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Background: Kabuki Syndrome is a rare and genetically heterogenous condition with both ophthalmic and systemic complications and typical facial features. We detail the macular phenotype in two unrelated patients with Kabuki syndrome due to de novo nonsense variants in KMT2D, one novel. A follow-up of 10 years is reported. Pathogenicity of both de novo nonsense variants is analyzed. Methods: Four eyes of two young patients were studied by full clinical examination, kinetic perimetry, short wavelength autofluorescence, full field (ff) ERGs, and spectral-domain optical coherence tomography (SD-OCT). One patient had adaptive optic (AO) imaging. Whole exome sequencing was performed in both patients. Results: Both patients had de novo nonsense variants in KMTD2. One patient had c.14843C>G; p. (Ser4948ter) novel variant and the second c.11119C>T; p. (Arg3707ter). Both had a stable Snellen visual acuity of 0.2–0.3. The retinal multimodal imaging demonstrated abnormalities at the fovea in both eyes: hyperreflectivity to blue light and a well-delimited gap—disruption of ellipsoid and interdigitation layer on OCT. The dark area on AO imaging is presumed to be absent for, or with structural change to photoreceptors. The ff ERGs and kinetic visual fields were normal. The foveal findings remained stable over several years. Conclusion: Kabuki syndrome–related maculopathy is a distinct loss of photoreceptors at the fovea as shown by multimodal imaging including, for the first time, AO imaging. This report adds to the literature of only one case with maculopathy with two additional macular dystrophies in patients with Kabuki syndrome. Although underestimated, these cases further raise awareness of the potential impact of retinal manifestations of Kabuki syndrome not only among ophthalmologists but also other healthcare professionals involved in the care of patients with this multisystem disorder. [ABSTRACT FROM AUTHOR]

Primary cilia are conserved organelles that integrate extracellular cues into intracellular signals and are critical for diverse processes, including cellular development and repair responses. Deficits in ciliary function cause multisystemic human diseases known as ciliopathies. In the eye, atrophy of the retinal pigment epithelium (RPE) is a common feature of many ciliopathies. However, the roles of RPE cilia in vivo remain poorly understood. In this study, we first found that mouse RPE cells only transiently form primary cilia. We then examined the RPE in the mouse model of Bardet-Biedl Syndrome 4 (BBS4), a ciliopathy associated with retinal degeneration in humans, and found that ciliation in BBS4 mutant RPE cells is disrupted early during development. Next, using a laser-induced injury model in vivo, we found that primary cilia in RPE reassemble in response to laser injury during RPE wound healing and then rapidly disassemble after the repair is completed. Finally, we demonstrated that RPE-specific depletion of primary cilia in a conditional mouse model of cilia loss promoted wound healing and enhanced cell proliferation. In summary, our data suggest that RPE cilia contribute to both retinal development and repair and provide insights into potential therapeutic targets for more common RPE degenerative diseases. [ABSTRACT FROM AUTHOR]

Preexisting immunity against Cas9 proteins in humans represents a safety risk for CRISPR–Cas9 technologies. However, it is unclear to what extent preexisting Cas9 immunity is relevant to the eye as it is targeted for early in vivo CRISPR–Cas9 clinical trials. While the eye lacks T-cells, it contains antibodies, cytokines, and resident immune cells. Although precise mechanisms are unclear, intraocular inflammation remains a major cause of vision loss. Here, we used immunoglobulin isotyping and ELISA platforms to profile antibodies in serum and vitreous fluid biopsies from human adult subjects and Cas9-immunized mice. We observed high prevalence of preexisting Cas9-reactive antibodies in serum but not in the eye. However, we detected intraocular antibodies reactive to S. pyogenes-derived Cas9 after S. pyogenes intraocular infection. Our data suggest that serum antibody concentration may determine whether specific intraocular antibodies develop, but preexisting immunity to Cas9 may represent a lower risk in human eyes than systemically. Pre-existing antibodies against Cas9 proteins represent a potential issue for gene therapies, including those targeting the eye. Here the authors assess the presence of intraocular antibodies, and show that Cas9 antibodies were prevalent in human serum but not the eye, unless prior bacterial infection occurred. [ABSTRACT FROM AUTHOR]

Purpose: This study reports the ophthalmic and genetic findings of a Cameroonian patient with autosomal recessive retinitis pigmentosa (arRP) caused by a novel Receptor Expression Enhancing Protein 6 (REEP6) homozygous mutation. Patient and methods: A 33-year-old man underwent comprehensive ophthalmic examinations, including visual acuity measurements, dilated fundus imaging, electroretinography (ERG), and spectral-domain optical coherence tomography (SD-OCT). Short-wavelength fundus autofluorescence (SW-AF) and near-infrared fundus autofluorescence (NIR-AF) were also evaluated. Whole exome sequencing (WES) was used to identify potential pathogenic variants. Results: Fundus examination revealed typical RP findings with additional temporal ten micron yellow dots. SD-OCT imaging revealed cystoid macular edema and perifoveal outer retinal atrophy with centrally preserved inner segment ellipsoid zone (EZ) bands. Hyperreflective spots were seen in the inner retinal layers. On SW-AF images, a hypoautofluorescent area in the perifoveal area was observed. NIR-AF imaging revealed an irregularly shaped hyperautofluorescent ring. His visual acuity was mildly affected. ERG showed undetectable rod responses and intact cone responses. Genetic testing via WES revealed a novel homozygous mutation (c.295G>A, p.Glu99Lys) in the gene encoding REEP6, which is predicted to alter the charge in the transmembrane helix. Conclusions: This report is not only the first description of a Cameroonian patient with arRP associated with a REEP6 mutation, but also this particular genetic alteration. Substitution of p.Glu99Lys in REEP6 likely disrupts the interactions between REEP6 and the ER membrane. NIR-AF imaging may be particularly useful for assessing functional photoreceptor cells and show an "avocado" pattern of hyperautofluorescence in patients with the REEP6 mutation. [ABSTRACT FROM AUTHOR]

D190N, a missense mutation in rhodopsin, causes photoreceptor degeneration in patients with autosomal dominant retinitis pigmentosa (adRP). Two competing hypotheses have been developed to explain why D190N rod photoreceptors degenerate: (a) defective rhodopsin trafficking prevents proteins from correctly exiting the endoplasmic reticulum, leading to their accumulation, with deleterious effects or (b) elevated mutant rhodopsin expression and unabated signaling causes excitotoxicity. A knock-in D190N mouse model was engineered to delineate the mechanism of pathogenesis. Wild type (wt) and mutant rhodopsin appeared correctly localized in rod outer segments of D190N heterozygotes. Moreover, the rhodopsin glycosylation state in the mutants appeared similar to that in wt mice. Thus, it seems plausible that the injurious effect of the heterozygous mutation is not related to mistrafficking of the protein, but rather from constitutive rhodopsin activity and a greater propensity for chromophore isomerization even in the absence of light. [ABSTRACT FROM AUTHOR]

Experimental autoimmune encephalomyelitis is a model for multiple sclerosis. Here we show that induction generates successive waves of clonally expanded CD4+, CD8+ and γδ+ T cells in the blood and central nervous system, similar to gluten-challenge studies of patients with coeliac disease. We also find major expansions of CD8+ T cells in patients with multiple sclerosis. In autoimmune encephalomyelitis, we find that most expanded CD4+ T cells are specific for the inducing myelin peptide MOG35–55. By contrast, surrogate peptides derived from a yeast peptide major histocompatibility complex library of some of the clonally expanded CD8+ T cells inhibit disease by suppressing the proliferation of MOG-specific CD4+ T cells. These results suggest that the induction of autoreactive CD4+ T cells triggers an opposing mobilization of regulatory CD8+ T cells. Activated clonally expanded CD4+ T cells display specificity to the myelin peptide MOG, whereas clonally expanded CD8+ T cells depend on T cell receptor recognition of unrelated surrogate peptides and have a regulatory function. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the progression of retinitis pigmentosa (RP) due to mutations in rhodopsin (RHO) by measuring the short-wavelength autofluorescence (SW-AF) increased autofluorescence ring and ellipsoid zone (EZ)-line width. Methods: Fundus autofluorescence (FAF) and spectral domain optical coherence tomography (SD-OCT) images were obtained from 10 patients with autosomal dominant RP due to mutations in the RHO gene. Measurements of ring area on FAF images, as well as the EZ line width on SD-OCT images and horizontal, vertical diameter, were performed by two independent masked graders. Results: The ring area decreased by a rate of 0.6 ± 0.2 mm2 per year. We observed that the EZ line width decreased by an average of 152 ± 37 μm per year, while the horizontal and vertical diameters decreased by 106 ± 35 μm and 125 ± 29 μm per year, respectively. Progression rates were similar between eyes. Conclusions: We observed SW-AF ring constriction and a progressive loss of EZ line width over time. [ABSTRACT FROM AUTHOR]

Purpose: To report a case of deferoxamine-induced retinopathy characterized by electroretinography (ERG), optical coherence tomography angiography (OCT-A), and other multimodal imaging.Methods: This is an observational case report of one patient. Full-field ERG was performed. OCT-A, spectral-domain optical coherence tomography (SD-OCT), color fundus photography, and fundus autofluorescence were used to characterize the retinopathy induced by deferoxamine use.Results: A 64-year-old man with a history of β-thalassemia intermedia presented with worsening visual acuity, nyctalopia, and electronegative ERG. OCT-A revealed atrophy of the choriocapillaris in areas of hypoautofluorescence, corresponding to regions of retinal atrophy. SD-OCT showed disruption of the ellipsoid zone, granular hyperreflective deposits within the retinal pigment epithelium, thinning of the retinal layers, and extensive choroidal sclerosis and atrophy of the retinal pigment epithelium.Conclusion: Deferoxamine-induced retinopathy can manifest with electronegative maximal ERG responses, and OCT-A can be used to detect deferoxamine toxicity. [ABSTRACT FROM AUTHOR]

CAPN5 Neovascular Inflammatory Vitreoretinopathy (CAPN5-NIV; OMIM 193235) is a poorly-understood rare, progressive inflammatory intraocular disease with limited therapeutic options. To profile disease effector proteins in CAPN5-NIV patient vitreous, liquid vitreous biopsies were collected from two groups: eyes from control subjects (n = 4) with idiopathic macular holes (IMH) and eyes from test subjects (n = 12) with different stages of CAPN5-NIV. Samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein expression changes were evaluated by principal component analysis, 1-way ANOVA (significant p-value < 0.05), hierarchical clustering, gene ontology, and pathway representation. There were 216 differentially-expressed proteins (between CAPN5-NIV and control vitreous), including those unique to and abundant in each clinical stage. Gene ontology analysis revealed decreased synaptic signaling proteins in CAPN5-NIV vitreous compared to controls. Pathway analysis revealed that inflammatory mediators of the acute phase response and the complement cascade were highly-represented. The CAPN5-NIV vitreous proteome displayed characteristic enrichment of proteins and pathways previously-associated with non-infectious posterior uveitis, rhegmatogenous retinal detachment (RRD), age-related macular degeneration (AMD), proliferative diabetic retinopathy (PDR), and proliferative vitreoretinopathy (PVR). This study expands our knowledge of affected molecular pathways in CAPN5-NIV using unbiased, shotgun proteomic analysis rather than targeted detection platforms. The high-levels and representation of acute phase response proteins suggests a functional role for the innate immune system in CAPN5-NIV pathogenesis. [ABSTRACT FROM AUTHOR]

Optical coherence tomography angiography (OCT-A) is a non-invasive alternative to fluorescein angiography that allows for the study of the retinal and choroidal vasculatures. In this retrospective cohort study of 28 patients with retinitis pigmentosa (RP), we used OCT-A to quantify changes in perfusion density, foveal avascular zone (FAZ) area, and choriocapillaris blood flow over time and correlated these variables with ellipsoid zone (EZ) line width and best-corrected visual acuity (BCVA). Perfusion density decreased by 2.42 ± 0.62% per year at the superior capillary plexus (SCP) (P = 0.001) and 2.41 ± 0.76% per year at the deep capillary plexus (DCP) (P = 0.004). FAZ area increased by 0.078 ± 0.021 mm2 per year (P = 0.001) at the SCP and 0.152 ± 0.039 mm2 per year (P = 0.001) at the DCP. No changes were observed in the choriocapillaris blood flow. EZ line width had the strongest correlation to perfusion density at the SCP (r = 0.660 and 0.635, first and second visit, respectively, P = 0.001), while BCVA most strongly correlated with FAZ area at the SCP (r = 0.679 and 0.548, P = 0.001 and 0.003). Our results suggest that OCT-A is a useful tool for monitoring RP disease progression and may be used to measure retinal vascular parameters as outcomes in clinical trials. [ABSTRACT FROM AUTHOR]