Changes in Circulating Acylated Ghrelin and Neutrophil Elastase in Diabetic Retinopathy.

Background and Objectives: The role and the levels of ghrelin in diabetes-induced retinal damage have not yet been explored. The present study aimed to measure the serum levels of total ghrelin (TG), and its acylated (AG) and des-acylated (DAG) forms in patients with the two stages of diabetic retinopathy (DR), non-proliferative (NPDR) and proliferative (PDR). Moreover, the correlation between serum ghrelin and neutrophil elastase (NE) levels was investigated. Materials and Methods: The serum markers were determined via enzyme-linked immunosorbent assays in 12 non-diabetic subjects (CTRL), 15 diabetic patients without DR (Diabetic), 15 patients with NPDR, and 15 patients with PDR. Results: TG and AG serum levels were significantly decreased in Diabetic (respectively, p < 0.05 and p < 0.01 vs. CTRL), NPDR (p < 0.01 vs. Diabetic), and in PDR patients (p < 0.01 vs. NPDR). AG serum levels were inversely associated with DR abnormalities (microhemorrhages, microaneurysms, and exudates) progression (r = -0.83, p < 0.01), serum neutrophil percentage (r = -0.74, p < 0.01), and serum NE levels (r = -0.73, p < 0.01). The latter were significantly increased in the Diabetic (p < 0.05 vs. CTRL), NPDR (p < 0.01 vs. Diabetic), and PDR (p < 0.01 vs. PDR) groups. Conclusions: The two DR stages were characterized by decreased AG and increased NE levels. In particular, serum AG levels were lower in PDR compared to NPDR patients, and serum NE levels were higher in the PDR vs. the NPDR group. Together with the greater presence of retinal abnormalities, this could underline a distinctive role of AG in PDR compared to NPDR.

Inhibition of Galectins and the P2X7 Purinergic Receptor as a Therapeutic Approach in the Neurovascular Inflammation of Diabetic Retinopathy.

Diabetic retinopathy (DR) is the most frequent microvascular retinal complication of diabetic patients, contributing to loss of vision. Recently, retinal neuroinflammation and neurodegeneration have emerged as key players in DR progression, and therefore, this review examines the neuroinflammatory molecular basis of DR. We focus on four important aspects of retinal neuroinflammation: (i) the exacerbation of endoplasmic reticulum (ER) stress; (ii) the activation of the NLRP3 inflammasome; (iii) the role of galectins; and (iv) the activation of purinergic 2X7 receptor (P2X7R). Moreover, this review proposes the selective inhibition of galectins and the P2X7R as a potential pharmacological approach to prevent the progression of DR.

Brolucizumab Intravitreal Injections for Wet Age-Related Macular Degeneration: Real-Life Study on a Cohort of Italian Patients.

Background and Objectives: To report the real-life Brolucizumab therapeutical outcomes of treatment-naïve and non-treatment-naïve eyes with neovascular age-related macular degeneration (nAMD) and to analyze the incidence of therapy-related adverse events. Materials and Methods: A total of 56 eyes of 54 patients diagnosed with nAMD were retrospectively evaluated over a 3-month follow-up. Naïve eyes received a 3-month loading phase, whereas non-naïve eyes were treated with one intravitreal injection + ProReNata scheme. The main outcome measures were best-corrected visual acuity (BCVA) and central retinal thickness (CRT) change. In addition, patients were stratified on the basis of fluid accumulation site, whether intra-retinal (IRF), sub-retinal (SRF), or sub-retinal pigmented epithelium (SRPE), to separately assess the eventual BCVA change in each subgroup. Finally, the incidence of ocular adverse events was evaluated. Results: In naïve eyes, a significant improvement of BCVA (LogMar) was observed at all timepoints from baseline (1 month-Mean Difference (MD): -0.13; 2 months MD: -0.17; 3 months MD: -0.24). In non-naïve eyes, a significant mean change was observed at all timepoints, with the exception of 1-month follow-up (2 months MD: -0.08; 3 months MD: -0.05). CRT significantly changed in both groups at all timepoints at a similar pace within the first two months, with naïve eyes displaying a larger overall thickness decrease at the end of the follow-up (Group 1 = MD: -123.91 µm; Group 2 = MD: -110.33 µm). With respect to the location of the edema, a significant BCVA change was observed in naïve patients with fluid in all three sites at the end of the follow-up (SRPE = MD: -0.13 (p = 0.043); SR = MD: -0.15 (p = 0.019); IR = MD: -0.19 (p = 0.041). Non-naïve patients exhibited significant mean BCVA changes only with respect to SR and IR fluid presence (SRPE = MD: -0.13 (p = 0.152); SR = MD: -0.15 (p = 0.007); IR = MD: -0.06 (p = 0.011). One naïve patient experienced acute-onset anterior and intermediate uveitis which completely resolved after therapy. Conclusions: Brolucizumab was demonstrated to be a safe and efficient alternative in improving both the anatomical and functional parameters of eyes with nAMD in this small, uncontrolled, series of patients.

Resolution of Inflammation in Retinal Disorders: Briefly the State.

The most frequent retinal diseases, such as diabetic retinopathy, age-related macular degeneration and posterior uveitis, are underlined by oxidative stress or aging-induced retinal inflammation, which contributes to vision impairing or loss. Resolution of inflammation is emerging as a critical phase able to counteract the inflammatory process leading to the progression of retinal damage. Particularly, pro-resolving mediators (PMs) play a key role in the modulation of inflammatory exudates and could be considered a new target to be investigated in different inflammatory-autoimmune pathologies. Here, we highlight the most recent studies concerning the role of the main PMs (lipoxins, resolvins, prtectins, maresins and annexins) in retinal inflammation, in order to collect the best evidence in the field of inflammatory retinal damage resolution and to propose novel pharmacological approaches in the management of the most common retinal diseases.

Systemic Beta-Hydroxybutyrate Affects BDNF and Autophagy into the Retina of Diabetic Mice.

Background: Diabetic retinopathy (DR) is a neurovascular disease, characterized by a deficiency of brain-derived neurotrophic factor (BDNF), a regulator of autophagy. Beta-hydroxybutyrate (BHB), previously reported as a protective agent in DR, has been associated with BDNF promotion. Here, we investigated whether systemic BHB affects the retinal levels of BDNF and local autophagy in diabetic mice with retinopathy; Methods: C57BL/6J mice were administered with intraperitoneal (i.p.) streptozotocin (STZ) (75 mg/kg) injection to develop diabetes. After 2 weeks, they received i.p. injections of BHB (25−50−100 mg/kg) twice a week for 10 weeks. Retinal samples were collected in order to perform immunofluorescence, Western blotting, and ELISA analysis; Results: BHB 50 mg/kg and 100 mg/kg significantly improved retinal BDNF levels (p < 0.01) in diabetic mice. This improvement was negatively associated with autophagosome−lysosome formations (marked by LC3B and ATG14) and to higher levels of connexin 43 (p < 0.01), a marker of cell integrity. Moreover, BHB administration significantly reduced M1 microglial activation and autophagy (p < 0.01); Conclusions: The systemic administration of BHB in mice with DR improves the retinal levels of BDNF, with the consequent reduction of the abnormal microglial autophagy. This leads to retinal cell safety through connexin 43 restoration.

Effects of the Calix[4]arene Derivative Compound OTX008 on High Glucose-Stimulated ARPE-19 Cells: Focus on Galectin-1/TGF-ß/EMT Pathway.

Diabetic retinopathy (DR) is a neurovascular disease characterized by the reduction of retina integrity and functionality, as a consequence of retinal pigment epithelial cell fibrosis. Although galectin-1 (a glycan-binding protein) has been associated with dysregulated retinal angiogenesis, no evidence has been reported about galectin-1 roles in DR-induced fibrosis. ARPE-19 cells were cultured in normal (5 mM) or high glucose (35 mM) for 3 days, then exposed to the selective galectin-1 inhibitor OTX008 (2.5-5-10 µM) for 6 days. The determination of cell viability and ROS content along with the analysis of specific proteins (by immunocytochemistry, Western blotting, and ELISA) or mRNAs (by real time-PCR) were performed. OTX008 5 µM and 10 µM improved cell viability and markedly reduced galectin-1 protein expression in cells exposed to high glucose. This was paralleled by a down-regulation of the TGF-ß/, NF-kB p65 levels, and ROS content. Moreover, epithelial-mesenchymal transition markers were reduced by OTX008 5 µM and 10 µM. The inhibition of galectin-1 by OTX008 in DR may preserve retinal pigment epithelial cell integrity and functionality by reducing their pro-fibrotic phenotype and epithelial-mesenchymal transition phenomenon induced by diabetes.

Two-year macular volume assessment in multiple sclerosis patients treated with fingolimod.

BACKGROUND: Fingolimod (FNG) is associated with the development of symptomatic macular edema (ME) in a small subset of multiple sclerosis (MS) patients. By using spectral domain optical coherence tomography (SD-OCT), an increase in the total macular volume (TMV) was rarely detected during the first months of treatment. OBJECTIVES: The objective of this study is to assess whether FNG treatment leads to long-term macular changes in a real-life setting. METHODS: Sixty RRMS patients starting FNG, according to therapeutic indication, were enrolled at three Italian MS centers and followed for 2 years. RESULTS: The mean TMV did not change between baseline and the follow-up. No patients experienced visual acuity drop during the follow-up. CONCLUSIONS: Initiation of FNG in MS is associated with a modest, not significant, increase in macular volume followed by no further significant changes over 2 years, highlighting the good safety profile of such treatment in MS.

Sex and Age-Related Differences in Neuroinflammation and Apoptosis in Balb/c Mice Retina Involve Resolvin D1.

(1) Background: The pro-resolving lipid mediator Resolvin D1 (RvD1) has already shown protective effects in animal models of diabetic retinopathy. This study aimed to investigate the retinal levels of RvD1 in aged (24 months) and younger (3 months) Balb/c mice, along with the activation of macro- and microglia, apoptosis, and neuroinflammation. (2) Methods: Retinas from male and female mice were used for immunohistochemistry, immunofluorescence, transmission electron microscopy, Western blotting, and enzyme-linked immunosorbent assays. (3) Results: Endogenous retinal levels of RvD1 were reduced in aged mice. While RvD1 levels were similar in younger males and females, they were markedly decreased in aged males but less reduced in aged females. Both aged males and females showed a significant increase in retinal microglia activation compared to younger mice, with a more marked reactivity in aged males than in aged females. The same trend was shown by astrocyte activation, neuroinflammation, apoptosis, and nitrosative stress, in line with the microglia and Müller cell hypertrophy evidenced in aged retinas by electron microscopy. (4) Conclusions: Aged mice had sex-related differences in neuroinflammation and apoptosis and low retinal levels of endogenous RvD1.

Bergmeister's papilla in a young patient with type 1 sialidosis: case report.

BACKGROUND: Sialidosis is a rare genetic lysosomal storage disorder caused by a deficit of neuraminidase enzyme activity. Patients with sialidosis present various neurological disorders such as: myoclonic epilepsy and hypotonia, often associated with visual impairment. A typical aspect of sialidosis is the finding of a macular cherry-red spot on ocular fundus examination. In this paper we describe a unilateral case of Bergmeister's papilla (BP) in a young female patient suffering from type 1 sialidosis. CASE PRESENTATION: A 28-year-old young woman suffering from type 1 sialidosis, confirmed by previously described compound heterozigosity Leu91Arg and Gly328Ser on N-acetyl-alpha-neuraminidase - 1 (NEU1) gene, underwent an opthalmological examination at the Eye Clinic of the University of Campania L. Vanvitelli, for bilateral visual deterioration. The patient was suffering from myoclonic epilepsy with hypotonia and severe motor disability. Fundoscopic examination showed a typical macular cherry-red spot with retinal pigment epithelium dystrophy in the middle periphery, in both eyes. Furthermore, in the left eye (OS), a vitreous thickening was observed in the nasal sector of the optic disc, remnant of fetal vasculature on the optic disc (Bergmeister's papilla). Optical coherence tomography (OCT) showed, in both eyes, a thickening of the ganglion cell layer (GCL) with a hyperreflective opacity as a cap on the left optic disc. CONCLUSIONS: In our paper we have described, for the first time in literature, a case of BP in a patient with type 1 sialidosis. The detection of BP with thickening of the peripapillary vitreous by SD-OCT is useful in monitoring any vitreo-retinal change that could cause future visual deterioration.

Melanocortin receptor agonists MCR1-5 protect photoreceptors from high-glucose damage and restore antioxidant enzymes in primary retinal cell culture.

Retinal photoreceptors are particularly vulnerable to local high-glucose concentrations. Oxidative stress is a risk factor for diabetic retinopathy development. Melanocortin receptors represent a family of G-protein-coupled receptors classified in five subtypes and are expressed in retina. Our previous data indicate that subtypes 1 and 5 receptor agonists exert a protective role on experimental diabetic retinopathy. This study focuses on their role in primary retinal cell cultures in high-glucose concentrations. After eye enucleation from wild-type male C57BL/6 mice, retinal cells were isolated, plated in high-glucose concentration and treated with melanocortin receptors 1 and 5 agonists and antagonists. Immunocytochemical and biochemical analysis showed that treatment with melanocortin receptors 1 and 5 agonists reduced anti-inflammatory cytokines and chemokines and enhanced manganese superoxide dismutase and glutathione peroxidase levels, preserving photoreceptor integrity. According with these evidences, we propose a major role of melanocortin receptors 1 and 5 on primary retinal cell response against high glucose or oxidative insults.

Macular hole closure patterns associated with different internal limiting membrane flap techniques.

PURPOSE: To compare the anatomic and functional outcome of two variants of the inverted internal limiting membrane (I-ILM) flap technique for idiopathic macular holes (IMH) larger than 400 µm. METHODS: Twenty-seven consecutive patients undergoing PPV for IMH were randomly assigned to different variants of I-ILM technique: the Cover group included 14 patients in which the I-ILM was folded upside-down over the MH as a single layer while the Fill group enrolled 13 patients in which the I-ILM was folded within the MH in multiple layers. RESULTS: MH closed in 12/14 Cover and in 13/13 Fill eyes (84.6 vs. 100%, p = 0.14; n.s.). Vision at 1 month was Snellen 0.44 ± 0.17 vs. 0.28 ± 0.21 (p = 0.05) and 0.48 ± 0.20 vs. 0.37 ± 0.25 (n.s.) at 3 months. IS/OS line interruption width was 463 ± 385 vs. 602 ± 210 µm, respectively, at 1 month (n.s.) and 602 ± 210 vs. 563 ± 209 µm at 3 months (n.s.). The Cover group showed outer retina cystic changes more often (p < 0.01). MH over 700 µm closed in 0/2 and in 2/2 cases, respectively, in the Cover and Fill groups (0.045). CONCLUSIONS: Cover and Fill I-ILM techniques allowed similar closure rates and post-operative vision at 3 months. The Cover group showed better anatomical restoration and vision at 1 month while the Fill technique might be more efficient in closing larger MHs.

High Levels of Serum Ubiquitin and Proteasome in a Case of HLA-B27 Uveitis.

In this paper, the authors describe a case of high serum levels of ubiquitin and proteasome in a woman under an acute attack of autoimmune uveitis. The woman was 52 years old, diagnosed as positive for the Human leukocyte antigen-B27 gene, and came to our observation in January 2013 claiming a severe uveitis attack that involved the right eye. During the acute attack of uveitis, this woman had normal serum biochemical parameters but higher levels of serum ubiquitin and proteasome 20S subunit, with respect to a healthy volunteer matched for age and sex. These levels correlated well with the clinical score attributed to uveitis. After the patient was admitted to therapy, she received oral prednisone in a de-escalation protocol (doses from 50 to 5 mg/day) for four weeks. Following this therapy, she had an expected reduction of clinical signs and score for uveitis, but concomitantly she had a reduction of the serum levels of ubiquitin, poliubiquitinated proteins (MAb-FK1) and proteasome 20S activity. Therefore, a role for ubiquitin and proteasome in the development of human autoimmune uveitis has been hypothesized.

Ocular pharmacological and biochemical profiles of 6-thioguanine: a drug repurposing study.

Introduction: The purine analog 6-thioguanine (6TG), an old drug approved in the 60s to treat acute myeloid leukemia (AML), was tested in the diabetic retinopathy (DR) experimental in vivo setting along with a molecular modeling approach. Methods: A computational analysis was performed to investigate the interaction of 6TG with MC1R and MC5R. This was confirmed in human umbilical vein endothelial cells (HUVECs) exposed to high glucose (25 mM) for 24 h. Cell viability in HUVECs exposed to high glucose and treated with 6TG (0.05-0.5-5 µM) was performed. To assess tube formation, HUVECs were treated for 24 h with 6TG 5 µM and AGRP (0.5-1-5 µM) or PG20N (0.5-1-5-10 µM), which are MC1R and MC5R antagonists, respectively. For the in vivo DR setting, diabetes was induced in C57BL/6J mice through a single streptozotocin (STZ) injection. After 2, 6, and 10 weeks, diabetic and control mice received 6TG intravitreally (0.5-1-2.5 mg/kg) alone or in combination with AGRP or PG20N. Fluorescein angiography (FA) was performed after 4 and 14 weeks after the onset of diabetes. After 14 weeks, mice were euthanized, and immunohistochemical analysis was performed to assess retinal levels of CD34, a marker of endothelial progenitor cell formation during neo-angiogenesis. Results: The computational analysis evidenced a more stable binding of 6TG binding at MC5R than MC1R. This was confirmed by the tube formation assay in HUVECs exposed to high glucose. Indeed, the anti-angiogenic activity of 6TG was eradicated by a higher dose of the MC5R antagonist PG20N (10 µM) compared to the MC1R antagonist AGRP (5 µM). The retinal anti-angiogenic effect of 6TG was evident also in diabetic mice, showing a reduction in retinal vascular alterations by FA analysis. This effect was not observed in diabetic mice receiving 6TG in combination with AGRP or PG20N. Accordingly, retinal CD34 staining was reduced in diabetic mice treated with 6TG. Conversely, it was not decreased in diabetic mice receiving 6TG combined with AGRP or PG20N. Conclusion: 6TG evidenced a marked anti-angiogenic activity in HUVECs exposed to high glucose and in mice with DR. This seems to be mediated by MC1R and MC5R retinal receptors.

Multimodal Assessment of the Prognostic Role of Ectopic Inner Foveal Layers on Epiretinal Membrane Surgery.

BACKGROUND: To perform a multimodal assessment of the ectopic inner foveal layers' (EIFL) prognostic role on idiopathic epiretinal membrane (ERM) surgery. METHODS: We retrospectively followed-up for 12 months 27 patients who underwent ERM surgery and stratified them based on EIFL presence (group 1) or absence (group 2) at baseline. Central Retinal Thickness (CRT) and best-corrected visual acuity (BCVA) were compared pre- and post-operatively at 1, 4 and 12 months, whereas fixation stability (FS), macular sensitivity (MS) and multifocal electroretinogram (mfERG) responses were confronted at baseline and 12 months. RESULTS: In group 1, BCVA improved at 4 and 12 months (MD = 0.14 (SE = 0.04); MD = 0.13 (SE = 0.05), respectively) as well as in group 2 (MD = 0.31 (SE = 0.07); MD = 0.41 (SE = 0.08), respectively). CRT did not change in group 1, whereas it decreased in group 2 at 4 and 12 months (MD = -73.13; SE = 23.56; MD = -76.20; SE = 23.56). MS showed no changes in both groups after surgery. FS did not change in group 1, whereas group 2 improved FS 2° (+8.91 ± 13.97) and FS 4° (+4.33 ± 3.84). MfERG P1 wave did not change in group 1, while in group 2 αP1-2, αP1-3 and αP1-4 improved postoperatively (27.97 ± 27.62; 12.51 ± 17.36; 10.49 ± 17.19, respectively). CONCLUSIONS: Multimodal assessment confirmed that EIFL negatively affected ERM surgery outcomes.

Oral Administration of Vitamin D3 Prevents Corneal Damage in a Knock-Out Mouse Model of Sjögren's Syndrome.

BACKGROUND: Vitamin D deficiency has been associated with dry eye development during Sjögren's syndrome (SS). Here, we investigated whether repeated oral vitamin D3 supplementation could prevent the corneal epithelium damage in an SS mouse model. METHODS: 30 female mouse knock-out for the thrombospondin 1 gene were randomized (six per group) in untreated mice euthanized at 6 weeks as negative control (C-) or at 12 weeks as the positive control for dry eye (C+). Other mice were sacrificed after 6 weeks of oral vitamin D3 supplementation in the drinking water (1000, 8000, and 20,000 IU/kg/week, respectively). RESULTS: The C+ mice showed alterations in their corneal epithelial morphologies and thicknesses (p < 0.01 vs. C-), while the mice receiving 8000 (M) and 20,000 (H) IU/kg/week of vitamin D3 showed preservation of the corneal epithelium morphology and thickness (p < 0.01 vs. C+). Moreover, while the C+ mice exhibited high levels and activity of corneal tumor necrosis factor alpha converting enzyme (TACE), neovascularization and fibrosis markers; these were all reduced in the M and H mice. CONCLUSIONS: Oral vitamin D3 supplementation appeared to counteract the negative effect of TACE on corneal epithelium in a mouse model of SS-associated dry eye.

Serum Iba-1, GLUT5, and TSPO in Patients With Diabetic Retinopathy: New Biomarkers for Early Retinal Neurovascular Alterations? A Pilot Study.

Purpose: This study explored the possibility of highlighting early retinal neurovascular alterations of diabetic retinopathy (DR) by monitoring in DR patients the serum levels of microglial biomarkers ionized calcium-binding adapter molecule 1 (Iba-1), glucose transporter 5 (GLUT5), and translocator protein (TSPO), along with serum changes of the endothelial dysfunction marker arginase-1. Methods: Serum markers were determined by enzyme-linked immunosorbent assay in 50 patients: 12 non-diabetic subjects, 14 diabetic patients without DR, 13 patients with non-proliferative DR (NPDR), and 11 patients with proliferative DR (PDR). The results were correlated with hyperreflective retinal spots (HRS), observed with optical coherence tomography (OCT). Results: Although HRS were absent in diabetic patients without DR, NPDR patients showed an average of 4 ± 1 HRS, whereas the highest presence was detected in PDR patients, with 8 ± 1 HRS (P < 0.01 vs. NPDR). HRS were positively correlated (P < 0.01) with serum levels of arginase-1 (r = 0.91), Iba-1 (r = 0.96), GLUT5 (r = 0.94), and TSPO (r = 0.88). Moreover, serum proinflammatory cytokines and chemokines showed a positive correlation (P < 0.01) with HRS number and the serum markers analyzed. Conclusions: Serum markers of microglial activation positively correlate with retinal HRS in NPDR and PDR patients. Translational Relevance: These data corroborate the possibility of highlighting early retinal neurovascular changes due to diabetes by monitoring circulating microglial markers.

Autophagy: A Novel Pharmacological Target in Diabetic Retinopathy.

Autophagy is the major catabolic pathway involved in removing and recycling damaged macromolecules and organelles and several evidences suggest that dysfunctions of this pathway contribute to the onset and progression of central and peripheral neurodegenerative diseases. Diabetic retinopathy (DR) is a serious complication of diabetes mellitus representing the main preventable cause of acquired blindness worldwide. DR has traditionally been considered as a microvascular disease, however this concept has evolved and neurodegeneration and neuroinflammation have emerged as important determinants in the pathogenesis and evolution of the retinal pathology. Here we review the role of autophagy in experimental models of DR and explore the potential of this pathway as a target for alternative therapeutic approaches.

Correlation Between Choriocapillaris Density and Retinal Sensitivity in Age-Related Macular Degeneration.

Purpose: The purpose of this study was to investigate the relationship between perfusion of the choriocapillaris (CC) and retinal sensitivity in eyes with intermediate age-related macular degeneration (iAMD). Methods: This prospective study included patients with iAMD and healthy controls. All enrolled subjects underwent optical coherence tomography angiography (OCT-A) in order to compute the percent perfused choriocapillaris area (PPCA). In patients with iAMD, microperimetry (MP) testing was performed in order to quantify: mean retinal sensitivity (MRS), over an area of 10 degrees; mean macular sensitivity (MMS), over the macular area scanned with OCT-A; and retinal sensitivity (RS) in each macular point. Results: Eighteen eyes of 13 patients were included in the analysis. In addition, 18 eyes of 12 healthy subjects were enrolled as controls. No statistically significant difference (P value > 0.2) was observed in age between patients (73.9 ± 2.0 years) and controls (70.1 ± 2.8 years). We observed significantly lower values of PPCA between patients with iAMD and healthy controls (42.0% ± 3.8% vs. 66.4% ± 3.0%; -ß = 23.8%; P value < 0.001). Among iAMD eyes, higher values of PPCA were significantly associated with higher values of MRS (P value = 0.002) and MMS (P value = 0.013). Finally, higher values of RS in each macular point analyzed with MP were significantly (P value < 0.001) associated with higher values of PPCA computed in circular regions of interest (ROIs) centered in each analyzed MP point with radii of 0.5 degrees and 1.0 degree. Conclusions: Using OCT-A, we demonstrated a significant association between CC impairment and macular dysfunction, quantified by MP, in iAMD eyes. Translational Relevance: OCT-A could be a useful tool for detecting CC alterations and to monitor disease progression.

Inclusion of a degron reduces levelsof undesired inteins after AAV-mediated proteintrans-splicing in the retina.

Split intein-mediated protein trans-splicing expands AAV transfer capacity, thus overcoming the limited AAV cargo. However, non-mammalian inteins persist as trans-splicing by-products, and this could raise safety concerns for AAV intein clinical applications. In this study, we tested the ability of several degrons to selectively decrease levels of inteins after protein trans-splicing and found that a version of E. coli dihydrofolate reductase, which we have shortened to better fit into the AAV vector, is the most effective. We show that subretinal administration of AAV intein armed with this short degron is both safe and effective in a mouse model of Stargardt disease (STGD1), which is the most common form of inherited macular degeneration in humans. This supports the use of optimized AAV intein for gene therapy of both STGD1 and other conditions that require transfer of large genes.

Corrigendum: Changes in Retinal Structure and Ultrastructure in the Aged Mice Correlate with Differences in the Expression of Selected Retinal miRNAs.

[This corrects the article DOI: 10.3389/fphar.2020.593514.].