Search

We have previously reported that reconstructed human skin, using deepidermized acellular sterilized dermis and allogeneic keratinocytes and fibroblasts, significantly contracts in vitro. Contracture of split skin grafts in burns injuries remains a serious problem and this in vitro model provides an opportunity to study keratinocyte/mesenchymal cell interactions and cell interactions with extracted normal human dermis. The aim of this study was to investigate the nature of this in vitro contraction and explore several approaches to prevent or reduce contraction. Three different methodologies for sterilization of the dermal matrix were examined: glycerol, ethylene oxide and a combination of glycerol and ethylene oxide. While the nature of the sterilization technique influenced the extent of contraction and thinner dermal matrices contracted proportionately more than thicker matrices, in all cases contraction was driven by the keratinocytes with relatively little influence from the fibroblasts. The contraction of the underlying dermis did not represent any change in tissue mass but rather a reorganization of the dermis which was rapidly reversed (within minutes) when the epidermal layer was removed. Pharmacological approaches to block contraction showed forskolin and mannose-6-phosphate to be ineffective and ascorbic acid-2-phosphate to exacerbate contraction. However, Galardin, a matrix metalloproteinase inhibitor and keratinocyte conditioned media, both inhibited contraction. [ABSTRACT FROM AUTHOR]

Purpose: Glaucoma is the leading cause of irreversible blindness worldwide. Despite growing concerns about air quality and its impact on ocular health, there remains a knowledge gap regarding the long-term association between air pollution and glaucoma risk. This study investigates the relationship between exposure to ambient air pollution and incidence of glaucoma., Methods: In this prospective study, we used land use regression models to estimate levels of various air pollutants, including fine particulate matter (PM2.5), PM2.5 absorbance, PM2.5-10, PM10, nitrogen dioxide (NO2), and nitrogen oxides (NOx). Incidents of glaucoma were ascertained through routinely collected hospital admission records. Multivariate Cox proportional hazards models were used to examine the associations between air pollution exposure and glaucoma incidence, adjusting for potential confounding sociodemographic, physical, and lifestyle factors., Results: Data from 481,113 participants were included. Over a median follow-up of 12.8 years, 9224 incident cases of glaucoma were identified. In the maximally adjusted model, per interquartile range increase in PM2.5 was associated with a 3% greater risk of developing glaucoma (hazard ratio [HR] = 1.03, 95% confidence interval [CI] = 1.00 to 1.06, P = 0.048). Participants in the highest quartile had a 10% increased risk of developing glaucoma compared to those in the lowest quartile (HR = 1.10, 95% CI = 1.03 to 1.17, P = 0.005)., Conclusions: Higher levels of exposure to ambient air pollutants, particularly PM2.5, are associated with an increased risk of developing glaucoma. These results highlight the potential public health impact of ambient air pollution on glaucoma risk and underscore the urgent need for further research into targeted environmental interventions in this domain.

We previously described FpFs 1̲ (Fab-PEG-Fab) as binding mimetics of IgGs. FpFs are prepared with di(bis-sulfone) conjugation reagents 3̲ that undergo disulfide rebridging conjugation with the accessible disulfide of each Fab (Scheme 1). We have now prepared bispecific FpFs 2̲ (bsFpF and Fab 1 -PEG-Fab 2 ) as potential bispecific antibody mimetics with the intent that bsFpFs could be used in preclinical antibody development since sourcing bispecific antibodies may be challenging during preclinical research. The di(bis-sulfone) reagent 3̲ was first used to prepare a bsFpF 2̲ by the sequential conjugation of a first Fab and then a second Fab to another target (Scheme 2). Seeking to improve bsFpF synthesis, the asymmetric conjugation reagent, bis-sulfone bis-sulfide 1̲6̲, with different thiol conjugation reactivities at each terminus (Scheme 4) was examined and the bsFpFs appeared to be formed at similar conversion to the di(bis-sulfone) reagent 3̲. To explore the advantages of using common intermediates in the preparation of bsFpF families, we investigated bsFpF synthesis with a protein conjugation-ligation approach (Scheme 5). Reagents with a bis-sulfone moiety for conjugation on one PEG terminus and a ligation moiety on the other terminus were examined. Bis-sulfone PEG trans -cyclooctene (TCO) 2̲8̲ and bis-sulfone PEG tetrazine (Tz) 3̲0̲ were used to prepare several bsFpFs targeting various therapeutic targets (TNF-α, IL6R, IL17, and VEGF) and tissue affinity targets (hyaluronic acid and collagen II). Surface plasmon resonance (SPR) binding studies indicated that there was little difference between the dissociation rate constant ( k d ) for the unmodified Fab, mono-conjugated PEG-Fab and the corresponding Fab in a bsFpF. The Fab association rate ( k a ) in the bsFpF was slower than for PEG-Fab, which may be because of mass differences that influence SPR results. These observations suggest that each Fab will bind to its target independently of the other Fab and that bsFpF binding profiles can be estimated using the corresponding PEG-Fab conjugates., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Background and Purpose: The eye is a well-established model of brain structure and function, yet region-specific structural correlations between the retina and the brain remain underexplored. Therefore, we aim to explore and describe the relationships between the retinal layer thicknesses and brain magnetic resonance image (MRI)-derived phenotypes in UK Biobank., Methods: Participants with both quality-controlled optical coherence tomography (OCT) and brain MRI were included in this study. Retinal sublayer thicknesses and total macular thickness were derived from OCT scans. Brain image-derived phenotypes (IDPs) of 153 cortical and subcortical regions were processed from MRI scans. We utilized multivariable linear regression models to examine the association between retinal thickness and brain regional volumes. All analyses were corrected for multiple testing and adjusted for confounders., Results: Data from 6446 participants were included in this study. We identified significant associations between volumetric brain MRI measures of subregions in the occipital lobe (intracalcarine cortex), parietal lobe (postcentral gyrus), cerebellum (lobules VI, VIIb, VIIIa, VIIIb, and IX), and deep brain structures (thalamus, hippocampus, caudate, putamen, pallidum, and accumbens) and the thickness of the innermost retinal sublayers and total macular thickness (all p < 3.3 × 10 -5 ). We did not observe statistically significant associations between brain IDPs and the thickness of the outer retinal sublayers., Conclusions: Thinner inner and total retinal thicknesses are associated with smaller volumes of specific brain regions. Notably, these relationships extend beyond anatomically established retina-brain connections., (© 2024 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Purpose: To compare the effectiveness and safety of the MicroShunt (Santen Inc) versus trabeculectomy in patients with primary open-angle glaucoma (POAG)., Design: Prospective, randomized, multicenter trial conducted in the United States and Europe., Participants: Adult patients (aged 40-85 years) with mild to severe POAG inadequately controlled on maximum tolerated medical therapy and intraocular pressure (IOP) ≥ 15 mmHg and ≤ 40 mmHg., Methods: Patients were randomized 3:1 to stand-alone MicroShunt implantation (n = 395) or trabeculectomy (n = 132), both augmented with mitomycin C (MMC) 0.2 mg/ml for 2 minutes., Main Outcome Measures: The primary effectiveness end point was surgical success, defined as ≥ 20% reduction in mean diurnal IOP from baseline with no increase in glaucoma medications. Secondary end points included changes in mean IOP and medication use from baseline and the need for postoperative interventions., Results: At 2 years, the rate of surgical success was lower in the MicroShunt group than in the trabeculectomy group (50.6% vs. 64.4%, P = 0.005). Mean diurnal IOP was reduced from 21.1 ± 4.9 mmHg at baseline to 13.9 ± 3.9 mmHg at 24 months in the MicroShunt group and from 21.1 ± 5.0 mmHg at baseline to 10.7 ± 3.7 mmHg at 24 months in the trabeculectomy group (P < 0.001 compared with baseline in both groups). Mean medication use decreased from 3.1 to 0.9 in the MicroShunt group and from 2.9 to 0.4 in the trabeculectomy group (P < 0.001 compared with baseline in both groups). Adverse events at 2 years were generally similar in the 2 groups, except that hypotony was more common in eyes undergoing trabeculectomy (51.1% vs. 30.9%, P < 0.001). Repositioning or explantation of the implant occurred in 6.8% of MicroShunt patients. The majority of these patients had device removal at the time of subsequent glaucoma surgery. Vision-threatening complications were uncommon in both groups., Conclusion: At 2 years, both the MicroShunt and trabeculectomy provided significant reductions in IOP and medication use, with trabeculectomy continuing to have greater surgical success., Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article., (Copyright © 2023 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Introduction: As with any other radial glia in the central nervous system, Müller glia derive from the same neuroepithelial precursors, perform similar functions, and exhibit neurogenic properties as radial glia in the brain. Müller glial cells retain progenitor-like characteristics in the adult human eye and can partially restore visual function upon intravitreal transplantation into animal models of glaucoma. Recently, it has been demonstrated that intracellular communication is possible via the secretion of nano-sized membrane-bound extracellular vesicles (EV), which contain bioactive molecules like microRNA (miRNA) and proteins that induce phenotypic changes when internalised by recipient cells., Methods: We conducted high-throughput sequencing to profile the microRNA signature of EV populations secreted by Müller glia in culture and used bioinformatics tools to evaluate their potential role in the neuroprotective signalling attributed to these cells., Results: Sequencing of miRNA within Müller EV suggested enrichment with species associated with stem cells such as miR-21 and miR-16, as well as with miRNA previously found to play a role in diverse Müller cell functions in the retina: miR-9, miR-125b, and the let-7 family. A total of 51 miRNAs were found to be differentially enriched in EV compared to the whole cells from which EV originated. Bioinformatics analyses also indicated that preferential enrichment of species was demonstrated to regulate genes involved in cell proliferation and survival, including PTEN, the master inhibitor of the PI3K/AKT pathway., Discussion: The results suggest that the release by Müller cells of miRNA-enriched EV abundant in species that regulate anti-apoptotic signalling networks is likely to represent a significant proportion of the neuroprotective effect observed after the transplantation of these cells into animal models of retinal ganglion cell (RGC) depletion. Future studies will seek to evaluate the modulation of putative genes as well as the activation of these pathways in in vitro and in vivo models following the internalisation of Müller-EV by target retinal neurons., Competing Interests: NS is employed by Santen Inc. The authors declare that this study received funding from Santen Inc, USA. The funder had the following involvement in the study: PhD studentship support for WL to undertake the work proposed by GL. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication. The funder collaborated with grammatical editing of the final manuscript. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Lamb, Eastlake, Luis, Sharif, Khaw and Limb.)

Importance: Calcium channel blocker (CCB) use has been associated with an increased risk of glaucoma in exploratory studies., Objective: To examine the association of systemic CCB use with glaucoma and related traits among UK Biobank participants., Design, Setting, and Participants: This population-based cross-sectional study included UK Biobank participants with complete data (2006-2010) for analysis of glaucoma status, intraocular pressure (IOP), and optical coherence tomography (OCT)-derived inner retinal layer thicknesses. Data analysis was conducted in January 2023., Exposure: Calcium channel blocker use was assessed in a baseline touchscreen questionnaire and confirmed during an interview led by a trained nurse., Main Outcomes and Measures: The primary outcome measures included glaucoma status, corneal-compensated IOP, and 2 OCT-derived inner retinal thickness parameters (macular retinal nerve fiber layer [mRNFL] and macular ganglion cell-inner plexiform layer [mGCIPL] thicknesses). We performed logistic regression and linear regression analyses to test for associations with glaucoma status and IOP and OCT-derived inner retinal thickness parameters, respectively., Results: This study included 427 480 adults. Their median age was 58 (IQR, 50-63) years, and more than half (54.1%) were women. There were 33 175 CCB users (7.8%). Participants who had complete data for glaucoma status (n = 427 480), IOP (n = 97 100), and OCT-derived inner retinal layer thicknesses (n = 41 023) were eligible for respective analyses. After adjustment for key sociodemographic, medical, anthropometric, and lifestyle factors, use of CCBs (but not other antihypertensive agents) was associated with greater odds of glaucoma (odds ratio [OR], 1.39 [95% CI, 1.14 to 1.69]; P = .001). Calcium channel blocker use was also associated with thinner mGCIPL (-0.34 μm [95% CI, -0.54 to -0.15 μm]; P = .001) and mRNFL (-0.16 μm [95% CI, -0.30 to -0.02 μm]; P = .03) thicknesses but not IOP (-0.01 mm Hg [95% CI, -0.09 to 0.07 mm Hg]; P = .84)., Conclusions and Relevance: In this study, an adverse association between CCB use and glaucoma was observed, with CCB users having, on average, 39% higher odds of glaucoma. Calcium channel blocker use was also associated with thinner mGCIPL and mRNFL thicknesses, providing a structural basis that supports the association with glaucoma. The lack of association of CCB use with IOP suggests that an IOP-independent mechanism of glaucomatous neurodegeneration may be involved. Although a causal relationship has not been established, CCB replacement or withdrawal may be considered should glaucoma progress despite optimal care.

Glaucomatous optic neuropathy (GON) is the major cause of irreversible visual loss worldwide and can result from a range of disease etiologies. The defining features of GON are retinal ganglion cell (RGC) degeneration and characteristic cupping of the optic nerve head (ONH) due to tissue remodeling, while intraocular pressure remains the only modifiable GON risk factor currently targeted by approved clinical treatment strategies. Efforts to understand the mechanisms that allow species such as the zebrafish to regenerate their retinal cells have greatly increased our understanding of regenerative signaling pathways. However, proper integration within the retina and projection to the brain by the newly regenerated neuronal cells remain major hurdles. Meanwhile, a range of methods for in vitro differentiation have been developed to derive retinal cells from a variety of cell sources, including embryonic and induced pluripotent stem cells. More recently, there has been growing interest in the implantation of glial cells as well as cell-derived products, including neurotrophins, microRNA, and extracellular vesicles, to provide functional support to vulnerable structures such as RGC axons and the ONH. These approaches offer the advantage of not relying upon the replacement of degenerated cells and potentially targeting earlier stages of disease pathogenesis. In order to translate these techniques into clinical practice, appropriate cell sourcing, robust differentiation protocols, and accurate implantation methods are crucial to the success of cell-based therapy in glaucoma. Translational Relevance: Cell-based therapies for glaucoma currently under active development include the induction of endogenous regeneration, implantation of exogenously derived retinal cells, and utilization of cell-derived products to provide functional support.

Purpose: To evaluate outcomes of glaucoma drainage device (GDD) implantation children with uveitic glaucoma., Design: Retrospective interventional case series., Methods: Success was defined as intraocular pressure (IOP) ≥5 and ≤21 mm Hg. Failure was defined at final follow-up when the IOP was outside the success criterion, and visual function was no perception of light or if further glaucoma surgery (excluding removal of intraluminal stent suture or needling) was required., Results: Fifty eyes of 36 children with uveitic glaucoma underwent GDD implantation. Mean age at surgery was 10.1±3.1 years (range 5-17) with a mean follow-up of 113±61 months (range 8-228). Mean cumulative probabilities of success (95% CI) were 0.98 (0.86-1.00) at 1 year, 0.87 (0.73-0.94) at 5 years, and 0.59 (0.32-0.78) at 15 years. Fourteen tubes were classified as failed, with 12 due to uncontrolled IOP (11 eyes required a second GDD); 1 eye, removal of the tube due to plate exposure; and 1 eye, lost light perception. Postoperative complications occurred in 36% of patients and included hypotony (22%), tube exposure (6%), tube obstruction (4%), corneal decompensation (2%), and cystoid macular edema (2%). Visual acuity remained stable (preoperation 0.35±0.42 vs postoperation 0.45±0.67, P = .49). IOP was significantly reduced from 31.4±7.5 mm Hg to 14.4±5.1 mm Hg (P < .0001) as were the number of glaucoma medications 3.5±1.0 vs 1.1±1.3 (P < .0001)., Conclusions: Refractory pediatric uveitic glaucoma can be treated successfully by GDD implantation. Further interventions to manage consequences of glaucoma or the underlying disease are common, and visual function is maintained in the majority of cases., (Copyright © 2023. Published by Elsevier Inc.)

Real-time measurement is important in modern dissolution testing to aid in parallel drug characterisation and quality control (QC). The development of a real-time monitoring platform (microfluidic system, a novel eye movement platform with temperature sensors and accelerometers and a concentration probe setup) in conjunction with an in vitro model of the human eye (PK-Eye™) is reported. The importance of surface membrane permeability when modelling the PK-Eye™ was determined with a "pursing model" (a simplified setup of the hyaloid membrane). Parallel microfluidic control of PK-Eye™ models from a single source of pressure was performed with a ratio of 1:6 (pressure source:models) demonstrating scalability and reproducibility of pressure-flow data. Pore size and exposed surface area helped obtain a physiological range of intraocular pressure (IOP) within the models, demonstrating the need to reproduce in vitro dimensions as closely as possible to the real eye. Variation of aqueous humour flow rate throughout the day was demonstrated with a developed circadian rhythm program. Capabilities of different eye movements were programmed and achieved with an in-house eye movement platform. A concentration probe recorded the real-time concentration monitoring of injected albumin-conjugated Alexa Fluor 488 (Alexa albumin), which displayed constant release profiles. These results demonstrate the possibility of real-time monitoring of a pharmaceutical model for preclinical testing of ocular formulations.

Müller glia play very important and diverse roles in retinal homeostasis and disease. Although much is known of the physiological and morphological properties of mammalian Müller glia, there is still the need to further understand the profile of these cells during human retinal development. Using human embryonic stem cell-derived retinal organoids, we investigated the transcriptomic profiles of CD29 + /CD44 + cells isolated from early and late stages of organoid development. Data showed that these cells express classic markers of retinal progenitors and Müller glia, including NFIX, RAX, PAX6, VSX2, HES1, WNT2B, SOX, NR2F1/2, ASCL1 and VIM, as early as days 10-20 after initiation of retinal differentiation. Expression of genes upregulated in CD29 + /CD44 + cells isolated at later stages of organoid development (days 50-90), including NEUROG1, VSX2 and ASCL1 were gradually increased as retinal organoid maturation progressed. Based on the current observations that CD24 + /CD44 + cells share the characteristics of early and late-stage retinal progenitors as well as of mature Müller glia, we propose that these cells constitute a single cell population that upon exposure to developmental cues regulates its gene expression to adapt to functions exerted by Müller glia in the postnatal and mature retina., (© 2023. The Author(s).)

Prcis: β-radiation is a neglected antiscarring therapy with past concerns for safety. This report found it safe and efficacious when used as an adjuvant to trabeculectomy surgery in 101 people (135 eyes) over 20 years., Purpose: β-radiation has been used as an adjunct to prevent scarring in trabeculectomy surgery for many decades. Safety concerns were raised with the use of high doses on the bare sclera. Moorfields Eye Hospital has a large cohort of patients who have received β-radiation therapy. We report a review of the long-term safety and efficacy., Methods: Cases undertaken between August 1992 and August 1996 were reviewed. Those with records available for postoperative review of more than 5 years were included. Failure (reintervention/>21 mm Hg on 2 successive occasions) and any complication previously reported in association with β-radiation were the primary outcomes., Results: In total, 292 operations using β-radiation were recorded and 101 people (135 eyes) with trabeculectomy surgery and postoperative follow-up for over 4.5 years were included. The median follow-up period was 22.5 years. At the final follow-up, 48 (48%) single eyes per person had failed and 20/51 (51%) eyes with primary open angle glaucoma had cataract surgery. Other complications were rare and associated with copathology., Conclusion: In glaucoma patients at risk of scarring and failure after trabeculectomy, as an antiscarring adjuvant, a 750 cGY dose of β-radiation was found to be safe and efficacious in the long term., Competing Interests: Disclosure: I.M. is an advisor and PTK is a board member of Radiance Therapeutics Inc. The remaining authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)