The 50 most-cited articles in Investigative Ophthalmology & Visual Science, 2023

The choroid is the richly vascular layer of the eye located between the sclera and Bruch's membrane. Early studies in animals, as well as more recent studies in humans, have demonstrated that the choroid is a dynamic, multifunctional structure, with its thickness directly and indirectly subject to modulation by a variety of physiologic and visual stimuli. In this review, the anatomy and function of the choroid are summarized and links between the choroid, eye growth regulation, and myopia, as demonstrated in animal models, discussed. Methods for quantifying choroidal thickness in the human eye and associated challenges are described, the literature examining choroidal changes in response to various visual stimuli and refractive error-related differences are summarized, and the potential implications of the latter for myopia are considered. This review also allowed for the reexamination of the hypothesis that short-term changes in choroidal thickness induced by pharmacologic, optical, or environmental stimuli are predictive of future long-term changes in axial elongation, and the…

Since long before the first approval of gene therapy for retinal disease, ocular gene therapy has captured the hopes of patients, clinicians, and scientists alike. Indeed, the retina provides a unique system for studying and treating ocular diseases, and it holds the distinction as the first tissue targeted by an approved gene therapy for inherited disorders in the United States. There are many methods for addressing genetic diseases in the eyes using a wide range of potential delivery systems and vectors. However, despite the immense progress over the last several decades, both old and new challenges remain, such as the long-term effects of treatments, immunogenicity, targeting, and manufacturing. This review provides a discussion of the history of ocular gene therapy, the various gene therapy approaches, methods to deliver a gene directly to ocular tissues (including both routes of administration and vectors), challenges to ocular gene therapy, the current clinical trial landscape, and future directions of the field.

Purpose: Surveys in 2015 and 2019 identified a high level of eye care practitioner concern/activity about myopia, but the majority still prescribed single vision interventions to young myopes. This research aimed to provide updated information. Methods: A self-administered, internet-based questionnaire was distributed in 13 languages, through professional bodies to eye care practitioners globally. The questions examined awareness of increasing myopia prevalence, perceived efficacy and adoption of available strategies, and reasons for not adopting specific strategies. Results: Of the 3195 respondents, practitioners' concern about the increasing frequency of pediatric myopia in their practices differed between continents (P < 0.001), being significantly higher in Asia (9.0 ± 1.5 of 10) than other continents (range 7.7-8.2; P ≤ 0.001). Overall, combination therapy was perceived by practitioners to be the most effective method of myopia control, followed by orthokeratology and pharmaceutical approaches. The least effective perceived methods were single vision distance undercorrection,…

Myopia typically starts and progresses during childhood, but onset and progression can occur during adulthood. The goals of this review are to summarize published data on myopia onset and progression in young adults, aged 18 to 40 years, to characterize myopia in this age group, to assess what is currently known, and to highlight the gaps in the current understanding. Specifically, the peer-reviewed literature was reviewed to: characterize the timeline and age of stabilization of juvenile-onset myopia; estimate the frequency of adult-onset myopia; evaluate the rate of myopia progression in adults, regardless of age of onset, both during the college years and later; describe the rate of axial elongation in myopic adults; identify risk factors for adult onset and progression; report myopia progression and axial elongation in adults who have undergone refractive surgery; and discuss myopia management and research study design. Adult-onset myopia is common, representing a third or more of all myopia in western populations, but less in East Asia, where onset during childhood is high.…

Myopia is a dynamic and rapidly moving field, with ongoing research providing a better understanding of the etiology leading to novel myopia control strategies. In 2019, the International Myopia Institute (IMI) assembled and published a series of white papers across relevant topics and updated the evidence with a digest in 2021. Here, we summarize findings across key topics from the previous 2 years. Studies in animal models have continued to explore how wavelength and intensity of light influence eye growth and have examined new pharmacologic agents and scleral cross-linking as potential strategies for slowing myopia. In children, the term premyopia is gaining interest with increased attention to early implementation of myopia control. Most studies use the IMI definitions of ≤-0.5 diopters (D) for myopia and ≤-6.0 D for high myopia, although categorization and definitions for structural consequences of high myopia remain an issue. Clinical trials have demonstrated that newer spectacle lens designs incorporating multiple segments, lenslets, or diffusion optics exhibit good efficacy.…

Purpose: The purpose of this study was to evaluate clinical reports of response-loss in patients with neovascular eye diseases, such as neovascular age-related macular degeneration (AMD) and diabetic macular edema (DME), after repeated anti-vascular endothelial growth factor (VEGF) therapy. To assess experimental evidence of associations of other angiogenic growth factors and endothelial glycolytic pathways with the diseases and to propose the underlying mechanisms. Methods: Review of published clinical studies and experimental investigations. Results: Intravitreal injection of anti-VEGF biologic drugs (e.g. bevacizumab, ranibizumab, and aflibercept) is the front-line treatment for neovascular AMD and DME, and acts by halting the progression of excess blood vessel growth and leakage. Despite favorable clinical results, exudation returns in a number of patients after repeated administrations over time. Patients suffering from disease recurrence may have developed an acquired resistance to anti-VEGF therapy. We have analyzed clinical and preclinical findings on changes to angiogenic…

Purpose: To describe nonpathological myopia-related characteristics of the human eye. Methods: Based on histomorphometric and clinical studies, qualitative and quantitative findings associated with myopic axial elongation are presented. Results: In axial myopia, the eye changes from a spherical shape to a prolate ellipsoid, photoreceptor, and retinal pigment epithelium cell density and total retinal thickness decrease, most marked in the retroequatorial region, followed by the equator. The choroid and sclera are thin, most markedly at the posterior pole and least markedly at the ora serrata. The sclera undergoes alterations in fibroblast activity, changes in extracellular matrix content, and remodeling. Bruch's membrane (BM) thickness is unrelated to axial length, although the BM volume increases. In moderate myopia, the BM opening shifts, usually toward the fovea, leading to the BM overhanging into the nasal intrapapillary compartment. Subsequently, the BM is absent in the temporal region (such as parapapillary gamma zone), the optic disc takes on a vertically oval shape, the…

Diabetic macular edema (DME) is a common complication of diabetic retinopathy and is the leading cause of vision loss in diabetic patients. Various factors, such as metabolic disorders and inflammation caused by hyperglycemia, are involved in the occurrence and development of DME, but the specific mechanism is still unclear. Müller cells are a type of macroglial cell unique to the fundus, distributed throughout the retina, and they play a unique role in retinal homeostasis. This article reviews the role of Müller cells in the pathological process of DME and the research progress in the treatment of DME by targeting Müller cells through gene therapy.

Purpose: To determine whether SIRT1 regulates high glucose (HG)-induced inflammation and cataract formation through modulating TXNIP/NLRP3 inflammasome activation in human lens epithelial cells (HLECs) and rat lenses. Methods: HG stress from 25 to 150 mM was imposed on HLECs, with treatments using small interfering RNAs (siRNAs) targeting NLRP3, TXNIP, and SIRT1, as well as a lentiviral vector (LV) for SIRT1. Rat lenses were cultivated with HG media, with or without the addition of NLRP3 inhibitor MCC950 or SIRT1 agonist SRT1720. High mannitol groups were applied as the osmotic controls. Real-time PCR, Western blots, and immunofluorescent staining evaluated the mRNA and protein levels of SIRT1, TXNIP, NLRP3, ASC, and IL-1β. Reactive oxygen species (ROS) generation, cell viability, and death were also assessed. Results: HG stress induced a decline in SIRT1 expression and caused TXNIP/NLRP3 inflammasome activation in a concentration-dependent manner in HLECs, which was not observed in the high mannitol-treated groups. Knocking down NLRP3 or TXNIP inhibited NLRP3 inflammasome-induced…

Purpose: The aim of this systematic review was to investigate the available data on the epidemiology of oculocutaneous albinism (OCA) around the world, and to determine whether a generalizable, worldwide prevalence figure could be proposed. Methods: Extensive literature search strategies were conducted, interrogating PubMed, Scopus, and Web of Science, to locate relevant literature. Ultimately 34 studies reporting original data were included for analysis. Results: Findings showed that most data were outdated, and only 6 of 34 articles (18%) were published after 2010. There were few good studies with sound methodology and large, clearly defined population samples. Only a small proportion of countries worldwide (26/193 [13%]) have produced prevalence figures for OCA. By continent, African studies were disproportionately represented (15/34 [44%]). The highest prevalence rates (range, 1 in 22 to 1 in 1300; mean, 1 in 464) were reported in population isolates. The mean prevalence from four African countries was 1 in 4264 (range, 1 in 1755 to 1 in 7900). Prevalence for three countries in…

D iabetes mellitus and diabetic retinopathy (DR) are diseases that pose global public health challenges on a massive scale.Professor Andrew Boulton, President of the International Diabetes Federation (IDF), recently declared diabetes a "pandemic of unprecedented magnitude," alongside the release of the latest epidemiologic estimates of the global disease burden. 1 The latest report from the IDF estimates that 10.5%, or over 1 in 10, of the world's adult population currently lives with diabetes, which in absolute terms accounts for more than half a billion individuals.2 Projections indicate that this burden is set to rise sharply, to almost 800 million individuals by 2045.Crucially, this disease burden is not restricted to any particular country or region, but has a major impact on all countries around the world, regardless of income and development status.2,3 Diabetes, along with other "noncommunicable diseases" were traditionally considered predominantly afflictions of high-income, developed countries, but this is no longer true, and in absolute terms there are now more individuals…

Purpose: The purpose of this study was to evaluate the epidemiology, etiology, clinical assessment, investigation, management, and visual consequences of high myopia (≤-6 diopters [D]) in infants and young children. Findings: High myopia is rare in pre-school children with a prevalence less than 1%. The etiology of myopia in such children is different than in older children, with a high rate of secondary myopia associated with prematurity or genetic causes. The priority following the diagnosis of high myopia in childhood is to determine whether there is an associated medical diagnosis that may be of greater overall importance to the health of the child through a clinical evaluation that targets the commonest features associated with syndromic forms of myopia. Biometric evaluation (including axial length and corneal curvature) is important to distinguishing axial myopia from refractive myopia associated with abnormal development of the anterior segment. Additional investigation includes ocular imaging, electrophysiological tests, genetic testing, and involvement of pediatricians and…

Purpose: The worldwide incidence of ocular melanoma (OM), uveal melanoma (UM), and conjunctival melanoma has last been reported on 15 years ago. Recently, light iris color and four specific single-nucleotide-polymorphisms (SNPs) have been identified as a UM-risk factor. Furthermore, six iris color predicting SNPs have been discovered (IrisPlex). Interestingly, two of these (rs129138329 and rs12203592) are also UM-risk factors. We collected worldwide incidence data of OM and investigated its correlations with iris color, IrisPlex SNPs, and UM-risk SNPs. Methods: Cases of OM, as defined by the International Classification of Diseases Oncology C69 (eye), 8720/3 to 8790/3 (malignant melanoma), and 8000 to 8005 (malignant neoplasm), between 1988 and 2012, were extracted from the Cancer Incidence in Five Continents. Incidence rates were age-standardized and their trends were analyzed with joinpoint regression and age period cohort modeling. Frequencies for each country of iris color, IrisPlex SNPs, and UM-risk SNPs were collected from the literature. Results: Incidence rates were…

Purpose: Human corneal endothelial cells (hCECs) have been considered unable to regenerate in vivo, resulting in corneal decompensation after significant loss of hCECs. adipose-derived mesenchymal stem cell (ASC)-derived exosomes can regenerate tissues and organs. In this study, we investigated whether ASC-derived exosomes could protect and regenerate CECs. Methods: We performed cell viability and cell-cycle analyses to evaluate the effect of ASC-derived exosomes on the regeneration capacity of cultured hCECs. Transforming growth factor-β (TGF-β) and hydrogen peroxide (H2O2) were used to induce biological stress in CECs. The effect of ASC-derived exosomes on CECs was investigated in vivo. ASC-derived exosomes were introduced into rat CECs using electroporation, and rat corneas were injured using cryoinjury. Next-generation sequencing analysis was performed to compare the differentially expressed microRNAs (miRNAs) between ASC-derived and hCEC-derived exosomes. Results: ASC-derived exosomes induced CEC proliferation and suppressed TGF-β- or H2O2-induced oxidative stress and…

Purpose: Despite the centrality of the retinal pigment epithelium (RPE) in vision and retinopathy our picture of RPE morphology is incomplete. With a volumetric reconstruction of human RPE ultrastructure, we aim to characterize major membranous features including apical processes and their interactions with photoreceptor outer segments, basolateral infoldings, and the distribution of intracellular organelles. Methods: A parafoveal retinal sample was acquired from a 21-year-old male organ donor. With serial block-face scanning electron microscopy, a tissue volume from the inner-outer segment junction to basal RPE was captured. Surface membranes and complete internal ultrastructure of an individual RPE cell were achieved with a combination of manual and automated segmentation methods. Results: In one RPE cell, apical processes constitute 69% of the total cell surface area, through a dense network of over 3000 terminal branches. Single processes contact several photoreceptors. Basolateral infoldings facing the choriocapillaris resemble elongated filopodia and comprise 22% of the cell…

Purpose: Progress toward treatment and prevention of age-related macular degeneration (AMD) requires imaging end points that relate to vision. We investigated choriocapillaris flow signal deficits (FD%) and visual function in eyes of individuals aged ≥60 years, with and without AMD. Methods: One eye of each participant in the baseline visit of the Alabama Study on Early Age-Related Macular Degeneration 2 (ALSTAR2; NCT04112667) was studied. AMD presence and severity was determined using the Age-Related Eye Disease Study (AREDS) grading system. FD% was quantified using macular spectral domain optical coherence tomography angiography (OCTA) scans. Vision tests included rod-mediated dark adaptation (RMDA), best-corrected visual acuity, and contrast sensitivity (photopic and mesopic), and microperimetric light sensitivity (scotopic, mesopic, and photopic). Presence of subretinal drusenoid deposits (SDD) was determined using multimodal imaging. Results: In 410 study eyes of 410 participants (mean [SD] age = 71.7 years [5.9]), FD% was higher in early AMD (mean [SD] = 54.0% [5.5], N = 122)…

Purpose: Little is known about whether sugar intake is a risk factor for myopia, and the influence of glycemic control remains unclear, with inconsistent results reported. This study aimed to clarify this uncertainty by evaluating the link between multiple glycemic traits and myopia. Methods: We employed a two-sample Mendelian randomization (MR) design using summary statistics from independent genome-wide association studies. A total of six glycemic traits, including adiponectin, body mass index, fasting blood glucose, fasting insulin, hemoglobin A1c (HbA1c), and proinsulin levels, were used as exposures, and myopia was used as the outcome. The inverse-variance-weighted (IVW) method was the main applied analytic tool and was complemented with comprehensive sensitivity analyses. Results: Out of the six glycemic traits studied, we found that adiponectin was significantly associated with myopia. The genetically predicted level of adiponectin was consistently negatively associated with myopia incidence: IVW (odds ratio [OR] = 0.990; P = 2.66 × 10-3), MR Egger (OR = 0.983; P = 3.47 ×…

Purpose: To investigate the effect of gamma interferon (IFN-γ) on corneal epithelial pyroptosis in an experimental dry eye (DE) model and explore the underlying molecular mechanisms. Methods: Experimental DE was established in adult wild-type (WT) C57BL/6 mice and Ifng-knockout mice on a C57BL/6 background by subcutaneous injection of scopolamine (1.5 mg/0.3 mL, three times per day) and exposure to desiccating stress. An immortalized human corneal epithelial cell line (HCE-T) was treated with IFN-γ under hyperosmolar conditions. Corneal epithelial defects, tear production, and conjunctival goblet cells were detected by fluorescein sodium staining, the phenol red cotton test, and periodic acid-Schiff staining. The mRNA expression was measured by quantitative real-time PCR. Changes in protein expression were analyzed by Western blotting and immunofluorescence staining. Cell Counting Kit-8 and lactate dehydrogenase assays and in situ TUNEL staining were used to assess cell death. Results: The expression of IFNG and its related genes was increased in the corneas of DE mice, whereas…

Purpose: To explore the mechanism underlying IL-8-induced neutrophil extracellular trap (NET) formation in patients with ocular-active Behçet's disease (BD) and the effect of inhibiting NET formation on the severity of inflammation in experimental autoimmune uveitis (EAU) mice. Methods: The serum extracellular DNA and neutrophil elastase (NE) and IL-8 levels in patients with ocular-active BD, the expression of myeloperoxidase, NE, and histone H3Cit in IL-8-induced neutrophils isolated from healthy controls, and the effects of NETs on HMC3 cells were detected. Female C57BL/6J mice were immunized with IRBP651-670 to induce EAU and EAU mice received intravitreal injection of the CXCR2 (IL-8 receptor) antagonist SB225002 or PBS. The serum levels of extracellular DNA, NE, and keratinocyte-derived chemokine (the mouse ortholog of human IL-8) and expression of myeloperoxidase, NE, and histone H3Cit in mouse retinas were detected. Disease severity was evaluated by clinical and histopathological scores. Results: Serum keratinocyte-derived chemokine expression levels in EAU mice and IL-8…

Purpose: Apigenin is a natural small molecule compound widely present in various vegetables and fruits. Recently, Apigenin was reported to inhibit lipopolysaccharide (LPS)-simulated microglial proinflammatory activation. Considering the important role of microglia in retinal disorders, we wonder whether Apigenin could exert a therapeutic effect on experimental autoimmune uveitis (EAU) through reprogramming retinal microglia to a beneficial subtype. Methods: EAU was induced in C57BL/6J mice by immunization with interphotoreceptor retinoid-binding protein (IRBP)651-670, followed by intraperitoneal administration of Apigenin. Disease severity was assessed based on clinical and pathological scores. In vivo, Western blotting was used to quantify protein levels of classical inflammatory factors, microglial M1/M2 markers and the tight junction protein of the blood-retinal-barrier (BRB). Immunofluorescence was used to determine the Apigenin's efficacy on microglial phenotype. In vitro, Apigenin was added in LPS and IFN-γ stimulated human microglial cell line. Western blotting and Transwell…

Purpose: To investigate the role of peripheral refraction in children's myopization. Methods: This 2-year study included 214 children (8-15 years old). Refraction across the retina (field of view: 60° × 36°) was measured with a custom-made aberrometer every year. Three datasets were established: dataset 1, 214 subjects from baseline to the first-year visit; dataset 2, 152 subjects from baseline to the second-year visit; and dataset 3, 59 initial emmetropes from baseline to the second-year visit. The baseline refraction of different retina regions was correlated with the central myopic shift, and was compared among groups with different levels of myopic shift. Results: In datasets 1 and 2, the refraction distribution across the retina was significantly different among the subjects who were initially emmetropes but not among those who were initially hyperopic or myopic. Refraction in the central vertical retina, especially in the superior retina (r = -0.5, P < 0.001), was significantly correlated with the myopic shift for emmetropes in that subjects with more relative myopia in the…

Purpose: The purpose of this study is to investigate the anti-pyroptotic effect of resveratrol in the context of ischemia-reperfusion (I/R)-induced retinal injury, with a particular focus on Müller glial cells (MGCs) and to elucidate the underlying molecular mechanisms. Methods: The retinal I/R model was constructed in mice and pyroptotic markers were measured at six, 12, 24, 48, and 72 hours after I/R injury to determine the peak of pyroptotic activity. The effects of resveratrol on pyroptosis, inflammasomes, and the activation of MGCs after I/R injury were observed on the retina of mice. Moreover, induction of pyroptosis in rat Müller glial cells (r-MC) via lipopolysaccharide was used to explore the effects of resveratrol on pyroptosis of r-MC in vitro. Results: After the induction of retinal I/R injury in mice, the intricate involvement of pyroptosis in the progressive degeneration of the retina was observed, reaching its zenith at the onset of 24 hours after I/R injury. Resveratrol treatment alleviated I/R injury on the retina, relieved retinal ganglion cells death. In addition,…

Purpose: Transforming growth factor (TGF)-β2 has been widely implicated in human glaucoma pathology. The purpose of this study was to determine the source of TGF-β2 in aqueous humor (AH) and its relationship with intraocular pressure (IOP) in an inherited large animal model of glaucoma. Methods: Sixty-six glaucomatous cats homozygous for LTBP2 mutation, and 42 normal cats were studied. IOP was measured weekly by rebound tonometry. AH was collected by anterior chamber paracentesis from each eye under general anesthesia, and serum samples collected from venous blood concurrently. Concentrations of total, active and latent TGF-β2 in AH and serum samples were measured by quantitative sandwich immunoassay. For comparisons between groups, unpaired t-test or Mann Whitney test were used, with P < 0.05 considered significant. The relationships between TGF-β2 concentrations and IOP values were examined by Pearson's correlation coefficient and generalized estimating equation. Results: IOP and AH TGF-β2 concentrations were significantly higher in glaucomatous than in normal cats. AH TGF-β2…

Purpose: To investigate the association of genetically determined primary open-angle glaucoma (POAG), myopic refractive error (RE), type 2 diabetes (T2D), blood pressure (BP), body mass index (BMI), cigarette smoking, and alcohol consumption with the risk of age-related cataract. Methods: To assess potential causal effects of clinical or behavioral factors on cataract risk, we conducted two-sample Mendelian randomization analyses. Genetic instruments, based on common genetic variants associated with risk factors at genome-wide significance (P < 5 × 10-8), were derived from published genome-wide association studies (GWAS). For age-related cataract, we used GWAS summary statistics from our previous GWAS conducted in the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort (28,092 cataract cases and 50,487 controls; all non-Hispanic whites) or in the UK Biobank (31,852 cataract cases and 428,084 controls; all European-descent individuals). We used the inverse-variance weighted (IVW) method as our primary source of Mendelian randomization estimates and conducted common…

Purpose: The metabolic alterations due to chronic hyperglycemia are well-known to cause diabetes-associated complications. Short-term hyperglycemia has also been shown to cause many acute changes, including hemodynamic alterations and osmotic, oxidative, and inflammatory stress. The present study was designed to investigate whether diabetes-associated hyperglycemia can cause rapid-onset detrimental effects on the tear film, goblet cells, and glycocalyx and can lead to activation of an inflammatory cascade or cellular stress response in the cornea. Methods: Mouse models of type 1 and type 2 diabetes were used. Tear film volume, goblet cell number, and corneal glycocalyx area were measured on days 7, 14, and 28 after the onset of hyperglycemia. Transcriptome analysis was performed to quantify changes in 248 transcripts of genes involved in inflammatory, apoptotic, and stress response pathways. Results: Our data demonstrate that type 1 and type 2 diabetes-associated hyperglycemia caused a significant decrease in the tear film volume, goblet cell number, and corneal glycocalyx area. The…

Purpose: To determine if macular reticular pseudodrusen (RPD) were associated with markers of impaired macular choroidal perfusion, we investigated measurements of macular choriocapillaris (CC) flow deficits (FDs), CC thickness, and mean choroidal thickness (MCT) in eyes with macular RPD compared with normal eyes and eyes with soft drusen. Methods: Eyes with intermediate age-related macular degeneration (iAMD) and normal eyes underwent 6 × 6 mm swept-source optical coherence tomography angiography (SS-OCTA) imaging to diagnose macular RPD, occupying over 25% of the fovea-centered 5 mm diameter circle, and measure outer retinal layer (ORL) thickness, CC FDs, CC thickness, MCT, and choroidal vascularity index (CVI) using previously published strategies within the same fovea-centered 5 mm circle. Results: Ninety eyes were included; 30 normal eyes, 30 eyes with soft drusen, and 30 eyes with macular RPD. The RPD eyes showed higher macular CC FDs than normal eyes (P < 0.001) and soft drusen eyes (P = 0.019). Macular CC thickness was decreased in RPD eyes compared with normal eyes (P <…

Purpose: This study aimed to elucidate the impact of upadacitinib, a Janus kinase 1 (JAK1)-specific inhibitor, on experimental autoimmune uveitis (EAU) and explore its underlying mechanisms. Methods: We utilized single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) to investigate the JAK/signal transducer and activator of transcription (STAT) pathway in peripheral blood mononuclear cells (PBMCs) of 12 patients with Vogt-Koyanagi-Harada (VKH) disease and cervical draining lymph node (CDLN) cells of EAU. After treating EAU with upadacitinib, we analyzed immune cell gene expression and cell-cell communication by integrating scRNA data. Additionally, we applied flow cytometry and western blot to analyze the CDLN cells. Results: The JAK/STAT pathway was found to be upregulated in patients with VKH disease and EAU. Upadacitinib effectively alleviated EAU symptoms, reduced JAK1 protein expression, and suppressed pathogenic CD4 T cell (CD4TC) proliferation and pathogenicity while promoting Treg proliferation. The inhibition…

Abstract Purpose We aimed to assess optic nerve head (ONH) deformations following acute intraocular pressure (IOP) elevations and horizontal eye movements (adduction and abduction) in control eyes, highly myopic (HM) eyes, HM eyes with glaucoma (HMG), and eyes with pathologic myopia alone (PM) or PM with staphyloma (PM+S). Methods We studied 282 eyes, comprising of 99 controls, 51 HM, 35 HMG, 21 PM and 75 PM+S eyes. For each eye, we imaged the ONH using spectral-domain optical coherence tomography (OCT) under the following conditions: (1) primary gaze, (2) 20° adduction, (3) 20° abduction and (4) primary gaze with acute IOP elevation (to ~35 mmHg) achieved through ophthalmodynamometry. For each OCT volume, we automatically segmented the ONH tissues using deep learning. We performed digital volume correlation (DVC) analysis to compute IOP- and gaze-induced ONH displacements and effective strains (i.e. local deformations). All biomechanical quantities were compared across groups. Results Under IOP elevation, we found that HM eyes exhibited significantly lower strains (3.9 ± 2.4 %)…

Purpose: Endoplasmic reticulum (ER) and mitochondrial stress are independently associated with corneal endothelial cell (CEnC) loss in many corneal diseases, including Fuchs' endothelial corneal dystrophy (FECD). However, the role of ER stress in mitochondrial dysfunction contributing to CEnC apoptosis is unknown. The purpose of this study is to explore the crosstalk between ER and mitochondrial stress in CEnC. Methods: Human corneal endothelial cell line (HCEnC-21T) and human corneal endothelial tissues were treated with ER stressor tunicamycin. ER stress-reducing chemical 4-phenyl butyric acid (4-PBA) was used in HCEnC-21T after tunicamycin. Fuchs' corneal endothelial cell line (F35T) was used to determine differential activation of ER stress with respect to HCEnC-21T at the baseline. ER stress, mitochondrial-mediated intrinsic apoptotic, mitochondrial fission, and fusion proteins were determined using immunoblotting and immunohistochemistry. Mitochondrial bioenergetics were assessed by mitochondrial membrane potential (MMP) loss and ATP production at 48 hours after tunicamycin.…

Purpose: Recently, the association between gut microbiota and age-related macular degeneration (AMD) through the gut-retina axis has attracted great interest. However, the causal relationship between them has not been elucidated. Using publicly available genome-wide association study summary statistics, we conducted a two-sample Mendelian randomization (MR) analysis to examine the causal relationship between the gut microbiota and the occurrence of AMD. Methods: The study used a variety of quality control techniques to select instrumental single nucleotide polymorphisms (SNPs) with strong exposure associations. We used a set of SNPs as instrumental variable that were below the genome-wide statistical significance threshold (5 × 10-8). Additionally, a separate group of SNPs below the locus-wide significance level (1 × 10-5) were selected as instrumental variables to ensure a comprehensive conclusion. Inverse variance-weighted (IVW) analysis was the primary technique we used to examine causality in order to confirm the validity of our findings. The MR-Egger intercept test, Cochran's Q…

Purpose: The purpose of this study was to evaluate and explore the determinants of choroidal vascularity and choriocapillaris perfusion in a Chinese population aged 8 to 30 years old. Methods: Three hundred eighty eyes from 380 subjects aged 8 to 30 years were included in this cross-sectional study. Submacular choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), and choriocapillaris flow deficit (CcFD) were estimated using images obtained from optical coherence tomography (OCT). Results: In this population, the mean ChT was 260.4 ± 63.3 µm, TCA was 1.56 ± 0.38 mm2, LA was 0.94 ± 0.25 mm2, and SA was 0.62 ± 0.15 mm2. The mean CVI was 60.25 ± 3.21% and CcFD was 11.95 ± 1.98%. Multivariable analyses showed that higher CVI and LA was associated with older age, thicker ChT, and shorter AL; and lower CcFD was associated with shorter AL. However, the associations were not uniformly rectilinear between CcFD and age. Specifically, CcFD was positively associated with age in subjects ≤19 years old and negatively…

Purpose: Corneal sensory nerves protect the cornea from injury. They are also thought to stimulate limbal stem cells (LSCs) to produce transparent epithelial cells constantly, enabling vision. In other organs, Schwann cells (SCs) associated with tissue-innervating axon terminals mediate tissue regeneration. This study defines the critical role of the corneal axon-ensheathing SCs in homeostatic and regenerative corneal epithelial cell renewal. Methods: SC localization in the cornea was determined by in situ hybridization and immunohistochemistry with SC markers. In vivo SC visualization and/or ablation were performed in mice with inducible corneal SC-specific expression of tdTomato and/or Diphtheria toxin, respectively. The relative locations of SCs and LSCs were observed with immunohistochemical analysis of harvested genetically SC-prelabeled mouse corneas with LSC-specific antibodies. The correlation between cornea-innervating axons and the appearance of SCs was ascertained using corneal denervation in rats. To determine the limbal niche cellular composition and gene expression…

Purpose: Oxidative stress and cellular senescence are risk factors for age-related cataract. Heme oxygenase 1 (HO-1) is a critical antioxidant enzyme and related to autophagy. Here, we investigate the crosstalk among HO-1, oxidative stress, and cellular senescence in mouse lens epithelial cells (LECs). Methods: The gene expression of HO-1, p21, LC3, and p62 was measured in human samples. The protective properties of HO-1 were examined in hydrogen peroxide (H2O2)-damaged LECs. Autophagic flux was examined by Western blot and mRFP-GFP-LC3 assay. Western blotting and lysotracker staining were used to analyze lysosomal function. Flow cytometry was used to detect intracellular reactive oxygen species and analyze cell cycle. Senescence-associated β-galactosidase assay was used to determine cellular senescence. The crosstalk between HO-1 and transcription factor EB (TFEB) was further observed in TFEB-knockdown cells. The TFEB binding site in the promoter region of Hmox1 was predicted by the Jasper website and was confirmed by chromatin immunoprecipitation assay. Results: HO-1 gene…

Purpose: To generate a single-cell RNA-sequencing (scRNA-seq) map and construct cell-cell communication networks of mouse corneas. Methods: C57BL/6 mouse corneas were dissociated to single cells and subjected to scRNA-seq. Cell populations were clustered and annotated for bioinformatic analysis using the R package "Seurat." Differential expression patterns were validated and spatially mapped with whole-mount immunofluorescence staining. Global intercellular signaling networks were constructed using CellChat. Results: Unbiased clustering of scRNA-seq transcriptomes of 14,732 cells from 40 corneas revealed 17 cell clusters of six major cell types: nine epithelial cell, three keratocyte, two corneal endothelial cell, and one each of immune cell, vascular endothelial cell, and fibroblast clusters. The nine epithelial cell subtypes included quiescent limbal stem cells, transit-amplifying cells, and differentiated cells from corneas and two minor conjunctival epithelial clusters. CellChat analysis provided an atlas of the complex intercellular signaling communications among all cell…

Purpose: Strategies for neuroprotection are the main targets of glaucoma research. The neuroprotective properties of SRT2104 administration have been proven in central nervous system degeneration diseases through the activation of nicotinamide adenine dinucleotide-dependent deacetylase-silence information regulator 1 (Sirt1). Here, we investigated whether SRT2104 could protect the retina from ischemia/reperfusion (I/R) injury and the underlying mechanisms. Methods: SRT2104 was intravitreally injected immediately after I/R induction. RNA and protein expression were detected by quantitative real-time PCR and Western blot. Protein expression and distribution were examined by immunofluorescence staining. Retinal structure and function were analyzed by hematoxylin and eosin staining, optical coherence tomography, and electroretinogram. Optic nerve axons were quantified using toluidine blue staining. Cellular apoptosis and senescence were evaluated by TUNEL assay and SA-β-gal staining. Results: The protein expression of Sirt1 decreased dramatically after I/R injury and SRT2104…

Purpose: To distinguish the effects of age and grade on the development of myopia. Methods: Grade 1 (n = 1465, mean age 6.71 ± 0.29 years; 53.5% male) and Grade 2 students (n = 1381, mean age 7.76 ± 0.30 years; 52.5% male) were examined in 2018, with a follow-up examination in 2019. Cycloplegic spherical equivalent (SE) in diopter (D) was measured. Regression discontinuity (RD) analysis was used to assess the causal effects on refraction at each visit. Results: The sample in a grade was divided into three 4-month age blocks according to their birth month, the youngest, middle, and the oldest. At the 2018 visit, within each grade, there were no significant differences in SE among age blocks (all P > 0.05), despite an age range of 12 months. However, comparing the youngest block in Grade 2 to the oldest block in Grade 1, an average age difference of four months, a significant difference in SE was found (0.82 ± 0.69 D vs. 1.05 ± 0.55 D, t-test P < 0.01). Formal RD analysis found a significant casual effect of grade increase on myopic refraction shift (β = -0.32 D; 95% CI, -0.73 to…

Purpose: Uveal melanoma (UM) is a rare disease with a high mortality, and new therapeutic options are being investigated. Preferentially Expressed Antigen in Melanoma (PRAME) is a cancer testis antigen, expressed in the testis, but also in cancers, including uveal melanoma. PRAME is considered a target for immune therapy in several cancers, and PRAME-specific T cell clones have been shown to kill UM cells. Methods: We studied the literature on PRAME expression in hematological and solid malignancies, including UM, and its role as a target for immunotherapy. The distribution of tumor features was compared between PRAME-high and PRAME-low UM in a 64-patient cohort from the Leiden University Medical Center (LUMC) and in the Cancer Genome Atlas (TCGA) cohort of 80 cases and differential gene expression analysis was performed in the LUMC cohort. Results: PRAME is expressed in many malignancies, it is frequently associated with a negative prognosis, and can be the target of T cell receptor (TCR)-transduced T cells, a promising treatment option with high avidity and safety. In UM, PRAME is…

Purpose: The purpose of this study was to investigate if education contributes to the risk of myopia because educational activities typically occur indoors or because of other factors, such as prolonged near viewing. Methods: This was a two-sample Mendelian randomization study. Participants were from the UK Biobank, Avon Longitudinal Study of Parents and Children, and Generation R. Genetic variants associated with years spent in education or time spent outdoors were used as instrumental variables. The main outcome measures were: (1) spherical equivalent refractive error attained by adulthood, and (2) risk of an early age-of-onset of spectacle wear (EAOSW), defined as an age-of-onset of 15 years or below. Results: Time spent outdoors was found to have a small genetic component (heritability 9.8%) that tracked from childhood to adulthood. A polygenic score for time outdoors was associated with children's time outdoors; a polygenic score for years spent in education was inversely associated with children's time outdoors. Accounting for the relationship between time spent outdoors and…

Purpose: To investigate longitudinal changes in axial length (AL) and spherical equivalent (SE) in children and adolescents with high myopia and to explore associated risk factors. Methods: This was a longitudinal, observational cohort study of highly myopic participants (aged 7-17 years) to evaluate the mean rates of change in AL and SE. Mixed effects regression models were used to explore the risk factors. Results: The sample consisted of 293 participants (mean age at the baseline, 13.63 ± 2.66 years; mean AL, 27.03 ± 1.30 mm diopters; mean SE, -8.99 ± 2.30 diopters) who were followed for 7.09 ± 1.64 years. Pathological myopia (PM) was present in 11.95% of the participants at the baseline. Over the follow-up period, the mean AL and SE progression rates were 0.13 mm/y (95% CI, 0.12-0.14) and -0.36 diopters/y (95% CI, -0.39 to -0.34). The multivariate analysis showed that the AL elongation and myopic SE progression decreased significantly after age 11 (β = -0.080, P < 0.001; β = 0.146, P < 0.001), increased with a greater baseline SE (β = -0.006, P = 0.014; β = 0.017, P = 0.005),…

Purpose: To estimate the impact of transition from intermediate to exudative neovascular age-related macular degeneration (AMD) on the inner retina and to assess the relationship of clinical characteristics and optical coherence tomography (OCT) findings with inner retinal changes. Methods: A total of 80 participants (80 eyes) with intermediate AMD at baseline who developed neovascular AMD within 3 months were included in the analysis. OCT scans at follow-up visits (after transition to neovascular AMD) were compared with values at the latest visit with evidence of intermediate AMD to quantify longitudinal inner retinal changes. OCT images were also reviewed for qualitative features reflecting distress of the outer retina or retinal pigment epithelium and for the presence and characteristics of exudation. Results: The parafoveal and perifoveal inner retinal thicknesses were 97.6 ± 12.9 µm and 103.5 ± 16.2 µm, respectively, at baseline, and a significant increase in values was detected at the visit with first evidence of neovascular AMD (parafoveal: 99.0 ± 12.8 µm, P = 0.040;…

Purpose: To evaluate the duration-dependent and synergetic impact of high-intensity light (HL) and unrestricted vision (UnV) on lens-induced myopia (LIM) development in chickens. Methods: Myopia was induced in one eye in chicks (10 groups, n = 126) from day 1 posthatching (D1) until day 8 (D8) using -10 diopter (D) lenses. Fellow eyes remained uncovered as controls. Nine groups were exposed daily to 2, 4, or 6 hours of HL (15,000 lux), UnV (removal of -10 D lens), or both (HL + UnV). One group served as the LIM group without any interventions. Ocular axial length (AL), refractive error, and choroidal thickness were measured on D1, D4, and D8. Outcome measures are expressed as interocular difference (IOD = experimental eye - control eye) ± SEM. Results: By D8, LIM increased AL (0.36 ± 0.04 mm), myopic refraction (-9.02 ± 0.37 D), and choroidal thinning (-90.27 ± 16.44 µm) in the LIM group (all, P < 0.001). Compared to the LIM group, exposure to 2, 4, or 6 hours of HL, UnV, or HL + UnV reduced myopic refraction in a duration-dependent manner, with UnV being more effective than HL (P <…

Purpose: Assessment of the relationship between in vivo foveolar cone density, cone outer segment length (OSL), and foveal retinal thickness (RT). Methods: Foveolar cone density maps covering the central ±300 µm of the retina were derived from adaptive optics scanning laser ophthalmoscopy images. The corresponding maps of foveal cone OSL and RT were derived from high-resolution optical coherence tomography volume scans. Alignment of the two-dimensional maps containing OSL and RT with the cone density map was achieved by placing the location of maximum OSL on the cone density centroid (CDC). Results: Across 10 participants (27 ± 9 years; 6 female), cone density at the CDC was found to be between 147,038 and 215,681 cones/mm². The maximum OSL and minimum RT were found to lie between 31 and 40, and 193 and 226 µm, respectively. A significant correlation was observed between cone density at the CDC and maximum OSL (P = 0.001), as well as the minimal RT (P < 0.05). Across all participants, the best fit for the relationship between normalized cone density and normalized OSL within the…

Purpose: To investigate the impact of diabetic retinopathy (DR) on morphological choriocapillaris (CC) modifications in eyes with type 1 macular neovascularization (MNV) secondary to AMD using optical coherence tomography angiography (OCTA). Methods: Eyes with AMD-related type 1 MNV with and without DR were prospectively included. We performed 3 × 3 mm OCTA scans at two visits: before the loading phase of intravitreal injections of aflibercept (T1) and 1 month after the last injection (T2). OCTA En face flow images of the CC were analyzed for flow deficit percentage (FD%), FD average area and FD number in a 500-µm-wide ring surrounding the dark halo (DH) around type 1 MNV. Results: A total of 65 eyes, out of which 30 eyes had mild DR, were included. In the group without diabetes, there was a gradual reduction in FD% in the CC ring around the DH after antiangiogenic therapy, indicating reperfusion of the CC (P = 0.003). However, in the DR group, there were no significant changes in CC parameters between the two study visits. Specifically, the FD% in the CC ring around the DH did not…

Purpose: Retinal pigment epithelium (RPE) oxidative metabolism is critical for normal retinal function and is often studied in cell culture systems. Here, we show that conventional culture media volumes dramatically impact O2 availability, limiting oxidative metabolism. We suggest optimal conditions to ensure cultured RPE is in a normoxic environment permissive to oxidative metabolism. Methods: We altered the availability of O2 to human primary and induced pluripotent stem cell-derived RPE cultures directly via a hypoxia chamber or indirectly via the amount of medium over cells. We measured oxygen consumption rates (OCRs), glucose consumption, lactate production, 13C6-glucose and 13C5-glutamine flux, hypoxia inducible factor 1α (HIF-1α) stability, intracellular lipid droplets after a lipid challenge, transepithelial electrical resistance, cell morphology, and pigmentation. Results: Medium volumes commonly employed during RPE culture limit diffusion of O2 to cells, triggering hypoxia, activating HIF-1α, limiting OCR, and dramatically altering cell metabolism, with only minor effects…

Purpose: Information on the relationship between meibum lipid composition and severity of meibomian gland dysfunction (MGD) is limited. The purpose of this study was to analyze the molecular components of meibum collected from individuals with no MGD, mild-to-moderate MGD, and severe MGD. Methods: Adults with and without MGD were enrolled in a prospective, multicenter, exploratory clinical trial (ClinicalTrials.gov Identifier: NCT01979887). Molar ratios of cholesteryl ester to wax ester (RCE/WE) and aldehyde to wax ester (Rald/WE) in meibum samples were measured with 1H-NMR spectroscopy. Results were evaluated for participants grouped by MGD disease status and severity (non-MGD, mild-to-moderate MGD, and severe MGD), as defined by maximum meibum quality scores, Schirmer test results, and Subject Ocular Symptom Questionnaire responses. Results: Sixty-nine meibum samples from 69 individuals were included in the analysis: 24 non-MGD, 24 mild-to-moderate MGD, and 21 severe MGD. Mean RCE/WE was 0.29 in non-MGD, 0.14 in mild-to-moderate MGD (P = 0.038 vs. non-MGD, 51% lower), and 0.07 in…

Purpose: Ocular all-trans retinoic acid (atRA) levels are influenced by visual cues, and exogenous atRA has been shown to increase eye size in chickens and guinea pigs. However, it is not clear whether atRA induces myopic axial elongation via scleral changes. Here, we test the hypothesis that exogenous atRA will induce myopia and alter scleral biomechanics in the mouse. Methods: Male C57BL/6J mice were trained to voluntarily ingest atRA + vehicle (1% atRA in sugar, 25 mg/kg) (RA: n = 16 animals) or vehicle only (Ctrl: n = 14 animals). Refractive error (RE) and ocular biometry were measured at baseline and after 1 and 2 weeks of daily atRA treatment. Eyes were used in ex vivo assays to measure scleral biomechanics (unconfined compression: n = 18), total scleral sulfated glycosaminoglycan (sGAG) content (dimethylmethylene blue: n = 23), and specific sGAGs (immunohistochemistry: n = 18). Results: Exogenous atRA caused myopic RE and larger vitreous chamber depth (VCD) to develop by 1 week (RE: -3.7 ± 2.2 diopters [D], P < 0.001; VCD: +20.7 ± 15.1 µm, P < 0.001), becoming more severe by…

Purpose: This study was conducted to investigate potential candidate pathogenic genes in early-onset high myopia (eoHM) in families with eoHM. Methods: Whole-exome sequencing was performed on probands with eoHM to identify potential pathogenic genes. Sanger sequencing was used to verify the identified gene mutations causing eoHM in first-degree relatives of the proband. The identified mutations were screened out by bioinformatics analysis combined with segregation analysis. Results: A total of 131 variant loci, involving 97 genes, were detected in the 30 families. A total of 28 genes (37 variants), which were carried by 24 families, were verified and analyzed by Sanger sequencing. We identified five genes and 10 loci associated with eoHM, which have not been reported in previous research. Hemizygous mutations in COL4A5, NYX, and CACNA1F were detected in this study. Inherited retinal disease-associated genes were found in 76.67% (23/30) of families. Genes that can be expressed in the retina in the Online Mendelian Inheritance in Man database were found in 33.33% (10/30) of families.…

Purpose: Visual physiology and various ocular diseases demonstrate sexual dimorphisms; however, how sex influences metabolism in different eye tissues remains undetermined. This study aims to address common and tissue-specific sex differences in metabolism in the retina, RPE, lens, and brain under fed and fasted conditions. Methods: After ad libitum fed or being deprived of food for 18 hours, mouse eye tissues (retina, RPE/choroid, and lens), brain, and plasma were harvested for targeted metabolomics. The data were analyzed with both partial least squares-discriminant analysis and volcano plot analysis. Results: Among 133 metabolites that cover major metabolic pathways, we found 9 to 45 metabolites that are sex different in different tissues under the fed state and 6 to 18 metabolites under the fasted state. Among these sex-different metabolites, 33 were changed in 2 or more tissues, and 64 were tissue specific. Pantothenic acid, hypotaurine, and 4-hydroxyproline were the top commonly changed metabolites. The lens and the retina had the most tissue-specific, sex-different…

Purpose: Fungal keratitis (FK) is a serious corneal infection with high morbidity. Host immune responses function as a double-edged sword by eradicating fungal pathogens while also causing corneal damage, dictating the severity, progression, and outcome of FK. However, the underlying immunopathogenesis remains elusive. Methods: Time-course transcriptome was performed to illustrate the dynamic immune landscape in a mouse model of FK. Integrated bioinformatic analyses included identification of differentially expressed genes, time series clustering, Gene Ontology enrichment, and inference of infiltrating immune cells. Gene expression was verified by quantitative polymerase chain reaction (qPCR), Western blot, or immunohistochemistry. Results: FK mice exhibited dynamic immune responses with concerted trends with clinical score, transcriptional alteration, and immune cell infiltration score peaking at 3 days post infection (dpi). Disrupted substrate metabolism, broad immune activation, and corneal wound healing occurred sequentially in early, middle, and late stages of FK. Meanwhile,…

Purpose: To determine the relationships of (1) tear osmolarity (TO) levels with the severity of signs and symptoms of dry eye disease (DED) and (2) changes in TO with changes in signs and symptoms. Methods: Patients (N = 405) with moderate to severe DED in the Dry Eye Assessment and Management (DREAM) Study were evaluated at baseline and at six and 12 months. Associations of TO with signs and symptoms were evaluated using Pearson correlation coefficient (r) and regression models. Results: The mean (standard deviation [SD]) TO was 303 (16) mOsm/L at baseline and 303 (18) mOsm/L at both six and 12 months. TO was higher in older patients (306 mOsm/L for ≥70 years vs. 300 mOsm/L for <50 years; P = 0.01) and those with Sjögren's disease (311 vs. 302 mOsm/L; P < 0.0001). TO did not differ between patients randomized to placebo and omega-3 fatty acid supplementation. TO was weakly correlated with conjunctival (r = 0.18; P < 0.001) and corneal staining scores (r = 0.17; P < 0.001), tear film break-up time (r = 0.06; P = 0.03), and Schirmer test score (r = -0.07; P = 0.02) but not with…