An adeno-associated virus variant enabling efficient ocular-directed gene delivery across species.

Recombinant adeno-associated viruses (rAAVs) have emerged as promising gene therapy vectors due to their proven efficacy and safety in clinical applications. In non-human primates (NHPs), rAAVs are administered via suprachoroidal injection at a higher dose. However, high doses of rAAVs tend to increase additional safety risks. Here, we present a novel AAV capsid (AAVv128), which exhibits significantly enhanced transduction efficiency for photoreceptors and retinal pigment epithelial (RPE) cells, along with a broader distribution across the layers of retinal tissues in different animal models (mice, rabbits, and NHPs) following intraocular injection. Notably, the suprachoroidal delivery of AAVv128-anti-VEGF vector completely suppresses the Grade IV lesions in a laser-induced choroidal neovascularization (CNV) NHP model for neovascular age-related macular degeneration (nAMD). Furthermore, cryo-EM analysis at 2.1 Å resolution reveals that the critical residues of AAVv128 exhibit a more robust advantage in AAV binding, the nuclear uptake and endosome escaping. Collectively, our findings highlight the potential of AAVv128 as a next generation ocular gene therapy vector, particularly using the suprachoroidal delivery route.

A novel capsid-XL32-derived adeno-associated virus serotype prompts retinal tropism and ameliorates choroidal neovascularization.

Gene therapy has been adapted, from the laboratory to the clinic, to treat retinopathies. In contrast to subretinal route, intravitreal delivery of AAV vectors displays the advantage of bypassing surgical injuries, but the viral particles are more prone to be nullified by the host neutralizing factors. To minimize such suppression of therapeutic effect, especially in terms of AAV2 and its derivatives, we introduced three serine-to-glycine mutations, based on the phosphorylation sites identified by mass spectrum analysis, to the XL32 capsid to generate a novel serotype named AAVYC5. Via intravitreal administration, AAVYC5 was transduced more effectively into multiple retinal layers compared with AAV2 and XL32. AAVYC5 also enabled successful delivery of anti-angiogenic molecules to rescue laser-induced choroidal neovascularization and astrogliosis in mice and non-human primates. Furthermore, we detected fewer neutralizing antibodies and binding IgG in human sera against AAVYC5 than those specific for AAV2 and XL32. Our results thus implicate this capsid-optimized AAVYC5 as a promising vector suitable for a wide population, particularly those with undesirable AAV2 seroreactivity.

Preclinical evaluation of KH631, a novel rAAV8 gene therapy product for neovascular age-related macular degeneration.

The upregulation of vascular endothelial growth factor (VEGF) is strongly associated with the development of choroidal neovascularization (CNV) in patients with neovascular age-related macular degeneration (nAMD). Currently, the standard treatment for nAMD involves frequent intravitreal injections of anti-VEGF agents, which inhibit the growth of new blood vessels and prevent leakage. However, this treatment regimen places a significant burden on patients, their families, and healthcare providers due to the need for repeated visits to the clinic for injections. Gene therapy, which enables the sustained expression of anti-VEGF proteins after a single injection, can dramatically reduce the treatment burden. KH631 is a recombinant adeno-associated virus 8 vector that encodes a human VEGF receptor fusion protein, and it is being developed as a long-term treatment for nAMD. In preclinical studies using non-human primates, subretinal administration of KH631 at a low dose of 3 × 108 vg/eye resulted in remarkable retention of the transgene product in the retina and prevented the formation and progression of grade IV CNV lesions. Furthermore, sustained transgene expression was observed for more than 96 weeks. These findings suggest that a single subretinal injection of KH631 has the potential to offer a one-time, low-dose treatment for nAMD patients.

Choroidal neovascularization removal with photo-mediated ultrasound therapy.

BACKGROUND: Age-related macular degeneration (AMD) is a major cause of irreversible central vision loss. The main reason for lost vision due to AMD is choroidal neovascularization (CNV). In the clinic, current treatments for CNV include photodynamic therapy, laser photocoagulation, and anti-vascular endothelial growth factor (VEGF) therapy. PURPOSE: This study evaluates a novel treatment technique combining synchronized nanosecond laser pulses and ultrasound bursts, namely photo-mediated ultrasound therapy (PUT) as a potential treatment method for CNV, for its efficacy and safety in the treatment of CNV via the experiments in a clinically-relevant rabbit model in vivo. METHODS: CNV was created by subretinal injection of Matrigel and vascular endothelial growth factor (M&V) in 10 New Zealand white rabbits. Six rabbits were used in the PUT group. In the control groups, two rabbits were treated by laser-only, and two rabbits were treated by ultrasound-only. The treatment efficacy was evaluated through fundus photography and fluorescein angiography (FA) longitudinally for up to 4 weeks. Rabbits were sacrificed for histopathology 3 months after treatment to examine the safety of PUT. RESULTS: The fluorescein leakage on FA was quantified to longitudinally evaluate treatment outcome. Compared with baseline, the relative intensity index was reduced by 26.57% ± 8.66% at 3 days after treatment, 27.24% ± 6.21% at 1 week after treatment, 27.79% ± 2.61% at 2 weeks after treatment, and 32.12% ± 3.23% at 4 weeks after treatment, all with a statistically significant difference of p < 0.01. The comparison between the relative intensity indexes from the two control groups (laser-only treatment and ultrasound-only treatment) did not show any statistically significant difference at all time points. Safety evaluation at 3 months with histopathology demonstrated that the PUT did not result in morphologic changes to the neurosensory retina. CONCLUSIONS: This study introduces PUT for the first time for the treatment of CNV. The results demonstrated good efficacy and safety of PUT to treat CNV in a clinically-relevant rabbit model. With a single session of treatment, PUT can safely reduce the leakage of CNV for at least 1 month after treatment.

CRISPR/Cas9 mediated specific ablation of vegfa in retinal pigment epithelium efficiently regresses choroidal neovascularization.

The CRISPR/Cas9 system easily edits target genes in various organisms and is used to treat human diseases. In most therapeutic CRISPR studies, ubiquitously expressed promoters, such as CMV, CAG, and EF1α, are used; however, gene editing is sometimes necessary only in specific cell types relevant to the disease. Therefore, we aimed to develop a retinal pigment epithelium (RPE)-specific CRISPR/Cas9 system. We developed a CRISPR/Cas9 system that operates only in retinal pigment epithelium (RPE) by expressing Cas9 under the RPE-specific vitelliform macular dystrophy 2 promoter (pVMD2). This RPE-specific CRISPR/pVMD2-Cas9 system was tested in human retinal organoid and mouse model. We confirmed that this system works specifically in the RPE of human retinal organoids and mouse retina. In addition, the RPE-specific Vegfa ablation using the novel CRISPR-pVMD2-Cas9 system caused regression of choroidal neovascularization (CNV) without unwanted knock-out in the neural retina in laser-induced CNV mice, which is a widely used animal model of neovascular age-related macular degeneration. RPE-specific Vegfa knock-out (KO) and ubiquitous Vegfa KO were comparable in the efficient regression of CNV. The promoter substituted, cell type-specific CRISPR/Cas9 systems can be used in specific 'target cell' therapy, which edits genes while reducing unwanted off- 'target cell' effects.

LATE CHOROIDAL NEOVASCULAR COMPLICATIONS IN A PATIENT TREATED FOR RETINOBLASTOMA. A CASE REPORT.

AIM: Case report of choroidal neovascularization (CNV) detection in patient who was treated for bilateral retinoblastoma in early childhood. MATERIAL AND METHODS: Patient at 1.5 years of age treated for endophytic retinoblastoma stage 4 (according to the Reese-Ellsworth classification) bilaterally, with a positive mutation in the Rb1 gene. After undergoing bilateral retinal laser treatment and 6 cycles of systemic chemotherapy, the tumor remained inactive without other complications. At the age of 14, the boy developed visual impairment in his left eye with metamorphosis. Based on a local finding and other auxiliary examinations, he was diagnosed with CNV in the macular area at the interface of the tumor scar and the healthy retina of the left eye. RESULTS: After three applications of anti-VEGF (antibodies blocking vascular endothelial growth factor) substance intravitreally (bevacizumab 1.2 mg), there was a reduction in CNV and also an improvement in visual function.

A Hypoxia-Regulated Retinal Pigment Epithelium-Specific Gene Therapy Vector Reduces Choroidal Neovascularization in a Mouse Model.

BACKGROUND: Wet age-related macular degeneration (wAMD) is characterized by the presence of choroidal neovascularization (CNV). Although there are some clinical drugs targeting vascular endothelial growth factor (VEGF) and inhibiting CNV, two major side effects limit their application, including the excessive activity of anti-VEGF and frequent intraocular injections. To explore better treatment strategies, researchers developed a hypoxic modulator retinal pigment epithelium (RPE)- specific adeno-associated virus (AAV) vector expressing endostatin to inhibit CNV. However, the mechanism of endostatin is complex. Instead, soluble fms-like tyrosine kinase-1 (sFlt-1) can inhibit VEGF-induced angiogenesis through two simple and clear mechanisms, giving rise to sequestration of VEGF and forming an inactive heterodimer with the membrane-spanning isoforms of the VEGF receptor Flt-1 and kinase insert domain-containing receptor. OBJECTIVE: In this study, we chose sFlt-1 as a safer substitute to treat wAMD by inhibiting VEGFinduced angiogenesis. METHODS: The AAV2/8-Y733F-REG-RPE-sFlt-1 vector was delivered by intravitreal injection to the eyes of mice. AAV2/8-Y733F vector is a mutant of the AAV2/8 vector, and the REG-RPE promoter is a hypoxia-regulated RPE-specific promoter. Two animal models were used to evaluate the function of the vector. RESULTS: In the cobalt chloride-induced hypoxia model, the results demonstrated that the AAV2/8- Y733F-REG-RPE-sFlt-1 vector induced the expression of the sFlt-1 gene in RPE cells through hypoxia. In the laser-induced CNV model, the results demonstrated that the AAV2/8-Y733F-REG-RPE-sFlt- 1 vector reduced laser-induced CNV. CONCLUSION: Hypoxia regulated, RPE-specific AAV vector-mediated sFlt-1 gene is a hypoxiaregulated antiangiogenic vector for wAMD.

The Anti-Inflammatory Effect of Hydrogen Gas Inhalation and Its Influence on Laser-Induced Choroidal Neovascularization in a Mouse Model of Neovascular Age-Related Macular Degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. Choroidal neovascularization (CNV) is the major pathologic feature of neovascular AMD. Oxidative damages and the ensuing chronic inflammation are representative of trigger events. Hydrogen gas (H2) has been demonstrated as an antioxidant and plays a role in the regulation of oxidative stress and inflammation. This experiment aimed to investigate the influence of H2 inhalation on a mouse model of CNV. METHODS: Laser was used to induce CNV formation. C57BL/6J mice were divided into five groups: the control group; the laser-only group; and the 2 h, 5 h, and 2.5 h/2.5 h groups that received laser and H2 inhalation (21% oxygen, 42% hydrogen, and 37% nitrogen mixture) for 2 h, 5 h, and 2.5 h twice every day, respectively. RESULTS: The severity of CNV leakage on fluorescence angiography showed a significant decrease in the H2 inhalation groups. The mRNA expression of hypoxia-inducible factor 1 alpha and its immediate downstream target vascular endothelial growth factor (VEGF) showed significant elevation after laser, and this elevation was suppressed in the H2 inhalation groups in an inhalation period length-related manner. The mRNA expression of cytokines, including tumor necrosis factor alpha and interlukin-6, also represented similar results. CONCLUSION: H2 inhalation could alleviate CNV leakage in a laser-induced mouse CNV model, and the potential mechanism might be related to the suppression of the inflammatory process and VEGF-driven CNV formation.

Macrophage-derived interleukin-6 is necessary and sufficient for choroidal angiogenesis.

Neovascular age-related macular degeneration (nAMD) commonly causes vision loss from aberrant angiogenesis, termed choroidal neovascularization (CNV). Interleukin-6 (IL6) is a pro-inflammatory and pro-angiogenic cytokine that is correlated with AMD progression and nAMD activity. We hypothesize that anti-IL6 therapy is a potential nAMD therapeutic. We found that IL6 levels were increased after laser injury and expressed by macrophages. Il6-deficiency decreased laser-induced CNV area and exogenous IL6 addition increased choroidal sprouting angiogenesis. Il6-null mice demonstrated equally increased macrophage numbers as wildtype mice. At steady state, IL6R expression was detected on peripheral blood and ocular monocytes. After laser injury, the number of IL6R+Ly6C+ monocytes in blood and IL6R+ macrophages in the eye were increased. In human choroid, macrophages expressed IL6, IL6R, and IL6ST. Furthermore, IL6R+ macrophages displayed a transcriptional profile consistent with STAT3 (signal transducer and activator of transcription 3) activation and angiogenesis. Our data show that IL6 is both necessary and sufficient for choroidal angiogenesis. Macrophage-derived IL6 may stimulate choroidal angiogenesis via classical activation of IL6R+ macrophages, which then stimulate angiogenesis. Targeting IL6 or the IL6R could be an effective adjunctive therapy for treatment-resistant nAMD patients.

Clinical course after the onset of choroidal neovascularization in eyes with central serous chorioretinopathy.

ABSTRACT: Chronic central serous chorioretinopathy (CSC) can be complicated with choroidal neovascularization (CNV); however, the timing of its occurrence and its clinical significance are not well understood. This study aimed to observe the time of choroidal neovascularization detection after CSC diagnosis and determine whether clinical features and prognosis differed in patients with chronic CSC or age-related retinal degeneration.In this retrospective study, medical records of CSC patients complicated with CNV who visited Seoul St. Mary's hospital of Korea between October 2009 and December 2020 were reviewed. The presence of CNV was determined using fluorescein, indocyanine green, or optical coherent tomography angiography (OCTA). Based on the patients' medical records, we observed the change of clinical pattern, best-corrected visual acuity (BCVA) and central macular thickness (CMT) at CNV detection and at 6 months, 1 year, 3 years, and 5 years following CNV detection.Thirty eyes of 30 patients (male: female ratio of 13:17) were enrolled. Mean age at diagnosis of CSC was 54.0 ±â€Š8.5 years (mean ±â€Šstandard deviation). On average, CNV was detected 1.65 ±â€Š2.30 years after the diagnosis of CSC. The mean CMT was significantly decreased at 6 months, 1 year, and 3 years after choroidal neovascularization detection (P < .001, P < .001, P = .001 respectively). BCVA tend to improve after CNV detection, but there was no statistical significance at 6 months, 1 year, 3 years, and 5 years (all with P > .05). There were no clinical findings suggesting age-related macular degeneration such as intraretinal, subretinal hemorrhage or drusen in any of the case during follow-up. None of the subjects had severe visual acuity loss of 1.0 logarithm of the minimum angle of resolution (logMAR) (20/200 Snellen equivalent) or greater. Among the subjects, 6 patients (20%) did not require any treatment during observation, while 24 other patients required anti-vascular endothelial growth factor (anti-VEGF) or photodynamic therapy. At the last visit, 22 patients (73.3%) remained stable for more than 6 months, without subretinal fluid recurrence.Choroidal neovascularization was detected earlier than previously reported. There was no rapid deterioration of visual acuity or clinical features even after CNV detection.

Reduction of choroidal neovascularization via cleavable VEGF antibodies conjugated to exosomes derived from regulatory T cells.

Choroidal neovascularization induced by age-related macular degeneration and retinal neovascularization induced by diabetic retinopathy-two leading causes of blindness-are often treated using antibodies targeting vascular endothelial growth factor (VEGF). Here we report a strong association between inflammation and high VEGF expression in aqueous humour samples from patients with choroidal or retinal neovascularization, and show that intravitreally injected exosomes derived from regulatory T cells and conjugated with an anti-VEGF antibody via a peptide linker that is cleavable by matrix metalloproteinases markedly suppressed ocular neovascularization in mouse and non-human primate models of choroidal neovascularization. The engineered exosomes, which selectively accumulate in the neovascularization lesions, could be adapted for other combination therapies of therapeutic antibodies and anti-inflammatory cargo.

Emerging biological therapies for the treatment of age-related macular degeneration.

INTRODUCTION: Age-related macular degeneration (AMD) is the leading cause of blindness in individuals over age 50 in developed countries. Current therapy for nonexudative AMD (neAMD) is aimed at modifying risk factors and vitamin supplementation to slow progression, while intravitreal anti-vascular endothelial factor (VEGF) injections are the mainstay for treatment of choroidal neovascularization in exudative AMD (eAMD). AREAS COVERED: Over the past decade, promising therapies have emerged that aim to improve the current standard of care for both diseases. Clinical trials for neAMD are investigating targets in the complement cascade, vitamin A metabolism, metformin, and tetracycline, whereas clinical trials for eAMD are aiming to decrease treatment burden through novel port delivery systems, increasing drug half-life, and targeting new sites of the VEGF cascade. Stem cell and gene therapy are also being evaluated for treatment of neAMD and eAMD. EXPERT OPINION: With an aging population, the need for effective, long term, low burden treatment options for AMD will be in increasingly high demand. Current investigations aim to address the shortcomings of current treatment options with breakthrough treatment approaches. Therapeutics in the pipeline hold promise for improving the treatment of AMD, and are on track for widespread use within the next decade.

Comprehensive Preclinical Assessment of ADVM-022, an Intravitreal Anti-VEGF Gene Therapy for the Treatment of Neovascular AMD and Diabetic Macular Edema.

Inhibition of vascular endothelial growth factor is the mode of action for several approved therapies, including aflibercept, for the treatment of neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME). Lack of compliance due to the frequent intravitreal dosing requirements may result in inadequately treated disease, leading to irreversible vision impairment. To date, the majority of gene therapy clinical trials providing sustained anti-VEGF levels in the retina have been limited to subretinal injections requiring a vitrectomy. A single intravitreal injection of a gene therapy product could drastically reduce the treatment burden and improve visual outcomes. ADVM-022, an adeno-associated virus vector encoding aflibercept, has been optimized for intravitreal delivery and strong protein expression. Long-term expression and efficacy of ADVM-022-derived aflibercept were evaluated in a laser-induced choroidal neovascularization (CNV) model in non-human primates. Ocular safety was evaluated following long-term suppression of VEGF by clinical scoring (inflammatory parameters) as well as optical coherence tomography (OCT) and electroretinography (ERG). Intravitreal administration of ADVM-022 was well tolerated and resulted in sustained aflibercept levels in ocular tissues. In addition, ADVM-022 administration 13 months before laser-induced CNV prevented the occurrence of clinically relevant CNV lesions, to the same degree as a bolus of aflibercept delivered at the time of laser. These results demonstrate that a single intravitreal administration of ADVM-022 may provide a safe and effective long-term treatment option for nAMD and DME, and may ultimately improve patients' visual outcomes. Clinical trials are currently underway, evaluating safety and efficacy following a single intravitreal injection of ADVM-022.

Comparison of visual outcomes between therapy choices and subtypes of polypoidal choroidal vasculopathy (PCV) in Taiwan: a real-world study.

Polypoidal choroidal vasculopathy (PCV) is a distinctive type of neovascular age-related macular degeneration prevalent in many Asian countries. However, there is still some controversy in how the subtypes of PCV are classified. This post-hoc study redefined the branching vascular network (BVN) and PCV subtypes through retrospective review of indocyanine green angiography (ICGA) and fluorescein angiography images from two observational studies (RENOWNED/REAL). Of the visual outcomes for each angiographic subtype and treatment pattern investigated, BVN was identified in 56.3% of PCV patients. The proportions and features of the re-defined PCV subtypes were 43.8%, 10.4%, and 45.8% for subtype A (without distinctive features of BVN), B (with BVN but no leakage), and C (with BVN and leakage), respectively. Subtype A had better visual outcomes when compared to subtype C. This possibly resulted from a better baseline visual acuity in subtype A. Moreover, combination therapy [photodynamic therapy plus anti-vascular endothelial growth factor (VEGF)] may lead to better visual improvement than mono-anti-VEGF treatment alone. This study provides the prevalence of PCV subtypes in Taiwan and may serve as a reference for PCV treatment strategies in a real-world setting, especially for the combination therapy and patients without distinctive features of BVN.

Idiopathic polypoidal choroidal vasculopathy: a review of literature with clinical update on current management practices.

PURPOSE: Polypoidal choroidal vasculopathy is a major cause of visual disability in a vast majority of Asian population due to exudative maculopathy. Although it is a distinctive disease entity with characteristic pathophysiology, genetics, immunology and clinical features, but it is still misdiagnosed as neovascular age related macular degeneration as both the diseases are a part of pachychoroid spectrum and have some similar features. Also, there are varied options for the management of this disease, but there are no clear recommendations. So, a detailed review of the literature has been done along with special attention to the recent therapeutic advances to help the readers get a better understanding of the disease and its current management practices. METHOD: Detailed review of literature regarding polypoidal choroidal vasculopathy was done. The disease pathophysiology, genetics, risk factors, diagnostic modalities along with current treatment guidelines were extensively studied and compiled. RESULT: A comprehensive clinical update on polypoidal choroidal vasculopathy was compiled with special emphasis on the recent diagnostic modalities and treatment guidelines. CONCLUSION: Polypoidal choroidal vasculopathy is a distinct clinical entity which can be diagnosed based on indocyanine green angiography and optical coherence tomography. Treatment includes various options like photodynamic therapy, anti VEGF agents and thermal laser ablation. A review of literature has been done and recent diagnostic modalities with management practices have been compiled for the better understanding of the disease.

Presumed ocular histoplasmosis syndrome in a commercially insured population, United States.

PURPOSE: To describe epidemiologic features of patients with presumed ocular histoplasmosis syndrome (POHS) in the United States using insurance claims data and compare POHS patients with and without choroidal neovascularization (CNV). DESIGN: Retrospective cohort study. METHODS: Patients with International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for histoplasmosis retinitis on an outpatient claim in the 2014 IBM® MarketScan® Commercial Database and the Medicare Supplemental Database who were enrolled for at least 2 years after the POHS code. MAIN OUTCOME MEASURES: Data related to testing, treatment, and direct medical costs. RESULTS: Among >50 million total MarketScan enrollees, 6,678 (13 per 100,000) had a POHS diagnosis code. Of those, 2,718 were enrolled for 2 years; 698 (25%) of whom had a CNV code. Eleven of the 13 states with the highest POHS rates bordered the Mississippi and Ohio rivers. CNV patients had significantly more eye care provider visits (mean 8.8 vs. 3.2, p<0.0001), more ophthalmic imaging tests, higher rates of treatment with anti-vascular endothelial growth factor injections (45% vs. 4%, p<0.0001), and incurred higher mean total yearly costs ($1,251.83 vs. $251.36, p<0.0001) than POHS patients without CNV. CONCLUSIONS: Although the relationship between Histoplasma and POHS remains controversial, geographic patterns of POHS patient residence were consistent with the traditionally reported range of the fungus. CNV in the context of POHS was associated with additional healthcare use and costs. Further research to understand POHS etiology, risk factors, prevalence, and complications is needed, along with early diagnosis and treatment strategies.

A new rat model of treatment-naive quiescent choroidal neovascularization induced by human VEGF165 overexpression.

Vascular endothelial growth factor (VEGF) is a crucial stimulator for choroidal neovascularization (CNV). Our aim was to develop a reproducible and valid treatment-naive quiescent CNV (i.e. without signs of exudation and with normal visual acuity) rat model by subretinal injection of an adeno-associated virus (AAV)-VEGFA165 vector. The CNV development was longitudinally followed up in vivo by scanning laser ophthalmoscopy/optical coherence tomography, fluorescein and Indocyanine Green angiographies and ex vivo by electron microscopy (EM) and immunohistochemistry. In total, 57 eyes were analysed. In vivo, a quiescent CNV was observed in 93% of the eyes 6 weeks post-transduction. In EM, CNV vessels with few fenestrations, multi-layered basement membranes and bifurcation of endothelial cells were observed sharing the human CNV features. Human VEGF overexpression, multi-layered retinal pigment epithelium (RPE) (RPE65) and macrophages/activated microglia (Iba1) were also detected. In addition, 19 CNV eyes were treated for up to 3 weeks with bevacizumab. The retinal and CNV lesion thickness decreased significantly in bevacizumab-treated CNV eyes compared with untreated CNV eyes 1 week after the treatment. In conclusion, our experimental CNV resembles those seen in patients suffering from treatment-naive quiescent CNV in wet age-related macular degeneration (AMD), and responds to short-term treatment with bevacizumab. Our new model can, therefore, be used to test the long-term effect of new drugs targeting CNV under precisely-defined conditions.

Idiopathic polypoidal choroidal vasculopathy in Caucasians: The POLYON real-life study in 50 naive patients.

OBJECTIVES: Polypoidal choroidal vasculopathy is a common disease in Asia, but it has been less described in the Caucasian population. The aim of this real-life observational study was to describe the diagnostic and therapeutic practices as well as the prognosis in this population. METHOD: Fifty Caucasian patients with polypoidal choroidal vasculopathy were included in this study. All patients underwent angiography to confirm the diagnosis. Patients were divided into two treatment groups: patients of group 1 only received anti-vascular endothelial growth factor injections and those of group 2 required photodynamic therapy rescue in addition to intravitreal injections in case of suboptimal (anatomically or functionally) response. Clinical (visual acuity, fundus examination), paraclinical (retinal pigment epithelium detachment height and central retinal thickness on optical coherence tomography), and therapeutic (number of intravitreal injections) criteria were analyzed after 24 months. RESULTS: Patient mean age was 73.9 ± 9.1 years, and half of the patients had age-related macular degeneration. In the whole cohort, the initial visual acuity was equivalent to the final visual acuity (59.9 ± 24.0 letters vs 62.5 ± 21.1 letters, p = 0.259). In group 1, the final visual acuity was significantly increased (from 56.9 ± 24.7 letters to 63.4 ± 21.6 letters, p = 0.016), while in group 2, it remained stable (from 61.7 ± 23.4 letters to 61.0 ± 21.4 letters, p = 0.249). The number of intravitreal injections was similar between both groups. CONCLUSION: In a Caucasian population, polypoidal choroidal vasculopathy seems to have a later onset. A non-standardized management allows stabilizing the functional prognosis. Patients requiring photodynamic therapy rescue have a poorer prognosis.

Optimal Inhibition of Choroidal Neovascularization by scAAV2 with VMD2 Promoter-driven Active Rap1a in the RPE.

Age-related macular degeneration (AMD) is a multifactorial chronic disease that requires long term treatment. Gene therapy is being considered as a promising tool to treat AMD. We found that increased activation of Rap1a in the retinal pigment epithelium (RPE) reduces oxidative signaling to maintain barrier integrity of the RPE and resist neural sensory retinal angiogenesis from choroidal endothelial cell invasion. To optimally deliver constitutively active Rap1a (CARap1a) into the RPE of wild type mice, self-complementary AAV2 (scAAV2) vectors driven by two different promoters, RPE65 or VMD2, were generated and tested for optimal active Rap1a expression and inhibition of choroidal neovascularization (CNV) induced by laser injury. scAAV2-VMD2, but not scAAV2-RPE65, specifically and efficiently transduced the RPE to increase active Rap1a protein in the RPE. Mice with increased Rap1a from the scAAV2-VMD2-CARap1a had a significant reduction in CNV compared to controls. Increased active Rap1a in the RPE in vivo or in vitro inhibited inflammatory and angiogenic signaling determined by decreased activation of NF-κB and expression of VEGF without causing increased cell death or autophagy measured by increased LCA3/B. Our study provides a potential future strategy to deliver active Rap1a to the RPE in order to protect against both atrophic and neovascular AMD.