therapy (rPDT) in patients with polypoidal choroidal vasculopathy (PCV).

DESIGN

This was a prospective multicenter, double-masked, sham-controlled randomized clinical study across 62 centers.

METHODS

In this phase 3b/4 study, patients with PCV with best-corrected visual acuity of 73-24 Early Treatment Diabetic Retinopathy Study letters (20/40-20/320 Snellen equivalent) received IAI 2 mg every 4 weeks until week 12, when they were randomized 1:1 to receive IAI or IAI plus rPDT if rescue criteria were met. Patients not requiring rescue received IAI every 8 weeks; those requiring rescue received IAI every 4 weeks plus sham/active PDT. At week 52 (the primary endpoint), IAI was noninferior to IAI plus rPDT. After week 52, treatment intervals could be extended beyond 8 weeks at the investigators' discretion. Noninferiority of IAI vs IAI plus rPDT for mean best-corrected visual acuity change from baseline to week 96 was evaluated.

RESULTS

Over 96 weeks, 54 patients (17.0%) met rescue criteria. At week 96, IAI was noninferior to IAI plus rPDT in terms of Early Treatment Diabetic Retinopathy Study letters gained (+10.7 vs +9.1, P = .48). Proportions of patients with complete polyp regression (33.1% vs 29.1%) or without active polyps (82.1% vs 85.6%) were similar. In year 2, the mean number of injections was 4.6 in both arms. No new safety signals were observed.

CONCLUSION

IAI monotherapy was noninferior to IAI with rescue PDT up to 96 weeks, and functional and anatomical improvements achieved at 52 weeks were maintained. Few patients required rescue PDT, which provided no additional visual benefit.

Efficacy of Photodynamic Therapy for Polypoidal Choroidal Vasculopathy Associated with and without Pachychoroid Phenotypes

PURPOSE

To compare the efficacy of photodynamic therapy (PDT) in eyes with polypoidal choroidal vasculopathy (PCV) associated with and without pachychoroid phenotypes (pachychoroid PCV and nonpachychoroid PCV, respectively).

DESIGN

Retrospective chart review.

PARTICIPANTS

Patients previously diagnosed with PCV and initially treated with PDT.

METHODS

Patients were classified as having pachychoroid- or nonpachychoroid-driven conditions. The long-term visual outcome and its associated factors were investigated.

MAIN OUTCOME MEASURES

Visual acuity (VA) outcomes at 1, 2, 3, 4, and 5 years after initial PDT in pachychoroid and nonpachychoroid PCV.

RESULTS

Of the 158 eyes, 88 (55.7%) met the criteria for pachychoroid PCV; 70 (44.3%) did not (nonpachychoroid PCV). In cases of pachychoroid PCV, VA improved significantly at 1 year (P = 0.042) and maintained baseline level at 5 years (P = 0.38). By contrast, VA continued to deteriorate in the nonpachychoroid PCV group during the follow-up period and had already declined significantly by the second year (P = 0.022, compared with baseline). Despite no difference in baseline VA between pachychoroid and nonpachychoroid PCV groups (P = 0.11), the VA at 5 years was significantly better in the pachychoroid PCV group compared with the nonpachychoroid PCV group (0.54±0.47 vs. 0.93±0.63, respectively; P = 0.23 × 10^-3). The incidence of massive submacular hemorrhage (SMH) or vitreous hemorrhage (VH) was not different between groups at 5 years (P = 0.67), and their occurrence was associated with decreased VA in both the nonpachychoroid and pachychoroid PCV groups (coefficient β, 0.361 and 0.481; P = 0.59 × 10^-3 and P < 1.0 × 10^-5, respectively).

CONCLUSIONS

Five years after PDT treatment, VA was maintained at the baseline level in the pachychoroid PCV group but not in the nonpachychoroid PCV group. Massive SMH or VH during the follow-up period affected the final visual outcomes in both conditions.

Prognostic factors for combined ranibizumab and prompt verteporfin photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To investigate the prognostic factors for the combined therapy of ranibizumab and prompt verteporfin photodynamic therapy (vPDT) for eyes with polypoidal choroidal vasculopathy (PCV).

METHODS

Sixty-two PCV eyes of 62 patients that received the initial treatment of intravitreal ranibizumab followed by vPDT within 1 week plus a 2nd intravitreal ranibizumab 1 month later in one single medical center were retrospectively enrolled. Best-corrected visual acuity (BCVA) and parameters obtained from optical coherence tomography at baseline, 3 months, 6 months and 1  year were measured and compared. Factors associated with polyp regression, recurrent hemorrhage and visual improvement were analyzed.

RESULTS

After the loading treatment, complete and partial polyp regression was achieved in 53.6% and 39.3% of cases, respectively at Month 3. The mean logarithm of the minimum angle of resolution of BCVA improved from 0.64 ± 0.38 to 0.55 ± 0.46 (P =  0.008) at Month 12. Recurrent hemorrhage (P =  0.001) and previous anti-vascular endothelial growth factor (VEGF) treatment (P =  0.017) were associated with poorer visual improvement at Month 12. Incomplete polyp regression (P =  0.038) and previous anti-VEGF treatment (P =  0.005) were associated with a higher risk of recurrent hemorrhage.

CONCLUSIONS

Recurrent hemorrhage was associated with poor visual improvement after combined ranibizumab and vPDT for PCV. Complete polyp eradication was associated with a lower risk of recurrent hemorrhage. Patients who had previously received anti-VEGF were associated with recurrent hemorrhage and poor visual improvement; more frequent follow-ups and more aggressive subsequent treatments may be needed for these cases.

Polypoidal choroidal vasculopathy: An update on current management and review of literature

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular age-related macular degeneration (nAMD), commonly seen in the Asian population. It is dissimilar in epidemiology, genetic heterogeneity, pathogenesis, natural history, and response to treatment in comparison to nAMD. Confocal scanning laser ophthalmoscopy-based simultaneous fluorescein angiography and indocyanine green angiography, spectral-domain optical coherence tomography (OCT) with enhanced depth imaging, swept-source OCT, and OCT angiography have improved the ability to detect PCV, understand its pathology, and monitor treatment response. A plethora of literature has discussed the efficacy of photodynamic therapy, anti-vascular endothelial growth factor (VEGF) monotherapy, and combination of both, but only a few studies with higher level of evidence and limited follow-up duration are available. This review discusses the understanding of PCV with respect to epidemiology, pathogenesis, clinical features, natural history, imaging techniques, and various treatment options. Recent clinical trials (EVEREST-II and PLANET study) have emphasized that either anti-VEGF monotherapy or combination treatment is equally capable to strike a balance between polyp regression and stabilization of visual acuity. The recurrent nature of the disease, the development of macular atrophy, and the long-term poor visual prognosis despite treatment are concerns that open avenues for further research.

Combined therapy and antivascular endothelial growth factor monotherapies for polypoidal choroidal vasculopathy: A protocol for the systematic review and network meta-analysis of efficacy and safety

BACKGROUND

Different antivascular endothelial growth factor (VEGF) monotherapy regimens and photodynamic therapy (PDT) combined with anti-VEGF therapy are available for patients with polypoidal choroidal vasculopathy (PCV). However, the comparative efficacy and safety of different anti-VEGF monotherapy regimens and combined therapy with PDT and anti-VEGF remains unknown. The aim of our study is to evaluate the efficacy and safety of anti-VEGF monotherapies and combined therapy in patients with PCV.

METHODS

We will systematically search PubMed, Embase, and the Cochrane library for eligible studies. The Cochrane Collaboration's tool for assessing the risk of bias in a randomized trial and the ROBINS-I tool will be used to assess the risk of bias in the included studies. The primary outcome is the mean change in best corrected visual acuity from baseline. The secondary outcomes are the mean change in central retinal thickness from baseline and the number of serious adverse events.

RESULTS

The result will generate a comprehensive suggestion for the treatment of PCV.

CONCLUSION

The results of the network meta-analysis will be submitted in a peer-reviewed journal for publication.

ETHICS AND DISSEMINATION

The study does not involve human subjects and requires no ethical approval or patient consent. The results of the network meta-analysis will be submitted in a peer-reviewed journal for publication and generate a comprehensive suggestion for the treatment of PCV.

The Use of Vascular Endothelial Growth Factor Inhibitors and Complementary Treatment Options in Polypoidal Choroidal Vasculopathy: A Subtype of Neovascular Age-Related Macular Degeneration

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular age-related macular degeneration (AMD; nAMD) which occurs more commonly in Asian populations as compared to Caucasians. PCV and nAMD share pathological mechanisms, including pathological expression of vascular endothelial growth factor (VEGF). The advent of anti-vascular endothelial growth factor (VEGF) revolutionized the treatment of nAMD. Despite being a subtype of nAMD, PCV responds less well to VEGF inhibitors; thus, photodynamic therapy (PDT) in combination with anti-VEGF treatment may be considered. This review aims to summarize the current evidence for the treatment of PCV, especially whether VEGF inhibitors should be used alone or in combination with PDT.

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.

Clinical outcomes in Caucasian patients with polypoidal choroidal vasculopathy

PURPOSE

To describe treatment outcomes in a cohort of Caucasian patients with polypoidal choroidal vasculopathy (PCV).

METHODS

Clinical charts from 48 eyes of 45 Caucasian patients with PCV were retrospectively reviewed. All cases were diagnosed with indocyanine green angiography. Best corrected visual acuity (BCVA) and optical coherence tomography (OCT) imaging were analyzed at baseline and final follow-up.

RESULTS

Eyes were treated with a combination of verteporfin photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) (n = 24), or PDT monotherapy (n = 9), or anti-VEGF monotherapy (n = 8), or no treatment (n = 7). Aflibercept was the anti-VEGF agent in 30 out of 32 eyes. Sixteen out of 24 eyes in the combination treatment group received initial PDT at diagnosis. All treatments led to stabilization of BCVA at final visit with a trend for better visual acuity in the anti-VEGF monotherapy group. There was a substantial reduction in central retinal thickness associated with resolution of subfoveal fluid and improvement in retinal pigment epithelial detachment in all treatment groups. BCVA and OCT findings remained stable in eyes which received no treatment. The use of PDT was associated with 0.5 fewer intravitreal injections per annum, which was not statistically significant.

CONCLUSIONS

In the largest series of Caucasian patients with PCV presented to date, anti-VEGF monotherapy, PDT, or their combination preserved visual acuity and improved subfoveal exudative changes. Combination treatment was not superior to anti-VEGF monotherapy.

ONE-YEAR RESULTS OF HALF- VERSUS STANDARD-DOSE PHOTODYNAMIC THERAPY COMBINED WITH RANIBIZUMAB FOR POLYPOIDAL CHOROIDAL VASCULOPATHY

PURPOSE

To explore the efficacy of half-dose verteporfin photodynamic therapy (hd-PDT) and standard-dose photodynamic therapy (sd-PDT), when combined with ranibizumab in the treatment of polypoidal choroidal vasculopathy.

METHODS

Subjects were allocated to either the hd-PDT arm or the sd-PDT arm. All subjects received an injection of ranibizumab and PDT treatment (dosage according to allocation) at baseline. Subjects were followed up monthly for 12 months, and re-treatment were given at each visit if criteria were met.

RESULTS

There were 26 subjects in the hd-PDT arm and 32 in the sd-PDT arm. Overall mean age was 69.3 ± 9.4 years. Baseline demographics and ocular features did not differ significantly between the two arms. Improvement in vision and reduction in central retinal thickness were similar between the two arms. When presenting, visual acuity was better than 20/50 (logarithm of the minimum angle of resolution 0.4), or when there were three or less polyps angiogram, those treated with hd-PDT tended to perform better than those treated with sd-PDT.

CONCLUSION

In general, hd-PDT was able to produce similar results as sd-PDT. Subgroup analysis revealed superior results with hd-PDT when baseline vision was 20/50 or better, or when there were three or less polyps on indocyanine green angiography.

Comparison of the effects of photodynamic therapy, intravitreal ranibizumab and combination for polypoidal choroidal vasculopathy under 1 + PRN regimen

Background

The optimal treatment for polypoidal choroidal vasculopathy (PCV) is still under debate. Little knowledge is known about the treatment effect of “1+pro re nata(PRN)” treatment regimen for PCV. The aim of this study was to compare the outcomes of photodynamic therapy (PDT), intravitreal ranibizumab injection (IVR) and combination therapy under the “1 + PRN” treatment regimen for PCV.

Methods

Fifty-seven eyes of 57 patients completed the 12 months’ follow-up in this prospective study. The patients in the PDT arm(n = 23), ranibizumab arm(n = 18), or combination arm(n = 16) underwent a session of PDT, IVR or combination of both at baseline followed by additional IVR as needed. Mean change of logarithm of the minimal angle of resolution (logMAR) visual acuity (VA), central foveal thickness (CFT) and the regression rate of polyps were evaluated. Cost-benefit analysis was also performed.

Results

At Month 12, the mean logMAR VA improved from 0.90 ± 0.52 to 0.75 ± 0.57 in the PDT group (P < 0.05), from 0.96 ± 0.58 to 0.77 ± 0.41 in the IVR group (P < 0.05), and from 0.94 ± 0.55 to 0.72 ± 0.44 in the combination group (P < 0.05), respectively. The CFT decreased from 478.04 ± 156.70 μm, 527.5 ± 195.90 μm, and 522.63 ± 288.40 μm at the baseline to 366.43 ± 148.28 μm, 373.17 ± 134.88 μm and 328.44 ± 103.25 in the PDT group (P < 0.05), IVR group (P < 0.01), and the combination group (P < 0.05), respectively. However, no statistical difference was found between groups (P > 0.05). PDT treatment (60.87%) was superior to the IVR therapy (22.22%) in achieving complete regression of polyps (P < 0.05). Cost-benefit analysis showed that IVR treatment cost the least money for improving per 0.1logMAR units and the combination therapy demanded the least money for reducing per 100 μm of CFT.

Conclusions

PDT, IVR and the combination therapy have similar efficacy in the VA improvement as well as the reduction of CFT under the “1 + PRN” treatment regimen.

Trial registration

Current Controlled Trials NCT03459144. Registered retrospectively on March 2, 2018.

Combination of bevacizumab and photodynamic therapy vs. bevacizumab monotherapy for the treatment of wet age-related macular degeneration: A meta-analysis of randomized controlled trials

The purpose of this meta-analysis was to compare the efficacy and safety of the combination of bevacizumab and photodynamic therapy (PDT) with bevacizumab monotherapy for the treatment of age-related macular degeneration (AMD). Patients with active choroidal neovascularization (CNV) secondary to AMD were included in the present study. The treatment group included patients treated with a combination of bevacizumab and PDT and patients treated with bevacizumab monotherapy. Only randomized controlled trials (RCTs) were included in the analysis. The PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases were searched. Meta-analysis was performed using RevMan v.5.3 software, and best-corrected visual acuity (BCVA), central retinal thickness (CRT) and the average number of bevacizumab retreatments were assessed. A total of 5 RCTs were included in the analysis. There were no significant differences observed in the mean BCVA change between the combination treatment group and the bevacizumab monotherapy group [standard mean difference 0.20; 95% confidence interval (CI) −0.53, 0.93, P=0.59]. There were also no significant differences in the CRT increases between the two groups [weighted mean difference (WMD) −22.16, 95% CI −52.01 to 7.69, P=0.15]. No significant differences were observed in the proportions of patients gaining >15 letters between the two groups [risk ratio (RR) 0.86, 95% CI 0.64, 1.15, P=0.30]. However, the average number of the ranibizumab retreatments was significantly lower in the combination treatment group compared with the bevacizumab monotherapy group (WMD, −2.70, 95% CI −3.93 to −1.46; P<0.0001). Additionally, there were no significant differences in the rate of ocular adverse events (RR, 0.57; 95% CI, 0.27 to 1.22; P=0.15) and systemic adverse events (RR, 5.42; 95% CI, 0.29 to 101.77; P=0.26) between the two groups. In conclusion there were no significant differences in mean BCVA change, CRT increases, the proportions of patients gaining >15 letters, or the incidences of ocular adverse events and systemic adverse events. However, combination treatment may significantly reduce the average number of bevacizumab retreatments compared with monotherapy.

N-acetylcysteine protects against chorioretinal damage induced by photodynamic therapy for experimental choroidal neovascularization in a rat model

PURPOSE

We explored the protective effects of N-acetylcysteine (NAC) on chorioretinal damage induced by photodynamic therapy (PDT) in an experimental rat model of choroidal neovascularization (CNV).

METHODS

Experimental CNV was induced by an argon laser in 24 Brown Norway rats 7 days prior to PDT. Commencing 1 day after CNV induction, 0.5 mL of NAC was orally administered daily to the NAC + group (12 rats), and 0.5 mL of normal saline to the NAC- group (12 rats). Diode laser treatment was delivered for 42 s (total energy, 25 J/cm2) to the left eye prior to verteporfin infusion (PDT-) and to the right eye 15-20 min after such infusion (PDT+). Fluorescein angiography was performed just prior to PDT and enucleation to evaluate fluorescein leakage and CNV closure. We compared the CNV thickness, PDT-induced apoptosis [evaluated via terminal dUTP nick-end labeling (TUNEL)], fluorescein angiographic data, and extents of immunohistofluorescent staining for cleaved caspase-3 and superoxide dismutase (SOD) between the two groups.

RESULTS

Fourteen days after diode laser treatment, the CNV closure rate was significantly higher in the PDT-treated than the control group. However, the CNV closure rates did not differ significantly between the NAC- and NAC + groups. The TUNEL activity (a measure of PDT-induced apoptosis) of retinal cells was higher in the NAC-/PDT + than the NAC+/PDT + group at 1, 3, 7, and 14 days. The cleaved caspase-3 and SOD levels were higher in the NAC-/PDT + than the NAC+/PDT + group at 3 and 7 days.

CONCLUSIONS

PDT triggers oxygen radical-induced injury to, and apoptosis in, the retina. NAC may reduce PDT-induced damage to the retina without compromising the therapeutic efficacy of CNV.

Intravitreal ranibizumab injection combined with photodynamic therapy for polypoidal choroidal vasculopathy

The aim of the present study was to evaluate the efficacy of combination treatment with intravitreal ranibizumab (IVR) injection and photodynamic therapy (PDT) for polypoidal choroidal vasculopathy (PCV). A total of 64 patients with PCV were included in the present study, which were divided into the IVR monotherapy group (Group A) and combination treatment groups (Groups B-D) with different treatment intervals. All subjects were followed-up at 1, 3, 6 and 12 months following treatment, and subjected to the detection of best-corrected visual acuity (BCVA) and central foveal thickness (CFT). Compared with the monotherapy group, more significant BCVA improvement was observed for the combination treatment groups, with the most evident effect exhibited in Group C. At the end of the follow-up period, visual acuity improvement rates were markedly elevated in the combination treatment groups, as compared with the monotherapy group. According to optical coherence tomography, the CFT for the combination treatment groups was thinner than the monotherapy group. Among the combination groups, CFT improvement for Group C was superior to other groups. Fundus angiography demonstrated that, compared with monotherapy, combination treatment may significantly promote the regression and prevent the recurrence of polyps and BVN. The most efficient effectiveness was observed for Group C. In addition, combination treatment may significantly reduce the IVR injection numbers required to treat PCV. Patients receiving combination treatment with IVR injection and PDT have greater vision improvements, reduced macular degeneration and decreased injection numbers. Combination therapy may therefore, represent an effective and safe therapeutic strategy for PCV clinical treatment.

Polypoidal choroidal vasculopathy treatment options: A meta-analysis

BACKGROUND

Combined treatment with intravitreal anti-vascular endothelial growth factor (anti-VEGF) and verteporfin photodynamic therapy (PDT) is widely used for patients with polypoidal choroidal vasculopathy (PCV), although clinical evidence regarding the therapeutic efficacy and safety of such treatment remains lacking.

DESIGN/METHODS

We performed a meta-analysis of previously reported studies comparing combination treatment, PDT monotherapy, and anti-VEGF monotherapy. Primary outcome measures included changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT). The proportion of patients with polyp regression was regarded as the secondary outcome measure.

RESULTS

Twenty studies (three RCTs and 19 retrospective studies) involving 1,178 patients with PCV were selected. Significant differences in the proportion of patients with polyps were observed between the PDT and anti-VEGF monotherapy groups at 3 and ≥6 months (P < .00001; and P = .0001, respectively). Significantly greater reductions in CRT were observed in the anti-VEGF than in the PDT group at the 3-month follow-up (P = .04). Significantly greater improvements in BCVA were observed in the combined therapy group than in the PDT monotherapy group at 3, 6, 12, and 24 months (P = .03; P = .005; P = .02; and P < .00001, respectively). Combined treatment also resulted in significantly greater improvements in BCVA than monotherapy with anti-VEGF at 6 and 24 months (P = .001; P < .00001, respectively), and significantly greater polyp regression than that observed following anti-VEGF treatment at 3 and ≥6 months (P < .00001; P < .0001, respectively).

CONCLUSIONS

Combined therapy involving anti-VEGF agents and PDT may be more effective in improving long-term outcomes for patients with PCV than monotherapy.

Inhibition of Laser-Induced Choroidal Neovascularization by Hematoporphyrin Dimethylether-Mediated Photodynamic Therapy in Rats

This study aimed to investigate the effect of hematoporphyrin dimethylether (HDME)-mediated photodynamic therapy for laser-induced choroidal neovascularization (CNV) in adult Brown Norway rats. HDME was administered via tail vein at 14 d after the laser photocoagulation, and the rats received irradiance with a laser light at 570 nm at 15 min after injection. CNV was evaluated by fundus photography, fundus fluorescein angiography, optical coherence tomography, and hematoxylin and eosin staining. We found that CNV was occurred at 7 d after photocoagulation and reaching peak activity at 14 d after photocoagulation. There is a significant reduction in the total area of the fluorescein leakage and the number of strong fluorescein leakage spots on 7 d after HDME-mediated photodynamic therapy (PDT). The results suggest that HDME-mediated PDT inhibits laser-induced CNV in rats, representing a promising therapy for wet age-related macular degeneration.

Incidence, outcomes, and risk factors for hemorrhagic complications in eyes with polypoidal choroidal vasculopathy following photodynamic therapy in Indian subjects

PURPOSE

To evaluate the incidence, outcomes, and risk factors for hemorrhagic complications in eyes with polypoidal choroidal vasculopathy (PCV) following photodynamic therapy (PDT).

METHODS

Medical records of 94 eyes of 86 consecutive patients with PCV who underwent PDT between January 2007 and December 2014 were retrospectively reviewed. The diagnosis of PCV was based on clinical features and indocyanine green angiography. Eyes were treated with PDT monotherapy or a combination of PDT plus anti-vascular endothelial growth factor. PDT was performed at (standard [SFPDT] or reduced fluence RFPDT).

RESULTS

Ninety-four eyes had 119 PDT treatment sessions (mean: 1.3 sessions). Mean presenting vision was 0.46 ± 0.44 logarithm of the minimum angle of resolution (logMAR). Following PDT, ten eyes (11%) of nine patients had hemorrhagic complications such as subretinal hemorrhage (SRH; n = 5), subretinal pigment epithelium (RPE) hemorrhage (n = 1), breakthrough vitreous hemorrhage (BVH; n = 3), and SRH with sub-RPE hemorrhage and BVH (n = 1). Median interval to hemorrhage following PDT was 2 months. Age (P = 0.842), duration of symptoms (P = 0.352), number of laser spots (P = 0.219), and laser spot size (LSS) (P = 0.096) were not significantly associated with increased risk of hemorrhagic complications. Female gender was associated with reduced risk of hemorrhage (P = 0.045). SFPDT was significantly associated with increased risk of hemorrhage (P = 0.026). The probability of developing hemorrhagic complications in SFPDT group was 0.24 compared to 0.07 in RFPDT group (P = 0.039). Multivariate logistic regression analysis showed SFPDT as the only significant risk factor for hemorrhage following PDT (odds ratio 5.3, 95% confidence interval 1.1-24.8, P = 0.03). Mean final vision was 0.61 ± 0.53 logMAR at mean follow-up of 33 months (median = 22 months; range = 2-157 months).

CONCLUSION

Age, LSS, number of laser spots, preexisting hemorrhages, or use of anticoagulants were not associated with increased risk of hemorrhagic complications. SFPDT was significantly associated with increased risk of hemorrhagic complications in such eyes.

Proteolytic Degradation and Inflammation Play Critical Roles in Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) is a common subtype of wet age-related macular degeneration in Asian populations, whereas choroidal neovascularization is the typical subtype in Western populations. The cause of PCV is unknown. By comparing the phenotype of a PCV mouse model expressing protease high temperature requirement factor A1 (HTRA1) in retinal pigment epithelium with transgenic mice expressing the inactive HTRA1S328A, we showed that HTRA1-mediated degradation of elastin in choroidal vessels is critical for the development of PCV, which exhibited destructive extracellular matrix remodeling and vascular smooth muscle cell loss. Compared with weak PCV, severe PCV exhibited prominent immune complex deposition, complement activation, and infiltration of inflammatory cells, suggesting inflammation plays a key role in PCV progression. More important, we validated these findings in human PCV specimens. Intravitreal delivery of an HTRA1 inhibitor (DPMFKLboroV) was effective (36% lesion reduction; P = 0.009) in preventing PCV initiation but ineffective in treating existing lesions. Anti-inflammatory glucocorticoid was effective in preventing PCV progression but ineffective in preventing PCV initiation. These results suggest that PCV pathogenesis occurs through two stages. The initiation stage is mediated by proteolytic degradation of extracellular matrix proteins attributable to increased HTRA1 activity, whereas the progression stage is driven by inflammatory cascades. This study provides a basis for understanding the differences between PCV and choroidal neovascularization, and helps guide the design of effective therapies for PCV.