Showing papers in "Investigative Ophthalmology & Visual Science in 2020"

The Complications of Myopia: A Review and Meta-Analysis

Abstract: Purpose To determine the risk between degree of myopia and myopic macular degeneration (MMD), retinal detachment (RD), cataract, open angle glaucoma (OAG), and blindness. Methods A systematic review and meta-analyses of studies published before June 2019 on myopia complications. Odds ratios (OR) per complication and spherical equivalent (SER) degree (low myopia SER -3.00 diopter [D]; moderate myopia SER ≤ -3.00 to > -6.00 D; high myopia SER ≤ -6.00 D) were calculated using fixed and random effects models. Results Low, moderate, and high myopia were all associated with increased risks of MMD (OR, 13.57, 95% confidence interval [CI], 6.18-29.79; OR, 72.74, 95% CI, 33.18-159.48; OR, 845.08, 95% CI, 230.05-3104.34, respectively); RD (OR, 3.15, 95% CI, 1.92-5.17; OR, 8.74, 95% CI, 7.28-10.50; OR, 12.62, 95% CI, 6.65-23.94, respectively); posterior subcapsular cataract (OR, 1.56, 95% CI, 1.32-1.84; OR, 2.55, 95% CI, 1.98-3.28; OR, 4.55, 95% CI, 2.66-7.75, respectively); nuclear cataract (OR, 1.79, 95% CI, 1.08-2.97; OR, 2.39, 95% CI, 1.03-5.55; OR, 2.87, 95% CI, 1.43-5.73, respectively); and OAG (OR, 1.59, 95% CI, 1.33-1.91; OR, 2.92, 95% CI, 1.89-4.52 for low and moderate/high myopia, respectively). The risk of visual impairment was strongly related to longer axial length, higher myopia degree, and age older than 60 years (OR, 1.71, 95% CI, 1.07-2.74; OR, 5.54, 95% CI, 3.12-9.85; and OR, 87.63, 95% CI, 34.50-222.58 for low, moderate, and high myopia in participants aged >60 years, respectively). Conclusions Although high myopia carries the highest risk of complications and visual impairment, low and moderate myopia also have considerable risks. These estimates should alert policy makers and health care professionals to make myopia a priority for prevention and treatment.

Fibrocytes, Wound Healing, and Corneal Fibrosis.

Abstract: Purpose This review highlights the roles of fibrocytes-their origin, markers, regulation and functions-including contributions to corneal wound healing and fibrosis. Methods Literature review. Results Peripheral blood fibroblast-like cells, called fibrocytes, are primarily generated as mature collagen-producing cells in the bone marrow. They are likely derived from the myeloid lineage, although the exact precursor remains unknown. Fibrocytes are identified by a combination of expressed markers, such as simultaneous expression of CD34 or CD45 or CD11b and collagen type I or collagen type III. Fibrocytes migrate into the wound from the blood where they participate in pathogen clearance, tissue regeneration, wound closure and angiogenesis. Transforming growth factor beta 1 (TGF-β1) and adiponectin induce expression of α-smooth muscle actin and extracellular matrix proteins through activation of Smad3 and adenosine monophosphate-activated protein kinase pathways, respectively. Fibrocytes are important contributors to the cornea wound healing response and there are several mechanisms through which fibrocytes contribute to fibrosis in the cornea and other organs, such as their differentiation into myofibroblasts, production of matrix metalloproteinase, secretion of tissue inhibitor of metalloproteinase, and release of TGF-β1. In some tissues, fibrocytes may also contribute to the basement membrane regeneration and to the resolution of fibrosis. Conclusions New methods that block fibrocyte generation, fibrocyte migration, and their differentiation into myofibroblasts, as well as their production of matrix metalloproteinases, tissue inhibitor of metalloproteinase, and TGF-β1, have therapeutic potential to reduce the accumulation of collagens, maintain tissue integrity and retard or prevent the development of fibrosis.

Prognostic Factors Five Years After Enucleation for Uveal Melanoma

Abstract: Destruction of the central endothelium of the rat cornea was produced by mechanical injury, total debridement, or transcorneal freezing. Endothelial repair was then studied using specular microscopy, histological staining, pachymetry, and autoradiographic analysis of the incorporation of tritiated thymidine into nuclear DNA. Following an initial process of cell slide to cover the endothelial defect, extensive cellular division occurred at the margins of the wound, with approximately 45% of cells in the wound area showing incorporation of tritiated thymidine. An intact monolayer of irregularly shaped cells was reestablished by 2-14 days, depending on the wound. These results suggest that the corneal endothelial repair processes in the rat are more analogous to those of the rabbit than to those of the cat or primate.

Measuring the Contributions of Basal Laminar Deposit and Bruch's Membrane in Age-Related Macular Degeneration.

Abstract: Purpose Basal laminar deposit (BLamD) is a consistent finding in age-related macular degeneration (AMD). We quantified BLamD thickness, appearance, and topography in eyes of aged donors with and without AMD and evaluated its relationship to other components of the retinal pigment epithelium-basal lamina/Bruch's membrane (RPE-BL-BrM) complex. Methods Donor eyes (n = 132) were classified as normal (n = 54), early to intermediate AMD (n = 24), geographic atrophy (GA; n = 13), and neovascular AMD (NV; n = 41). In high-resolution histology, we assessed RPE, BLamD, and BrM thicknesses and phenotypes at 3309 predefined locations in the central (foveal and perifovea) and superior (perifoveal) sections. Pre-mortem optical coherence tomography (OCT) imaging of a 90-year-old woman was compared to postmortem histopathology. Results In non-atrophic areas of AMD eyes, the RPE-BLamD is thick (normal = 13.7 µm, early-intermediate = 16.8 µm, GA = 17.4 µm, NV = 18.7 µm), because the BLamD is thick (normal = 0.3 µm, early-intermediate = 5.5 µm, GA = 4.1 µm, NV = 5.3 µm). RPE layer thickness is similar across these stages. Disease-associated variants of BLamD (thick, late, basal mounds) cluster subfoveally. A thick BLamD is visible on OCT as a hyporeflective split in the RPE-BL-BrM complex. BrM is thin (3.5 µm) in NV (normal = 4.2 µm, early to intermediate = 4.4 µm, and GA = 4.2 µm). Conclusions The RPE-BL-BrM complex is thick in AMD, driven by the accumulation and expansion of BLamD rather than expansion of either three-layer BrM, RPE-BL, or RPE. BLamD is clinically appreciable by OCT in some patients as a non-neovascular "split RPE-BL-BrM complex" or "double-layer sign." BLamD may contribute toward the formation and progression of high-risk drusen yet also exhibit protective properties.

Higher-order aberrations and axial elongation in myopic children treated with orthokeratology

Abstract: PURPOSE. This retrospective longitudinal study aimed to examine the relationship between ocular higher-order aberrations (HOA) and axial eye growth in young myopic children undergoing orthokeratology (ortho-k) treatment. METHODS. Axial length and ocular HOA, measured under cycloplegia annually over a 2-year period from the right eyes of myopic children, who previously completed ortho-k clinical trials, were retrieved. Linear mixed model analyses were applied to determine the association between ocular HOA, other known confounding variables (age, sex, and refractive error), and axial eye growth. RESULTS. Data from 103 subjects were analyzed. The root-mean square (RMS) values of total ocular HOA (third to sixth orders combined), spherical (Z0 4 and Z0 6 combined), and comatic (Z− 3 1, Z1 3, Z− 5 1, and Z1 5 combined) aberrations increased by approximately 3, 9, and 2 times, respectively, after 2 years of ortho-k treatment. After adjusting for age, sex, and refractive error, higher RMS values of total HOA and spherical aberrations were associated with both longer axial length and slower axial elongation (all P

Correlation of Aqueous, Vitreous, and Plasma Cytokine Levels in Patients With Proliferative Diabetic Retinopathy.

Abstract: Author(s): Wu, Frances; Phone, Audrey; Lamy, Ricardo; Ma, Dahui; Laotaweerungsawat, Sawarin; Chen, Yi; Zhao, Tong; Ma, Wei; Zhang, Fuyan; Psaras, Catherine; Stewart, Jay M | Abstract: Purpose:To investigate the relationship between proangiogenic and inflammatory cytokines in concurrent vitreous, aqueous, and plasma samples from patients with proliferative diabetic retinopathy (PDR). Methods:Vitreous, aqueous, and plasma samples were analyzed using multiplex immunoassay for 10 PDR-related cytokines (IL-6, IL-8, TNF-α, monocyte chemoattractant protein-1 [MCP-1], macrophage inflammatory protein-1β [MIP-1β], VEGF receptor 1 [Flt-1], placental growth factor [PlGF], VEGF-A, VEGF-C, VEGF-D). A total of 17 patients with PDR and 7 controls were included. The primary outcome was correlation of cytokines in vitreous, aqueous, and plasma. The secondary outcome was the comparison of cytokine levels in controls and diabetics with and without recent anti-VEGF injection. Results:The following factors were elevated in diabetics compared with controls: vitreous IL-6, IL-8, TNF-α, MCP-1, MIP-1β, PlGF, and VEGF-A; and aqueous IL-6, IL-8, PlGF, and VEGF-C (all P l 0.05). Vitreous and aqueous IL-8, PlGF, and VEGF-A were significantly correlated in patients with PDR (all P l 0.05). Plasma cytokines were not correlated with those in vitreous and aqueous (all P g 0.05). Vitreous and aqueous IL-6, IL-8, TNF-α, PlGF, and VEGF-A differed among controls and diabetics with and without recent anti-VEGF injection (all P l 0.05). In one-to-one comparisons, aqueous VEGF-A levels were lower in diabetic patients who had recent anti-VEGF injection compared with those who did not (P = 0.01). Conclusions:In this proof-of-concept study, IL-8, VEGF-A, and PlGF demonstrated a strong correlation in vitreous and aqueous of patients with PDR. The aqueous may serve as a proxy for vitreous for some cytokines involved in PDR. Recent anti-VEGF injections decreased VEGF-A levels in aqueous, but did not significantly affect other cytokines, suggesting a role for other targeted therapies in PDR management.

Choroidal Thickness in Diabetes and Diabetic Retinopathy: A Swept Source OCT Study.

Abstract: Purpose Previous studies on the association between choroidal thickness (CT) and severity of diabetic retinopathy (DR) gave conflicting results. The aim of this study was to evaluate the CT changes in diabetic patients and associated factors in a large sample of Chinese patients with diabetes. Methods Type 2 diabetes mellitus patients without history of ocular treatment were recruited from the community health system in Guangzhou, China. The swept source OCT instrument was used to obtain high-definition retina and choroid images. The diabetic retinopathy (DR) status was graded based on the guidelines of the United Kingdom National Diabetic Eye Screening Programme. Univariate and multivariate linear regression analyses was used to explore the association of CT with DR severity, diabetic macular edema (DME), hemoglobin A1c, and vision function. Results A total of 1347 patients were included in the final analysis. After adjusting for other factors, the patients with stage R3 DR had significantly thinner CT (β = -29.1 µm, 95% CI -53.8 to -4.4, P = 0.021) in comparison in those with R0. After adjusting for other factors, the CTs were thicker than those in R0 patients with difference of 15.6 µm (95% CI 4.3-26.9, P = 0.007) for outer nasal sector, 15.7 µm (95% CI 3.8-25.5, P = 0.008) for outer inferior, and 12.2 µm (95% CI 0.4-24.0, P = 0.042) for inner inferior sector. The presence of DME and hemoglobin A1c levels did not significantly affect average CT. Higher average CT was significantly associated with better best corrected visual acuity, with a -0.02 LogMAR unit per 100 µm increase in average CT (95% CI -0.03 to -0.01, P < 0.001). Conclusions CT increased in the early stage of DR, and further decreased with DR progression. DME was not significantly associated with CT. These findings provide more clues to suggest that choroid alterations play a role in the pathogenesis of DR.

Clinical and Prodromal Ocular Symptoms in Coronavirus Disease: A Systematic Review and Meta-Analysis.

Abstract: Purpose This systematic review aimed to determine currently reported clinical and prodromal ocular symptoms in patients with coronavirus disease 2019 (COVID-19). Methods An online article search was performed in PubMed and EMBASE. Altogether 15 studies (retrospective, prospective, or case studies) involving 1533 patients with COVID-19, reporting on ocular symptoms, and with outcome data available were identified. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines were followed. Study-specific estimates (incidence rates of ocular symptoms in patients with COVID-19) of cases were combined using one-group meta-analysis in a random-effects model. Results Of all included studies, 11.2% (95% confidence interval, 5.5-16.9; 78/1526 cases) reported ocular symptoms. The most common ocular finding was conjunctivitis. Prodromal ocular symptoms occurred in 12.5% (13/104 cases) of patients with COVID-19. Positive real-time polymerase chain reaction results were obtained for 16.7% (10/60 cases) of conjunctival samples and 0% (0/17 cases) of tear samples. Twelve ocular conjunctival swab samples tested positive for SARS-CoV-2. Ten cases were from subjects showing ocular symptoms (16.7%, 10/60 cases), and the remaining two cases were from subjects without ocular manifestation (1.8%, 2/113 cases). Limitations included the short study period, small sample size, findings were limited to the Asian population, only seven articles included ophthalmologic examination details, and there is currently no consensus on COVID-19 management. Conclusions Ocular symptoms may occur in the presymptomatic phase as a prodromal symptom (12.5%, 13/104 cases), suggesting the possibility of viral transmission from the conjunctiva.

Autofluorescent Granules of the Human Retinal Pigment Epithelium: Phenotypes, Intracellular Distribution, and Age-Related Topography.

Abstract: Purpose The human retinal pigment epithelium (RPE) accumulates granules significant for autofluorescence imaging. Knowledge of intracellular accumulation and distribution is limited. Using high-resolution microscopy techniques, we determined the total number of granules per cell, intracellular distribution, and changes related to retinal topography and age. Methods RPE cells from the fovea, perifovea, and near-periphery of 15 human RPE flat mounts were imaged using structured illumination microscopy (SIM) and confocal fluorescence microscopy in young (≤51 years, n = 8) and older (>80 years, n = 7) donors. Using custom FIJI plugins, granules were marked with computer assistance, classified based on morphological and autofluorescence properties, and analyzed with regard to intracellular distribution, total number per cell, and granule density. Results A total of 193,096 granules in 450 RPE cell bodies were analyzed. Based on autofluorescence properties, size, and composition, the RPE granules exhibited nine different phenotypes (lipofuscin, two; melanolipofuscin, five; melanosomes, two), distinguishable by SIM. Overall, lipofuscin (low at the fovea but increases with eccentricity and age) and melanolipofuscin (equally distributed at all three locations with no age-related changes) were the major granule types. Melanosomes were under-represented due to suboptimal visualization of apical processes in flat mounts. Conclusions Low lipofuscin and high melanolipofuscin content within foveal RPE cell bodies and abundant lipofuscin at the perifovea suggest a different genesis, plausibly related to the population of overlying photoreceptors (fovea, cones only; perifovea, highest rod density). This systematic analysis provides further insight into RPE cell and granule physiology and links granule load to cell autofluorescence, providing a subcellular basis for the interpretation of clinical fundus autofluorescence.

Increased Choroidal Blood Perfusion Can Inhibit Form Deprivation Myopia in Guinea Pigs.

Abstract: Purpose In guinea pigs, choroidal thickness (ChT) and choroidal blood perfusion (ChBP) simultaneously decrease in experimental myopia, and both increase during recovery. However, the causal relationship between ChBP and myopia requires further investigation. In this study, we examined the changes of ChBP with three different antimyopia treatments. We also actively increased ChBP to examine the direct effect on myopia development in guinea pigs. Methods Experiment 1: Guinea pigs wore occluders on the right eye for two weeks to induce form-deprivation myopia (FDM). Simultaneously they received daily antimyopia treatments: peribulbar injections of atropine or apomorphine or exposure to intense light. Experiment 2: The vasodilator prazosin was injected daily into the form-deprivation eyes to increase ChBP during the two-week induction of FDM. Other FDM animals received appropriate control treatments. Changes in refraction, axial length, ChBP, ChT, and hypoxia-labeled pimonidazole adducts in the sclera were measured. Results The antimyopia treatments atropine, apomorphine, and intense light all significantly inhibited myopia development and the decrease in ChBP. The treatments also reduced scleral hypoxia, as indicated by the decrease in hypoxic signals. Furthermore, actively increasing ChBP with prazosin inhibited the progression of myopia, as well as the increase in axial length and scleral hypoxia. Conclusions Our data strongly indicate that increased ChBP attenuates scleral hypoxia, and thereby inhibits the development of myopia. Thus ChBP may be a promising target for myopia retardation. As such, it can serve as an immediate predictor of myopia development as well as a long-term marker of it.

The Spatial Frequency Content of Urban and Indoor Environments as a Potential Risk Factor for Myopia Development.

Abstract: Purpose To examine the hypothesis that the spatial frequency spectra of urban and indoor environments differ from the natural environment in ways that may promote the development of myopia. Methods A total of 814 images were analyzed from three datasets; University of California Berkeley (UCB), University of Texas (UT), and Botswana (UPenn). Images were processed in Matlab (Mathworks Inc) to map the camera color characteristics to human cone sensitivities. From the photopic luminance images generated, two-dimensional spatial frequency (SF) spectra were calculated and converted to one-dimensional spectra by rotational averaging. The spatial filtering profile of a 0.4 Bangerter foil, which has been shown to induce myopia experimentally, was also determined. Results The SF slope for natural scenes followed the recognized 1/fα relationship with mean slopes of -1.08, -0.90, and -1.04 for the UCB, UT and UPenn image sets, respectively. Indoor scenes had a significantly steeper slope (-1.48, UCB; -1.52, UT; P < 0.0001). Urban environments showed an intermediate slope (-1.29, UCB; -1.22, UT) that was significantly different from the slopes derived from the natural scenes (P < 0.0001). The change in SF content between natural outdoor scenes and indoors was comparable to that induced by a 0.4 Bangerter foil, which reduced the SF slope of a natural scene from -0.88 to -1.47. Conclusions Compared to natural outdoor images, man-made outdoor and indoor environments have spatial frequency characteristics similar to those known to induce form-deprivation myopia in animal models. The spatial properties of the man-made environment may be one of the missing drivers of the human myopia epidemic.

The Microbiome of the Meibum and Ocular Surface in Healthy Subjects

Abstract: Purpose The purpose of this study was to investigate the microbiome in the meibum, conjunctival sac, and eyelid skin in young and elderly healthy subjects, and analyze the effect that age, sex, and region have on microbiome composition. Methods This study involved 36 healthy subjects (young-age subjects: 9 men/9 women, age range: 20-35 years; elderly age subjects: 9 men/9 women, age range: 60-70 years). In all subjects, lower-eyelid meibum, lower conjunctival sac, and lower-eyelid skin specimens were collected from one eye, and then stored at -20°C. Taxonomic composition of the microbiome was obtained via 16S rRNA gene sequencing, and then analyzed. Results The meibum microbiome showed a high α-diversity (within-community diversity), particularly in the young subjects. However, in approximately 30% of the elderly subjects, a low-diversity microbiome dominated by Corynebacterium sp. or Neisseriaceae was observed. In the young subjects, the microbiome of the meibum resembled that of the conjunctival-sac, yet in the elderly subjects, the microbiome of the conjunctival-sac became more similar to that of the eyelid skin. The eyelid-skin microbiome was relatively simple, and was typically dominated by Propionibacterium acnes in the young subjects, or by Corynebacterium sp. or Neisseriaceae in the elderly subjects. In both age groups, no significant difference was seen between the men and women in regard to the meibum, conjunctival-sac, and eyelid-skin microbiome. Conclusions Our findings confirmed that the meibum of healthy adult-age subjects harbors highly diverse microbiota, and revealed that the meibum microbiome, especially the decrease of its diversity, alters with aging and may affect the homeostasis of the ocular surface.

TNFα-Mediated Priming of Mesenchymal Stem Cells Enhances Their Neuroprotective Effect on Retinal Ganglion Cells.

Abstract: Purpose To determine whether priming of bone marrow mesenchymal stem cells (MSCs) by signals from injured retina, particularly tumor necrosis factor α (TNFα), increase their exosomes' neuroprotective efficacy on retinal ganglion cells (RGCs). Methods MSCs were primed with retinal cell culture conditioned medium, with or without the TNFα blocker etanercept or TNFα prior to isolation of exosomes. MSC conditioned medium or exosomes were added to rat retinal cultures or human stem cell-derived retinal ganglion cell (hRGC) cultures, and RGC neuroprotective effects were quantified. Luminex assays were used to compare primed versus unprimed exosomes. Results MSC conditioned medium and exosomes exerted a significant neuroprotective effect on injured rat and hRGC. This effect was significantly increased after MSCs were primed with retinal conditioned medium or TNFα. Blocking of TNFα signaling with etanercept prevented priming-induced RGC neuroprotective efficacy. Priming increased PEDF and VEGF-AA exosomal abundance. Conclusions MSC exosomes promote RGC survival not just in rodent retinal cultures but also with hRGC. Their efficacy can be further enhanced through TNFα priming with the mechanism of action potentially mediated, at least in part, through increased levels of PEDF and VEGF-AA.

Microvascular Changes in the Choriocapillaris of Diabetic Patients Without Retinopathy Investigated by Swept-Source OCT Angiography

Abstract: Purpose To investigate the microvascular changes in macular retina and choriocapillaris (CC) in diabetic eyes without retinopathy using swept-source optical coherence tomography angiography (SS-OCTA). Methods A commercial SS-OCTA system was used to collect 6 × 6-mm macular scans from patients. Three depth-resolved retinal slabs and a CC slab were segmented by a validated semiautomated algorithm. Retinal vessel area density, vessel skeleton density, and nonperfusion area were calculated on segmented retinal slabs. Foveal avascular zone was automatically measured based on en face image of the whole retinal layer. For CC quantification, the percentage of flow deficits (FD%) and the flow deficit (FD) sizes were measured. Results Sixteen eyes from 16 diabetic patients without clinically detectable retinopathy and 16 eyes from 16 age-matched nondiabetic controls were included. There was no significant difference between the two groups in all retinal vessel quantitative parameters (all P > 0.05). However, the mean FD% and mean FD sizes were significantly increased in CC in the central 1.0-mm disk (P = 0.011 and P = 0.017, respectively), the central 1.5-mm rim (P = 0.003 and P = 0.009, respectively), the central 2.5-mm rim (P = 0.018 and P = 0.020, respectively), and the entire 5.0-mm disk (P = 0.009 and P = 0.008, respectively) in diabetic eyes compared with controls. Conclusions CC perfusion in the macula is decreased in diabetic patients without retinopathy as compared to age-matched normal controls. Decreased CC perfusion in the macula may be an early indicator of otherwise clinically undetectable diabetic vasculopathy.

Complement Activation Levels Are Related to Disease Stage in AMD

Abstract: Purpose: To study the levels of complement activation in different disease stages of AMD and the influence of genetic polymorphisms in complement genes. Methods: We included 797 patients with AMD and 945 controls from the European Genetic Database. Patients were grouped into five AMD stages: early AMD, intermediate AMD, central geographic atrophy, active choroidal neovascularization or inactive choroidal neovascularization. Differences in complement activation, as defined by the systemic C3d/C3 ratio, between AMD stages were evaluated using general linear modeling. In addition, we evaluated the influence of 18 genetic AMD polymorphisms in complement genes and their effect on complement activation. Differences in complement activation between stages were evaluated stratifying by complement associated haplotypes. Results: Complement activation levels differed significantly between AMD disease stages. As compared with controls, the C3d/C3 ratio was higher in patients with intermediate AMD (P < 0.001) and central geographic atrophy (P = 0.001). Two polymorphisms in CFH (rs10922109 and rs570618) and one in CFB (rs116503776) were significantly associated with complement activation. The association between AMD disease stage and complement activation was more pronounced in patients with haplotypes associated with the highest complement activation. Conclusions: In general, consecutive AMD disease stages showed increasing levels of complement activation, especially in individuals with a genetic burden in complement genes. These findings contribute to the discussion on the pathogenesis of AMD in relation to complement activation and might suggest refinement in patient selection and the optimum window of treatment with complement inhibitors. Prospective studies are needed to confirm these results.

Short-Wavelength (Violet) Light Protects Mice From Myopia Through Cone Signaling.

Abstract: Purpose Exposure to short-wavelength light influences refractive development and inhibits myopic development in many animal models. Retinal mechanisms underlying this response remain unknown. This study used a mouse model of lens-induced myopia to evaluate the effect of different wavelength light on refractive development and dopamine levels in the retina. A possible retinal pathway is tested using a mutant mouse with dysfunctional cones. Methods Wild-type C57BL/6J (WT) and ALS/LtJ/Gnat2cpfl3 (Gnat2-/-) mice were exposed to one of three different light conditions beginning at postnatal day 28: broad-spectrum "white" (420-680 nm), medium wavelength "green" (525 ± 40 nm), and short wavelength "violet" (400 ± 20 nm). One-half of the mice received hyperopic lens defocus. All mice were exposed to the light for 4 weeks; animals were measured weekly for refractive error and axial parameters. Retinal dopamine and the dopamine metabolite 3,4-dihydroxyphenylacetic acid were measured by HPLC. Results In WT mice, short-wavelength violet light induced hyperopia and violet light inhibited lens-induced myopia when compared with mice exposed to white light. Hyperopia could be attributed to shallower vitreous chambers in WT animals. There were no changes in the levels of dopamine or its metabolite. In Gnat2-/- mice, violet light did not induce hyperopia or inhibit lens-induced myopia. Conclusions These findings show that short-wavelength light slows refractive eye growth, producing hyperopic responses in mice and inhibiting lens-induced myopia. The lack of inhibition in mice with dysfunctional cones suggests that cone signaling plays a role in the hyperopic response to short-wavelength (violet) light.

Activating Transcription Factor 3 (ATF3) Protects Retinal Ganglion Cells and Promotes Functional Preservation After Optic Nerve Crush.

Abstract: Purpose To investigate the possible role of activating transcription factor 3 (ATF3) in retinal ganglion cell (RGC) neuroprotection and optic nerve regeneration after optic nerve crush (ONC). Methods Overexpression of proteins of interest (ATF3, phosphatase and tensin homolog [PTEN], placental alkaline phosphatase, green fluorescent protein) in the retina was achieved by intravitreal injections of recombinant adenovirus-associated viruses (rAAVs) expressing corresponding proteins. The number of RGCs and αRGCs was evaluated by immunostaining retinal sections and whole-mount retinas with antibodies against RNA binding protein with multiple splicing (RBPMS) and osteopontin, respectively. Axonal regeneration was assessed via fluorophore-coupled cholera toxin subunit B labeling. RGC function was evaluated by recording positive scotopic threshold response. Results The level of ATF3 is preferentially elevated in osteopontin+/RBPMS+ αRGCs following ONC. Overexpression of ATF3 by intravitreal injection of rAAV 2 weeks before ONC promoted RBPMS+ RGC survival and preserved RGC function as assessed by positive scotopic threshold response recordings 2 weeks after ONC. However, overexpression of ATF3 and simultaneous downregulation of PTEN, a negative regulator of the mTOR pathway, combined with ONC, only moderately promoted short distance RGC axon regeneration (200 μm from the lesion site) but did not provide additional RGC neuroprotection compared with PTEN downregulation alone. Conclusions These results reveal a neuroprotective effect of ATF3 in the retina following injury and identify ATF3 as a promising agent for potential treatments of optic neuropathies.

Deep Retinal Capillary Plexus Decreasing Correlated With the Outer Retinal Layer Alteration and Visual Acuity Impairment in Pathological Myopia.

Abstract: Purpose The purpose of this study was to measure alterations of inner retinal microvascular density and outer retinal sublayer thicknesses in pathological myopia, and to correlate the measured parameters with best corrected visual acuity (BCVA). Methods Optical coherence tomography (OCT) and OCT angiography (OCTA) images of 21 control, 48 simple high myopia, and 22 pathological myopia eyes were analyzed to quantify the thicknesses of the outer retinal sublayers and the density of the inner retinal microvascular network that includes the superficial retinal capillary plexus (SRCP) and deep retinal capillary plexus (DRCP). Retinal sublayer thicknesses and microvascular densities were compared among the three groups, and correlations of sublayer thicknesses and microvascular densities with BCVA were determined. Results In pathological myopia, density of the DRCP, thicknesses of myoid and ellipsoid zone (MEZ), interdigitation zone and retinal pigment epithelium/Bruch complex (IZ + RPE), and choroid were lower than in simple high myopia (P 0.05). Simple linear regression showed that axial length, female, thicknesses of outer plexiform layer (OPL), MEZ, IZ + RPE, choroid, and density of the SRCP and DRCP were correlated with BCVA. In multiple regression analysis, worse BCVA was associated only with thinner MEZ, thinner choroid, and decreased DRCP (P < 0.05). Conclusions Alteration of inner retinal microvascular density and outer retinal sublayer thicknesses occurred in pathological myopia, especially decreased DRCP and thinner MEZ, which were significantly associated with worse BCVA.

Imaging of Macrophage-Like Cells in Living Human Retina Using Clinical OCT.

Abstract: Purpose To image retinal macrophages at the vitreoretinal interface in the living human retina using a clinical optical coherence tomography (OCT) device Methods Eighteen healthy controls and three patients with retinopathies were imaged using a clinical spectral-domain OCT In controls, 10 sequential scans were collected at three different locations: (1) ∼9 degrees temporal to the fovea, (2) the macula, and (3) the optic nerve head (ONH) Intervisit repeatability was evaluated by imaging the temporal retina twice on the same day and 3 days later Only 10 scans at the temporal retina were obtained from each patient A 3-µm OCT reflectance (OCT-R) slab located above the inner limiting membrane (ILM) surface was averaged Results In controls, ramified macrophage-like cells with regular spatial separation were visualized in the temporal and ONH OCT-R images; however, cell structures were not resolvable at the macula Interim changes in cell position suggestive of cell translocation were observed between images collected on the same day and those collected 3 days later There was considerable variation in cell density and nearest-neighbor distance (NND) across controls Mean ± SD cell densities measured at the temporal and ONH were 78 ± 23 cells/mm2 and 57 ± 16 cells/mm2, respectively Similarly, mean ± SD NNDs measured at the temporal and ONH were 743 ± 133 µm and 933 ± 200 µm, respectively Nonuniform spatial distribution and altered morphology of the cells were identified in patients with retinopathies Conclusions Our findings showed regular spatial separation and ramified morphology of macrophage-like cells on the ILM surface with cell translocation over time in controls Their distribution and morphology suggest an origin of macrophage-like cells such as microglia or hyalocytes

Prostaglandin F2α Agonists Negatively Modulate the Size of 3D Organoids from Primary Human Orbital Fibroblasts.

Abstract: Purpose To elucidate the molecular etiology of deepening of the upper eyelid sulcus (DUES) induced by prostaglandin (PG) analogs, a three-dimensional (3D) tissue culture system was employed using human orbital fibroblasts (HOFs). Methods During adipogenesis, changes in HOF 3D organoid sizes, as well as their lipids stained by BODIPY and expression of the extracellular matrix (ECM) by immunolabeling and/or quantitative PCR, were studied in the presence or absence of either 100-nM bimatoprost acid or 100-nM prostaglandin F2α. Results The size of the 3D organoids increased remarkably during adipogenesis, but such increases were significantly inhibited by the presence of PG analogs. Staining intensities by BODIPY and mRNA expression of peroxisome proliferator-activated receptor gamma were significantly increased upon adipogenesis but were not influenced by the presence of PG analogs. Unique changes in ECM expression observed with or without adipogenic differentiation were significantly modified by the presence of PG analogs. Conclusions Our present study indicates that PG analogs have the potential to modulate the ECM network within HOF 3D organoids. Thus, a 3D tissue culture system may be a suitable strategy for understanding the disease etiology of DUES.

Genomewide association study of acute anterior uveitis identifies new susceptibility loci

Abstract: PURPOSE. Acute anterior uveitis (AAU) is a common intraocular inflammatory disease. AAU occurs in 30% to 50% of patients with ankylosing spondylitis (AS), and both conditions are strongly associated with human leukocyte antigen (HLA)-B 27 , implying a shared etiology. This study aims to apply genomewide association study (GWAS) to characterize the genetic associations of AAU and their relationship to the genetics of AS.METHODS. We undertook the GWAS analyses in 2752 patients with AS with AAU (cases) and 3836 patients with AS without AAU (controls). There were 7,436,415 single-nucleotide polymorphisms (SNPs) available alter SNP microarray genotyping, imputation, and quality-control filtering.RESULTS. We identified one locus associated with AAU at genomewide significance: rs9378248 (P = 2.69 x 10(-8), odds ratio [OR] = 0.78), lying close to HLA-B. Suggestive association was observed at 11 additional loci, including previously reported AS loci ERAP1 (rs27529, P = 2.19 x 10(-7), OR = 1.22) and NOS2 (rs2274894, P = 8.22 x 10(-7), OR = 0.83). Multiple novel suggestive associations were also identified, including MERTK (rsl0171979, P = 2.56 x 10(-6), OR = 1.20), KIFAP3 (rs508063, P = 5.64 x 10(-7), OR = 1.20), CLCN7 (rs67412457, P = 1.33 x 10(-6), OR = 1.25), ACAA2 (rs9947182, P = 9.70 x 10(-7), OR = 1.37), and 5 intergenic loci. The SNP-based heritability is approximately 0.5 for AS alone, and is much higher (approximately 0.7) for AS with AAU. Consistent with the high heritability, a genomewide polygenic risk score shows strong power in identifying individuals at high risk of either AS with AAU or AS alone.CONCLUSIONS. We report here the first GWAS for AAU and identify new susceptibility loci. Our findings confirm the strong overlap in etiopathogenesis of AAU with AS, and also provide new insights into the genetic basis of AAU.

Changes in Retinal Vessel and Retinal Layer Thickness After Vitrectomy in Retinal Detachment via Swept-Source OCT Angiography

Abstract: Purpose To compare postvitrectomy retinal and choroidal vessel density (VD) and retinal layer thickness between eyes with macula-off and macula-on rhegmatogenous retinal detachment (RRD) using swept-source optical coherence tomography (SS-OCT) and optical coherence tomography angiography (OCTA) and to identify OCTA factors associated with visual outcomes.

Ambient Air Pollution Associations with Retinal Morphology in the UK Biobank.

Abstract: Purpose: Because air pollution has been linked to glaucoma and AMD, we characterized the relationship between pollution and retinal structure. / Methods: We examined data from 51,710 UK Biobank participants aged 40 to 69 years old. Ambient air pollution measures included particulates and nitrogen oxides. SD-OCT imaging measured seven retinal layers: retinal nerve fiber layer, ganglion cell–inner plexiform layer, inner nuclear layer, outer plexiform layer + outer nuclear layer, photoreceptor inner segments, photoreceptor outer segments, and RPE. Multivariable regression was used to evaluate associations between pollutants (per interquartile range increase) and retinal thickness, adjusting for age, sex, race, Townsend deprivation index, body mass index, smoking status, and refractive error. / Results: Participants exposed to greater particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) and higher nitrogen oxides were more likely to have thicker retinal nerve fiber layer (β = 0.28 µm; 95% CI, 0.22–0.34; P = 3.3 × 10−20 and β = 0.09 µm; 95% CI, 0.04–0.14; P = 2.4 × 10−4, respectively), and thinner ganglion cell–inner plexiform layer, inner nuclear layer, and outer plexiform layer + outer nuclear layer thicknesses (P < 0.001). Participants resident in areas of higher levels of PM2.5 absorbance were more likely to have thinner retinal nerve fiber layer, inner nuclear layer, and outer plexiform layer + outer nuclear layers (β = –0.16 [95% CI, –0.22 to –0.10; P = 5.7 × 10−8]; β = –0.09 [95% CI, –0.12 to –0.06; P = 2.2 × 10−12]; and β = –0.12 [95% CI, –0.19 to –0.05; P = 8.3 × 10−4], respectively). / Conclusions: Greater exposure to PM2.5, PM2.5 absorbance, and nitrogen oxides were all associated with apparently adverse retinal structural features.

Vascular Density of Deep, Intermediate and Superficial Vascular Plexuses Are Differentially Affected by Diabetic Retinopathy Severity.

Abstract: Purpose The purpose of this study was to evaluate differences in optical coherence tomography angiography (OCTA) metrics in the superficial (SCP), intermediate (ICP), and deep (DCP) vascular plexuses across diabetic retinopathy (DR) severity levels. Methods This was a cross sectional observational retrospective chart review study. Eligible patients with diabetes who underwent same day RTVue XR Avanti OCTA, spectral-domain optical coherence tomography (SD-OCT), and 200-degree Optos ultrawide field color imaging. SCP, ICP, and DCP vessel density (VD) and vessel length density (VLD) were assessed using 3-D projection artifact removal software (PAROCTA) software. Results Of 396 eyes (237 patients), 16.1% had no DR, 26.9% mild nonproliferative DR (NPDR), 21.1% moderate NPDR, 12.1% severe NPDR, 10.1% proliferative DR (PDR) without panretinal photocoagulation (PRP), and 13.4% PDR with PRP. When comparing mild NPDR to no DR eyes, ICP and DCP VD and VLD were significantly lower, but there was no difference for SCP metrics. In eyes with more severe DR, there were significant differences in SCP VD and VLD between DR severity levels (mild versus moderate NPDR: VD 35.45 ± 3.31 vs. 34.14 ± 3.38, P = 0.008 and VLD 17.59 ± 1.83 vs. 16.80 ± 1.83, P = 0.003; moderate versus severe NPDR: VLD 16.80 ± 1.83 vs. 15.79 ± 1.84, P = 0.019), but no significant differences in ICP or DCP. Conclusions Although VD of each of the three individual layers decreases with increasing DR severity, DR severity has a substantially different effect on OCTA parameters within each layer. Vascular changes in eyes with no to early DR were present primarily in the deeper vascular layers, whereas in eyes with advanced DR the opposite was observed. This study highlights the effects of ICP and the importance of assessing SCP and DCP changes independently across each DR severity level.

Diabetic Neuropathy Is Characterized by Progressive Corneal Nerve Fiber Loss in the Central and Inferior Whorl Regions

Abstract: Purpose We hypothesized that longitudinal changes in corneal nerve morphology would differ between the central cornea and inferior whorl in relation to other measures of diabetic neuropathy. Methods Thirty patients with diabetes (age: 54.08 ± 15.86, duration: 23.95 ± 14.2, HbA1c: 7.51 ± 1.37) and 19 age-matched healthy controls (age: 49.47 ± 13.25) underwent assessment of neuropathy disability score (NDS), vibration perception threshold (VPT), cold (CPT) and warm (WPT) perception thresholds, peroneal motor nerve conduction velocity (PMNCV), corneal nerve fiber density (CNFD), branch density (CNBD), fiber length (CNFL), inferior whorl length (IWL), and the average of CNFL and IWL (ANFL) at baseline and after 1 to 8 years. Results In patients with diabetes, between baseline and follow-up, there was a significant reduction in CNBD (57.72 ± 30.08 vs. 44.04 ± 23.69; P = 0.02), CNFL (21.77 ± 5.19 vs. 15.65 ± 4.7; P < 0.0001), IWL (24.69 ± 8.67 vs. 14.23 ± 6.13; P < 0.0001), ANFL (23.26 ± 5.53 vs. 15.09 ± 4.48; P < 0.0001), and WPT (43.56 ± 4.43 vs. 40.78 ± 4.93; P = 0.01), and an increase in VPT (12.9 ± 8.96 vs. 13.78 ± 8.99; P = 0.02). There was no significant change in CNFD (27.12 ± 8.2 vs. 25.43 ± 7.11; P = 0.2), NDS (3.38 ± 3.35 vs. 2.61 ± 2.8; P = 0.08), CPT (17.7 ± 10.59 vs. 22.45 ± 9.23; P = 0.06), or PMNCV (42.4 ± 4.21 vs. 42.16 ± 6.3; P = 0.2). Conclusions There is evidence of corneal nerve loss in patients with diabetes, particularly at the inferior whorl during follow-up.

IRT5 Probiotics Changes Immune Modulatory Protein Expression in the Extraorbital Lacrimal Glands of an Autoimmune Dry Eye Mouse Model.

Abstract: Purpose While the association between the gut microbiome and the immune system has been studied in autoimmune disorders, little is known about ocular disease. Previously we reported that IRT5, a mixture of five probiotic strains, could suppress autoimmune dry eye. In this study, we investigated the mechanism by which IRT5 performs its immunomodulatory function in a mouse model of autoimmune dry eye. Methods NOD.B10.H2b mice were used as an autoimmune dry eye model. Either IRT5 or PBS was gavaged orally for 3 weeks, with or without 5 days of antibiotic pretreatment. The effects on clinical features, extraorbital lacrimal gland and spleen proteins, and fecal microbiota were analyzed. Results The ocular staining score was lower, and tear secretion was higher, in the IRT5-treated groups than in the PBS-treated groups. After IRT5 treatment, the downregulated lacrimal gland proteins were enriched in the biological processes of defense response and immune system process. The relative abundances of 33 operational taxonomic units were higher, and 53 were lower, in the feces of the IRT5-treated groups than in those of the PBS-treated groups. IRT5 administration without antibiotic pretreatment also showed immunomodulatory functions with increases in the Lactobacillus helveticus group and Lactobacillus hamsteri. Additional proteomic assays revealed a decrease of proteins related to antigen-presenting processes in the CD11b+ and CD11c+ cells of spleen in the IRT5-treated groups. Conclusions Changes in the gut microbiome after IRT5 treatment improved clinical manifestations in the autoimmune dry eye model via the downregulation of antigen-presenting processes in immune networks.

Anterior Sclera Undergoes Thinning with Increasing Degree of Myopia

Abstract: Purpose Considering that ocular expansion is associated with scleral thinning, this study investigated variation in scleral thickness (anterior scleral thickness [AST] and posterior scleral thickness [PST]) in different meridians across emmetropes and a wide range of myopes. Methods A total of 95 participants (mean age, 24 ± 4 years) including emmetropes (spherical equivalent refractive error, ±0.75 diopters [D]; n = 20) and myopes (-1.00 to -27.25 D; n = 75) underwent ocular imaging with swept-source optical coherence tomography. All the images were analyzed using semiautomated custom-designed software to determine scleral thickness in 1-mm intervals. AST was estimated from limbus to 5 mm (n = 95), and PST from fovea to 5 mm (n = 25; high myopes only) along the horizontal and vertical meridian. Results The median spherical equivalent refractive error and axial length were -4.25 D (IQR, -12.50 to -1.00 D) and 25 mm (IQR, 23.72-28.35 mm), respectively. The anterior sclera was thinnest in the superior and thickest in the inferior region (475.3 ± 19.0 vs. 605.9 ± 18.6 µm; P 0.05). The mean subfoveal PST for the subset of high myopes was 251.7 ± 12.0 µm which was thinner than mean AST along all the meridians by more than 45%. The averaged scleral thickness peripheral to fovea (1-5 mm) was similar along different meridians (P > 0.05). Conclusions The relative significant thinning of the anterior sclera along the inferior meridian with increasing degree of myopia compared with the other three meridians indicates the potential role of AST, especially in the inferior meridian, to act as a marker for myopia progression.

The Role of Autophagy in the Innate Immune Response to Fungal Keratitis Caused by Aspergillus fumigatus Infection.

Abstract: Purpose To determine the role of autophagy in the innate immune response to fungal keratitis (FK) caused by Aspergillus fumigatus infection. Methods Corneal samples obtained from patients and mice with FK were visualized via transmission electron microscopy (TEM). Autophagy-related proteins LC3B-II, Beclin-1, LAMP-1, and p62 in A. fumigatus-infected corneas of C57BL/6 mice were tested by Western blot. After treatment with autophagy inhibitors 3-methyladenine (3-MA), chloroquine (CQ), or inducer rapamycin, autophagy-related proteins were detected by Western blot. Corneas were photographed with slit lamp microscopy and pathological changes were observed by hematoxylin and eosin staining. Polymorphonuclear neutrophilic leukocytes (PMNs) were assessed by immunofluorescent staining and observed under TEM. The levels of CXCL-1, IL-1β, HMGB1, IL-18, TNF-α, and IL-10 were tested by reverse transcription polymerase chain reaction and Western blot. The quantification of fungal loads was detected and photographed. Results The accumulation of autophagosomes in corneas of patients and mice with FK was observed with TEM. The expression of LC3B-II, Beclin-1, and LAMP-1 was elevated in corneas after fungal infection, whereas p62 was reduced. Treatment with 3-MA or CQ upregulated clinical scores, pathological changes, and the expression of CXCL-1, IL-1β, HMGB1, IL-18, and TNF-α except IL-10. The morphology of PMNs was changed and PMN recruitment was increased in mice corneas treated with 3-MA or CQ, whereas rapamycin reduced the inflammatory response to keratitis. These results were statistically significant. Conclusions A. fumigatus infection increases the expression of autophagy in corneas. Autophagy plays an anti-inflammatory role in the innate immune response to A. fumigatus keratitis.

Retina Organoid Transplants Develop Photoreceptors and Improve Visual Function in RCS Rats With RPE Dysfunction.

Abstract: Author(s): Lin, Bin; McLelland, Bryce T; Aramant, Robert B; Thomas, Biju B; Nistor, Gabriel; Keirstead, Hans S; Seiler, Magdalene J | Abstract: PurposeTo study if human embryonic stem cell-derived photoreceptors could survive and function without the support of retinal pigment epithelium (RPE) after transplantation into Royal College of Surgeons rats, a rat model of retinal degeneration caused by RPE dysfunction.MethodsCSC14 human embryonic stem cells were differentiated into primordial eye structures called retinal organoids. Retinal organoids were analyzed by quantitative PCR and immunofluorescence and compared with human fetal retina. Retinal organoid sheets (30-70 day of differentiation) were transplanted into immunodeficient RCS rats, aged 44 to 56 days. The development of transplant organoids in vivo in relation to the host was examined by optical coherence tomography. Visual function was assessed by optokinetic testing, electroretinogram, and superior colliculus electrophysiologic recording. Cryostat sections were analyzed for various retinal, synaptic, and donor markers.ResultsRetinal organoids showed similar gene expression to human fetal retina transplanted rats demonstrated significant improvement in visual function compared with RCS nonsurgery and sham surgery controls by ERGs at 2 months after surgery (but not later), optokinetic testing (up to 6 months after surgery) and electrophysiologic superior colliculus recordings (6-8 months after surgery). The transplanted organoids survived more than 7 months; developed photoreceptors with inner and outer segments, and other retinal cells; and were well-integrated within the host.ConclusionsThis study, to our knowledge, is the first to show that transplanted photoreceptors survive and function even with host's dysfunctional RPE. Our findings suggest that transplantation of organoid sheets from stem cells may be a promising approach/therapeutic for blinding diseases.

Retinal Neurovascular Impairment in Patients with Essential Hypertension: An Optical Coherence Tomography Angiography Study.

Abstract: Purpose To investigate retinal neurovascular structural changes in patients with essential hypertension. Methods This observational cross-sectional study consisted of 199 right eyes from 169 nondiabetic essential hypertensive patients, divided into groups as follows: group A, 113 patients with hypertensive retinopathy (HTNR); group B, 56 patients without HTNR; and a control group of 30 healthy subjects. Peripapillary retinal nerve fiber layer (RNFL), radial peripapillary segmented (RPC), ganglion cell-inner plexiform layer (GC-IPL), and superficial (SVP) and deep (DVP) vascular plexus density at the macula (6 × 6 mm2) were measured by optical coherence tomography angiography (OCTA). Results DVP density was significantly reduced in groups A and B compared to the control group (group A DVP, P = 0.001; group B DVP P = 0.002). GC-IPL, RNFL thickness, and RPC and SVP density in group A were significantly decreased compared to the control group or group B (all P < 0.05). In hypertensive patients, GC-IPL and RNFL thickness were negatively correlated with severity of HTNR (GC-IPL, r = -0.331, P < 0.001; RNFL, r = -0.583, P < 0.001) and level of home blood pressure monitoring (HBPM) (GC-IPL, r = -0.160, P = 0.050; RNFL, r = -0.282, P = 0.001) and were positively correlated with SVP (GC-IPL, r = 0.267, P = 0.002; RNFL, r = 0.361, P < 0.001) and RPC density (GC-IPL, r = 0.298, P < 0.001; RNFL, r = 0.663, P < 0.001). Among subjects with grade 2 or 3 retinopathy, the superior RNFL was significantly thinner in patients with high HBPM level than in those with normal HBPM level (grade 2, P = 0.016; grade 3, P = 0.006). Conclusions Reduction of retinal vessel density and RNFL thickness is observed in patients with HTNR and is inversely associated with level of HBPM.