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Intravitreal injection is the most widely used injection technique for ocular gene delivery. However, vector diffusion is attenuated by physical barriers and neutralizing antibodies in the vitreous. The 13-lined ground squirrel (13-LGS), as in humans, has a larger relative vitreous body volume than the more common rodent models such as rats and mice, which would further reduce transduction efficiency with the intravitreal injection route. We report here a “pre-retinal” injection approach that leads to detachment of the posterior hyaloid membrane and delivers vector into the space between vitreous and inner retina. Vectors carrying a ubiquitously expressing mCherry reporter were injected into the deep vitreous or pre-retinal space in adult wild-type 13-LGSs. Then, adeno-associated virus (AAV)-mediated mCherry expression was evaluated with non-invasive imaging, immunofluorescence, and flow cytometry. Compared to deep vitreous delivery, pre-retinal administration achieved pan-retinal gene expression with a lower vector dose volume and significantly increased the number of transduced cone photoreceptors. These results suggest that pre-retinal injection is a promising tool in the development of gene therapy strategies in animal models and is a potential approach for use in human research, particularly in younger individuals with an intact posterior hyaloid membrane and stable vitreous., Graphical abstract, We demonstrate that transduction of cone photoreceptors using rAAV can be significantly improved through delivery of vector into the pre-retinal space located between the inner limiting membrane and posterior hyaloid membrane. If translated to human subjects, this novel delivery approach could improve gene delivery efficiency and surgical safety.

Retinal image quality assessment (RIQA) is essential to assure that images used for medical analysis are of sufficient quality for reliable diagnosis. A modified VGG16 network with transfer learning is introduced in order to classify retinal images into good or bad quality images. Both spatial and wavelet detail subbands are compared as inputs to the modified VGG16 network. Three public retinal image datasets captured with different imaging devices are used, both individually and collectively. Superior performance was attained by the modified VGG16 network, where accuracies in the range of 99–100% were achieved regardless of whether retinal images from the same or different sources were considered and whether the spatial or wavelet images were used. The implemented RIQA algorithm was also found to outperform other RIQA deep learning algorithms from literature by 1.5–10% and to achieve accuracies that are up to 32% higher than traditional RIQA methods for the same dataset.

Purpose To investigate the clinical course, genetic findings, and phenotypic spectrum of autosomal recessive bestrophinopathy (ARB) in a large cohort of children and adults. Design Retrospective case series. Participants Patients with a detailed clinical phenotype consistent with ARB, biallelic likely disease-causing sequence variants in the BEST1 gene, or both identified at a single tertiary referral center. Methods Review of case notes, retinal imaging (color fundus photography, fundus autofluorescence, OCT), electrophysiologic assessment, and molecular genetic testing. Main Outcome Measures Visual acuity (VA), retinal imaging, and electrophysiologic changes over time. Results Fifty-six eyes of 28 unrelated patients were included. Compound heterozygous variants were detected in most patients (19/27), with 6 alleles recurring in apparently unrelated individuals, the most common of which was c.422G→A, p.(Arg141His; n = 4 patients). Mean presenting VA was 0.52 ± 0.36 logarithm of the minimum angle of resolution (logMAR), and final VA was 0.81 ± 0.75 logMAR (P = 0.06). The mean rate of change in VA was 0.05 ± 0.13 logMAR/year. A significant change in VA was detected in patients with a follow-up of 5 years or more (n = 18) compared with patients with a follow-up of 5 years or less (n = 10; P = 0.001). Presence of subretinal fluid and vitelliform material were early findings in most patients, and this did not change substantially over time. A reduction in central retinal thickness was detected in most eyes (80.4%) over the course of follow-up. Many patients (10/26) showed evidence of generalized rod and cone system dysfunction. These patients were older (P < 0.001) and had worse VA (P = 0.02) than those with normal full-field electroretinography results. Conclusions Although patients with ARB are presumed to have no functioning bestrophin channels, significant phenotypic heterogeneity is evident. The clinical course is characterized by a progressive loss of vision with a slow rate of decline, providing a wide therapeutic window for anticipated future treatment strategies.

Summary Retinal ganglion cell (RGC) replacement holds potential for restoring vision lost to optic neuropathy. Transplanted RGCs must undergo neuroretinal integration to receive afferent visual signals for processing and efferent transmission. To date, retinal integration following RGC transplantation has been limited. We sought to overcome key barriers to transplanted human stem cell-derived RGC integration. Following co-culture ex vivo on organotypic mouse retinal explants, human RGCs cluster and extend bundled neurites that remain superficial to the neuroretina, hindering afferent synaptogenesis. To enhance integration, we increased the cellular permeability of the internal limiting membrane (ILM). Extracellular matrix digestion using proteolytic enzymes achieved ILM disruption while minimizing retinal toxicity and preserving glial reactivity. ILM disruption is associated with dispersion rather than clustering of co-cultured RGC bodies and neurites, and increased parenchymal neurite ingrowth. The ILM represents a significant obstacle to transplanted RGC connectivity and its circumvention may be necessary for functional RGC replacement., Graphical Abstract, Highlights • hES-derived RGCs cultured on neuroretina are excluded from parenchymal engraftment • Proteolytic enzyme digestion of the ILM can be titrated to minimize retinal toxicity • ILM disruption reduced co-cultured hES-RGC clustering and neurite bundling • ILM disruption permits robust neurite ingrowth into the recipient neuroretina, In this article, Johnson and colleagues co-cultured human embryonic stem cell-derived retinal ganglion cells (RGCs) on the surface of adult organotypic retinal explants. The authors showed that RGCs spontaneously clustered and extended neurites that were excluded from the retinal parenchyma, but that internal limiting membrane (ILM) digestion permitted robust neurite engraftment with little toxicity, thereby identifying the ILM as a barrier to transplanted RGC retinal integration.

The loss of photoreceptors in individuals with retinal degenerative diseases leads to partial or complete blindness. Optogenetic therapy is a promising approach for restoring vision to the blind. Multiple strategies have been employed by targeting genetically encoded light sensors, particularly channelrhodopsins, to surviving retinal neurons in animal models. In particular, the strategy of targeting retinal bipolar cells has commonly been expected to result in better vision than ubiquitous expression in retinal ganglion cells. However, a direct comparison of the channelrhodopsin-restored vision between these two strategies has not been performed. Here, we compared the restored visual functions achieved by adeno-associated virus (AAV)-mediated expression of a channelrhodopsin in ON-type bipolar cells and retinal ganglion cells driven by an improved mGluR6 promoter and a CAG promoter, respectively, in a blind mouse model by performing electrophysiological recordings and behavioral assessments. Unexpectedly, the efficacy of the restored vision based on light sensitivity and visual acuity was much higher following ubiquitous retinal ganglion cell expression than that of the strategy targeting ON-type bipolar cells. Our study suggests that, at least based on currently available gene delivery techniques, the expression of genetically encoded light sensors in retinal ganglion cells is likely a practical and advantageous strategy for optogenetic vision restoration., Graphical Abstract, The strategy of targeting retinal bipolar cells has been considered advantageous for optogenetic vision restoration. Here, Lu and colleagues report that AAV-mediated ubiquitous expression of a channelrhodopsin in retinal ganglion cells shows higher functional efficacy of the restored vision than ON-type bipolar cell targeting in a mouse model of blindness.

Intravitreal administration for human adeno-associated vector (AAV) delivery is easier and less traumatic to ocular tissues than subretinal injection, but it gives limited retinal transduction. AAV vectors are large (about 4,000 kDa) compared with most intraocular drugs, such as ranibizumab (48 kDa), and the large size impedes diffusion to reach the retina from the usual injection site in the anterior/mid-vitreous. Intuitively, a preferred placement for the vector would be deep in the vitreous near the retina, which we term “para-retinal” delivery. We explored the consequences of para-retinal intravitreal delivery in the rabbit eye and in non-human primate (NHP) eye. 1 h after para-retinal administration in the rabbit eye, the vector concentration near the retina remained four times greater than in the anterior vitreous, indicating limited vector diffusion through the gelatinous vitreous matrix. In NHP, para-retinal placement showed greater transduction in the fovea than vector applied in the mid-vitreous. More efficient retinal delivery translates to using lower vector doses, with reduced risk of ocular inflammatory exposure. These results indicate that para-retinal delivery yields more effective vector concentration near the retina, thereby increasing the potential for better retinal transduction in human clinical application., Graphical Abstract, The authors explored an alternate approach to standard intravitreal administration called “para-retinal” delivery where AAV vectors were placed deep into the vitreous near the retina surface. This modification increased vector concentration in the posterior vitreous in rabbit eyes, minimized vector losses, and enhanced foveal transgene expression in NHP eyes.

No treatment is available for nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1)-associated retinal degeneration, an inherited disease that leads to severe vision loss early in life. Although the causative gene, NMNAT1, plays an essential role in nuclear nicotinamide adenine dinucleotide (NAD)+ metabolism in tissues throughout the body, NMNAT1-associated disease is isolated to the retina. Since this condition is recessive, supplementing the retina with a normal copy of NMNAT1 should protect vulnerable cells from disease progression. We tested this hypothesis in a mouse model that harbors the p.Val9Met mutation in Nmnat1 and consequently develops a retinal degenerative phenotype that recapitulates key features of the human disease. Gene augmentation therapy, delivered by subretinal injection of adeno-associated virus (AAV) carrying a normal human copy of NMNAT1, rescued retinal structure and function. Due to the early-onset profile of the phenotype, a rapidly activating self-complementary AAV was required to initiate transgene expression during the narrow therapeutic window. These data represent the first proof of concept for a therapy to treat patients with NMNAT1-associated disease., Graphical Abstract, This study demonstrates that gene therapy rescues retinal structure and function in a mouse model of NMNAT1-associated retinal degeneration, a disease that causes severe, early-onset vision loss and has no treatment available to patients. A self-complementary AAV delivery vector, rather than a single-stranded vector, proved necessary because of the rapid disease progression.

Objective: To study the therapeutic effect and mechanism of levotinib on choroidal neovascularization (CNV) in mice. Methods: 45 healthy C57BL/6 mice were selected and randomly divided into three groups: control group (group A), model group (group B) and levotinib group (group C). The model of CNV in mice was established. The fluorescence leakage of choroidal lesions in mice was observed by fundus fluorescein angiography. The morphological changes of retinal vessels in mice were observed by retinal slice preparation, the pathological changes of eyeball tissues in mice were observed by hematoxylin-eosin (HE) staining, the expression of vascular endothelial growth factor (VEGF) in mice retina was detected by real-time quantitative fluorescence PCR, and the protein expression of VEGF in mice retina was detected by Western blotting. Result: On the 7th, 14th and 21st day after modeling, compared with group B, the fluorescence leakage area of group C mice was significantly reduced, and the difference was statistically significant (P

Several standard-of-care therapies for the treatment of retinal disease, including aflibercept, inhibit vascular endothelial growth factor (VEGFA). The main shortcoming of these therapies is potential undertreatment due to a lack of compliance resulting from the need for repeated injections. Gene therapy may provide sustained levels of anti-VEGFA proteins in the retina following a single injection. In this nonhuman primate study, we explored whether ADVM-022, a recombinant adeno-associated virus (AAV) vector designed to express aflibercept, could induce anti-VEGFA protein levels comparable with those observed following a single-bolus intravitreal (IVT) injection of the standard-of-care aflibercept recombinant protein. The results demonstrated that intraocular levels of aflibercept measured at 56 days after a single IVT injection of ADVM-022 were equivalent to those in the aflibercept recombinant protein-injected animals measured 21–32 days post-administration. ADVM-022-injected animals exhibited signs of an initial self-limiting inflammatory response, but overall all doses were well tolerated. ADVM-022 administration did not result in systemic exposure to aflibercept at any dose evaluated. These results demonstrated that a single IVT injection of ADVM-022 resulted in safe and efficacious aflibercept levels in the therapeutic range, suggesting the potential of a gene therapy approach for long-term treatment of retinal disease with anti-VEGF therapy., Graphical Abstract, Current treatments of nAMD require frequent intravitreal injections of VEGF inhibitors. ADVM-022 is a one-time intravitreal gene therapy designed to express aflibercept. Kiss et al. demonstrated a range of ADVM-022 doses in non-human primates that resulted in safe ocular expression of aflibercept in the therapeutic range, without systemic exposure.

Summary Stem cell-based transplantation therapies offer hope for currently untreatable retinal degenerations; however, preclinical progress has been largely confined to rodent models. Here, we describe an experimental platform for accelerating photoreceptor replacement therapy in the nonhuman primate, which has a visual system much more similar to the human. We deployed fluorescence adaptive optics scanning light ophthalmoscopy (FAOSLO) to noninvasively track transplanted photoreceptor precursors over time at cellular resolution in the living macaque. Fluorescently labeled photoreceptors generated from a CRX+/tdTomato human embryonic stem cell (hESC) reporter line were delivered subretinally to macaques with normal retinas and following selective ablation of host photoreceptors using an ultrafast laser. The fluorescent reporter together with FAOSLO allowed transplanted photoreceptor precursor survival, migration, and neurite formation to be monitored over time in vivo. Histological examination suggested migration of photoreceptor precursors to the outer plexiform layer and potential synapse formation in ablated areas in the macaque eye., Highlights • Longitudinal imaging of single fluorescently tagged donor photoreceptors in primates • Donor photoreceptor migration and neurite outgrowth were detected in the living eye • In a photoreceptor ablation model, donor photoreceptors migrated to the OPL • Donor photoreceptors structurally made synaptic connections with host bipolar cells, In this article, David Williams and colleagues demonstrate the capability of fluorescence adaptive optics imaging that allows longitudinal tracking of the behavior of transplanted photoreceptors at a single-cell level in living primate eyes. This study shows transplanted photoreceptors migrated to the outer plexiform layer through the laser lesion sites and often extended neurites containing presynaptic proteins toward the host inner nuclear layer.

The inhibition of retinal ischemia-induced damage by post-ischemic prothymosin alpha (ProTα) was not affected in toll-like receptor 4 knockout (TLR4-/-) mice but blocked by the pretreatment with antibody against F0/F1 ATPase α- or β-subunit, novel candidate for ProTα-receptor. In addition to the previous observation of ProTα-induced ATP release from cells, the present study showed a ProTα-induced enhancement of ATP hydrolysis activity of recombinant ATP5A1/5B complex. As the protection of retinal function by post-ischemic ProTα was abolished by anti-P2Y12 antibody, the activation of F0/F1 ATPase and subsequent P2Y12 receptor system may play roles in beneficial actions by post-ischemic ProTα.

Retinal photoreceptor degeneration occurs frequently in several neurodegenerative retinal diseases such as age-related macular degeneration, retinitis pigmentosa, or genetic retinal diseases related to the photoreceptors. Despite the impact on daily life and the social and economic consequences, there is no cure for these diseases. Considering this, cell-based therapy may be an optimal therapeutic option. This study evaluated the neuroprotective in vitro potential of a secretome of human bone marrow mesenchymal stem cells (MSCs) for retinal photoreceptors in vitro. We analyzed the photoreceptor morphologic changes and the paracrine factors secreted by human bone marrow MSCs in a physically separated co-culture with degenerated neuroretinas, using organotypic neuroretinal cultures. The results showed that the secretome of human bone marrow MSCs had a neuroprotective effect over the neuroretinal general organization and neuropreserved the photoreceptors from degeneration probably by secretion of neuroprotective proteins. The study of the expression of 1,000 proteins showed increased paracrine factors secreted by MSCs that could be crucial in the neuroprotective effect of the stem cell secretome over in vitro retinal degeneration. The current results reinforce the hypothesis that the paracrine effect of the human bone marrow MSCs may slow photoreceptor neurodegeneration and be a therapeutic option in retinal photoreceptor degenerative diseases., This work was supported by grants from Fondo Europeo de Desarrollo Regional (FEDER) and Consejería de Educación from Junta de Castilla y León, Spain (grant VA077P17), and from the Spanish Health Institute Carlos III (ISCIII) (grants PI17/01930 and CB16/12/00400). The Proteomics Unit belongs to ProteoRed (PRB3-ISCIII) supported by grant PT17/0019/0023, of the PEI+D+I 2017-2020, funded by ISCIII and FEDER. R.U.-M. was supported by FEDER and Consejería de Educación from Junta de Castilla y León, Spain (grant VA077P17); K.P.-N. was supported by Fundación Carolina, Madrid, Spain; and I.F.-B. was supported by Centro en Red de Medicina Regenerativa y Terapia Celular, Junta de Castilla y León, Spain.

Summary RP2 mutations cause a severe form of X-linked retinitis pigmentosa (XLRP). The mechanism of RP2-associated retinal degeneration in humans is unclear, and animal models of RP2 XLRP do not recapitulate this severe phenotype. Here, we developed gene-edited isogenic RP2 knockout (RP2 KO) induced pluripotent stem cells (iPSCs) and RP2 patient-derived iPSC to produce 3D retinal organoids as a human retinal disease model. Strikingly, the RP2 KO and RP2 patient-derived organoids showed a peak in rod photoreceptor cell death at day 150 (D150) with subsequent thinning of the organoid outer nuclear layer (ONL) by D180 of culture. Adeno-associated virus-mediated gene augmentation with human RP2 rescued the degeneration phenotype of the RP2 KO organoids, to prevent ONL thinning and restore rhodopsin expression. Notably, these data show that 3D retinal organoids can be used to model photoreceptor degeneration and test potential therapies to prevent photoreceptor cell death., Graphical Abstract, Highlights • Isogenic RP2 knockouts match the phenotype of RP2 patient-derived organoids • Retinal organoids from RP2 nulls undergo rod photoreceptor cell death • Cell death correlates with rod photoreceptor differentiation • AAV gene therapy improved photoreceptor viability and increased rhodopsin expression, Cheetham and colleagues show that 3D retinal organoids lacking the RP2 protein develop rod photoreceptor degeneration that can be prevented with AAV gene augmentation for RP2.

Non-viral delivery of therapeutic genes into targeted areas of retina is essential for re-functionalizing the retinal circuitry. While a focused ultrafast laser beam has been recently used for intra-ocular delivery of molecules, it poses the significant technical challenge of overcoming aberrations of the eye and maintaining a tightly focused spot on the retinal cell membrane. Furthermore, to minimize collateral damage and increase the throughput of gene delivery, we introduced a weakly focused near-infrared (NIR) continuous wave (CW) or pulsed laser beam on to the cells wherein the intensity is locally enhanced by gold nanorods bound to the cell membranes to permit gene insertion. Parametric optimization of nano-enhanced optical delivery (NOD) was carried out by varying the exposure time, as well as the power of the CW NIR beam or the energy of the pulsed NIR beam. Using this NOD method, therapeutic genes encoding for multi-characteristic opsins (MCOs) were delivered to spatially targeted regions of degenerated retina ex vivo as well as in vivo. NOD-mediated cell membrane-specific expression of MCOs in targeted retinal regions with photoreceptor degeneration will allow functional recovery in an ambient light environment., Graphical Abstract, Nanoscope researchers describe a non-viral method using nanotechnology and light for in vivo delivery of the therapeutic multi-characteristic opsin gene into the targeted area of a photoreceptor-degenerated retina. This delivery approach mitigates limitation associated with viral methods such as immunogenic reaction and allows spatially targeted delivery for treatment of geographic atrophies, as in dry-AMD.

SUMMARY Retinal degeneration is a form of neurodegenerative disease and is the leading cause of vision loss globally. The Toll-like receptors (TLRs) are primary components of the innate immune system involved in signal transduction. Here we show that TLR2 induces complement factors C3 and CFB, the common and rate-limiting factors of the alternative pathway in both retinal pigment epithelial (RPE) cells and mononuclear phagocytes. Neutralization of TLR2 reduces opsonizing fragments of C3 in the outer retina and protects photoreceptor neurons from oxidative stress-induced degeneration. TLR2 deficiency also preserves tight junction expression and promotes RPE resistance to fragmentation. Finally, oxidative stress-induced formation of the terminal complement membrane attack complex and Iba1+ cell infiltration are strikingly inhibited in the TLR2-deficient retina. Our data directly implicate TLR2 as a mediator of retinal degeneration in response to oxidative stress and present TLR2 as a bridge between oxidative damage and complement-mediated retinal pathology., Graphical Abstract, In Brief Oxidative stress and complement deposition are common to many retinal degenerative diseases. Mulfaul et al. demonstrate that TLR2 blockade protects against photoreceptor neuronal cell death and RPE fragmentation in experimental models of oxidative stress-induced retinal degeneration and present TLR2 as a bridge between oxidative damage and complement-mediated retinal pathology.

The eyes are tools that extract visual information from the surrounding environment. Acting like a digital camera, we use them daily to capture and convert light stimuli into images. This activity is highly regulated and is the direct responsibility of the numerous cell types of the retina. Strikingly, loss of any one of these retinal cells, whether a result of genetic complications or traumatic injury, culminates in blindness. Therefore, it is understandable why diseases affecting the eyes are extremely debilitating and studied worldwide. With the advent of stem cell biology, scientists are now able to design retinal disease-specific models that recapitulate patient clinical phenotypes. In this review, we summarize some of the recent advances in modeling of inherited retinal dystrophies (IRDs) using patient-derived induced pluripotent stem cells (pd-iPSCs). Methods have been developed to direct the differentiation of iPSC into bonafide retinal cells in both two-dimensional adherent cultures and three-dimensional organoid systems. This novel approach to studying IRDs such as retinitis pigmentosa, leber congenital amaurosis, choroideremia, Bests disease, and Stargardt maculopathy has yielded valuable insights into the molecular and cellular basis of these currently untreatable maladies.

In order to study the protection mechanism of liraglutide on the infectious lesion of the retina of type I diabetes, in this experiment, a mouse model of type I diabetes was established by induction with streptozotocin (STZ) and feeding with high-fat and high-sugar diet. After observing the living conditions of the modeled mice and detecting their fasting blood glucose (FBG), it was found that the modeled mice exhibited clinically similar symptoms in patients with type I diabetes, and their FBG was larger than 16.7 mmol/L, indicating that the experimental mouse model was obtained. The mice were divided into groups. The control group was divided into negative control group (A), light positive control group (B), diabetic control group (C), and diabetes care group (D) according to different treatment methods, and the experimental group was divided into treatment group 1 (LR1), treatment group 2 (LR2) and treatment group 3 (LR3) according to different injection doses. The eyes of mice in each group were extracted and retinal tissue sections were made, and the sections were stained with HE. The retinal morphology was observed and it was found that compared with group A, the outer nucleus layer was significantly thinner in group B and C, and the group D was the thinnest. After treatment with liraglutide, the outer nuclear layer of LR1 group and LR2 group LR3 group recovered significantly, indicating that liraglutide had protective effect on type I diabetes and light-induced damage of mouse retinal photoreceptor cells. Immunohistochemistry was used to detect p-Erk1/2 and ASK1 protein contents in retina. It was found that compared with the negative control group and the light control group, p-Erk1/2 protein contents in LR1, LR2 and LR3 groups were significantly increased, showing statistical significance. Compared with the negative control group and the light control group, ASK1 protein content in LR1, LR2 and LR3 groups significantly decreased. This suggested that the protective mechanism of liraglutide on retinopathy was related to up-regulation of antioxidant protein p-Erk1/2 and down-regulation of apoptosis-related protein ASK1, that is to say, the action site of liraglutide may be related to this. Through real-time quantitative detection of the Trx gene expression level in diabetic and photodamaged mice, it was found that compared with the diabetic light group, the Trx expression level in mice treated with liraglutide showed a significant up-regulated trend, suggesting that the protective mechanism of liraglutide on retinopathy was related to the up-regulated expression of antioxidant protein Trx. Therefore, liraglutide has a certain protective effect on diabetic retinal injury, and its mechanism is related to the up-regulation of p-Erk1/2 and Trx antioxidant protein, and the down-regulation of apoptosis-related protein ASK1. Keywords: Diabetic retinopathy, Diabetes, Liraglutide, Retina, Mouse

Purpose To assess the impact of two TYR hypomorphic alleles (R402Q and S192Y) on foveal pit and FAZ morphology. Design Prospective cross-sectional study Participants One hundred sixty-four participants with normal vision (67 males and 97 females; mean ± SD age = 30.5 ± 12.8 years) were recruited. Methods Sequencing of over 100 pigmentation-related genes was performed, and results were reviewed for the presence or absence of the TYR polymorphisms R402Q (rs1126809) and S192Y (rs1042602). Volumetric scans of the macula were obtained for each participant using optical coherence tomography (OCT) and retinal thickness maps were analyzed using custom software. OCT angiography (OCT-A) was used to image the foveal avascular zone (FAZ) which was manually segmented and measured. Linear mixed model analysis was used to assess associations between genotype and foveal pit morphology Main Outcome Measures Foveal pit depth, diameter, volume and FAZ area in relation to the presence of hypomorphic alleles R402Q and S192Y on the TYR gene. Results Heterozygosity for the TYR R402Q allele was associated with decreased pit diameter (p = 0.0094) and decreased FAZ area (p = 0.025). Homozygosity for the TYR R402Q allele was associated with reduced pit volume (p = 0.0005), decreased pit depth (p = 0.007), reduced pit diameter (p = 0.0052) and reduced FAZ area (p = 0.0012). Homozygosity for TYR S192Y was associated with reduced FAZ area (p = 0.016). Heterozygosity for the TYR S192Y allele was not associated with differences in foveal pit depth, diameter, volume or FAZ area (p > 0.05). Conclusion While the role of the TYR R402Q and S192Y hypomorphic alleles in albinism remains controversial, our data suggest that these variants contribute to the extensive inter-individual variability in foveal morphology in the normal population. Our results contribute to the evolving picture of the relationship between ocular pigmentation and foveal morphology.

Purpose To describe a case of combined branch retinal vein and artery occlusion (CBRVAO) complicated by foveal neovascularization (FNV). Observations A 52-year-old healthy woman presented at the Eye Clinic of Sacco Hospital (Milan, Italy) with a 3-year history of CBRVAO in her right eye. At baseline, her visual acuity was 20/20 Snellen with unremarkable anterior segment and normal intra-ocular pressure. On fundoscopy, a reddish foveal lesion with an underlying crescent-shaped pre-retinal subhyaloid hemorrhage could be appreciated. FNV was confirmed by means of fluorescein angiography and optical coherence tomography angiography; no signs of macular edema were present. The patient was treated with two intravitreal injections of anti-VEGF agents and with completion of scatter retinal photocoagulation. At her last follow-up (6 months later), shrinkage of FNV and resorption of the pre-retinal subhyaloid hemorrhage were documented by means of multimodal imaging. Conclusions and importance FNV is a rare clinical finding that can complicate retinal vascular disorders and can be effectively managed with good visual outcomes. Our case highlights the importance of multimodal imaging to diagnose FNV in retinal vaso-occlusive disorders and then to assess the response to treatment during the follow-up.

Purpose The pathogenesis of proliferative vitreoretinopathy (PVR), the most important cause of retinal detachment surgery failure, is still not fully understood. We previously hypothesized a causal link between vitreoschisis-induced vitreous cortex remnants (VCR) and PVR formation. The purpose of this case report is to demonstrate this association by showing the clinical occurrence of PVR in the presence of VCR across the retinal surface, illustrated by histopathological analysis. Observations A 69-year-old male was referred because of widespread epiretinal membrane formation after treatment of recurrent retinal detachments. During surgery with extensive membrane peeling, a large continuous membrane was peeled from the superior arcade towards the inferior temporal mid-periphery. Histopathological analysis of this membrane revealed areas with different characteristics: paucicellular laminar collagen-rich areas, suggestive for VCR, areas with increased cellularity, and more fibrotic areas with low cellularity. The immunohistochemical analysis identified cell type variety in these areas: collagen-rich areas showed glial cells and hyalocytes, while in areas with high cellularity fibroblasts, macrophages and retinal pigment epithelial cells were found, which have previously been shown to play an important role in the development of PVR as they can transdifferentiate into myofibroblasts, which were seen in the more fibrotic areas. Conclusions and importance These findings support the theory that VCR have a role in PVR development, where VCR can act as a scaffold for fibrocellular proliferation. We suggest that the presence of VCR over the retinal surface should be qualified as a risk factor for PVR formation. Detection and adequate removal of VCR may improve the success rate of retinal detachment surgery.

Introduction: Multiple Sclerosis (MS) is a chronic neuro inflammatory disease which leads to progressive disability. Recent evidence suggests that vascular impairment may contribute to MS onset and progression. Optical Coherence Tomography Angiography (OCT-A) has emerged as an important imaging tool which should allow further exploration of the vessel changes in the pathogenesis and prognosis of MS. Purpose: To quantify the vascular density (VD) of the choroid (CH) and choriocapillaris (CC) in patients with MS, comparing with normal eyes. Materials and Methods: 45 eyes of 45 MS patients [31 female; mean age (years ± SD) 41,87 ± 11.04; axial length (AL) (AL ± SD) 23.68 ± 0.90) and 45 aged-matched control subjects (33 female; mean age 39,.6 ± 8,93; AL 23.36 ± 0.75] were enrolled in this prospective study. We obtained OCT-A images based on a full-spectrum amplitude de-correlation angiography (FSADA) algorithm. The OCT-A images of the CH and CC were used for quantitative assessment in three regions of the fovea, namely, Region 1 (0–500 μm) Region 2 (500–1000 μm) and Region 3 (1000−1500 μm). Relationships of VD between MS patients with and without optic neuritis (ON) and controls were investigated by binary vessel maps generated from OCT-A slabs and analyzed using ImageJ software. Results: Compared to controls, in eyes with MS, CH VD was significantly decreased in Region 2 (p = 0.01) and Region 3 (p < 0.01). CCVD was not different between the groups although showing a decreasing tendency in the MS group. Between eyes with and without ON there were a tendency to reduced VD in the ON group in all regions analyzed for both CH and CC layer. All the layers analyzed revealed a positive correlation between CH VD and CC VD and a negative correlation between CC VD and AL. Conclusions: Although studies have assessed retinal VD in MS using OCT-A, the choroidal vasculature in MS remains understudied. Our results cautiously suggest a functional circulatory disturbance of choroidal vasculatures in MS patients, mainly in those who have previous ON history.

Purpose: To assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor during robotic vitreoretinal surgery using the Preceyes Surgical System (PSS; Preceyes B.V.). Design: Single-center interventional study. Participants: Patients requiring vitreoretinal surgery. Methods: Five patients were enrolled. Standard preoperative OCT images were obtained. After vitrectomy, a predefined set of actions was performed using the iiOCT-based sensor. Images then were processed to assess the signal-to-noise ratio (SNR) at various angles to the retina and at different distances between the instrument tip and the retinal surface. Preoperative and intraoperative OCT images were compared qualitatively and quantitatively. Main Outcomes Measures: The feasibility in performing surgical tasks using the iiOCT-based sensor during vitreoretinal surgery, the SNR when imaging the retina, differences among intraoperative and preoperative OCT images, and characteristics of intraoperative retinal movements detected with the iiOCT-based probe. Results: Surgeons were able to perform all the tasks but one. The PSS was able to maintain a fixed distance. The SNR of the iiOCT-based sensor signal was adequate to determine the distance to the retina and to control the PSS. Analysis of iiOCT-based sensor A-scans identified 3 clearly distinguishable retinal layers, including the inner retinal boundary and the interface at the retinal pigment epithelium–Bruch’s membrane. Thickness values differed by less than 5% from that measured by preoperative OCT, indicating its accuracy. The Fourier analysis of iiOCT-based sensor recordings identified anteroposterior retinal movements attributed to heartbeat and respiration. Conclusions: This iiOCT-based sensor was tested successfully and promises reliable use during robot-assisted surgery. An iiOCT-based sensor is a promising step toward OCT-guided robotic retinal surgery.

Objective Retinal ischemic disease is a major cause of vision loss. Current treatment options are limited to late-stage diseases, and the molecular mechanisms of the initial insult are not fully understood. We have previously shown that the deletion of the mitochondrial arginase isoform, arginase 2 (A2), limits neurovascular injury in models of ischemic retinopathy. Here, we investigated the involvement of A2-mediated alterations in mitochondrial dynamics and function in the pathology. Methods We used wild-type (WT), global A2 knockout (A2KO-) mice, cell-specific A2 knockout mice subjected to retinal ischemia/reperfusion (I/R), and bovine retinal endothelial cells (BRECs) subjected to an oxygen-glucose deprivation/reperfusion (OGD/R) insult. We used western blotting to measure levels of cell stress and death markers and the mitochondrial fragmentation protein, dynamin related protein 1 (Drp1). We also used live cell mitochondrial labeling and Seahorse XF analysis to evaluate mitochondrial fragmentation and function, respectively. Results We found that the global deletion of A2 limited the I/R-induced disruption of retinal layers, fundus abnormalities, and albumin extravasation. The specific deletion of A2 in endothelial cells was protective against I/R-induced neurodegeneration. The OGD/R insult in BRECs increased A2 expression and induced cell stress and cell death, along with decreased mitochondrial respiration, increased Drp1 expression, and mitochondrial fragmentation. The overexpression of A2 in BREC also decreased mitochondrial respiration, promoted increases in the expression of Drp1, mitochondrial fragmentation, and cell stress and resulted in decreased cell survival. In contrast, the overexpression of the cytosolic isoform, arginase 1 (A1), did not affect these parameters. Conclusions This study is the first to show that A2 in endothelial cells mediates retinal ischemic injury through a mechanism involving alterations in mitochondrial dynamics and function., Highlights • Ischemic retinopathy is a common feature of blinding eye disease. • Arginase 2 overexpression in endothelial cells induces mitochondrial dysfunction. • Endothelial-specific arginase 2 deletion improves neuronal survival after ischemia. • Endothelial cell arginase 2 plays a crucial role in ischemic retinal injury.

Introduction Diabetic retinopathy (DR) increases the risk of blindness by 25 times. Advanced researchs are justified for better management, leading to the role of Optical Coherence Tomography-Angiography (OCT-A), a new non-invasive imaging technique exploring retinal vascularization. Our purpose is to identify microvascular macular anomalies of DR on OCT-A with qualitative and quantitative evaluation of their impact on retinal vascularization. Patients and methods This is a descriptive cross-sectional study where 120 eyes of 66 diabetic patients were enrolled. All patients were diabetic and went through OCT-A imaging. Results Microanevrysms were identified in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) where they were more frequently visualized. Macular edema was present in 16,7% of cases in the SCP, and in 30% in DCP. Edema spaces were more frequently present in DCP (p, Highlights • Retinal microvascular abnormalities on OCT-A are observed in diabetic retinopathy and are proportional to its severity. • Deep capillary plexus was more severely affected than superficial capillary plexus. • The assessment of macular ischemia could be based on the identification of areas of vascular rarefaction. • Quantitative assessment of vascular density and the study of the foveal avascular zone can assess the macular ischemia

Purpose Lafora disease is a genetic neurodegenerative metabolic disorder caused by insoluble polyglucosan aggregate accumulation throughout the central nervous system and body. The retina is an accessible neural tissue, which may offer alternative methods to assess neurological diseases quickly and noninvasively. In this way, noninvasive imaging may provide a means to characterize neurodegenerative disease, which enables earlier identification and diagnosis of disease and the ability to monitor disease progression. In this study, we sought to characterize the retina of individuals with Lafora disease using non-invasive retinal imaging. Methods One eye of three individuals with genetically confirmed Lafora disease were imaged with optical coherence tomography (OCT) and adaptive optics scanning light ophthalmoscopy (AOSLO). When possible, OCT volume and line scans were acquired to assess total retinal thickness, ganglion cell-inner plexiform layer thickness, and outer nuclear layer + Henle fiber layer thickness. OCT angiography (OCTA) scans were acquired in one subject at the macula and optic nerve head (ONH). AOSLO was used to characterize the photoreceptor mosaic and examine the retinal nerve fiber layer (RNFL). Results Two subjects with previous seizure activity demonstrated reduced retinal thickness, while one subject with no apparent symptoms had normal retinal thickness. All other clinical measures, as well as parafoveal cone density, were within normal range. Nummular reflectivity at the level of the RNFL was observed using AOSLO in the macula and near the ONH in all three subjects. Conclusions This multimodal retinal imaging approach allowed us to observe a number of retinal structural features in all three individuals. Most notably, AOSLO revealed nummular reflectivity within the inner retina of each subject. This phenotype has not been reported previously and may represent a characteristic change produced by the neurodegenerative process.

High resolution imaging with optical coherence tomography angiography and offset pinhole adaptive optics scanning light ophthalmoscope helped us visualize the hemodynamic and structural changes in a ruptured retinal arterial macroaneurysm in a 78-year-old woman. Intravitreal injection of anti-vascular endothelial growth factor was administered to ameliorate the condition.

Purpose Subretinal injections (SRis) are commonly used in retinal gene therapy procedures to deliver adeno-associated virus (AAV) to photoreceptors and retinal pigment epithelial cells. We present an optimized surgical protocol to minimize off-target application of AAV in the vitreous, which in turn reduces the risk of extensive biodistribution and inflammation, ultimately leading to enhanced safety of the therapy. Design Experimental animal research study. Participants Eight cynomolgus monkeys (Macaca fascicularis). Methods Subretinal injections with an AAV2/8 vector were performed. The animals were allocated to 2 different vector dose groups (1×10ˆ11 and 5×10ˆ11 viral genomes [vg]). Samples of intravitreal fluid were taken at the end of the SRi procedure and again after a 3-minute lavage (wash-out) with balanced salt solution (BSS). Main Outcome Measures Intravitreal vector genome copies were analyzed with quantitative polymerase chain reaction and compared between groups. Results Even uneventful SRi leads to dissemination of millions of AAV particles (0.1–0.7% of viral vector loading dose) into the vitreous cavity. Three minutes of lavage led to a substantial decrease (on average 96%) of intravitreal vector load. Conclusions Multiple studies have shown that the intravitreal space is not as immune privileged as the subretinal space. Intravitreal AAV particles disseminate into the bloodstream, lead to increased biodistribution into lymphatic tissue, and help to stage an immune response with implications for both safety and efficacy. Therefore, minimizing off-target vector application after reflux of vector from the subretinal space is of significant interest. We show that a simple lavage of intravitreal fluid efficiently decreases the intravitreal vector load. Such a step should be considered when performing subretinal gene therapy.

Author(s): Mekonnen, Zesemayat K; Everett, Lesley A; Hetts, Steven W; Afshar, Armin R | Abstract: PurposeTo describe acute and chronic retinal ischemic changes following an internal carotid artery pseudoaneurysm stenting procedure, and to review current evidence for risk factors and management of post-procedural retinal ischemic events.ObservationA 50-year-old man presented with a 3-month history of pulsatile tinnitus, headache, and intermittent blurry vision. A CT angiogram of head and neck showed bilateral cervicopetrous internal carotid artery (ICA) pseudoaneurysms. The patient underwent successful repair with angioplasty and stenting of the flow-limiting high-grade (g95%) stenosis of his left high cervical ICA. On post-operative day 1, the patient reported monocular vision loss with a large central scotoma. He was found to have a central macular area of retinal whitening and multiple areas of perivascular retinal whitening on exam, concerning for retinal artery occlusions secondary to peri-procedural emboli. Dual antiplatelet therapy was started and a stroke evaluation was performed. Two months later, his visual acuity in the affected eye was counting fingers and his left eye fundus examination was notable for multiple areas of scattered hemorrhages, microaneurysms, and retinal exudates in the distribution of prior retinal ischemia. OCT imaging revealed atrophic changes in the left macula. Subsequently, the patient completed stage-2 repair of the left ICA pseudoaneurysm followed by uncomplicated repair of the right ICA. Four months later, his left eye visual acuity and retinal findings remained stable.Conclusions and importancePost-procedure retinal emboli and ischemia are important, vision threatening possible ocular complications for patients undergoing carotid vascular and endovascular procedures.

Purpose To use new adaptive optics scanning laser ophthalmoscopy (AOSLO) technology to better image macular pathology in poppers maculopathy. Observations A 40-year-old patient was found to have poppers maculopathy. Best corrected visual acuity was decreased to 20/40 OD and 20/50 OS, spectral domain optical coherence tomography found outer retinal disruption of the fovea, and AOSLO imaging showed significant decrease in cone density of the fovea of both eyes. Conclusions and importance Poppers maculopathy is a rare, but visually significant, complication of popper abuse. AOSLO technology demonstrates significant cone damage in poppers maculopathy. The striking loss of cones revealed by AOSLO imaging shows how AOSLO imaging can elucidate macular pathology., Highlights • Poppers maculopathy can cause a significant decrease in BCVA despite relatively minimal changes observed on DFE and SD-OCT. • AOSLO imaging in this case of poppers maculopathy reveals a striking decrease in central cone density. • This report demonstrates that AOSLO can elucidate macular pathology not seen in more widely used retinal imaging modalities.

Purpose To illustrate the spectrum of clinical and imaging features in patients with unilateral Coats’ disease at baseline and in response to treatment with laser, intravitreal bevacizumab, and regional steroids. Observations Telangiectasias, macular exudates, and vascular leakage were present in all 3 patients included in this series. After treatment with laser and bevacizumab, OCT angiography findings included an anomalous foveal vascular loop and chorioretinal anastomoses. Choroidal flow voids appeared to improve after intravitreal bevaziumab and laser treatment in 2 patients with OCT angiography obtained at follow up. A-scan axial lengths in affected eyes were 1.5–1.8 mm smaller than fellow eyes. Conclusions and importance OCT angiography is a non-invasive tool that can be a useful adjunct to multimodal imaging studies in the management of Coats’ disease. Improved vascular density following anti-VEGF injection suggests a possible role of the choroidal vasculature in this retinal vascular pathology.

The present study explores the optical properties of retinal molecules in presence of small gold cluster (Au14), where the cluster motifs are varied through Oh, D2h and C4v symmetries. The constructive interference of the transition dipole moments (TDMs) in retinal-gold nanoconjugates is responsible for most intense electronic transitions. The charge transfer transition from the occupied Au cluster orbital to the unoccupied retinal orbital is playing significant role in the spectral shift of the conjugates. The vibrational frequency analysis of 11-cis retinal and its conjugate (Au14 in D2h symmetry) reveal that the different vibrational modes associated with the isomerization process are red shifted in the conjugate. The conjugation of isolated retinal with gold probes makes the process of 11-cis to all-trans isomerization thermodynamically favorable. The entire evaluation reflects the effect of gold cluster in the spectral tuning of retinal molecules and reveals its relevant consequences on photoisomerization and hence the process of vision.

PURPOSE: To compare foveal hypoplasia and the appearance of the ellipsoid zone (EZ) at the fovea in patients with genetically confirmed achromatopsia (ACHM) and blue cone monochromacy (BCM). DESIGN: Retrospective, multi-center observational study. SUBJECTS: Molecularly confirmed patients with ACHM (n = 89) and BCM (n = 33). METHODS: We analyzed high-resolution spectral domain optical coherence tomography (SD-OCT) images of the macula from aforementioned patients with BCM. Three observers independently graded SD-OCT images for foveal hypoplasia (i.e. retention of one or more inner retinal layers at the fovea) and four observers judged the integrity of the EZ at the fovea, based on an established grading scheme. These measures were compared with previously published data from the ACHM patients. MAIN OUTCOME MEASURES: Presence of foveal hypoplasia and EZ grade. RESULTS: Foveal hypoplasia was significantly more prevalent in ACHM than in BCM (p

Purpose To report and discuss the association between pre- or juxtapapillary arterial loops and tilted disc syndrome (TDS). Observations Three patients, aged 43–59 years, with both conditions were examined in a tertiary referral center, and underwent fluorescein angiography, optical coherence tomography (OCT) and/or OCT-angiography. They all presented with a typical inferior staphyloma associated with TDS and anomalies of insertion of retinal vessels. The vascular malformation consisted in one acquired arterial loop or cilioretinal collateral circulation occurring after central artery occlusion, and two more complex pre- and juxtapapillary arterial loops. In all cases, the vascular loops extended inferiorly, in the area of the staphyloma. Conclusion and importance We hypothesized that the local anatomical changes in the peripapillary area, observed in eyes with TDS and inferior staphyloma, could have promoted the occurrence and/or extent of the arterial loops.

Summary The mouse eye is used to model central nervous system development, pathology, angiogenesis, tumorigenesis, and regenerative therapies. To facilitate the analysis of these processes, we developed an optimized tissue clearing and depigmentation protocol, termed InVision, that permits whole-eye fluorescent marker tissue imaging. We validated this method for the analysis of normal and degenerative retinal architecture, transgenic fluorescent reporter expression, immunostaining and three-dimensional volumetric (3DV) analysis of retinoblastoma and angiogenesis. We also used this method to characterize material transfer (MT), a recently described phenomenon of horizontal protein exchange that occurs between transplanted and recipient photoreceptors. 3D spatial distribution analysis of MT in transplanted retinas suggests that MT of cytoplasmic GFP between photoreceptors is mediated by short-range, proximity-dependent cellular interactions. The InVision protocol will allow investigators working across multiple cell biological disciplines to generate novel insights into the local cellular networks involved in cell biological processes in the eye., Graphical abstract, Highlights • InVision is an optimized tissue clearing protocol for the rodent eye • InVision can be used to study a wide variety of physiological processes in the eye • Material transfer between transplanted and host photoreceptors is spatially correlated, Optical imaging; Biological sciences; Neuroscience; Biotechnology; Biological sciences research methodologies; Biology experimental methods

International audience; Purpose: Post-transplant lymphoproliferative disorder (PTLD) represents a spectrum of disorders associated with Epstein Barr Virus infection in up to 80% of cases in the setting of pharmacologic immunosuppression following hematopoietic stem cell or solid organ transplantation. Ocular involvement is a rare finding in PTLD.Observation: We report the case of a 38-year-old man who presented with unilateral retinal infiltrates as first manifestation of PTLD relapse. Diagnosis relied on the presence of EBV DNA in anterior chamber fluids and vitrectomy that showed the presence of a B cell clone. Systemic relapse of PTLD was detected 12 weeks after retinal findings. Treatment of ocular disease included systemic injections of rituximab and intravitreal injections of methotrexate, halting the extension of retinal infiltrates.Conclusion: Ocular involvement in PTLD is rare and needs to be acknowledged because it can precede a systemic relapse of the hematological condition.

Pathophysiological consequences of focal non-convulsive status epilepticus (fNCSE) have been difficult to demonstrate in humans. In rats fNCSE pathology has been identified in the eyes. Here we evaluated the use of high-resolution 7 T structural T1-weighted magnetic resonance imaging (MRI) and 9.4 T diffusion tensor imaging (DTI) for detecting hippocampal fNCSE-induced retinal pathology ex vivo in mice. Seven weeks post-fNCSE, increased number of Iba1+ microglia were evident in the retina ipsilateral to the hemisphere with fNCSE, and morphologically more activated microglia were found in both ipsi- and contralateral retina compared to non-stimulated control mice. T1-weighted intensity measurements of the contralateral retina showed a minor increase within the outer nuclear and plexiform layers of the lateral retina. T1-weighted measurements were not performed in the ipsilateral retina due to technical difficulties. DTI fractional anisotropy(FA) values were discretely altered in the lateral part of the ipsilateral retina and unaltered in the contralateral retina. No changes were observed in the distal part of the optic nerve. The sensitivity of both imaging techniques for identifying larger retinal alteration was confirmed ex vivo in retinitis pigmentosa mice where a substantial neurodegeneration of the outer retinal layers is evident. With MR imaging a 50 % decrease in DTI FA values and significantly thinner retina in T1-weighted images were detected. We conclude that retinal pathology after fNCSE in mice is subtle and present bilaterally. High-resolution T1-weighted MRI and DTI independently did not detect the entire pathological retinal changes after fNCSE, but the combination of the two techniques indicated minor patchy structural changes.

Purpose To report a case of vitreous hemorrhage as the presenting sign of retinal cavernous hemangioma (RCH) in a newborn. Observations A five-week-old full-term male with a history of seizures and birth trauma underwent ophthalmology screening. Initial eye examination revealed vitreous hemorrhage. Subsequent examination under anesthesia with multi-modal imaging revealed vitreous hemorrhage and an intra-retinal mass with numerous sac-like aneurysmal dilatations, consistent with RCH. Conclusions and importance Vitreous hemorrhage in a neonate is an atypical presentation of RCH. Clinicians should be aware that birth trauma may lead to vitreous hemorrhage from RCH. This is the first description of RCH, a rare retinal vascular tumor, in a newborn.

Purpose To present a 22-month-old girl with a complete retinal detachment who was found to have systemic exam findings consistent with neurofibromatosis type 1 during the course of multi-specialty exam under anesthesia. Observations During examination under anesthesia, ophthalmic exam findings demonstrated retinal detachment with cyst formation, as well as peripheral non-perfusion of the retina in the left eye. Non-ophthalmic findings discovered on difficulty with intubation included a laryngeal plexiform neurofibroma and cafe-au-lait spots. Conclusions Pediatric retinal detachments are uncommon compared to those in adults. Pediatric patients with neurofibromatosis type 1 can present with vision loss as the presenting symptom. Systemic signs and symptoms should be carefully screen and monitored.

A splitting of the outer plexiform retinal layer in a saw-like hyporeflective pattern in addition to partially formed concentric circles centred at the foveola were observed using en-face OCT and OCT-angiography in a 27-year-old female patient with rhegmatogenous retinal detachment and a 50-year-old female patient with Vogt-Koyanagi-Harada chorioretinopathy.

Fatty acids, and especially docosahexaenoic acid (DHA), are essential for photoreceptor cell integrity and are involved in the phototransduction cascade. In this study, we analyzed the changes in the fatty acid profile in the retina of the rd10 mouse model of retinitis pigmentosa in order to identify potential risk factors for retinal degeneration and possible therapeutic approaches. Fatty acids from C57BL/6J and rd10 mouse retinas were extracted with Folch's method and analyzed by gas chromatography/mass spectrometry. Changes in retinal morphology were evaluated by immunohistochemistry. The rd10 mouse retina showed a decreased number of photoreceptor rows and alterations in photoreceptor morphology compared to C57BL/6J mice. The total amount of fatty acids dropped by 29.4% in the dystrophic retinas compared to C57BL/6J retinas. A positive correlation was found between the retinal content of specific fatty acids and the number of photoreceptor rows. We found that the amount of several short-chain and long-chain saturated fatty acids, as well as monounsaturated fatty acids, decreased in the retina of rd10 mice. Moreover, the content of the n-6 polyunsaturated fatty acid arachidonic acid and the n-3 polyunsaturated DHA decreased markedly in the dystrophic retina. The fall of DHA was more pronounced, hence the n-6/n-3 ratio was significantly increased in the diseased retina. The content of specific fatty acids in the retina decreases with photoreceptor degeneration in retinitis pigmentosa mice, with a remarkable reduction in DHA and other saturated and unsaturated fatty acids. These fatty acids could be essential for photoreceptor cell viability, and they should be evaluated for the design of therapeutical strategies and nutritional supplements. This work was supported by Spanish Ministry of Economy and Competitiveness [MICINN-FEDER PID 2019-106230RB-I00, 2020]; Instituto de Salud Carlos III [RETICS-FEDER RD16/0008/0016, 2016]; and Generalitat Valenciana [ACIF/2020/203, 2020], [IDIFEDER/2017/064, 2017].

Purpose To evaluate the effect of central serous chorioretinopathy (CSCR) on retinal function using dark adaptation in a human subject, and to follow it through resolution of the disease. Patients Single patient, 50 years old male patient, with acute CSCR in one eye and resolved old CSCR in the other eye. Observations Observational study in patient with CSCR followed through resolution of the subretinal fluid (52 days). Dark adaptation was assessed using the AdaptDx® (Maculogix Inc.) measured by Rod Intercept time (RIT) in minutes. A normal retinal locus of the same eye on the opposite side of the fovea was used as control. Retinal separation (microns) was measured using Spectralis Optical Coherence Tomography (Spectralis®, HRA + OCT, Heidelberg engineering). Change in time to dark adapt, were correlated with retinal separation measured in microns, during the course of CSCR.The Rod Intercept time was delayed in the area of detached retina compared to the normal region (control) on presentation with retinal separation (RS) of 104 μm. The Rod Intercept time returned to normal as the retinal separation from retinal pigment epithelium decreased and eventually resolved. Conclusions This case shows that delay in dark adaptation is proportional to the amount of separation of neurosensory retina from retinal pigment epithelium in CSCR, this may offer a potential of using DA to characterize visual function in CSCR. The association of dark adaptation response with the state of retinal pigment epithelial function and its ability to predict the recurrence of CSCR needs further evaluation.