Acute zonal occult outer retinopathy presenting as optic neuritis.

Acute zonal occult outer retinopathy (AZOOR) is an outer retinal disorder characterized by the acute loss of visual functions. Herein, we report a case of AZOOR presenting features mimicking optic neuritis. A 17-year-old healthy male reported fogginess in the right eye for 2 weeks. His best-corrected visual acuity was 20/20 in both eyes. Results of a color vision test and pupillary reaction were unremarkable. Funduscopic examination revealed a subtle hyperemic disc surrounded by hyperpigmentation in the right eye. Visual field examination confirmed an enlarged blind spot in the affected eye. Fundus autofluorescence imaging revealed zonal hyperautofluorescence around the optic disc. Fluorescein angiography showed optic disc staining and a window defect in the retinal pigment epithelium. Optical coherence tomography demonstrated loss of the ellipsoid line at the corresponding hyperautofluorescent region. All these characteristics indicated a diagnosis of AZOOR. However, the prolonged P100 wave observed through visual-evoked potential examination, hyperintensity T2 signal at the retrobulbar optic nerve through magnetic resonance imaging, and mild hyperemic optic disc along with optic disc staining through fluorescein angiography resemble the characteristics of optic neuritis. Because the clinical features of AZOOR are similar to those of optic neuritis, ophthalmologists should be able to differentiate between these two diseases to achieve a timely and correct diagnosis.

Changes in the Systemic Expression of Sirtuin-1 and Oxidative Stress after Intravitreal Anti-Vascular Endothelial Growth Factor in Patients with Retinal Vein Occlusion.

OBJECTIVES: Retinal vein occlusions (RVO) are associated with systemic risk factors. However, the ocular occlusive events might also influence a patient's systemic condition. This study tried to investigate serum biomarkers associated with oxidative stress, before and after intravitreal anti-vascular endothelial growth factor (aVEGF) therapy in patients with RVOs. METHODS: Newly-onset RVO patients were categorized into two groups: comorbid with macular edema requiring aVEGF therapy (treatment group) and no edema (observation group). Age and sex-matched patients (who received cataract surgery) were included as the control group. Intravitreal ranibizumab with a pro-re-nata regimen were administered. Serum samples were collected prior to treatment, at 6 and 12 months after therapy/observation and were collected once before controls who received cataract surgery. mRNA expression of sirtuin-1, its downstream genes, anti-oxidative biomarkers, and proinflammatory cytokines were measured. RESULTS: There were 32, 26, and 34 patients enrolled in the treatment, observation, and control groups, respectively. The expressions of sirtuin-1 and its downstream genes were significantly lower in patients with RVO compared with the control group. Sirtuin-1 gene expression increased after 1 year of aVEGF therapy in the treatment group but remained unchanged in the observation group. Biomarkers of oxidative stress and proinflammatory cytokines were reduced after 1 year of aVEGF therapy. These biomarkers remained with no changes in the observation group. CONCLUSIONS: Our study showed that the systemic oxidative stress increased in RVO patients. The aVEGF therapy could alter the gene expression of anti-oxidative proteins and reduce systemic oxidative stress in these patients.

Morphological and Molecular Defects in Human Three-Dimensional Retinal Organoid Model of X-Linked Juvenile Retinoschisis.

X-linked juvenile retinoschisis (XLRS), linked to mutations in the RS1 gene, is a degenerative retinopathy with a retinal splitting phenotype. We generated human induced pluripotent stem cells (hiPSCs) from patients to study XLRS in a 3D retinal organoid in vitro differentiation system. This model recapitulates key features of XLRS including retinal splitting, defective retinoschisin production, outer-segment defects, abnormal paxillin turnover, and impaired ER-Golgi transportation. RS1 mutation also affects the development of photoreceptor sensory cilia and results in altered expression of other retinopathy-associated genes. CRISPR/Cas9 correction of the disease-associated C625T mutation normalizes the splitting phenotype, outer-segment defects, paxillin dynamics, ciliary marker expression, and transcriptome profiles. Likewise, mutating RS1 in control hiPSCs produces the disease-associated phenotypes. Finally, we show that the C625T mutation can be repaired precisely and efficiently using a base-editing approach. Taken together, our data establish 3D organoids as a valid disease model.

Modulation of osmotic stress-induced TRPV1 expression rescues human iPSC-derived retinal ganglion cells through PKA.

BACKGROUND: Transient receptor potential vanilloid 1 (TRPV1), recognized as a hyperosmolarity sensor, is a crucial ion channel involved in the pathogenesis of neural and glial signaling. Recently, TRPV1 was determined to play a role in retinal physiology and visual transmission. In this study, we sought to clarify the role of TRPV1 and the downstream pathway in the osmotic stress-related retina ganglion cell (RGC) damage. METHODS: First, we modified the RGC differentiation protocol to obtain a homogeneous RGC population from human induced pluripotent stem cells (hiPSCs). Subsequently, we induced high osmotic pressure in the hiPSC-derived RGCs by administering NaCl solution and observed the behavior of the TRPV1 channel and its downstream cascade. RESULTS: We obtained a purified RGC population from the heterogeneous retina cell population using our modified method. Our findings revealed that TRPV1 was activated after 24 h of NaCl treatment. Upregulation of TRPV1 was noted with autophagy and apoptosis induction. Downstream protein expression analysis indicated increased phosphorylation of CREB and downregulated brain-derived neurotrophic factor (BDNF). However, hyperosmolarity-mediated defective morphological change and apoptosis of RGCs, CREB phosphorylation, and BDNF downregulation were abrogated after concomitant treatment with the PKA inhibitor H89. CONCLUSION: Collectively, our study results indicated that the TRPV1-PKA pathway contributed to cellular response under high levels of osmolarity stress; furthermore, the PKA inhibitor had a protective effect on RGCs exposed to this stress. Therefore, our findings may assist in the treatment of eye diseases involving RGC damage.

Nanomedicine-based Curcumin Approach Improved ROS Damage in Best Dystrophy-specific Induced Pluripotent Stem Cells.

Best dystrophy (BD), also termed best vitelliform macular dystrophy (BVMD), is a juvenile-onset form of macular degeneration and can cause central visual loss. Unfortunately, there is no clear definite therapy for BD or improving the visual function on this progressive disease. The human induced pluripotent stem cell (iPSC) system has been recently applied as an effective tool for genetic consultation and chemical drug screening. In this study, we developed patient-specific induced pluripotent stem cells (BD-iPSCs) from BD patient-derived dental pulp stromal cells and then differentiated BD-iPSCs into retinal pigment epithelial cells (BD-RPEs). BD-RPEs were used as an expandable platform for in vitro candidate drug screening. Compared with unaffected sibling-derived iPSC-derived RPE cells (Ctrl-RPEs), BD-RPEs exhibited typical RPE-specific markers with a lower expression of the tight junction protein ZO-1 and Bestrophin-1 (BEST1), as well as reduced phagocytic capabilities. Notably, among all candidate drugs, curcumin was the most effective for upregulating both the BEST1 and ZO-1 genes in BD-RPEs. Using the iPSC-based drug-screening platform, we further found that curcumin can significantly improve the mRNA expression levels of Best gene in BD-iPSC-derived RPEs. Importantly, we demonstrated that curcumin-loaded PLGA nanoparticles (Cur-NPs) were efficiently internalized by BD-RPEs. The Cur-NPs-based controlled release formulation further increased the expression of ZO-1 and Bestrophin-1, and promoted the function of phagocytosis and voltage-dependent calcium channels in BD-iPSC-derived RPEs. We further demonstrated that Cur-NPs enhanced the expression of antioxidant enzymes with a decrease in intracellular ROS production and hydrogen peroxide-induced oxidative stress. Collectively, these data supported that Cur-NPs provide a potential cytoprotective effect by regulating the anti-oxidative abilities of degenerated RPEs. In addition, the application of patient-specific iPSCs provides an effective platform for drug screening and personalized medicine in incurable diseases.

Glutamate Stimulation Dysregulates AMPA Receptors-Induced Signal Transduction Pathway in Leber's Inherited Optic Neuropathy Patient-Specific hiPSC-Derived Retinal Ganglion Cells.

The mitochondrial genetic disorder, Leber's hereditary optic neuropathy (LHON), is caused by a mutation in MT-ND4 gene, encoding NADH dehydrogenase subunit 4. It leads to the progressive death of retinal ganglion cells (RGCs) and causes visual impairment or even blindness. However, the precise mechanisms of LHON disease penetrance and progression are not completely elucidated. Human-induced pluripotent stem cells (hiPSCs) offer unique opportunities to investigate disease-relevant phenotypes and regulatory mechanisms underlying LHON pathogenesis at the cellular level. In this study, we successfully generated RGCs by differentiation of LHON patient-specific hiPSCs. We modified the protocol of differentiation to obtain a more enriched population of single-cell RGCs for LHON study. Based on assessing morphology, expression of specific markers and electrophysiological activity, we found that LHON-specific hiPSC-derived were more defective in comparison with normal wild-type RGCs. Based on our previous study, whereby by using microarray analysis we identified that the components of glutamatergic synapse signaling pathway were significantly downregulated in LHON-specific RGCs, we focused our study on glutamate-associated α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors. We found that the protein expression levels of the subunits of the AMPA receptor, GluR1 and GluR2, and their associated scaffold proteins were decreased in LHON-RGCs. By performing the co-immunoprecipitation assay, we found several differences in the efficiencies of interaction between AMPA subunits and scaffold proteins between normal and LHON-specific RGCs.

P3HT:Bebq2-Based Photovoltaic Device Enhances Differentiation of hiPSC-Derived Retinal Ganglion Cells.

Electric field stimulation is known to affect various cellular processes, including cell fate specification and differentiation, particularly towards neuronal lineages. This makes it a promising therapeutic strategy to stimulate regeneration of neuronal tissues. Retinal ganglion cells (RGCs) is a type of neural cells of the retina responsible for transduction of visual signals from the retina to the brain cortex, and is often degenerated in various blindness-causing retinal diseases. The organic photovoltaic materials such as poly-3-hexylthiophene (P3HT) can generate electric current upon illumination with light of the visible spectrum, and possesses several advantageous properties, including light weight, flexibility and high biocompatibility, which makes them a highly promising tool for electric stimulation of cells in vitro and in vivo. In this study, we tested the ability to generate photocurrent by several formulations of blend (bulk heterojunction) of P3HT (which is electron donor material) with several electron acceptor materials, including Alq3 and bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq2). We found that the photovoltaic device based on bulk heterojunction of P3HT with Bebq2 could generate photocurrent when illuminated by both green laser and visible spectrum light. We tested the growth and differentiation capacity of human induced pluripotent stem cells (hiPSC)-derived RGCs when grown in interface with such photostimulated device, and found that they were significantly increased. The application of P3HT:Bebq2-formulation of photovoltaic device has a great potential for developments in retinal transplantation, nerve repair and tissue engineering approaches of treatment of retinal degeneration.

Artificial intelligence-based decision-making for age-related macular degeneration.

Artificial intelligence (AI) based on convolutional neural networks (CNNs) has a great potential to enhance medical workflow and improve health care quality. Of particular interest is practical implementation of such AI-based software as a cloud-based tool aimed for telemedicine, the practice of providing medical care from a distance using electronic interfaces. Methods: In this study, we used a dataset of labeled 35,900 optical coherence tomography (OCT) images obtained from age-related macular degeneration (AMD) patients and used them to train three types of CNNs to perform AMD diagnosis. Results: Here, we present an AI- and cloud-based telemedicine interaction tool for diagnosis and proposed treatment of AMD. Through deep learning process based on the analysis of preprocessed optical coherence tomography (OCT) imaging data, our AI-based system achieved the same image discrimination rate as that of retinal specialists in our hospital. The AI platform's detection accuracy was generally higher than 90% and was significantly superior (p < 0.001) to that of medical students (69.4% and 68.9%) and equal (p = 0.99) to that of retinal specialists (92.73% and 91.90%). Furthermore, it provided appropriate treatment recommendations comparable to those of retinal specialists. Conclusions: We therefore developed a website for realistic cloud computing based on this AI platform, available at https://www.ym.edu.tw/~AI-OCT/. Patients can upload their OCT images to the website to verify whether they have AMD and require treatment. Using an AI-based cloud service represents a real solution for medical imaging diagnostics and telemedicine.

Establishing Liposome-Immobilized Dexamethasone-Releasing PDMS Membrane for the Cultivation of Retinal Pigment Epithelial Cells and Suppression of Neovascularization.

Age-related macular degeneration (AMD) is the eye disease with the highest epidemic incidence, and has great impact on the aged population. Wet-type AMD commonly has the feature of neovascularization, which destroys the normal retinal structure and visual function. So far, effective therapy options for rescuing visual function in advanced AMD patients are highly limited, especially in wet-type AMD, in which the retinal pigmented epithelium and Bruch's membrane structure (RPE-BM) are destroyed by abnormal angiogenesis. Anti-VEGF treatment is an effective remedy for the latter type of AMD; however, it is not a curative therapy. Therefore, reconstruction of the complex structure of RPE-BM and controlled release of angiogenesis inhibitors are strongly required for sustained therapy. The major purpose of this study was to develop a dual function biomimetic material, which could mimic the RPE-BM structure and ensure slow release of angiogenesis inhibitor as a novel therapeutic strategy for wet AMD. We herein utilized plasma-modified polydimethylsiloxane (PDMS) sheet to create a biomimetic scaffold mimicking subretinal BM. This dual-surface biomimetic scaffold was coated with laminin and dexamethasone-loaded liposomes. The top surface of PDMS was covalently grafted with laminin and used for cultivation of the retinal pigment epithelial cells differentiated from human induced pluripotent stem cells (hiPSC-RPE). To reach the objective of inhibiting angiogenesis required for treatment of wet AMD, the bottom surface of modified PDMS membrane was further loaded with dexamethasone-containing liposomes via biotin-streptavidin linkage. We demonstrated that hiPSC-RPE cells could proliferate, express normal RPE-specific genes and maintain their phenotype on laminin-coated PDMS membrane, including phagocytosis ability, and secretion of anti-angiogenesis factor PEDF. By using in vitro HUVEC angiogenesis assay, we showed that application of our membrane could suppress oxidative stress-induced angiogenesis, which was manifested in decreased secretion of VEGF by RPE cells and suppression of vascularization. In conclusion, we propose modified biomimetic material for dual delivery of RPE cells and liposome-enveloped dexamethasone, which can be potentially applied for AMD therapy.

Elevation of serum oxidative stress in patients with retina vein occlusions.

PURPOSE: Retina vein occlusion (RVO) is a visual-threatening retinal disease that causes irreversible impaired quality of life. The contribution of oxidative stress behind clinical course of RVO was rarely investigated. The study aimed to measure the serum oxidative biomarker in patients with RVO to investigate further physical response. METHODS: We measured the serum levels of malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8OHdG), Sirutin 1 (SIRT1), peroxisome proliferator- activated receptor gamma (PPAR-r), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), orkhead box protein O1 (FOXO1), orkhead box protein O3 (FOXO3), catalase, (SOD) and hydrogen peroxide (H2 O2 ) among 19 patients with cataract as control group and 36 patients with RVO, respectively. RESULTS: The mean MDA, 8OHdG and hydrogen peroxide in the serum were significantly higher in patients with RVO compared with the results in control group subjects. Whereas SIRT1, PPAR-r, PGC-1, FOXO1, FOXO3, catalase and SOD levels in serum were significantly decreased in patients with RVO compared with control group. CONCLUSION: We demonstrated that the serum level of MDA, 8OHdG and hydrogen peroxide is increased in patients with RVO. Among these, the elevation of MDA, 8OHdG and hydrogen peroxide suggests the increasing of serum oxidative stress in RVO patients. All enzymes related reactive oxygen species scavenge were decreased. Thus, focal RVO may increase systemic oxidative stress within serum.

Acoustic waves improves retroviral transduction in human retinal stem cells.

BACKGROUNDS: The plasticity of retinal stem cells (RSCs), a type of cells that can differentiate into neuron cells and photoreceptor cells, endows them with potential therapeutic properties that can be applied to regenerative medicine. Gene modification of these stem cells before trans-differentiation and transplantation enhances their survival and increases their therapeutic function. The different ways to effectively deliver gene into RSCs are still discussed. This study aimed to use the acoustic waves to improve the efficacy of gene delivery for RSCs. METHODS: RSCs were obtained from non-fetal human ocular pigmented ciliary margin tissues. The enhanced green fluorescent protein-encoded murine stem cell retroviruses (MSCV) were prepared and used to infect RSCs. Glass chambers containing RSCs, retroviruses, and various concentrations of polybrene (0, 0.8, 2, 4 and 8 µg/mL) were exposed under 20 or 25 Vp-p ultrasonic standing wave fields (USWF) for 5 min. The percentage of green fluorescent protein positive cells in each sample was calculated and compared to test the efficacy of gene transduction. RESULTS: Our results showed that the efficiency of gene transduction by MSCV infection was enhanced following the concentration of polybrene and the energy of USWF. The percentage of green fluorescent protein positive cells was significantly higher in chambers that contained 8 µg/mL of polybrene and was exposed to 20Vp-p of USWF for 5 min. In addition, the percentage increased in chambers contained 2, 4 and 8 µg/mL of polybrene when they were exposed to 25Vp-p of USWF. Comparing to those did not treated with ultrasound, the efficiency of retroviral transduction to RSCs increased 4-fold after exposed to USWF for 5 min. CONCLUSION: We demonstrated the ability of ultrasound standing waves to improve retroviral transduction into RSCs. We believe that this may be applied to the experimental designs of future studies and may have possible therapeutic uses.

Expression profiling of cell-intrinsic regulators in the process of differentiation of human iPSCs into retinal lineages.

BACKGROUND: Differentiation of human induced pluripotent stem cells (hiPSCs) into retinal lineages offers great potential for medical application. Therefore, it is of crucial importance to know the key intrinsic regulators of differentiation and the specific biomarker signatures of cell lineages. METHODS: In this study, we used microarrays to analyze transcriptomes of terminally differentiated retinal ganglion cell (RGC) and retinal pigment epithelium (RPE) lineages, as well as intermediate retinal progenitor cells of optic vesicles (OVs) derived from hiPSCs. In our analysis, we specifically focused on the classes of transcripts that encode intrinsic regulators of gene expression: the transcription factors (TFs) and epigenetic chromatin state regulators. We applied two criteria for the selection of potentially important regulators and markers: firstly, the magnitude of fold-change of upregulation; secondly, the contrasted pattern of differential expression between OV, RGC and RPE lineages. RESULTS: We found that among the most highly overexpressed TF-encoding genes in the OV/RGC lineage were three members of the Collier/Olfactory-1/Early B-cell family: EBF1, EBF2 and EBF3. Knockdown of EBF1 led to significant impairment of differentiation of hiPSCs into RGCs. EBF1 was shown to act upstream of ISL1 and BRN3A, the well-characterized regulators of RGC lineage specification. TF-encoding genes DLX1, DLX2 and INSM1 were the most highly overexpressed genes in the OVs, indicating their important role in the early stages of retinal differentiation. Along with MITF, the two paralogs, BHLHE41 and BHLHE40, were the most robust TF markers of RPE cells. The markedly contrasted expression of ACTL6B, encoding the component of chromatin remodeling complex SWI/SNF, discriminated hiPSC-derived OV/RGC and RPE lineages. CONCLUSIONS: We identified novel, potentially important intrinsic regulators of RGC and RPE cell lineage specification in the process of differentiation from hiPSCs. We demonstrated the crucial role played by EBF1 in differentiation of RGCs. We identified intrinsic regulator biomarker signatures of these two retinal cell types that can be applied with high confidence to confirm the cell lineage identities.

Generation of induced pluripotent stem cells from a patient with X-linked juvenile retinoschisis.

X-linked juvenile retinoschisis (XLRS) is a hereditary retinal dystrophy manifested as splitting of anatomical layers of retina. In this report, we generated a patient-specific induced pluripotent stem cell (iPSC) line, TVGH-iPSC-013-05, from the peripheral blood mononuclear cells of a male patient with XLRS by using the Sendai-virus delivery system. We believe that XLRS patient-specific iPSCs provide a powerful in vitro model for evaluating the pathological phenotypes of the disease.

Generation of induced pluripotent stem cells from a patient with Best Dystrophy carrying 11q12.3 (BEST1 (VMD2)) mutation.

Best disease (BD), also termed Best vitelliform macular dystrophy (BVMD), is a juvenile-onset form of macular degeneration and central visual loss. In this report, we generated an induced pluripotent stem cell (iPSC) line, TVGH-iPSC-012-04, from the peripheral blood mononuclear cells of a female patient with BD by using the Sendai virus delivery system. The resulting iPSCs retained the disease-causing DNA mutation, expressed pluripotent markers and could differentiate into three germ layers. We believe that BD patient-specific iPSCs provide a powerful in vitro model for evaluating the pathological phenotypes of the disease.

Bioactivity and gene expression profiles of hiPSC-generated retinal ganglion cells in MT-ND4 mutated Leber's hereditary optic neuropathy.

Leber's hereditary optic neuropathy (LHON) is the maternally inherited mitochondrial disease caused by homoplasmic mutations in mitochondrial electron transport chain Complex I subunit genes. The mechanism of its incomplete penetrance is still largely unclear. In this study, we created the patient-specific human induced pluripotent stem cells (hiPSCs) from MT-ND4 mutated LHON-affected patient, asymptomatic mutation carrier and healthy control, and differentiated them into retinal ganglion cells (RGCs). We found the defective neurite outgrowth in affected RGCs, but not in the carrier RGCs which had significant expression of SNCG gene. We observed enhanced mitochondrial biogenesis in affected and carrier derived RGCs. Surprisingly, we observed increased NADH dehydrogenase enzymatic activity of Complex I in hiPSC-derived RGCs of asymptomatic carrier, but not of the affected patient. LHON mutation substantially decreased basal respiration in both affected and unaffected carrier hiPSCs, and had the same effect on spare respiratory capacity, which ensures normal function of mitochondria in conditions of increased energy demand or environmental stress. The expression of antioxidant enzyme catalase was decreased in affected and carrier patient hiPSC-derived RGCs as compared to the healthy control, which might indicate to higher oxidative stress-enriched environment in the LHON-specific RGCs. Microarray profiling demonstrated enhanced expression of cell cycle machinery and downregulation of neuronal specific genes.

Protective effect of metformin against retinal vein occlusions in diabetes mellitus - A nationwide population-based study.

Previous studies have found that metformin can reduce cardiovascular risk, but its association with retinal vein occlusion (RVO) is unknown. In this population-based cohort study using the Taiwan National Health Insurance Research Database (NHIRD), we demonstrated the protective effect of metformin against RVO in diabetes mellitus (DM) and explored the incidence rate and factors associated with RVO development in general and diabetic populations. One million patients were randomly selected from the registry files of the NHIRD, and all their claims data were collected for the 1996-2011 period. Patients with a new diagnosis of central or branch RVO were identified using International Classification of Disease codes. DM was defined for patients with diagnoses and treatments. Factors associated with RVO development in the non-DM and DM cohorts were explored using Cox proportional regression models. In total, 1,018 RVO patients were identified from the database. The average incidence of RVO was 9.93 and 53.5 cases per 100,000 person-years in the non-DM and DM cohorts, respectively. Older age, DM, hypertension, and glaucoma were significant risk factors for RVO, whereas the prescription of anticoagulants was a significant protective factor. In the DM cohort, older age, hypertension, and diabetic retinopathy were significant risk factors for RVO, whereas metformin treatment was a significant protective factor. These results confirmed the risk factors for RVO and demonstrated the protective effect of metformin against RVO in DM patients. Prescribing metformin for DM patients may be beneficial for reducing the incidence of RVO, along with its hypoglycemic action.

Elongation of Axon Extension for Human iPSC-Derived Retinal Ganglion Cells by a Nano-Imprinted Scaffold.

Optic neuropathies, such as glaucoma and Leber's hereditary optic neuropathy (LHON) lead to retinal ganglion cell (RGC) loss and therefore motivate the application of transplantation technique into disease therapy. However, it is a challenge to direct the transplanted optic nerve axons to the correct location of the retina. The use of appropriate scaffold can promote the proper axon growth. Recently, biocompatible materials have been integrated into the medical field, such as tissue engineering and reconstruction of damaged tissues or organs. We, herein, utilized nano-imprinting to create a scaffold mimicking the in vitro tissue microarchitecture, and guiding the axonal growth and orientation of the RGCs. We observed that the robust, long, and organized axons of human induced pluripotent stem cell (iPSC)-derived RGCs projected axially along the scaffold grooves. The RGCs grown on the scaffold expressed the specific neuronal biomarkers indicating their proper functionality. Thus, based on our in vitro culture system, this device can be useful for the neurophysiological analysis and transplantation for ophthalmic neuropathy treatment.

COMPARISON OF PHOTODYNAMIC THERAPY USING HALF-DOSE OF VERTEPORFIN OR HALF-FLUENCE OF LASER LIGHT FOR THE TREATMENT OF CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To compare the efficacy and the detrimental effects of half-drug dose and half-laser light fluence of photodynamic therapy (PDT) for the treatment of chronic central serous chorioretinopathy. DESIGN: We conducted a prospective randomized, observer-masked comparison study. METHODS: Forty eyes (40 patients) with chronic central serous chorioretinopathy were enrolled in this study and were equally divided into 2 groups. The first (half-dose) group received only half the standard dose of verteporfin infusion (3 mg/m) and were irradiated by the standard 83 seconds of laser light (50 J/cm) for the PDT treatment; the second (half-fluence) group received the standard dose of verteporfin infusion (6 mg/m) and were irradiated by only 42 seconds of laser light (25 J/cm). Patients were examined at baseline and 1 week, 1 month, 3 months, and 6 months after PDT treatments with best-corrected visual acuity and optical coherence tomography. Fluorescein angiography and indocyanine green angiography (ICGA) were performed at baseline and at 1 month, 3 months, and 6 months after PDT treatment. Primary outcome measures were the changes in the best-corrected visual acuity and in central retinal thickness and subretinal fluid in optical coherence tomography. Secondary outcomes were the changes in the choroidal perfusion in the ICGA, which was measured as the fluorescein ratio of the PDT-treated area to a nontreated reference area in ICGA. RESULTS: Best-corrected visual acuity was significantly improved at post-PDT 1 month, 3 months, and 6 months (all P < 0.01) in both the half-dose and the half-fluence group. Central retinal thickness was significantly improved at all post-PDT time points in both groups (P < 0.05). All patients in the half-dose group and 19 patients (95%) in the half-fluence group had complete absorption of subretinal fluid at post-PDT 3 months and 6 months. The choroidal perfusion (as reflected by the decrease of the ratio of fluorescence) in ICGA was significantly decreased at all post-PDT follow-up time points in both groups (P < 0.01). However, there were no significant differences in all the measurements between the two groups, including best-corrected visual acuity, central retinal thickness, and hypofluorescence in ICGA at baseline and at each post-PDT follow-up time point. CONCLUSION: Both half-dose and half-fluence modifications of PDT were similarly effective in improving the visual acuity and subretinal fluid for chronic CSC. Both types of modification of PDT were also similar in causing postlaser choroidal hypoperfusion.

Laminin modification subretinal bio-scaffold remodels retinal pigment epithelium-driven microenvironment in vitro and in vivo.

Advanced age-related macular degeneration (AMD) may lead to geographic atrophy or fibrovascular scar at macular, dysfunctional retinal microenvironment, and cause profound visual loss. Recent clinical trials have implied the potential application of pluripotent cell-differentiated retinal pigment epithelial cells (dRPEs) and membranous scaffolds implantation in repairing the degenerated retina in AMD. However, the efficacy of implanted membrane in immobilization and supporting the viability and functions of dRPEs, as well as maintaining the retinal microenvironment is still unclear. Herein we generated a biomimetic scaffold mimicking subretinal Bruch's basement from plasma modified polydimethylsiloxane (PDMS) sheet with laminin coating (PDMS-PmL), and investigated its potential functions to provide a subretinal environment for dRPE-monolayer grown on it. Firstly, compared to non-modified PDMS, PDMS-PmL enhanced the attachment, proliferation, polarization, and maturation of dRPEs. Second, PDMS-PmL increased the polarized tight junction, PEDF secretion, melanosome pigment deposit, and phagocytotic-ability of dRPEs. Third, PDMS-PmL was able to carry a dRPEs/photoreceptor-precursors multilayer retina tissue. Finally, the in vivo subretinal implantation of PDMS-PmL in porcine eyes showed well-biocompatibility up to 2-year follow-up. Notably, multifocal ERGs at 2-year follow-up revealed well preservation of macular function in PDMS-PmL, but not PDMS, transplanted porcine eyes. Trophic PEDF secretion of macular retina in PDMS-PmL group was also maintained to preserve retinal microenvironment in PDMS-PmL eyes at 2 year. Taken together, these data indicated that PDMS-PmL is able to sustain the physiological morphology and functions of polarized RPE monolayer, suggesting its potential of rescuing macular degeneration in vivo.