Retina

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Han H, Yang Y, Liu B, Tian J, Dong L, Qi H, Zhu W, Wang J, Lei H. Chalcomoracin prevents vitreous-induced activation of AKT and migration of retinal pigment epithelial cells. J Cell Mol Med 2021;25(19):9102-9111.Abstract
Retinal pigment epithelial (RPE) cells are the major cell type in the epi- or sub-retinal membranes in the pathogenesis of proliferative vitreoretinopathy (PVR), which is a blinding fibrotic eye disease and still short of effective medicine. The purpose of this study is to demonstrate whether Chalocomoracin (CMR), a novel purified compound from fungus-infected mulberry leaves, is able to inhibit vitreous-induced signalling events and cellular responses intrinsic to PVR. Our studies have revealed that the CMR IC50 for ARPE-19 cells is 35.5 μmol/L at 72 hours, and that 5 μmol/L CMR inhibits vitreous-induced Akt activation and p53 suppression; in addition, we have discovered that this chemical effectively blocks vitreous-stimulated proliferation, migration and contraction of ARPE-19 cells, suggesting that CMR is a promising PVR prophylactic.
Han H, Yang Y, Wu Z, Liu B, Dong L, Deng H, Tian J, Lei H. Capilliposide B blocks VEGF-induced angiogenesis in vitro in primary human retinal microvascular endothelial cells. Biomed Pharmacother 2021;133:110999.Abstract
Abnormal angiogenesis is associated with intraocular diseases such as proliferative diabetic retinopathy and neovascular age-related macular degeneration, and current therapies for these eye diseases are not satisfactory. The purpose of this study was to determine whether capilliposide B (CPS-B), a novel oleanane triterpenoid saponin derived from Lysimachia capillipes Hemsl, can inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis signaling events and cellular responses in primary human retinal microvascular endothelial cells (HRECs). Our study revealed that the capilliposide B IC for HRECs was 8.5 μM at 72 h and that 1 μM capilliposide B specifically inhibited VEGF-induced activation of VEGFR2 and its downstream signaling enzymes Akt and Erk. In addition, we discovered that this chemical effectively blocked VEGF-stimulated proliferation, migration and tube formation of the HRECs, suggesting that capilliposide B is a promising prophylactic for angiogenesis-associated diseases such as proliferative diabetic retinopathy.
Han H, Chen N, Huang X, Liu B, Tian J, Lei H. Phosphoinositide 3-kinase δ inactivation prevents vitreous-induced activation of AKT/MDM2/p53 and migration of retinal pigment epithelial cells. J Biol Chem 2019;294(42):15408-15417.Abstract
Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that play a critical role in transmitting signals from cell-surface molecules to intracellular protein effectors. Key PI3Ks include PI3Kα, PI3Kβ, and PI3Kδ, which are regulated by receptors. The signaling pathway comprising the PI3Ks, along with a Ser/Thr kinase (AKT), a proto-oncogene product (mouse double minute (MDM)2), and a tumor suppressor protein (p53), plays an essential role in experimental proliferative vitreoretinopathy (PVR), which is a fibrotic blinding eye disorder. However, which PI3K isoforms are involved in PVR is unknown. A major characteristic of PVR is the formation of epi (or sub)-retinal membranes that consist of extracellular matrix and cells, including retinal pigment epithelium (RPE) cells, glial cells, and macrophages. RPE cells are considered key players in PVR pathogenesis. Using immunoblotting and immunofluorescence analyses, we herein provide the evidence that PI3Kδ is highly expressed in human RPEs when it is primarily expressed in leukocytes. We also found that PI3Kδ inactivation through two approaches, CRISPR/Cas9-mediated depletion and a PI3Kδ-specific inhibitor (idelalisib), not only blocks vitreous-induced activation of AKT and MDM2 but also abrogates a vitreous-stimulated decrease in p53. Furthermore, we demonstrate that PI3Kδ inactivation prevents vitreous-induced proliferation, migration, and contraction of human RPEs. These results suggest that PI3Kδ may represent a potential therapeutic target for RPE-related eye diseases, including PVR.
Han H, Yang Y, Han Z, Wang L, Dong L, Qi H, Liu B, Tian J, Vanhaesebroeck B, Kazlauskas A, Zhang G, Zhang S, Lei H. NFκB-Mediated Expression of Phosphoinositide 3-Kinase δ Is Critical for Mesenchymal Transition in Retinal Pigment Epithelial Cells. Cells 2023;12(2)Abstract
Epithelial mesenchymal transition (EMT) plays a vital role in a variety of human diseases including proliferative vitreoretinopathy (PVR), in which retinal pigment epithelial (RPE) cells play a key part. Transcriptomic analysis showed that the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway was up-regulated in human RPE cells upon treatment with transforming growth factor (TGF)-β2, a multifunctional cytokine associated with clinical PVR. Stimulation of human RPE cells with TGF-β2 induced expression of p110δ (the catalytic subunit of PI3Kδ) and activation of NFκB/p65. CRISPR-Cas9-mediated depletion of p110δ or NFκB/p65 suppressed TGF-β2-induced fibronectin expression and activation of Akt as well as migration of these cells. Intriguingly, abrogating expression of NFκB/p65 also blocked TGF-β2-induced expression of p110δ, and luciferase reporter assay indicated that TGF-β2 induced NFκB/p65 binding to the promoter of the PIK3CD that encodes p110δ. These data reveal that NFκB/p65-mediated expression of PI3Kδ is essential in human RPE cells for TGF-β2-induced EMT, uncovering hindrance of TGF-β2-induced expression of p110δ as a novel approach to inhibit PVR.
Hansen RM, Moskowitz A, Akula JD, Fulton AB. The neural retina in retinopathy of prematurity. Prog Retin Eye Res 2017;56:32-57.Abstract

Retinopathy of prematurity (ROP) is a neurovascular disease that affects prematurely born infants and is known to have significant long term effects on vision. We conducted the studies described herein not only to learn more about vision but also about the pathogenesis of ROP. The coincidence of ROP onset and rapid developmental elongation of the rod photoreceptor outer segments motivated us to consider the role of the rods in this disease. We used noninvasive electroretinographic (ERG), psychophysical, and retinal imaging procedures to study the function and structure of the neurosensory retina. Rod photoreceptor and post-receptor responses are significantly altered years after the preterm days during which ROP is an active disease. The alterations include persistent rod dysfunction, and evidence of compensatory remodeling of the post-receptor retina is found in ERG responses to full-field stimuli and in psychophysical thresholds that probe small retinal regions. In the central retina, both Mild and Severe ROP delay maturation of parafoveal scotopic thresholds and are associated with attenuation of cone mediated multifocal ERG responses, significant thickening of post-receptor retinal laminae, and dysmorphic cone photoreceptors. These results have implications for vision and control of eye growth and refractive development and suggest future research directions. These results also lead to a proposal for noninvasive management using light that may add to the currently invasive therapeutic armamentarium against ROP.

Hanumunthadu D, Lescrauwaet B, Jaffe M, Sadda SV, Wiecek E, Hubschman JP, Patel PJ. Clinical Update on Metamorphopsia: Epidemiology, Diagnosis and Imaging. Curr Eye Res 2021;46(12):1777-1791.Abstract
Purpose: To discuss the pathophysiology of metamorphopsia, its characterisation using retinal imaging and methods of assessment of patient symptoms and visual function.Methods: A literature search of electronic databases was performedResults: Metamorphopsia has commonly been associated with vitreomacular interface disorders (such as epiretinal membrane) and has also regularly been noted in diseases of the retina and choroid, particularly age-related macular degeneration and central serous chorioretinopathy. Developments in optical coherence tomography retinal imaging have enabled improved imaging of the foveal microstructure and have led to the localisation of the pathophysiology of metamorphopsia within the retinal layers of the macula. Alteration of alignment of inner and outer retinal layers at various retinal loci has been identified using multimodal imaging in patients with metamorphopsia in a range of conditions. Although the Amsler Grid assessment of metamorphopsia is a useful clinical indicator, new emerging methods of metamorphopsia assessment with psychophysical tests such as M-CHARTS and preferential hyperacuity perimetry, have been developed.Conclusions: It appears that there is a complex relationship between visual acuity and metamorphopsia symptoms that vary between retinal conditions. Although metamorphopsia has traditionally been challenging to measure in the clinic, advances in technology promise more robust, easy-to-use tests. It is possible that home assessment of metamorphopsia, particularly in conditions such as age-related macular degeneration, may help to guide the need for further clinic evaluation and consideration of treatment.
Harman JC, Pivodic A, Nilsson AK, Boeck M, Yagi H, Neilsen K, Ko M, Yang J, Kinter M, Hellström A, Fu Z. Postnatal hyperglycemia alters amino acid profile in retinas (model of Phase I ROP). iScience 2023;26(10):108021.Abstract
Nutritional deprivation occurring in most preterm infants postnatally can induce hyperglycemia, a significant and independent risk factor for suppressing physiological retinal vascularization (Phase I retinopathy of prematurity (ROP)), leading to compensatory but pathological neovascularization. Amino acid supplementation reduces retinal neovascularization in mice. Little is known about amino acid contribution to Phase I ROP. In mice modeling hyperglycemia-associated Phase I ROP, we found significant changes in retinal amino acids (including most decreased L-leucine, L-isoleucine, and L-valine). Parenteral L-isoleucine suppressed physiological retinal vascularization. In premature infants, severe ROP was associated with a higher mean intake of parenteral versus enteral amino acids in the first two weeks of life after adjustment for treatment group, gestational age at birth, birth weight, and sex. The number of days with parenteral amino acids support independently predicted severe ROP. Further understanding and modulating amino acids may help improve nutritional intervention and prevent Phase I ROP.
Harris JM, Han IC, Sachdeva MM, Zhang AY, Zebardast N. Post-operative intracranial gas migration with optic nerve infiltration and atrophy following retinal detachment repair. Am J Ophthalmol Case Rep 2020;20:100920.Abstract
Purpose: To report a patient with post-operative gas migration into the optic nerve and lateral ventricles after retinal detachment repair. Observations: A 78-year-old pseudophakic man developed a temporal visual field cut in his non-operative, right eye 3 weeks after repair of a recurrent, shallow, macula-involving retinal detachment with perfluoropropane intraocular gas in the left eye. Visual acuity in the right eye measured 20/40, and static perimetry demonstrated temporal visual field loss that respected the vertical midline. Dilated fundus examination of the right eye was unrevealing for any retinal cause, raising suspicion for an intracranial etiology. An urgent CT scan of the brain demonstrated gas in all segments of the left optic nerve and lateral ventricles, consistent with intracranial gas migration along the optic nerve. Given the absence of systemic neurologic symptoms, cautious observation was advised on consultation with neuroradiology and neurosurgery, and follow-up CT scan 1 week later showed resolution of the intracranial gas. By 10-weeks post-operatively, vision returned to 20/20 in the right eye with persistent temporal field loss, and the left eye was hand motions (20/70 pre-operatively) with evidence of optic nerve atrophy and severe cupping. Conclusions: Intracranial gas migration is a rare complication of retinaldetachment repair with intraocular gas and may occur in the setting of structural defects of the optic nerve and high post-operative intraocular pressure. Clinicians should be alert to this rare but serious complication, which can cause neurologic symptoms and result in vision loss in both the operative and non-operative eyes.
Harrison WJ, Bex PJ. Integrating retinotopic features in spatiotopic coordinates. J Neurosci 2014;34(21):7351-60.Abstract
The receptive fields of early visual neurons are anchored in retinotopic coordinates (Hubel and Wiesel, 1962). Eye movements shift these receptive fields and therefore require that different populations of neurons encode an object's constituent features across saccades. Whether feature groupings are preserved across successive fixations or processing starts anew with each fixation has been hotly debated (Melcher and Morrone, 2003; Melcher, 2005, 2010; Knapen et al., 2009; Cavanagh et al., 2010a,b; Morris et al., 2010). Here we show that feature integration initially occurs within retinotopic coordinates, but is then conserved within a spatiotopic coordinate frame independent of where the features fall on the retinas. With human observers, we first found that the relative timing of visual features plays a critical role in determining the spatial area over which features are grouped. We exploited this temporal dependence of feature integration to show that features co-occurring within 45 ms remain grouped across eye movements. Our results thus challenge purely feedforward models of feature integration (Pelli, 2008; Freeman and Simoncelli, 2011) that begin de novo after every eye movement, and implicate the involvement of brain areas beyond early visual cortex. The strong temporal dependence we quantify and its link with trans-saccadic object perception instead suggest that feature integration depends, at least in part, on feedback from higher brain areas (Mumford, 1992; Rao and Ballard, 1999; Di Lollo et al., 2000; Moore and Armstrong, 2003; Stanford et al., 2010).
Haruta M, Arai M, Sueda J, Hirose T, Yamakawa R. Patching retinal breaks with Seprafilm for treating retinal detachments in humans: 9 years of follow-up. Eye (Lond) 2017;31(5):776-780.Abstract
PurposeTo describe the long-term surgical outcomes of four patients treated for retinal detachment using Seprafilm as a novel technique.MethodsRetinal breaks in four eyes were covered with Seprafilm using a transvitreal approach after cataract surgery, pars plana vitrectomy, fluid-air exchange, and laser photocoagulation. Neither long-standing gas nor silicone oil was used. The patients were not instructed to maintain a specific head positioning postoperatively.ResultsSuccessful retinal reattachment was achieved with a single surgery in all four eyes, and none developed proliferative vitreoretinopathy. The mean best-corrected visual acuity preoperatively and 9 years postoperatively were 20/97 and 20/33, respectively. The intraocular pressure increased several days postoperatively that lasted no longer than 2 weeks. Visual field defects either in the inferonasal or inferotemporal quadrant were detected postoperatively. The mean electroretinogram a- and b-wave amplitude ratios of the operated eyes to the fellow eyes were 0.68 and 0.64 preoperatively and 0.87 and 0.92 postoperatively, respectively. The mean corneal endothelial cell density was 2365 cells/mm(2) preoperatively and 2592 cells/mm(2) postoperatively.ConclusionCovering retinal breaks with Seprafilm may promote retinal reattachment without gas tamponade and postoperative head positioning. The visual outcomes 9 years postoperatively showed no apparent adverse effects of intraocular application of Seprafilm.
Heiferman MJ, Rahmani S, Jampol LM, Nesper PL, Skondra D, Kim LA, Fawzi AA. ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY. Retina 2017;37(11):2084-2094.Abstract
PURPOSE: To investigate choroidal involvement in acute posterior multifocal placoid pigment epitheliopathy (APMPPE). METHODS: A retrospective observational case series using multimodal imaging including optical coherence tomography (OCT) angiography. RESULTS: Five patients with APMPPE were included. In most acute lesions, OCT angiography revealed outer retinal and retinal pigment epithelium (RPE) hyperreflective lesions with attenuated OCT signal in the underlying choroid, but careful examination allowed us to identify a single lesion with decreased choriocapillaris flow outside the signal attenuation. Optical coherence tomography angiography obtained after healing of lesions revealed areas of hypointense circular flow voids clustered in groups surrounded by either isointense or hyperintense signal background. Point-by-point evaluation revealed these flow voids did not correspond to areas of RPE thickening or focal pigmentary changes. Larger hypointense lesions were observed and did correlate with pigmentary changes. CONCLUSION: Our case series demonstrates choriocapillaris flow abnormalities in acute APMPPE extending beyond the OCT lesions, and distinct residual vascular abnormalities in healed APMPPE lesions on OCT angiography. Our findings support a primary ischemic insult to the photoreceptors and RPE, but choriocapillaris flow abnormalities could be secondary to (OCT invisible) retinal and RPE involvement. The lack of understanding of the etiology along with the inability to visualize most of the choroid in acute lesions precludes definite conclusions about the true pathogenesis of APMPPE.
Hellgren G, Löfqvist C, Hansen-Pupp I, Gram M, Smith LE, Ley D, Hellström A. Increased postnatal concentrations of pro-inflammatory cytokines are associated with reduced IGF-I levels and retinopathy of prematurity. Growth Horm IGF Res 2018;39:19-24.Abstract
OBJECTIVE: Retinopathy of prematurity (ROP) is a multifactorial disease linked to low insulin-like growth factor (IGF)-I levels and perhaps to postnatal inflammation. Here, we investigated the longitudinal postnatal serum concentrations of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α in relation to IGF-I levels and ROP. DESIGN: The study cohort included 52 infants born before 31 gestational weeks. The infants were screened for ROP and classified as non-ROP (n=33), non-proliferative ROP (stages 1 and 2; n=10), or proliferative ROP (stage 3, all treated for ROP; n=9). Blood samples were collected at birth, 24h after birth, and then weekly until at least 36weeks postmenstrual age (PMA) (i.e., up to 13weeks after birth). Circulating levels of IL-6 and TNF-α were evaluated in relation to circulating IGF-I levels and ROP. RESULTS: IL-6 levels negatively correlated with IGF-I levels between 5 and 8weeks after birth, (p<0.01 to p<0.05). At birth, the IL-6 and TNF-α levels were similar independent of later ROP. Twenty-four hours after birth, both IL-6 and TNF-α levels had increased in infants later treated for ROP (p<0.05). Postnatal, infants treated for ROP had higher IL-6 levels than infants without ROP. CONCLUSIONS: The pro-inflammatory response is associated with low IGF-I levels and the development of ROP.
Hellgren G, Löfqvist C, Hård A-L, Hansen-Pupp I, Gram M, Ley D, Smith LE, Hellström A. Serum concentrations of vascular endothelial growth factor in relation to retinopathy of prematurity. Pediatr Res 2015;Abstract

BACKGROUND: The role of VEGF in the pathogenesis of retinopathy of prematurity (ROP) has been clearly established. However, little is known about temporal changes in circulating VEGF concentrations in the preterm infant. The objective was to determine the longitudinal serum concentrations of VEGF in relation to ROP. METHODS: This study included 52 infants born at <31 weeks gestational age (non-ROP n=33, non-proliferative ROP n=10, treated for ROP n=9). VEGF concentrations were analyzed in blood samples collected at birth, at 3 days postnatal age, and then weekly until at least a gestational age of 35 weeks. RESULTS: VEGF concentrations at birth did not differ between groups, independent of later ROP status. In contrast, VEGF serum concentrations were significantly higher at first detection of ROP in infants who were later treated for ROP compared to infants without ROP. At the time of laser therapy, serum VEGF concentrations did not differ between groups. CONCLUSION: Circulatory concentrations of VEGF, in infants who later developed severe ROP, were elevated at the time when ROP first was detected but not at the time when current treatment most often occurred. This supports the need for further studies of circulating VEGF in relation to the timing of ROP treatment.Pediatric Research (2015); doi:10.1038/pr.2015.181.

Hellström A, Pivodic A, Gränse L, Lundgren P, Sjöbom U, Nilsson AK, Söderling H, Hård A-L, Smith LEH, Löfqvist CA. Association of Docosahexaenoic Acid and Arachidonic Acid Serum Levels With Retinopathy of Prematurity in Preterm Infants. JAMA Netw Open 2021;4(10):e2128771.Abstract
Importance: Supplementing preterm infants with long-chain polyunsaturated fatty acids (LC-PUFA) has been inconsistent in reducing the severity and incidence of retinopathy of prematurity (ROP). Furthermore, few studies have measured the long-term serum lipid levels after supplementation. Objective: To assess whether ROP severity is associated with serum levels of LC-PUFA, especially docosahexaenoic acid (DHA) and arachidonic acid (AA), during the first 28 postnatal days. Design, Setting, and Participants: This cohort study analyzed the Mega Donna Mega study, a randomized clinical trial that provided enteral fatty acid supplementation at 3 neonatal intensive care units in Sweden. Infants included in this cohort study were born at a gestational age of less than 28 weeks between December 20, 2016, and August 6, 2019. Main Outcomes and Measures: Severity of ROP was classified as no ROP, mild or moderate ROP (stage 1-2), or severe ROP (stage 3 and type 1). Serum phospholipid fatty acids were measured through gas chromatography-mass spectrometry. Ordinal logistic regression, with a description of unadjusted odds ratio (OR) as well as gestational age- and birth weight-adjusted ORs and 95% CIs, was used. Areas under the curve were used to calculate mean daily levels of fatty acids during postnatal days 1 to 28. Blood samples were obtained at the postnatal ages of 1, 3, 7, 14, and 28 days. Results: A total of 175 infants were included in analysis. Of these infants, 99 were boys (56.6%); the median (IQR) gestational age was 25 weeks 5 days (24 weeks 3 days to 26 weeks 6 days), and the median (IQR) birth weight was 785 (650-945) grams. A higher DHA proportion was seen in infants with no ROP compared with those with mild or moderate ROP or severe ROP (OR per 0.5-molar percentage increase, 0.49 [95% CI, 0.36-0.68]; gestational age- and birth weight-adjusted OR, 0.66 [95% CI, 0.46-0.93]). The corresponding adjusted OR for AA levels per 1-molar percentage increase was 0.83 (95% CI, 0.66-1.05). The association between DHA levels and ROP severity appeared only in infants with sufficient AA levels, suggesting that a mean daily minimum level of 7.8 to 8.3 molar percentage of AA was necessary for a detectable association between DHA level and less severe ROP. Conclusions and Relevance: This cohort study found that higher mean daily serum levels of DHA during the first 28 postnatal days were associated with less severe ROP even after adjustment for known risk factors, but only in infants with sufficiently high AA levels. Further studies are needed to identify LC-PUFA supplementation strategies that may prevent ROP and other morbidities.
Hicks PM, Haaland B, Feehan M, Crandall AS, Pettey JH, Nuttall E, Self W, Hartnett ME, Bernstein P, Vitale A, Shakoor A, Shulman JP, Sieminski SF, Kim I, Owen LA, Murtaugh MA, Noyes A, Deangelis MM. Systemic Disease and Ocular Comorbidity Analysis of Geographically Isolated Federally Recognized American Indian Tribes of the Intermountain West. J Clin Med 2020;9(11)Abstract
BACKGROUND: The American Indian Navajo and Goshute peoples are underserved patient populations residing in the Four Corners area of the United States and Ibupah, Utah, respectively. METHODS: We conducted a cross-sectional study of epidemiological factors and lipid biomarkers that may be associated with type II diabetes, hypertension and retinal manifestations in tribal and non-tribal members in the study areas (n = 146 participants). We performed multivariate analyses to determine which, if any, risk factors were unique at the tribal level. Fundus photos and epidemiological data through standardized questionnaires were collected. Blood samples were collected to analyze lipid biomarkers. Univariate analyses were conducted and statistically significant factors at < 0.10 were entered into a multivariate regression. RESULTS: Of 51 participants for whom phenotyping was available, from the Four Corners region, 31 had type II diabetes (DM), 26 had hypertension and 6 had diabetic retinopathy (DR). Of the 64 participants from Ibupah with phenotyping available, 20 had diabetes, 19 had hypertension and 6 had DR. Navajo participants were less likely to have any type of retinopathy as compared to Goshute participants (odds ratio (OR) = 0.059; 95% confidence interval (CI) = 0.016-0.223; < 0.001). Associations were found between diabetes and hypertension in both populations. Older age was associated with hypertension in the Four Corners, and the Navajo that reside there on the reservation, but not within the Goshute and Ibupah populations. Combining both the Ibupah, Utah and Four Corners study populations, being American Indian ( = 0.022), residing in the Four Corners ( = 0.027) and having hypertension ( < 0.001) increased the risk of DM. DM ( < 0.001) and age ( = 0.002) were significantly associated with hypertension in both populations examined. When retinopathy was evaluated for both populations combined, hypertension ( = 0.037) and living in Ibupah ( < 0.001) were associated with greater risk of retinopathy. When combining both American Indian populations from the Four Corners and Ibupah, those with hypertension were more likely to have DM ( < 0.001). No lipid biomarkers were found to be significantly associated with any disease state. CONCLUSIONS: We found different comorbid factors with retinal disease outcome between the two tribes that reside within the Intermountain West. This is indicated by the association of tribe and with the type of retinopathy outcome when we combined the populations of American Indians. Overall, the Navajo peoples and the Four Corners had a higher prevalence of chronic disease that included diabetes and hypertension than the Goshutes and Ibupah. To the best of our knowledge, this is the first study to conduct an analysis for disease outcomes exclusively including the Navajo and Goshute tribe of the Intermountain West.
Hikage F, Lennikov A, Mukwaya A, Lachota M, Ida Y, Utheim TP, Chen DF, Huang H, Ohguro H. NF-κB activation in retinal microglia is involved in the inflammatory and neovascularization signaling in laser-induced choroidal neovascularization in mice. Exp Cell Res 2021;403(1):112581.Abstract
PURPOSE: To evaluate Nuclear Factor NF-κB (NF-κB) signaling on microglia activation, migration, and angiogenesis in laser-induced choroidal neovascularization (CNV). METHODS: Nine-week-old C57BL/6 male mice were randomly assigned to IMD-0354 treated or untreated groups (5 mice, 10 eyes per group). CNV was induced with a 532-nm laser. Laser spots (power 250 mW, spot size 100 μm, time of exposure 50 ms) were created in each eye using a slit-lamp delivery system. Selective inhibitor of nuclear factor kappa-B kinase subunit beta (IKK2) inhibitor IMD-0354 (10 μg) was delivered subconjunctivally; vehicle-treated mice were the control. The treatment effect on CNV development was assessed at five days post-CNV induction in vivo in C57BL/6 and Cx3cr1gfp/wt mice by fluorescent angiography, fundus imaging, and ex vivo by retinal flatmounts immunostaining and Western blot analysis of RPE/Choroidal/Scleral complexes (RCSC) lysates. In vitro evaluations of IMD-0354 effects were performed in the BV-2 microglial cell line using lipopolysaccharide (LPS) stimulation. RESULTS: IMD-0354 caused a significant reduction in the fluorescein leakage and size of the laser spot, as well as a reduction in microglial cell migration and suppression of phospho-IκBα, Vascular endothelial growth factor (VEGF-A), and Prostaglandin-endoperoxide synthase 2 (COX-2). In vivo and ex vivo observations demonstrated reduced lesion size in mice, CD68, and Allograft inflammatory factor 1 (IBA-1) positive microglia cells migration to the laser injury site in IMD-0354 treated eyes. The data further corroborate with GFP-positive cells infiltration of the CNV site in Cx3cr1wt/gfp mice. In vitro IMD-0354 (10-25 ng/ml) treatment reduced NF-κB activation, expression of COX-2, caused decreased Actin-F presence and organization, resulting in reduced BV-2 cells migration capacity. CONCLUSION: The present data indicate that NF-κB activation in microglia and it's migration capacity is involved in the development of laser CNV in mice. Its suppression by NF-κB inhibition might be a promising therapeutic strategy for wet AMD.
Hong GJ, Koerner JC, Weinert MC, Stinnett SS, Freedman SF, Wallace DK, Riggins WJ, Gallaher KJ, Prakalapakorn GS. Quantitatively comparing weekly changes in retinal vascular characteristics of eyes eventually treated versus not treated for retinopathy of prematurity. J AAPOS 2021;Abstract
PURPOSE: To quantitatively compare retinal vascular characteristics over time in eyes eventually treated versus not treated for retinopathy of prematurity (ROP), using ROPtool analysis of narrow-field retinal images. METHODS: This longitudinal study used prospectively collected narrow-field retinal images of infants screened for ROP, prior to treatment, if needed. Images were analyzed using a methodology that combines quadrant-level measures from several images of the same eye. For the longitudinal analysis, one examination per postmenstrual age (PMA) was included per eye. We compared the following ROPtool indices and their change per week between eyes eventually treated versus not treated for ROP: tortuosity index (TI), dilation index (DI), sum of adjusted indices (SAI), and tortuosity-weighted plus (TWP). Analysis was performed on three levels: eye (mean value/eye), quadrant (highest quadrant value/eye), and blood vessel (highest blood vessel value/eye). RESULTS: Of 832 examinations (99 infants), 745 images (89.5%) had 3-4 quadrants analyzable by ROPtool. On the eye level, ROPtool indices differed between eyes eventually treated versus not treated at PMA of 33-35 and 37 weeks for TI, SAI, and TWP, and at PMA of 33-34 and 37 weeks for DI (P ≤ 0.0014), and change per week differed between eyes eventually treated versus not treated only for SAI at PMA of 32 weeks (P < 0.001). CONCLUSIONS: Quantitative analysis of retinal vascular characteristics using ROPtool can help predict eventual need for treatment for ROP as early as 32 weeks PMA. ROPtool index values were more useful than change in these indices to predict eyes that would eventually need treatment for ROP.
Hong EH, Shin YU, Bae GH, Choi Y, Ahn SJ, Sobrin L, Hong R, Kim I, Cho H. Nationwide incidence and treatment pattern of retinopathy of prematurity in South Korea using the 2007-2018 national health insurance claims data. Sci Rep 2021;11(1):1451.Abstract
The aim of this study is to investigate the nationwide incidence and treatment pattern of retinopathy of prematurity (ROP) in South Korea. Using the population-based National Health Insurance database (2007-2018), the nationwide incidence of ROP among premature infants with a gestational age (GA) < 37 weeks (GA < 28 weeks, GA28; 28 weeks ≤ GA < 37 weeks; GA28-37) and the percentage of ROP infants who underwent treatment [surgery (vitrectomy, encircling/buckling); retinal ablation (laser photocoagulation, cryotherapy)] were evaluated. We identified 141,964 premature infants, 42,300 of whom had ROP, with a nationwide incidence of 29.8%. The incidence of ROP in GA28 group was 4.3 times higher than in GA28-37 group (63.6% [2240/3522] vs 28.9% [40,060/138,442], p < 0.001). As for the 12-year trends, the incidence of ROP decreased from 39.5% (3308/8366) in 2007 to 23.5% (2943/12,539) in 2018. 3.0% of ROP infants underwent treatment (25.0% in GA28; 1.7% in GA28-37); 0.2% (84/42,300) and 2.9% (1214/42,300) underwent surgery and retinal ablation, respectively. The overall percentage of ROP infants who underwent treatment has decreased from 4.7% in 2007 to 1.8% in 2018. This first Korean nationwide epidemiological study of ROP revealed a decreased incidence of ROP and a decreased percentage of ROP infants undergoing conventional treatment during a 12-year period.
Hoshi S, Okamoto F, Arai M, Hirose T, Sugiura Y, Murakami T, Oshika T. Patching retinal breaks with polyethylene glycol-based synthetic hydrogel sealant for retinal detachment in rabbits. Exp Eye Res 2018;177:117-121.Abstract
The purpose of this study was to evaluate absorbable polyethylene glycol (PEG)-based synthetic hydrogel as a sealant for retinal breaks in rhegmatogenous retinal detachment (RD). A three-port, 25-gauge vitrectomy was performed on nine Dutch pigmented rabbit eyes. Subsequently, RD was induced by creating a retinal break. The retina was then reattached by fluid-air exchange. In six of nine eyes (RD-PEG group), PEG sealant was applied to completely cover the retinal breaks, and then photopolymerized with light; thereafter, intravitreous air was replaced with balanced salt solution (BSS). In the remaining three eyes (RD group), PEG sealant was not applied, but the intravitreous air was replaced with BSS. Ophthalmological examinations and intraocular pressure measurements were conducted preoperatively, and at 1 and 7 days, and 1, 3, and 6 months postoperatively. Histological examinations of the eyes were performed after 6 postoperative months. At surgery, retinal reattachment with PEG sealant was achieved in all eyes in the RD-PEG group. Fundoscopic and optical coherence tomographic examinations revealed that the retina remained attached in all the eyes of the RD-PEG group throughout the 6-month observation period. Histological examination revealed no signs of damage in the retinal layers at the edges of the retinal breaks that were in contact with the sealant. In the RD group, the retinas detached in all eyes within 7 days postoperatively. The PEG sealant closed the retinal breaks and maintained retinal reattachment. Intraocular tamponade was not necessary.
Hoshi S, Okamoto F, Arai M, Hirose T, Sugiura Y, Kaji Y, Oshika T. In Vivo and In Vitro Feasibility Studies of Intraocular Use of Polyethylene Glycol-Based Synthetic Sealant to Close Retinal Breaks in Porcine and Rabbit Eyes. Invest Ophthalmol Vis Sci 2015;56(8):4705-11.Abstract

PURPOSE: Absorbable polyethylene glycol-based synthetic sealant (PEG sealant) polymerizes under xenon illumination and forms a clear, flexible, and firmly adherent hydrogel. The intraocular biocompatibility of PEG sealant and efficacy for closing retinal breaks were evaluated. METHODS: In an in vitro study, retinal detachment with a tear was created in porcine eyecups after vitreous gel removal. Polyethylene glycol-based synthetic sealant was applied to cover the tear and polymerized with a 40-second application of xenon light. Retinal adhesion strength was tested by forcefully squirting balanced salt solution (BSS) onto the retinal tear. Polyethylene glycol-based synthetic sealant was soaked in the BSS, incubated at 37°C, and the pH measured periodically over 72 hours. In an in vivo study, PEG sealant was injected into the vitreous cavity of the left eyes of rabbits. Ophthalmologic examinations were performed and bilateral ERGs were recorded simultaneously before and 28 days after injection. The eyes were enucleated for histological evaluation. RESULTS: Adhesion of PEG sealant to the retina was good in BSS. A forceful squirt of BSS onto the retinal tear covered with PEG sealant did not detach the retina; the retinal tear without PEG sealant detached immediately. The pH of the BSS containing PEG sealant was between 7.2 and 8.2. No inflammatory reaction was observed in the eyes throughout 28 days of follow-up. The ERGs recorded before and after injection showed typical patterns. Histological examinations did not reveal any abnormality or inflammation. CONCLUSIONS: Polyethylene glycol-based synthetic sealant appeared to effectively seal retinal breaks and was not toxic to the eye.

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