PURPOSE: To determine the association of the multifocal electroretinographic (mfERG) response amplitude with the volumes of the inner, postreceptor, and photoreceptor retinal layers in the region stimulated by each mfERG element. METHODS: Sixteen healthy, young adult control subjects were studied. Each of the 103 hexagonal elements of the standard, scaled mfERG were aligned, where possible, with patches of retina imaged using optical coherence tomography. Stimuli falling on the fovea and on the optic nerve head were excluded. Linear mixed-effects modeling was then used to derive estimated coefficients (voltage/volume) for the mfERG response throughout the full 80 ms standard epoch. The resulting predicted response amplitudes originating in each layer were then compared to pharmacologically "dissected" mfERGs obtained from other studies in monkey eyes. RESULTS: Across the duration of the response, the amplitude of the modeled contribution from (1) the inner retina was small-to-modest, (2) the postreceptor retina was larger and contained two prominent peaks, and (3) the photoreceptor response was the largest and most closely paralleled the overall (i.e., intact) response, including late-appearing oscillations. The significance of each layer's contribution was greatest when the absolute amplitude of that layer's response was largest. The contribution of the inner retina was maximally significant in the interval between the prominent troughs and peaks of the intact response. The contributions of the postreceptor and photoreceptor responses were maximally significant at the prominent troughs and peaks of the intact response. CONCLUSIONS: The results of the model were in good overall agreement with previous interpretations of the cellular contributions to the mfERG. There was also fair agreement with pharmacologically dissected monkey mfERG responses. Thus, the estimations of the contributions of the retinal layers to the mfERG so produced appeared plausible.
The Notch signaling pathway is a highly versatile and evolutionarily conserved mechanism with an important role in cell fate determination. Notch signaling plays a vital role in vascular development, regulating several fundamental processes such as angiogenesis, arterial/venous differentiation, and mural cell investment. Aberrant Notch signaling can result in severe vascular phenotypes as observed in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and Alagille syndrome. It is known that vascular endothelial cells and mural cells interact to regulate vessel formation, cell maturation, and stability of the vascular network. Defective endothelial-mural cell interactions are a common phenotype in diseases characterized by impaired vascular integrity. Further refinement of the role of Notch signaling in the vascular junctions will be critical to attempts to modulate Notch in the context of human vascular disease. In this review, we aim to consolidate and summarize our current understanding of Notch signaling in the vascular endothelial and mural cells during development and in the adult vasculature.
In this study, a one-step electrochemical aptasensor was developed to detect the biomarker vascular endothelial growth factor (VEGF), an important protein in the pathogenesis of many retinal diseases, including age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, and retinal vein occlusion. The aptamer has a good affinity and can rapidly identify and capture VEGF based on its unique structure. We designed a VEGF aptasensor based on the aptamer recognition and complex metallo nanoenzyme particles as an electron exchange center and bridge between capture DNA and electrode. The aptamers maintained the hairpin structure to avoid nonspecific surface adsorption and expose the capture sequence outwards when the target was inexistent. Conversely, the aptamers opened the hairpin structure to release space to accomplish binding between VEGF and DNA, resulting in increased impedance. The performance of the electrochemical aptasensor is detected by electrochemical impedance spectroscopy (EIS). The limit of detection by EIS was as low as 8.2 pg ml-1, and the linear range was 10 pg ml-1-1 μg ml-1. The electrochemical aptasensor also showed high specificity and reproducibility.
SignificanceThe optic nerve conveys information from retinal ganglion cells (RGCs) to visual processing areas of the brain. Although this pathway normally cannot regenerate when injured nor in degenerative diseases such as glaucoma, this failure can be partially reversed by eliciting a controlled immune reaction in the eye. We show here that the chemokine SDF1 (stromal cell-derived factor 1) is an important contributor to this phenomenon. SDF1 is produced by infiltrative monocytes and acts through its cognate receptor to enhance RGC survival, promote optic nerve regeneration, and sensitize subtypes of RGCs that normally fail to respond to a complementary treatment to exhibit robust, long-distance regeneration. These findings establish SDF1 as an important therapeutic candidate for repairing the injured optic nerve.
PURPOSE: To search findings that can explain the heterogeneity between Resistant and Responsive patients with birdshot chorioretinopathy. PATIENTS AND METHODS: This was a retrospective observational case series on "Responsive" versus "Resistant" birdshot chorioretinopathy. RESULTS: One-hundred-eighty and Ninety-nine patients were included in the Responsive and Resistant groups respectively. Multivariate analysis of paraclinical variables at the first visit demonstrated that mean deviation (p = .04), pattern standard deviation (p < .001), optic nerve head leakage (p = .012), large vessel leakage and staining (p = .01), and macular small vessel leakage (p = .03) were statistically significantly different between the two groups; however, at the visit preceding successful therapy, only macular small vessel leakage (p = .01) was statistically significantly different between the two groups. CONCLUSION: .Small vessel leakage in the macular area and/or optic nerve head leakage at the earliest visit might be risk factors for resistant birdshot chorioretinopathy.
AIM: To evaluate the effect of repository corticotropin injection (RCI) on regulatory T cell population in patients with noninfectious retinal vasculitis. PATIENTS AND METHODS: Patients with active noninfectious retinal vasculitis were included in a prospective nonrandomized open-label study. RESULTS: Eighteen patients (33 eyes) were included in the study. Eleven (61.1%) patients [20 (60.6%) eyes] and 7 (38.9%) patients [13 (33.3%) eyes] were in the responsive and non-responsive groups, respectively. We did not find any statistically significant difference within the PPP-R group, within the PPP-NR group, or between these two groups in regard to regulatory T cell population. No significant systemic or ocular complications were found. CONCLUSION: RCI may be a complementary treatment in patients with non-infectious retinal vasculitis with or without uveitis. This study did not demonstrate an increase in regulatory T cell population in patients with noninfectious retinal vasculitis.
Purpose: To report a Coats-like exudative vitreoretinopathy in Goldmann-Favre syndrome. Observations: A 64 year-old woman with prior diagnosis of retinal dystrophy presented with decreased vision in the right eye (OD). Ophthalmologic examination was remarkable for bilateral arteriolar attenuation, mid-peripheral bony-spicules, and waxy disc pallor. Coats-like exudative vitreoretinopathy and cystoid macular edema were present OD. Genetic testing showed a homozygous pathogenic mutation in gene NR2E3, variant c.932G>A (p.Arg311Gln), consistent with Goldmann-Favre syndrome. Targeted laser ablation and combination intravitreal therapy were effective in decreasing macular edema. Conclusions and Importance: A Coats-like exudative vitreoretinopathy may occur in the setting of Goldmann-Favre syndrome. Targeted laser ablation in combination with intravitreal therapy can be efficacious in select patients.
BACKGROUND: To characterise the contrast sensitivity function (CSF) in central serous chorioretinopathy (CSCR) compared with healthy controls using novel computerised contrast sensitivity (CS) testing with active learning algorithms. METHODS: Prospective observational study measuring CSF in CSCR eyes and controls using the Manifold Platform (Adaptive Sensory Technology, San Diego, California). Mixed effects multivariate regression models were used. Outcomes included area under the log CSF (AULCSF), CS thresholds at 1, 1.5, 3, 12 and 18 cycles per degree (cpd) and best-corrected visual acuity (BCVA). Associations of contrast outcomes with structural findings on optical coherence tomography (OCT) and subjective symptomatology were investigated. RESULTS: Forty CSCR eyes and 89 controls were included with median BCVA logarithm of median angle of resolution 0.10 (20/25) versus 0.00 (20/20), respectively (p=0.01). When accounting for age, CSCR was associated with significantly reduced median AULCSF (p=0.02, β=-0.14) and reduced CS thresholds at 6 cpd (p=0.009, β=-0.18), 12 cpd (p<0.001, β=-0.23) and 18 cpd (p=0.04, β=-0.09), versus controls. Within the CSCR group, subjectively perceived visual impairment (N=22) was associated with significantly decreased CS thresholds at all spatial frequencies and in AULCSF compared with asymptomatic CSCR eyes (N=18). Ellipsoid zone attenuation and subfoveal fluid on OCT were associated with decreased AULCSF and CS thresholds specifically at 3, 6 and 12 cpd, whereas presence of extrafoveal fluid at 1.5 and 3 cpd. CONCLUSION: Contrast sensitivity is significantly reduced in CSCR, and strongly correlates with subjective visual impairment. Different structural biomarkers correlate with contrast thresholds reductions at different spatial frequencies.
Grotz S, Schäfer J, Wunderlich KA, Ellederova Z, Auch H, Bähr A, Runa-Vochozkova P, Fadl J, Arnold V, Ardan T, Veith M, Santamaria G, Dhom G, Hitzl W, Kessler B, Eckardt C, Klein J, Brymova A, Linnert J, Kurome M, Zakharchenko V, Fischer A, Blutke A, Döring A, Suchankova S, Popelar J, Rodríguez-Bocanegra E, Dlugaiczyk J, Straka H, May-Simera H, Wang W, Laugwitz K-L, Vandenberghe LH, Wolf E, Nagel-Wolfrum K, Peters T, Motlik J, Fischer DM, Wolfrum U, Klymiuk N. Early disruption of photoreceptor cell architecture and loss of vision in a humanized pig model of usher syndromes. EMBO Mol Med 2022;14(4):e14817.Abstract
Usher syndrome (USH) is the most common form of monogenic deaf-blindness. Loss of vision is untreatable and there are no suitable animal models for testing therapeutic strategies of the ocular constituent of USH, so far. By introducing a human mutation into the harmonin-encoding USH1C gene in pigs, we generated the first translational animal model for USH type 1 with characteristic hearing defect, vestibular dysfunction, and visual impairment. Changes in photoreceptor architecture, quantitative motion analysis, and electroretinography were characteristics of the reduced retinal virtue in USH1C pigs. Fibroblasts from USH1C pigs or USH1C patients showed significantly elongated primary cilia, confirming USH as a true and general ciliopathy. Primary cells also proved their capacity for assessing the therapeutic potential of CRISPR/Cas-mediated gene repair or gene therapy in vitro. AAV-based delivery of harmonin into the eye of USH1C pigs indicated therapeutic efficacy in vivo.
PURPOSE: Venous thromboembolic complications have been reported in association with COVID-19 infection. We raise awareness of a potential temporal association between COVID-19 infection and retinal vein occlusion (RVO). DESIGN: Retrospective, non-consecutive case series. METHODS: Setting: Multicenter STUDY POPULATION: Patients presenting with hemi-RVO (HRVO) or central RVO (CRVO) between 3/2020 and 3/2021, with confirmed COVID-19 infection. EXCLUSION CRITERIA: age >50 years, hypertension, diabetes, glaucoma, obesity, underlying hypercoagulable states, and those requiring intubation during hospitalization. OUTCOMES: Ophthalmic findings including presenting and final visual acuity (VA), imaging findings, and clinical course. RESULTS: Twelve eyes of 12 patients with CRVO (9/12) or HRVO (3/12) following COVID-19 infection were included. Median age was 32 (range 18-50) years. Three patients were hospitalized, but none were intubated. Median time from COVID-19 diagnosis to ophthalmic symptoms was 6.9 weeks. Presenting VA ranged from 20/20 to counting fingers (CF), with over half (7/12) having VA ≥20/40. Optical coherence tomography (OCT) revealed macular edema in 33% of eyes, 80% (4/5) treated with anti-VEGF injections. Ninety-two percent (11/12) had partial or complete resolution of ocular findings at final follow up. Four eyes (33%) had retinal thinning on OCT by the end of the study interval. Final visual acuity ranged from 20/20 to 20/60, with 11/12 (92%) eyes achieving ≥20/40 VA eyes at a median final follow-up of 13 (range 4-52) weeks. CONCLUSIONS: While we acknowledge a high seroprevalence of COVID-19 and that a causal relationship cannot be established, we report this series to raise awareness of the potential risk of retinal vascular events due to a heightened thrombo-inflammatory state associated with COVID-19 infection.
Retinal pigment epithelium (RPE) dysfunction and atrophy occur in dry age-related macular degeneration (AMD), often leading to photoreceptor degeneration and vision loss. Accumulated oxidative stress during aging contributes to RPE dysfunction and degeneration. Here we show that the nuclear receptor REV-ERBα, a redox sensitive transcription factor, protects RPE from age-related degeneration and oxidative stress-induced damage. Genetic deficiency of REV-ERBα leads to accumulated oxidative stress, dysfunction and degeneration of RPE, and AMD-like ocular pathologies in aging mice. Loss of REV-ERBα exacerbates chemical-induced RPE damage, and pharmacological activation of REV-ERBα protects RPE from oxidative damage both in vivo and in vitro. REV-ERBα directly regulates transcription of nuclear factor erythroid 2-related factor 2 (NRF2) and its downstream antioxidant enzymes superoxide dismutase 1 (SOD1) and catalase to counter oxidative damage. Moreover, aged mice with RPE specific knockout of REV-ERBα also exhibit accumulated oxidative stress and fundus and RPE pathologies. Together, our results suggest that REV-ERBα is a novel intrinsic protector of the RPE against age-dependent oxidative stress and a new molecular target for developing potential therapies to treat age-related retinal degeneration.
Kuht HJ, Maconachie GDE, Han J, Kessel L, van Genderen MM, McLean RJ, Hisaund M, Tu Z, Hertle RW, Gronskov K, Bai D, Wei A, Li W, Jiao Y, Smirnov V, Choi J-H, Tobin MD, Sheth BMedSci V, Purohit R, Dawar B, Girach A, Strul S, May L, Chen FK, Heath Jeffery RC, Aamir A, Sano R, Jin J, Brooks BP, Kohl S, Arvelier B, Montoliu L, Engle EC, Proudlock FA, Nishad G, Pani P, Varma G, Gottlob I, Thomas MG. Genotypic and Phenotypic Spectrum of Foveal Hypoplasia: A Multi-centre Study. Ophthalmology 2022;Abstract
PURPOSE: To characterise the genotypic and phenotypic spectrum of foveal hypoplasia (FH) DESIGN: Multi-centre, observational study SUBJECTS: 907 patients with a confirmed molecular diagnosis of albinism, PAX6, SLC38A8, FRMD7, AHR or achromatopsia (ACHM) from twelve centres in nine countries (n=523), or, extracted from publicly available datasets from previously reported literature (n=384). METHODS: Individuals with a confirmed molecular diagnosis and availability of foveal optical coherence tomography (OCT) scans were identified from twelve centres or from the literature, between January 2011 and March 2021. A genetic diagnosis was confirmed by sequence analysis. Grading of FH was derived from OCTs. MAIN OUTCOME MEASURES: Grade of FH, presence or absence of photoreceptor specialisation (PRS+ vs PRS-), molecular diagnosis and visual acuity (VA). RESULTS: The most common genetic etiology for typical FH in our cohort was albinism (67.5%), followed by PAX6 (21.8%), SLC38A8 (6.8%) and FRMD7 (3.5%) variants. AHR variants were rare (0.4%). Atypical FH was seen in 67.4% of ACHM cases. Atypical FH in ACHM had significantly worse VA compared to typical FH (p<0.0001). There was a significant difference in the spectrum of FH grades based on the molecular diagnosis (X2=60.4, p<0.0001). All SLC38A8 cases were PRS- (p=0.003), while all FRMD7 cases were PRS+ (p<0.0001). Analysis of albinism sub-types revealed a significant difference in the grade of FH (X2=31.4, p<0.0001) and VA (p=0.0003) between oculocutaneous albinism (OCA) compared to ocular albinism (OA) and Hermansky-Pudlak syndrome (HPS). OA and HPS demonstrated higher grades of FH and worse VA than OCA. There was a significant difference (p<0.0001) in VA between FRMD7 variants compared to other diagnoses associated with FH. CONCLUSION: We characterised the phenotypic and genotypic spectrum of FH. Atypical FH is associated with much worse prognosis compared to all other forms of FH. In typical FH, our data suggests that arrested retinal development occurs earlier in SLC38A8, OA, HPS and AHR variants and much later in FRMD7 variants. The defined time-period of foveal developmental arrest for OCA and PAX6 variants appears to demonstrate more variability. Our findings provide mechanistic insight into disorders associated with FH and also have significant prognostic and diagnostic value.
BACKGROUND: Variants in RCBTB1 were recently described to cause a retinal dystrophy with only eight families described to date and a predominant phenotype of macular atrophy and peripheral reticular degeneration. Here, we further evaluate the genotypic and phenotypic characteristics of biallelic RCBTB1-associated retinal dystrophy in a North American clinic population. METHODS: A retrospective analysis of genetic and clinical features was performed in individuals with biallelic variants in RCBTB1. RESULTS: Three unrelated individuals of French-Canadian descent with rare biallelic RCBTB1 variants were identified. All individuals shared a novel p.(Ser342Leu) missense variant; one patient was homozygous whereas the other two each possessed a second unique novel variant p.(Gln120*) and p.(Pro224Leu). All three had macula-predominant disease with symptom onset in the fifth decade of life. CONCLUSION: This report adds to the genetic diversity of RCBTB1-associated disease. These cases confirm the later-onset, relative to many other retinal dystrophies, and macular focus of disease described in most cases to-date. They are thus a reminder of considering hereditary disease in the differential for later-onset macular atrophy.
PURPOSE: To describe the clinical course and outcomes of aggressive retinal astrocytic hamartoma (RAH) treated with oral mechanistic target of rapamycin inhibitors (mTORis). DESIGN: A retrospective clinical case series. PARTICIPANTS: Five patients with genetically confirmed tuberous sclerosis complex and visually significant RAH due to tumor growth or exudation. METHODS: In this retrospective clinical case series, a review of electronic medical records was performed to determine baseline and follow-up ophthalmic examination characteristics, along with ancillary imaging findings, in patients receiving off-label treatment with either oral sirolimus or everolimus for symptomatic RAH. MAIN OUTCOME MEASURES: Visual acuity, change in tumor size, degree of exudation, and adverse effects of the mTORis were evaluated. RESULTS: The 5 patients in this series ranged in age from 8 months to 54 years. Four were treated with sirolimus, and 1 received everolimus. In all the cases, the tumor height was stable or decreased after the treatment (median follow-up duration, 39 months; range, 11-73 months). Exudation improved after the treatment in all the cases. In an 8-month-old infant, frequent upper respiratory tract infections prompted the cessation of treatment. In 1 patient, the mTORi was temporarily withheld because of elevated liver enzyme levels. No other significant adverse effects were noted. CONCLUSIONS: Sirolimus and everolimus should be considered in the management of vision-threatening RAH, particularly in the setting of exudative and rapidly growing tumors. Four of the 5 patients in this series tolerated the oral mTORi and continued with the therapy. There were no serious complications.