An intersectional genetic approach for simultaneous cell type-specific labelling and gene knockout in the mouse.

Precise genome manipulation in specific cell types and subtypes in vivo is crucial for neurobiological research because of the cellular heterogeneity of the brain. Site-specific recombinase systems in the mouse, such as Cre-loxP, improve cell type-specific genome manipulation; however, undesirable expression of cell type-specific Cre can occur. This could be due to transient expression during early development, natural expression in more than one cell type, kinetics of recombinases, sensitivity of the Cre reporter, and disruption in cis-regulatory elements by transgene insertion. Moreover, cell subtypes cannot be distinguished in cell type-specific Cre mice. To address these issues, we applied an intersectional genetic approach in mouse using triple recombination systems (Cre-loxP, Flp-FRT and Dre-rox). As a proof of principle, we labelled heterogeneous cell subtypes and deleted target genes within given cell subtypes by labelling neuropeptide Y (NPY)-, calretinin (calbindin 2) (CR)- and cholecystokinin (CCK)-expressing GABAergic neurons in the brain followed by deletion of RNA-binding Fox-1 homolog 3 (Rbfox3) in our engineered mice. Together, our study applies an intersectional genetic approach in vivo to generate engineered mice serving dual purposes of simultaneous cell subtype-specific labelling and gene knockout.

Genetics in neovascular age-related macular degeneration susceptibility and treatment response to anti-VEGF intravitreal injection: A case series study.

BACKGROUND: To identify genotypes associated with neovascular age-related macular degeneration (nAMD) and investigate the associations between genotype variations and anti-vascular endothelial growth factor (VEGF) treatment response. METHODS: This observational, retrospective, case series study enrolled patients diagnosed with nAMD who received anti-VEGF treatment in National Taiwan University Hospital with at least one-year follow-up between 2012 and 2020. A genome-wide association study (GWAS) was conducted on enrolled patients and controls. Correlations between the genotypes identified from GWAS and the treatment response of functional/anatomical biomarkers, including visual acuity (VA), presence of intraretinal or subretinal fluid (SRF), serous or fibrovascular pigmented epithelium detachment (PED), and disruption of the ellipsoid zone (EZ), were analysed. RESULTS: In total, 182 patients with nAMD and 1748 controls were enrolled. GWAS revealed 16 single nucleotide polymorphisms (SNPs) as risk loci for nAMD, including seven loci in CFH and ARMS2/HTRA1 and nine novel loci, including rs117517872 and rs79835234(COPB2-DT), rs7525578(RAP1A), rs2123738(LOC105376755), rs1374879(CNTN3), rs3812692(SAR1A), rs117501587(PRKCA), rs9965945(CNDP1), and rs189769231(MATK). Our study revealed rs800292(CFH), rs11200638(HTRA1), and rs2123738(LOC105376755) correlated with poor treatment response in VA (P = 0.005), SRF (P = 0.044), and fibrovascular PED (P = 0.007), respectively. Rs9965945(CNDP1) was correlated with poor response in disruption of EZ (P = 0.046) and serous PED (P = 0.049). CONCLUSIONS: Among the 16 SNPs found in the GWAS, four loci-CFH, ARMS2/HTRA1, and two novel loci-were correlated with the susceptibility of nAMD and anatomical/functional responses after anti-VEGF treatment.

Association between non-steroidal anti-inflammatory drug use and development of age-related macular degeneration-A 10-year retrospective cohort study.

PURPOSE: To analyze the associations between development of age-related macular degeneration (AMD) and regular use of aspirin or non-aspirin non-steroidal anti-inflammatory drugs (NA-NSAIDs). METHODS: We retrospectively recruited individuals who received ≥28-day prescriptions of aspirin or NA-NSAIDs exclusively between 2008 and 2017 in one tertiary center as regular users. Non-regular users were free from regular use of any anti-inflammatory drugs and were matched to regular users in terms of age, sex, and visit date at a ratio of 1-4:1. The aspirin cohort included 36,771 regular users and 110,808 matched non-regular users, while the NA-NSAID cohort included 59,569 regular users and 179,732 matched non-regular users. Stratified multivariate Cox regression analyses with adjustment for systemic confounding factors were performed for the development of AMD and neovascular AMD. RESULTS: In the aspirin cohort, the adjusted hazard ratios of aspirin use for AMD in the whole cohort, individuals without cardiovascular diseases (CVDs), and those with CVDs were 0.664, 0.618, and 0.702, respectively (P < 0.0001 for all), while those of aspirin use for neovascular AMD were 0.486, 0.313, and 0.584 (P < 0.05 for all), respectively. In the NA-NSAID cohort, regular use of NA-NSAIDs was associated with a decreased risk of AMD (hazard ratio = 0.823, P < 0.0001) and neovascular AMD (hazard ratio = 0.720, P = 0.040) only in people without arthritis. CONCLUSIONS: Regular use of aspirin or NA-NSAIDs had protective effects on AMD and neovascular AMD. The effect of aspirin was observed in all patients, while the effect of NA-NSAIDs was observed only in people without arthritis.

Beneficial Effects of Fibroblast Growth Factor-1 on Retinal Pigment Epithelial Cells Exposed to High Glucose-Induced Damage: Alleviation of Oxidative Stress, Endoplasmic Reticulum Stress, and Enhancement of Autophagy.

Diabetic retinopathy (DR) severely affects vision in individuals with diabetes. High glucose (HG) induces oxidative stress in retinal cells, a key contributor to DR development. Previous studies suggest that fibroblast growth factor-1 (FGF-1) can mitigate hyperglycemia and protect tissues from HG-induced damage. However, the specific effects and mechanisms of FGF-1 on DR remain unclear. In our study, FGF-1-pretreated adult retinal pigment epithelial (ARPE)-19 cells were employed to investigate. Results indicate that FGF-1 significantly attenuated HG-induced oxidative stress, including reactive oxygen species, DNA damage, protein carbonyl content, and lipid peroxidation. FGF-1 also modulated the expression of oxidative and antioxidative enzymes. Mechanistic investigations showed that HG induced high endoplasmic reticulum (ER) stress and upregulated specific proteins associated with apoptosis. FGF-1 effectively alleviated ER stress, reduced apoptosis, and restored autophagy through the adenosine monophosphate-activated protein kinase/mammalian target of the rapamycin signaling pathway. We observed that the changes induced by HG were dose-dependently reversed by FGF-1. Higher concentrations of FGF-1 (5 and 10 ng/mL) exhibited increased effectiveness in mitigating HG-induced damage, reaching statistical significance (p < 0.05). In conclusion, our study underscores the promising potential of FGF-1 as a safeguard against DR. FGF-1 emerges as a formidable intervention, attenuating oxidative stress, ER stress, and apoptosis, while concurrently promoting autophagy. This multifaceted impact positions FGF-1 as a compelling candidate for alleviating retinal cell damage in the complex pathogenesis of DR.

Light activates Ube3a, an Angelman syndrome-associated gene, by mediating the chromatin structures during postnatal development of mouse retina.

Angelman syndrome, a severe neurodevelopmental disorder, is primarily caused by mutations or deletions of maternally inherited ubiquitin protein ligase E3A (UBE3A). Activation of the silenced paternal copy of UBE3A can occur with pharmacological perturbation; however, an environmental approach has not been examined. Here, we found Ube3a is highly expressed in embryonic and early neonatal mouse retina and is maternally-, but not paternally-, expressed in ganglion cells, amacrine cells, and horizontal cells. Moreover, we analyzed UBE3A expression in the retina and visual cortex of postnatal day 28 mice (P28) following exposure to light emissions from white compact-fluorescent bulbs or blue light-emitting diodes from postnatal day 0 (P0) to 28 (P28), encompassing a crucial phase of visual system development. We found higher levels of Ube3a RNA and protein in the retina, but not visual cortex compared with tissues from P28 mice exposure to typical lighting (controls). Levels of both paternal- and maternal-UBE3A protein in mouse retina were higher than controls in P28 mice exposed to white or blue light. Moreover, levels of open and repressive chromatin structures, indicated by histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3), respectively, were increased in the Ube3a promoter from mouse retina exposed to white or blue light. Our findings strongly suggest that extended exposure to white or blue light constitutes a substantial environmental factor that can effectively promote UBE3A expression within the central nervous system.

Refining vitrectomy for proliferative diabetic retinopathy.

Pars plana vitrectomy (PPV) is the main treatment modality for patients with severe diabetic retinopathy. With the development of systems for microincision, wide-angle viewing, digitally assisted visualization, and intraoperative optical coherence tomography, contemporary PPV for diabetic retinopathy has been performed on a wider range of indications than previously considered. In this article, we reviewed, in conjunction with our collective experiences with Asian patients, the applications of new technologies for PPV in eyes with diabetic retinopathy and highlighted several important procedures and entities not generally reiterated in the literature, in order for vitreoretinal surgeons to optimize their approaches when facing the challenges imposed by the complications in diabetic eyes.

Dilated choroidal vascular channels in pachychoroid neovasculopathy.

BACKGROUND: To elucidate the pattern of the choroidal vasculature in exudative pachychoroid neovasculopathy (PNV) and its correlation with the clinical course and treatment outcomes. METHODS: The retrospective study included consecutive patients in National Taiwan University Hospital between 2014 and 2020 who fulfilled the criteria for exudative PNV defined as active type 1 macular neovascularization (MNV) on optical coherence tomography angiography (OCTA) and with leakage on fluorescein angiography (FA) or indocyanine green angiography (ICGA) associated with pachychoroid features. The corrected distance visual acuity (CDVA), FA, ICGA, and OCT images obtained by Optovue (Optovue Inc, Freemont CA, USA) spectral domain OCT were evaluated at baseline and various time points during the 12-month treatment period. The correlations between the choroidal vascular patterns, specifically those with or without dilated choroidal vascular channels (DCVC) revealed by ICGA, and baseline characteristics and treatment outcomes were evaluated using multiple regression models. RESULTS: The study enrolled 34 eyes of 31 patients. The average age was 59.0 ± 9.3 years, and 20 participants were men. ICGA revealed DCVCs in 21 eyes, while the remaining 13 eyes did not have DCVCs. At baseline, DCVC group was older (p = 0.03) and had a longer duration of visual symptoms (p = 0.02), with a higher vessel density (defined as the percentage of the measured area occupied by flow area) of MNV (p = 0.04), higher proportion of ellipsoid zone disruption (p = 0.01), and poorer CDVA (p = 0.03). After the 12-month treatment period, the frequency of requirement of anti-VEGF injections (p < 0.01) was higher, and the risk for CDVA <20/40 was higher (adjusted OR: 5.29, 95% CI: 1.24-22.48, p = 0.02) in eyes with DCVCs. CONCLUSIONS: For PNV, eyes with DCVCs were associated with higher vessel density of macular neovascularization and poorer CDVA at baseline, and had poorer visual and anatomical outcomes although more anti-VEGF injections were given.

Cytomegalovirus Uveitis: Taiwan expert consensus.

Cytomegalovirus (CMV) uveitis, a type of herpetic uveitis, is a major cause of infectious uveitis. Anterior and posterior CMV uveitis have diverse clinical presentations and treatment modalities. Based on expert consensus in Taiwan, this article provides suggestions regarding clinical manifestations, diagnosis, and treatment strategies for CMV uveitis based on clinical practice experience in Taiwan. CMV uveitis may have a distinct clinical presentation. Polymerase chain reaction (PCR) is an essential diagnostic tool to confirm a diagnosis. Antiviral therapy is the mainstay of treatment. Different agents, routes, and other supplemental treatments have been summarized and discussed in this article. Early diagnosis and appropriate treatment of CMV uveitis are crucial to avoid irreversible complications and vision loss. This consensus provides practical guidelines for ophthalmologists in Taiwan.

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.

HYPERREFLECTIVE FOCI AS IMPORTANT PROGNOSTIC INDICATORS OF PROGRESSION OF RETINITIS PIGMENTOSA.

PURPOSE: To investigate the presence and clinical relevance of hyperreflective foci (HRFs) in retinitis pigmentosa. METHODS: Seventy seven retinitis pigmentosa cases were retrospectively reviewed. The 10-mm wide cross-line macular scans in optical coherence tomography were acquired. Hyperreflective foci were classified according to the location in optical coherence tomography: outer layers within the macula (HRF-outer-central), macular border beyond the central 3 mm (HRF-outer-perifoveal), and choroid (HRF-choroidal). The visual acuity at baseline, at 12 months, and other fundus characteristics were collected. RESULTS: The mean logMAR best-corrected visual acuity decreased from 0.59 ± 0.66 (20/78 in Snellen) to 0.74 ± 0.81 (20/106 in Snellen) in 1 year. Sixty-six (42.9%), 105 (68.2%), and 98 (63.6%) eyes were classified to HRF-outer-central, HRF-outer-perifoveal, and HRF-choroidal group, respectively. Hyperreflective foci were positively correlated with poorer vision, central macular thinning, and ellipsoid zone disruption (all P < 0.001). Worse vision was associated with older age, macular involvement, and the coexistence of two or three HRF groups (P = 0.014, 0.047, 0.019, <0.001, respectively). Hyperreflective foci developed more frequently in patients with thick choroid than in those with thin choroid. The coexistence of three HRF groups was correlated with quicker visual deterioration (P = 0.034). CONCLUSION: Hyperreflective foci are common in retinitis pigmentosa and can be a negative prognostic indicator of macular thickness and visual preservation. Thick choroid was associated with all groups of HRFs, especially HRF-choroidal.

PREDICTED PROTEIN STRUCTURE VARIATIONS INDICATE THE CLINICAL PRESENTATION OF CYP4V2-RELATED BIETTI CRYSTALLINE DYSTROPHY.

PURPOSE: To investigate the relationship between different CYP4V2 disease-causing variants and disease severity in Bietti crystalline dystrophy (BCD). METHODS: Twenty-one subjects from 19 unrelated families with a clinical diagnosis of BCD were enrolled. A novel severity prediction score for BCD based on the predicted molecular impact of CYP4V2 variants was applied for grouping and subsequent analyses. The more severe variants led to less CYP4V2 protein function preservation and a higher severity prediction score. RESULTS: All subjects harbored two alleles of CYP4V2 disease-causing variants, of which c.802-8_810del17insGC was the most prevalent (14/21, 66.67%) and c.1507G>C was novel. According to the severity score, the subjects were categorized into severe, moderate, and mild groups with different preservation of central vision (mean logMAR visual acuity 0.95 ± 0.82, 0.89 ± 1.22, and 0.56 ± 0.64, respectively). The patients with a lower severity score had slower disease progression. CONCLUSION: This is the first cohort study of BCD in Taiwan, and we established a novel BCD severity index based on the molecular impact of different CYP4V2 variants. More severe impairment of CYP4V2 protein led to a more severe disease course with earlier progression. Our results could be helpful in identifying a therapeutic window for patients with BCD.

Optimal approaches and criteria to treat-and-extend regimen implementation for Neovascular age-related macular degeneration: experts consensus in Taiwan.

The management of neovascular age-related macular degeneration (nAMD) has taken a major stride forward with the advent of anti-VEGF agents. The treat-and-extend (T&E) approach is a refined management strategy, tailoring to the individual patient's disease course and treatment outcome. To provide guidance to implementing anti-VEGF T&E regimens for nAMD in resource-limited health care systems, an advisory board was held to discuss and generate expert consensus, based on local and international guidelines, current evidence, as well as local experience and reimbursement policies. In the experts' opinion, treatment of nAMD should aim to maximize and maintain visual acuity benefits while minimizing treatment burden. Based on current evidence, treatment could be initiated with 3 consecutive monthly injections. After the initial period, treatment interval may be extended by 2 or 4 weeks each time for the qualified patients (i.e. no BCVA loss ≥5 ETDRS letters and dry retina), and a maximum interval of 16 weeks is permitted. For patients meeting the shortening criteria (i.e. any increased fluid with BCVA loss ≥5 ETDRS letters, or presence of new macular hemorrhage or new neovascularization), the treatment interval should be reduced by 2 or 4 weeks each time, with a minimal interval of 4 weeks. Discontinuation of anti-VEGF may be considered for those who have received 2-3 consecutive injections spaced 16 weeks apart and present with stable disease. For these individuals, regular monitoring (e.g. 3-4 months) is recommended and monthly injections should be reinstated upon signs of disease recurrence.

Flap technique-assisted surgeries for advanced retinitis pigmentosa complicated with macular hole: a case report and literature review.

BACKGROUND: Full-thickness macular hole (FTMH) is a rare complication in retinitis pigmentosa (RP) patients and may increase intraoperative challenges. Furthermore, lens capsular flap transplantation and inverted internal limiting membrane (ILM) flap were reported to close complicated FTMH successfully. Here, we present a case of bilateral advanced RP complicated by a FTMH treated with a novel lens capsular flap transplantation and inverted internal limiting membrane flap. CASE PRESENTATION: A 46-year-old presented to our hospital with a complaint of progressively blurred vision and metamorphopsia in both eyes. Spectral-domain optical coherence tomography revealed a FTMH with retinoschisis in the right eye and another FTMH in the left eye. ILM peeling with inverted ILM flap technique was performed on the right eye and ILM peeling with anterior lens capsular flap technique was performed on the left eye. Post-operative follow-up showed successful closure of the FTMH and improved vision in both eyes. CONCLUSIONS: In our present case, flap-assisted techniques for retinitis pigmentosa with macular hole result in excellent visual and anatomic outcomes.

Simvastatin Inhibits CYR61 Expression in Orbital Fibroblasts in Graves' Ophthalmopathy through the Regulation of FoxO3a Signaling.

Graves' ophthalmopathy (GO), which is characterized by orbital tissue inflammation, expansion, and fibrosis, is the ocular manifestation in 25% to 50% of patients with Graves' disease. As the pathology of GO is driven by autoimmune inflammation, many proinflammatory cytokines/chemokines, including TNF-α, IL-1ß, IL-6, and CCL20, are crucial in the pathogenesis of GO to activate the orbital fibroblasts. Cysteine-rich protein 61 (CYR61), which is known to regulate cell proliferation, adhesion, and migration, plays a proinflammatory role in the pathogenesis of many inflammatory diseases, such as rheumatoid arthritis. CYR61 was considered a potential biomarker of GO in recent studies. Statins, which are cholesterol-lowering drugs, were found to reduce the risk of GO, probably through their anti-inflammatory and immunomodulatory effects. In this study, we established a link between CYR61 and statins in the pathogenesis and potential treatment for GO. Firstly, our data showed the overexpression of CYR61 in the orbital tissue (n = 4) and serum specimens (n = 6) obtained from the patients with inactive GO. CYR61 could induce the production of IL-6 and CCL20 in cultured GO orbital fibroblasts. The expression of CYR61 in cultured GO orbital fibroblasts was upregulated via TNF-α stimulation. Secondly, we pretreated cultured GO orbital fibroblasts using simvastatin, a statin, followed by TNF-α stimulation. The data revealed that simvastatin could inhibit TNF-α-induced CYR61 expression by modulating the activity of transcription factor FoxO3a. Our results provided insights into some cellular mechanisms that may explain the possible protective effects of simvastatin against the development of GO.

Management of neovascular age-related macular degeneration: Taiwan expert consensus.

Neovascular age-related macular degeneration (nAMD) is a leading cause of irreversible vision loss. The present consensus provides suggestions on diagnosis, evaluation, treatment, and follow-up strategies for nAMD from a panel of 11 practicing ophthalmologists. The experts suggest that the baseline visit for nAMD management should include a comprehensive ophthalmologic examination via a multimodal approach consisting of visual and anatomical evaluation. Patients diagnosed with nAMD should be subjected to treatment with the goal of maintaining visual function while diminishing anatomical disease activity and minimizing treatment burden. Currently, anti-VEGF therapy is the main treatment strategy for nAMD, and evaluation involving comprehensive ophthalmologic examination within 1 month of completion of the loading phase comprising three monthly injections is recommended to guide subsequent management. Either a treat-and-extend or pro re nata regimen can be considered for the maintenance phase of anti-VEGF therapy, and the regimen should be chosen and adjusted according to disease activity, reimbursement criteria, financial burden, and patient preferences. In the event of inactive nAMD or poor treatment outcomes, after thorough evaluation and patient education, anti-VEGF therapy may be stopped. The consensus provides practical nAMD management guidelines for ophthalmologists and fellow healthcare professionals.

Application of deep learning image assessment software VeriSee™ for diabetic retinopathy screening.

PURPOSE: To develop a deep learning image assessment software VeriSee™ and to validate its accuracy in grading the severity of diabetic retinopathy (DR). METHODS: Diabetic patients who underwent single-field, nonmydriatic, 45-degree color retinal fundus photography at National Taiwan University Hospital between July 2007 and June 2017 were retrospectively recruited. A total of 7524 judgeable color fundus images were collected and were graded for the severity of DR by ophthalmologists. Among these pictures, 5649 along with another 31,612 color fundus images from the EyePACS dataset were used for model training of VeriSee™. The other 1875 images were used for validation and were graded for the severity of DR by VeriSee™, ophthalmologists, and internal physicians. Area under the receiver operating characteristic curve (AUC) for VeriSee™, and the sensitivities and specificities for VeriSee™, ophthalmologists, and internal physicians in diagnosing DR were calculated. RESULTS: The AUCs for VeriSee™ in diagnosing any DR, referable DR and proliferative diabetic retinopathy (PDR) were 0.955, 0.955 and 0.984, respectively. VeriSee™ had better sensitivities in diagnosing any DR and PDR (92.2% and 90.9%, respectively) than internal physicians (64.3% and 20.6%, respectively) (P < 0.001 for both). VeriSee™ also had better sensitivities in diagnosing any DR and referable DR (92.2% and 89.2%, respectively) than ophthalmologists (86.9% and 71.1%, respectively) (P < 0.001 for both), while ophthalmologists had better specificities. CONCLUSION: VeriSee™ had good sensitivity and specificity in grading the severity of DR from color fundus images. It may offer clinical assistance to non-ophthalmologists in DR screening with nonmydriatic retinal fundus photography.

Artificial Intelligence-Assisted Early Detection of Retinitis Pigmentosa - the Most Common Inherited Retinal Degeneration.

The purpose of this study was to detect the presence of retinitis pigmentosa (RP) based on color fundus photographs using a deep learning model. A total of 1670 color fundus photographs from the Taiwan inherited retinal degeneration project and National Taiwan University Hospital were acquired and preprocessed. The fundus photographs were labeled RP or normal and divided into training and validation datasets (n = 1284) and a test dataset (n = 386). Three transfer learning models based on pre-trained Inception V3, Inception Resnet V2, and Xception deep learning architectures, respectively, were developed to classify the presence of RP on fundus images. The model sensitivity, specificity, and area under the receiver operating characteristic (AUROC) curve were compared. The results from the best transfer learning model were compared with the reading results of two general ophthalmologists, one retinal specialist, and one specialist in retina and inherited retinal degenerations. A total of 935 RP and 324 normal images were used to train the models. The test dataset consisted of 193 RP and 193 normal images. Among the three transfer learning models evaluated, the Xception model had the best performance, achieving an AUROC of 96.74%. Gradient-weighted class activation mapping indicated that the contrast between the periphery and the macula on fundus photographs was an important feature in detecting RP. False-positive results were mostly obtained in cases of high myopia with highly tessellated retina, and false-negative results were mostly obtained in cases of unclear media, such as cataract, that led to a decrease in the contrast between the peripheral retina and the macula. Our model demonstrated the highest accuracy of 96.00%, which was comparable with the average results of 81.50%, of the other four ophthalmologists. Moreover, the accuracy was obtained at the same level of sensitivity (95.71%), as compared to an inherited retinal disease specialist. RP is an important disease, but its early and precise diagnosis is challenging. We developed and evaluated a transfer-learning-based model to detect RP from color fundus photographs. The results of this study validate the utility of deep learning in automating the identification of RP from fundus photographs.

Fibroblast Growth Factor Type 1 Ameliorates High-Glucose-Induced Oxidative Stress and Neuroinflammation in Retinal Pigment Epithelial Cells and a Streptozotocin-Induced Diabetic Rat Model.

Diabetic retinopathy (DR) is a common complication of diabetes that causes severe visual impairment globally. The pathogenesis of DR is related to oxidative stress and chronic inflammation. The fibroblast growth factor type 1 (FGF-1) mitogen plays crucial roles in cell function, development, and metabolism. FGF-1 is involved in blood sugar regulation and exerts beneficial antioxidative and anti-inflammatory effects on various organ systems. This study investigated the antioxidative and anti-inflammatory neuroprotective effects of FGF-1 on high-glucose-induced retinal damage. The results revealed that FGF-1 treatment significantly reversed the harmful effects of oxidative stress and inflammatory mediators in retinal tissue in a streptozotocin-induced diabetic rat model. These protective effects were also observed in the in vitro model of retinal ARPE-19 cells exposed to a high-glucose condition. We demonstrated that FGF-1 attenuated p38 mitogen-activated protein kinase and nuclear factor-κB pathway activation under the high-glucose condition. Our results indicated that FGF-1 could effectively prevent retinal injury in diabetes. The findings of this study could be used to develop novel treatments for DR that aim to reduce the cascade of oxidative stress and inflammatory signals in neuroretinal tissue.

Doxycycline Ameliorates the Severity of Experimental Proliferative Vitreoretinopathy in Mice.

After successful surgeries for patients with rhegmatogenous retinal detachment, the most common cause of retinal redetachment is proliferative vitreoretinopathy (PVR), which causes severe vision impairment and even blindness worldwide. Until now, the major treatment for PVR is surgical removal of the epiretinal membrane, while effective treatment to prevent PVR is still unavailable. Therefore, we investigated the potential of doxycycline, an antibiotic in the tetracycline class, to treat PVR using a mouse model. We used the human retinal pigment epithelial cell line, ARPE-19, for in vitro and in vivo studies to test doxycycline for PVR treatment. We found that doxycycline suppressed the migration, proliferation, and contraction of ARPE-19 cells with reduced p38 MAPK activation and total MMP activity. Intravitreal doxycycline and topical tetracycline treatment significantly ameliorated the PVR severity induced by ARPE-19 cells in mice. PVR increased the expression of MMP-9 and IL-4 and p38 MAPK phosphorylation and modestly decreased IL-10. These effects were reversed by doxycycline and tetracycline treatment in the mouse retina. These results suggest that doxycycline will be a potential treatment for PVR in the future.

Analysis of experience-regulated transcriptome and imprintome during critical periods of mouse visual system development reveals spatiotemporal dynamics.

Visual system development is light-experience dependent, which strongly implicates epigenetic mechanisms in light-regulated maturation. Among many epigenetic processes, genomic imprinting is an epigenetic mechanism through which monoallelic gene expression occurs in a parent-of-origin-specific manner. It is unknown if genomic imprinting contributes to visual system development. We profiled the transcriptome and imprintome during critical periods of mouse visual system development under normal- and dark-rearing conditions using B6/CAST F1 hybrid mice. We identified experience-regulated, isoform-specific and brain-region-specific imprinted genes. We also found imprinted microRNAs were predominantly clustered into the Dlk1-Dio3 imprinted locus with light experience affecting some imprinted miRNA expression. Our findings provide the first comprehensive analysis of light-experience regulation of the transcriptome and imprintome during critical periods of visual system development. Our results may contribute to therapeutic strategies for visual impairments and circadian rhythm disorders resulting from a dysfunctional imprintome.