Zolotukhin S, Vandenberghe LH. AAV capsid design: A Goldilocks challenge. Trends Mol Med 2022;28(3):183-193.Abstract
In vivo therapeutic gene transfer has emerged as a novel class of medicines. Its feasibility relies on the safe and efficacious delivery of genetic cargo to the appropriate targets. The adeno-associated virus (AAV) vector manifested itself as a preferred gene delivery vehicle enabling therapeutic gene expression for several clinical indications. Here, we cover the recent trends in AAV capsid engineering to enhance its targeting specificity, safety, and endurance. While each and every desirable trait can be individually remodeled, combining several attributes in one capsid amounts to a significant engineering challenge. Taking advantage of virion structure and phylogenetics, harnessing directed evolution, sequence analyses, and machine learning, researchers develop novel capsid variants to realize the goals of safe and enduring gene therapy.
Pham AT, Whitescarver TD, Beatson B, Purt B, Yonekawa Y, Shah AS, Colyer MH, Woreta FA, Justin GA. Ophthalmic trauma: the top 100 cited articles in Ophthalmology journals. Eye (Lond) 2022;Abstract
OBJECTIVES: To analyze the top 100 cited papers on ophthalmic trauma. METHODS: A literature search of Ophthalmology journals within the ISI Web of Science database for the most cited papers related to ophthalmic trauma. RESULTS: The most cited articles were published between 1943 and 2013, the greatest number being published in 2000. Ophthalmology (45), Archives of Ophthalmology (17), and the American Journal of Ophthalmology (15) published most of the articles. The institutions with the highest number of publications were Wilmer Eye Institute (10) and Massachusetts Eye and Ear Infirmary (7). Sixty-seven percent of the articles originated from the USA. The most common type of trauma studied was non-open-globe injuries and the most frequent topic studied were pathological conditions secondary to trauma (34), particularly endophthalmitis (8), and optic neuropathy (6). Articles presenting a standardized classification system for eye injury received the highest average of citations per publication. Types of research most frequently cited were observational clinical studies (62) and epidemiological studies (30); the least frequent were clinical trials (2). CONCLUSION: This bibliographic study provides a historical perspective of the literature and identifies trends within the most highly influential papers on ophthalmic trauma. Many of these articles emerged within the past three decades and came from Ophthalmology journals that remain high impact to this day. Clinical trials have been difficult to conduct and are lacking, reflecting a critical need in ophthalmic trauma research, as most of our understanding of ophthalmic trauma comes from observational and epidemiological studies.
Natera-de Benito D, Jurgens JA, Yeung A, Zaharieva IT, Manzur A, DiTroia SP, Di Gioia SA, Pais L, Pini V, Barry BJ, Chan W-M, Elder JE, Christodoulou J, Hay E, England EM, Munot P, Hunter DG, Feng L, Ledoux D, O'Donnell-Luria A, Phadke R, Engle EC, Sarkozy A, Muntoni F. Recessive variants in COL25A1 gene as novel cause of arthrogryposis multiplex congenita with ocular congenital cranial dysinnervation disorder. Hum Mutat 2022;43(4):487-498.Abstract
A proper interaction between muscle-derived collagen XXV and its motor neuron-derived receptors protein tyrosine phosphatases σ and δ (PTP σ/δ) is indispensable for intramuscular motor innervation. Despite this, thus far, pathogenic recessive variants in the COL25A1 gene had only been detected in a few patients with isolated ocular congenital cranial dysinnervation disorders. Here we describe five patients from three unrelated families with recessive missense and splice site COL25A1 variants presenting with a recognizable phenotype characterized by arthrogryposis multiplex congenita with or without an ocular congenital cranial dysinnervation disorder phenotype. The clinical features of the older patients remained stable over time, without central nervous system involvement. This study extends the phenotypic and genotypic spectrum of COL25A1 related conditions, and further adds to our knowledge of the complex process of intramuscular motor innervation. Our observations indicate a role for collagen XXV in regulating the appropriate innervation not only of extraocular muscles, but also of bulbar, axial, and limb muscles in the human.
Göz Aytürk D, You W, Cepko CL. Mouse Lines with Cre-Mediated Recombination in Retinal Amacrine Cells. eNeuro 2022;9(1)Abstract
Amacrine cells (ACs) are the most diverse neuronal cell type in the vertebrate retina. Yet little is known about the contribution of ACs to visual processing and retinal disease. A major challenge in evaluating AC function is genetic accessibility. A classic tool of mouse genetics, Cre-mediated recombination, can provide such access. We have screened existing genetically-modified mouse strains and identified multiple candidates that express Cre-recombinase in subsets of retinal ACs. The Cre-expressing mice were crossed to fluorescent-reporter mice to assay Cre expression. In addition, a Cre-dependent fluorescent reporter plasmid was electroporated into the subretinal space of Cre strains. Herein, we report three mouse lines (Tac1::IRES-cre, Camk2a-cre, and Scx-cre) that express Cre recombinase in sub-populations of ACs. In two of these lines, recombination occurred in multiple AC types and a small number of other retinal cell types, while recombination in the Camk2a-cre line appears specific to a morphologically distinct AC. We anticipate that these characterized mouse lines will be valuable tools to the community of researchers who study retinal biology and disease.
Catomeris AJ, Ballios BG, Sangermano R, Wagner NE, Comander JI, Pierce EA, Place EM, Bujakowska KM, Huckfeldt RM. Novel RCBTB1 variants causing later-onset non-syndromic retinal dystrophy with macular chorioretinal atrophy. Ophthalmic Genet 2022;43(3):332-339.Abstract
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.
Lains I, Mendez K, Nigalye A, Katz R, Douglas VP, Kelly RS, Kim IK, Miller JB, Vavvas DG, Liang L, Lasky-Su J, Miller JW, Husain D. Plasma Metabolomic Profiles Associated with Three-Year Progression of Age-Related Macular Degeneration. Metabolites 2022;12(1)Abstract
Plasma metabolomic profiles have been shown to be associated with age-related macular degeneration (AMD) and its severity stages. However, all studies performed to date have been cross-sectional and have not assessed progression of AMD. This prospective, longitudinal, pilot study analyzes, for the first time, the association between plasma metabolomic profiles and progression of AMD over a 3-year period. At baseline and 3 years later, subjects with AMD (n = 108 eyes) and controls (n = 45 eyes) were imaged with color fundus photos for AMD staging and tested for retinal function with dark adaptation (DA). Fasting plasma samples were also collected for metabolomic profiling. AMD progression was considered present if AMD stage at 3 years was more advanced than at baseline (n = 26 eyes, 17%). Results showed that, of the metabolites measured at baseline, eight were associated with 3-year AMD progression (p < 0.01) and 19 (p < 0.01) with changes in DA. Additionally, changes in the levels (i.e., between 3 years and baseline) of 6 and 17 metabolites demonstrated significant associations (p < 0.01) with AMD progression and DA, respectively. In conclusion, plasma metabolomic profiles are associated with clinical and functional progression of AMD at 3 years. These findings contribute to our understanding of mechanisms of AMD progression and the identification of potential therapeutics for this blinding disease.
Banskota S, Raguram A, Suh S, Du SW, Davis JR, Choi EH, Wang X, Nielsen SC, Newby GA, Randolph PB, Osborn MJ, Musunuru K, Palczewski K, Liu DR. Engineered virus-like particles for efficient in vivo delivery of therapeutic proteins. Cell 2022;185(2):250-265.e16.Abstract
Methods to deliver gene editing agents in vivo as ribonucleoproteins could offer safety advantages over nucleic acid delivery approaches. We report the development and application of engineered DNA-free virus-like particles (eVLPs) that efficiently package and deliver base editor or Cas9 ribonucleoproteins. By engineering VLPs to overcome cargo packaging, release, and localization bottlenecks, we developed fourth-generation eVLPs that mediate efficient base editing in several primary mouse and human cell types. Using different glycoproteins in eVLPs alters their cellular tropism. Single injections of eVLPs into mice support therapeutic levels of base editing in multiple tissues, reducing serum Pcsk9 levels 78% following 63% liver editing, and partially restoring visual function in a mouse model of genetic blindness. In vitro and in vivo off-target editing from eVLPs was virtually undetected, an improvement over AAV or plasmid delivery. These results establish eVLPs as promising vehicles for therapeutic macromolecule delivery that combine key advantages of both viral and nonviral delivery.
Li H, Deng Y, Sampani K, Cai S, Li Z, Sun JK, Karniadakis GE. Computational investigation of blood cell transport in retinal microaneurysms. PLoS Comput Biol 2022;18(1):e1009728.Abstract
Microaneurysms (MAs) are one of the earliest clinically visible signs of diabetic retinopathy (DR). MA leakage or rupture may precipitate local pathology in the surrounding neural retina that impacts visual function. Thrombosis in MAs may affect their turnover time, an indicator associated with visual and anatomic outcomes in the diabetic eyes. In this work, we perform computational modeling of blood flow in microchannels containing various MAs to investigate the pathologies of MAs in DR. The particle-based model employed in this study can explicitly represent red blood cells (RBCs) and platelets as well as their interaction in the blood flow, a process that is very difficult to observe in vivo. Our simulations illustrate that while the main blood flow from the parent vessels can perfuse the entire lumen of MAs with small body-to-neck ratio (BNR), it can only perfuse part of the lumen in MAs with large BNR, particularly at a low hematocrit level, leading to possible hypoxic conditions inside MAs. We also quantify the impacts of the size of MAs, blood flow velocity, hematocrit and RBC stiffness and adhesion on the likelihood of platelets entering MAs as well as their residence time inside, two factors that are thought to be associated with thrombus formation in MAs. Our results show that enlarged MA size, increased blood velocity and hematocrit in the parent vessel of MAs as well as the RBC-RBC adhesion promote the migration of platelets into MAs and also prolong their residence time, thereby increasing the propensity of thrombosis within MAs. Overall, our work suggests that computational simulations using particle-based models can help to understand the microvascular pathology pertaining to MAs in DR and provide insights to stimulate and steer new experimental and computational studies in this area.
Manny RE, Holmes JM, Kraker RT, Li Z, Waters AL, Kelly KR, Kong L, Crouch ER, Lorenzana IJ, Alkharashi MS, Galvin JA, Rice ML, Melia MB, Cotter SA, Cotter SA. A Randomized Trial of Binocular Dig Rush Game Treatment for Amblyopia in Children Aged 4 to 6 Years of Age. Optom Vis Sci 2022;Abstract
SIGNIFICANCE: Binocular treatment for unilateral amblyopia is an emerging treatment that requires evaluation through a randomized clinical trial. PURPOSE: To compare change in amblyopic eye visual acuity (VA) in children aged 4 to 6 years treated with the dichoptic binocular Dig Rush iPad game plus continued spectacle correction vs. continued spectacle correction alone. METHODS: Children (mean 5.7 years) were randomly assigned to home treatment for 8 weeks with the iPad game (n = 92, prescribed 1 hour/day, 5 days/week or continued spectacle correction alone n = 90) in a multi-center randomized clinical trial. Prior to enrollment, children wearing spectacles were required to have at least 16 weeks of wear or no improvement in amblyopic-eye VA (< 0.1 logMAR) for at least 8 weeks. Outcome was change in amblyopic-eye VA from baseline to 4 weeks (primary) and 8 weeks (secondary) assessed by masked examiner. RESULTS: 182 children with anisometropic (63%), strabismic (16%) (<5[INCREMENT] near, simultaneous prism and cover test), or combined-mechanism (20%) amblyopia (20/40 to 20/200, mean 20/63) were enrolled. After 4 weeks, mean amblyopic VA improved 1.1 logMAR lines with binocular treatment and 0.6 logMAR lines with spectacles alone (adjusted difference = 0.5 lines; 95.1% CI: 0.1 to 0.9). After 8 weeks, results (binocular treatment: mean amblyopic-eye VA improvement = 1.3 logMAR lines vs. 1.0 logMAR lines with spectacles alone, adjusted difference = 0.3 lines; 98.4% CI: -0.2 to 0.8) were inconclusive because the confidence interval included both zero and the pre-defined difference in mean VA change of 0.75 logMAR lines. CONCLUSIONS: In 4- to 6-year-old children with amblyopia, binocular Dig Rush treatment resulted in greater improvement in amblyopic-eye VA over 4 weeks but not 8 weeks. Future work is required to determine if modifications to the contrast increment algorithm or other aspects of the game or its implementation could enhance the treatment effect.
Meshkin RS, Armstrong GW, Hall NE, Rossin EJ, Hymowitz MB, Lorch AC. Effectiveness of a telemedicine program for triage and diagnosis of emergent ophthalmic conditions. Eye (Lond) 2022;Abstract
BACKGROUND: To study the utility of a teleophthalmology program to diagnose and triage common ophthalmic complaints presenting to an ophthalmic emergency room. METHODS: Prospective, observational study of 258 eyes of 129 patients presenting to the Massachusetts Eye and Ear Infirmary Emergency Ward (MEE EW) who completed a questionnaire to gather chief complaint (CC), history of present illness, and medical history. Anterior and posterior segment photographs were collected via iPhone 5 C camera and a Canon non-mydriatic fundus camera, respectively. Ophthalmic vital signs were collected. All information was reviewed remotely by three ophthalmologists; a diagnosis and urgency designation were recorded. The remote assessment was compared to gold standard in-person assessment. RESULTS: The 129 recruited patients collectively contributed 220 visual complaints, of which 121 (55%) were from females with mean age 56.5 years (range 24-89). Sensitivities and specificities for telemedical triage were as follows: eye pain (n = 56; sensitivity: 0.58, CI [0.41, 0.74]; specificity: 0.91, CI [0.80, 1]), eye redness (n = 54; 0.68, CI [0.50, 0.86]; 0.93, CI [0.84, 1]), blurry vision (n = 68; 0.73, CI [0.60, 0.86]; 0.91, CI [0.80, 1]), and eyelid complaints (n = 42; 0.67, CI [0.43, 0.91]; 0.96, CI [0.89, 1]). The remote diagnostic accuracies, as stratified by CC, were eye pain (27/56; 48.21%), eye redness: (32/54; 59.26%), blurry vision: (30/68; 44.11%), eyelid (24/42; 57.14%). CONCLUSIONS: Telemedical examination of emergent ophthalmic complaints consisting of a patient questionnaire, anterior segment and fundus photos, and ophthalmic vital signs, may be useful to reliably triage eye disease based on presenting complaint.
Elbasiony E, Cho W, Mittal SK, Chauhan SK. Suppression of lipopolysaccharide-induced corneal opacity by hepatocyte growth factor. Sci Rep 2022;12(1):494.Abstract
Keratitis induced by bacterial toxins, including lipopolysaccharide (LPS), is a major cause of corneal opacity and vision loss. Our previous study demonstrates hepatocyte growth factor (HGF) promotes epithelial wound healing following mechanical corneal injury. Here, we investigated whether HGF has the capacity to suppress infectious inflammatory corneal opacity using a new model of LPS-induced keratitis. Keratitis, induced by two intrastromal injections of LPS on day 1 and 4 in C57BL/6 mice, resulted in significant corneal opacity for up to day 10. Following keratitis induction, corneas were topically treated with 0.1% HGF or PBS thrice daily for 5 days. HGF-treated mice showed a significantly smaller area of corneal opacity compared to PBS-treated mice, thus improving corneal transparency. Moreover, HGF treatment resulted in suppression of α-SMA expression, compared to PBS treatment. HGF-treated corneas showed normalized corneal structure and reduced expression of pro-inflammatory cytokine, demonstrating that HGF restores corneal architecture and immune quiescence in corneas with LPS-induced keratitis. These findings offer novel insight into the potential application of HGF-based therapies for the prevention and treatment of infection-induced corneal opacity.
Bowe T, Serina A, Armstrong M, Welcher JE, Adebona O, Gore C, Staffa SJ, Zurakowski D, Shah AS. Timing of Ocular Hypertension After Pediatric Closed-Globe Traumatic Hyphema: Implications for Surveillance. Am J Ophthalmol 2022;233:135-143.Abstract
PURPOSE: To evaluate the timing of ocular hypertension (OHT) after pediatric closed-globe injury (CGI) and traumatic hyphema. We hypothesize that OHT will occur at different times based on injury characteristics. DESIGN: Retrospective, cohort study. METHODS: Setting: Single-center, tertiary-care, pediatric hospital. PARTICIPANTS: Subjects included patients ≤18 years of age at the time of injury who suffered CGI and traumatic hyphema between 2002 and 2019. Observation Procedure(s): Intraocular pressure and injury demographics were abstracted for every visit after injury. OHT was defined as >21 mm Hg at presentation or after a reading of ≤21 mm Hg at a prior visit. MAIN OUTCOME MEASURES: The primary outcome measure was the timing of OHT categorized into 4 periods: presentation, acute (days 1-7), subacute (days 8-28), or late (day >28). Secondary outcome measures were identification of risks factors for OHT by multivariable logistic regression. RESULTS: OHT occurred in 119 of the 305 (39%) subject eyes. OHT occurred in 35 patients at presentation, 69 times acutely, 35 times subacutely, and 36 times late. Pupil damage predicted acute-period OHT (P = .004). OHT at presentation predicted subacute period OHT (P = .004). Iridodialysis and cataract predicted late-period OHT (P = .007 and P < .001, respectively). CONCLUSIONS: OHT after CGI and traumatic hyphema in pediatric patients is common. Injury demographics predict this complication. Integration of these risk factors with current literature allows proposal of a risk-stratification tool to guide efficient surveillance for OHT.
Sharifi S, Sharifi H, Akbari A, Lei F, Dohlman CH, Gonzalez-Andrades M, Guild C, Paschalis EI, Chodosh J. Critical media attributes in E-beam sterilization of corneal tissue. Acta Biomater 2022;138:218-227.Abstract
When ionizing irradiation interacts with a media, it can form reactive species that can react with the constituents of the system, leading to eradication of bioburden and sterilization of the tissue. Understanding the media's properties such as polarity is important to control and direct those reactive species to perform desired reactions. Using ethanol as a polarity modifier of water, we herein generated a series of media with varying relative polarities for electron beam (E-beam) irradiation of cornea at 25 kGy and studied how the irradiation media's polarity impacts properties of the cornea. After irradiation of corneal tissues, mechanical (tensile strength and modulus, elongation at break, and compression modulus), chemical, optical, structural, degradation, and biological properties of the corneal tissues were evaluated. Our study showed that irradiation in lower relative polarity media improved structural properties of the tissues yet reduced optical transmission; higher relative polarity reduced structural and optical properties of the cornea; and intermediate relative polarity (ethanol concentrations = 20-30% (v/v)) improved the structural properties, without compromising optical characteristics. Regardless of media polarity, irradiation did not negatively impact the biocompatibility of the corneal tissue. Our data shows that the absorbed ethanol can be flushed from the irradiated cornea to levels that are nontoxic to corneal and retinal cells. These findings suggest that the relative polarity of the irradiation media can be tuned to generate sterilized tissues, including corneal grafts, with engineered properties that are required for specific biomedical applications. STATEMENT OF SIGNIFICANCE: Extending the shelf-life of corneal tissue can improve general accessibility of cornea grafts for transplantation. Irradiation of donor corneas with E-beam is an emerging technology to sterilize the corneal tissues and enable their long-term storage at room temperature. Despite recent applications in clinical medicine, little is known about the effect of irradiation and preservation media's characteristics, such as polarity on the properties of irradiated corneas. Here, we have showed that the polarity of the media can be a valuable tool to change and control the properties of the irradiated tissue for transplantation.
Su T, Zhu P-W, Li B, Shi W-Q, Lin Q, Yuan Q, Jiang N, Pei C-G, Shao Y. Gray matter volume alterations in patients with strabismus and amblyopia: voxel-based morphometry study. Sci Rep 2022;12(1):458.Abstract
This study proposes the use of the voxel-based morphometry (VBM) technique to investigate structural alterations of the cerebral cortex in patients with strabismus and amblyopia (SA). Sixteen patients with SA and sixteen healthy controls (HCs) underwent magnetic resonance imaging. Original whole brain images were analyzed using the VBM method. Pearson correlation analysis was performed to evaluate the relationship between mean gray matter volume (GMV) and clinical manifestations. Receiver operating characteristic (ROC) curve analysis was applied to classify the mean GMV values of the SA group and HCs. Compared with the HCs, GMV values in the SA group showed a significant difference in the right superior temporal gyrus, posterior and anterior lobes of the cerebellum, bilateral parahippocampal gyrus, and left anterior cingulate cortex. The mean GMV value in the right superior temporal gyrus, posterior and anterior lobes of the cerebellum, and bilateral parahippocampal gyrus were negatively correlated with the angle of strabismus. The ROC curve analysis of each cerebral region confirmed the accuracy of the area under the curve. Patients with SA have reduced GMV values in some brain regions. These findings might help to reveal the potential pathogenesis of SA and its relationship with the atrophy of specific regions of the brain.