Retina Publications

Norsworthy MW, Bei F, Kawaguchi R, Wang Q, Tran NM, Li Y, Brommer B, Zhang Y, Wang C, Sanes JR, Coppola G, He Z. Sox11 Expression Promotes Regeneration of Some Retinal Ganglion Cell Types but Kills Others. Neuron 2017;94(6):1112-1120.e4.Abstract
At least 30 types of retinal ganglion cells (RGCs) send distinct messages through the optic nerve to the brain. Available strategies of promoting axon regeneration act on only some of these types. Here we tested the hypothesis that overexpressing developmentally important transcription factors in adult RGCs could reprogram them to a "youthful" growth-competent state and promote regeneration of other types. From a screen of transcription factors, we identified Sox11 as one that could induce substantial axon regeneration. Transcriptome profiling indicated that Sox11 activates genes involved in cytoskeletal remodeling and axon growth. Remarkably, α-RGCs, which preferentially regenerate following treatments such as Pten deletion, were killed by Sox11 overexpression. Thus, Sox11 promotes regeneration of non-α-RGCs, which are refractory to Pten deletion-induced regeneration. We conclude that Sox11 can reprogram adult RGCs to a growth-competent state, suggesting that different growth-promoting interventions promote regeneration in distinct neuronal types.
Silva PS, Gupta A, Ajlan RS, Schlossman DK, Tolson AM, Cavallerano JD, Aiello LP. Ultrawide field scanning laser ophthalmoscopy imaging of lipemia retinalis. Acta Ophthalmol 2017;Abstract
OBJECTIVE: To describe the characteristic retinal features of lipemia retinalis when using ultrawide field scanning laser ophthalmoscopy. MAIN POINTS: We report a case series of three subjects with ultrawide field retinal images showing cream discoloration of the fundus, light salmon-coloured posterior retinal vessels and greyish pink peripheral vasculature. On green-only imaging, many of the vessels appear light rather than typically dark. CONCLUSION: Lipemia retinalis is readily apparent on ultrawide field imaging and illustrates the alterations that systemic diseases may induce in the posterior and peripheral retinal vasculature. Ultrawide field imaging highlights the disparate vascular appearance of the posterior pole and retinal periphery in this condition.
Veronese C, Maiolo C, Morara M, Armstrong GW, Ciardella AP. Bilateral multiple evanescent white dot syndrome. Int Ophthalmol 2017;Abstract
PURPOSE: To present a single case of bilateral multiple evanescent white dot syndrome (MEWDS). METHODS: A single case with three months of follow-up using imaging studies including fundus color photography (FP), fluorescein angiography (FA), indocyanine green angiography (ICGA), fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT), en face SD-OCT and optical coherence tomography angiography (OCTA) is presented. RESULTS: The patient presented with bilateral MEWDS, ultimately with complete resolution of symptoms. FP revealed foveal granularity and white punctate deep retinal spots, FA found early wreath-like hyperfluorescence, while ICGA showed hypofluorescent dots and spots in the early and late stages. FAF showed areas of hyperautofluorescence. SD-OCT revealed disruption of the ellipsoid zone (EZ) and accumulation of hyperreflective material of variable size and shape. En face SD-OCT demonstrated hyporeflective areas corresponding to areas of EZ disruption as well as hyperreflective dots in the outer nuclear layer. OCTA showed areas of photoreceptor slab black-out corresponding to areas of EZ disruption and light areas of flow void or flow disturbance in the choriocapillaris slab. CONCLUSIONS: This case represents an unusual case of bilateral MEWDS with complete resolution within three months.
Amarnani D, Machuca-Parra AI, Wong LL, Marko CK, Stefater JA, Stryjewski TP, Eliott D, Arboleda-Velasquez JF, Kim LA. Effect of Methotrexate on an In Vitro Patient-Derived Model of Proliferative Vitreoretinopathy. Invest Ophthalmol Vis Sci 2017;58(10):3940-3949.Abstract
Purpose: The purpose of this study was to develop a method for isolating, culturing, and characterizing cells from patient-derived membranes in proliferative vitreoretinopathy (PVR) to be used for drug testing. Methods: PVR membranes were obtained from six patients with grade C PVR. Membrane fragments were analyzed by gross evaluation, fixed for immunohistologic studies to establish cell identity, or digested with collagenase II to obtain single cell suspensions for culture. PVR-derived primary cultures were used to examine the effects of methotrexate (MTX) on proliferation, migration, and cell death. Results: Gross analysis of PVR membranes showed presence of pigmented cells, indicative of retinal pigment epithelial cells. Immunohistochemistry identified cells expressing α-smooth muscle actin, glial fibrillary acidic protein, Bestrophin-1, and F4/80, suggesting the presence of multiple cell types in PVR. Robust PVR primary cultures (C-PVR) were successfully obtained from human membranes, and these cells retained the expression of cell identity markers in culture. C-PVR cultures formed membranes and band-like structures in culture reminiscent of the human condition. MTX significantly reduced the proliferation and band formation of C-PVR, whereas it had no significant effect on cell migration. MTX also induced regulated cell death within C-PVR as assessed by increased expression of caspase-3/7. Conclusions: PVR cells obtained from human membranes can be successfully isolated, cultured, and profiled in vitro. Using these primary cultures, we identified MTX as capable of significantly reducing growth and inducing cell death of PVR cells in vitro.
Vera-Diaz FA, Woods RL, Peli E. Blur Adaptation to Central Retinal Disease. Invest Ophthalmol Vis Sci 2017;58(9):3646-3655.Abstract
Purpose: The long-term, low-resolution vision experienced by individuals affected by retinal disease that causes central vision loss (CVL) may change their perception of blur through adaptation. This study used a short-term adaptation paradigm to evaluate adaptation to blur and sharpness in patients with CVL. Methods: A variation of Webster's procedure was used to measure the point of subjective neutrality (PSN). The image that appeared normal after adaptation to each of seven blur and sharpness levels (PSN) was measured in 12 patients with CVL (20/60 to 20/320) and 5 subjects with normal sight (NS). Patients with CVL used a preferred retinal locus to view the images. Small control studies investigated the effects of long-term and medium-term (1 hour) defocus and diffusive blur. Results: Adaptation was reliably measured in patients with CVL and in the peripheral vision of NS subjects. The shape of adaptation curves was similar in patients with CVL and both central and peripheral vision of NS subjects. No statistical correlations were found between adaptation and age, visual acuity, retinal eccentricity, or contrast sensitivity. Long-term blur experience by a non-CVL myopic participant caused a shift in the adaptation function. Conversely, medium-term adaptation did not cause a shift in the adaptation function. Conclusions: Blur and sharp short-term adaptation occurred in peripheral vision of normal and diseased retinas. In most patients with CVL, neither adaptation nor blur perception was affected by long-term attention to peripheral low-resolution vision. The impact of blur/sharp adaptation on the benefit of image enhancement techniques for patients with CVL is discussed.
Feng L, Ju M, Vivian Lee KY, Mackey A, Evangelista M, Iwata D, Adamson P, Lashkari K, Foxton R, Shima D, Ng YS. A pro-inflammatory function of toll-like receptor 2 in the retinal pigment epithelium as a novel target for reducing choroidal neovascularization in age-related macular degeneration. Am J Pathol 2017;Abstract
Current treatments for choroidal neovascularization, a major cause of blindness for patients with age-related macular degeneration, treat symptoms but not the underlying causes of the disease. Inflammation has been strongly implicated in the pathogenesis of choroidal neovascularization. We examined the inflammatory role of toll-like receptor 2 (TLR2) in age-related macular degeneration. TLR2 was robustly expressed by the retinal pigment epithelium in mouse and human eyes, both normal and with macular degeneration/choroidal neovascularization. Nuclear localization of NF-κB, a major downstream target of TLR2 signaling, was detected in the retinal pigment epithelium of human eyes, particularly in those with advanced stages of age-related macular degeneration. TLR2 antagonism effectively suppressed initiation and growth of spontaneous choroidal neovascularization in a mouse model, and the combination of anti-TLR2 and anti-vascular endothelial growth factor receptor 2 yielded an additive therapeutic effect on both area and number of spontaneous choroidal neovascularization lesions. Lastly, in primary human fetal retinal pigment epithelium cells, ligand binding to TLR2 induced robust expression of pro-inflammatory cytokines, and end products of lipid oxidation had a synergistic effect on TLR2 activation. Our data illustrate a functional role for TLR2 in the pathogenesis of choroidal neovascularization, likely by promoting inflammation of the retinal pigment epithelium, and validate TLR2 as a novel therapeutic target for reducing choroidal neovascularization.
da Silva S, Cepko CL. Fgf8 Expression and Degradation of Retinoic Acid Are Required for Patterning a High-Acuity Area in the Retina. Dev Cell 2017;42(1):68-81.e6.Abstract
Species that are highly reliant on their visual system have a specialized retinal area subserving high-acuity vision, e.g., the fovea in humans. Although of critical importance for our daily activities, little is known about the mechanisms driving the development of retinal high-acuity areas (HAAs). Using the chick as a model, we found a precise and dynamic expression pattern of fibroblast growth factor 8 (Fgf8) in the HAA anlage, which was regulated by enzymes that degrade retinoic acid (RA). Transient manipulation of RA signaling, or reduction of Fgf8 expression, disrupted several features of HAA patterning, including photoreceptor distribution, ganglion cell density, and organization of interneurons. Notably, patterned expression of RA signaling components was also found in humans, suggesting that RA also plays a role in setting up the human fovea.
Ismail EN, Ruberti JW, Malek G. Quick-freeze/deep-etch electron microscopy visualization of the mouse posterior pole. Exp Eye Res 2017;Abstract
The mouse is one of the most commonly used mammalian systems to study human diseases. In particular it has been an invaluable tool to model a multitude of ocular pathologies affecting the posterior pole. The aim of this study was to create a comprehensive map of the ultrastructure of the mouse posterior pole using the quick-freeze/deep-etch method (QFDE). QFDE can produce detailed three-dimensional images of tissue structure and macromolecular moieties, without many of the artifacts introduced by structure-altering post-processing methods necessary to perform conventional transmission electron microscopy (cTEM). A total of 18 eyes from aged C57BL6/J mice were enucleated and the posterior poles were processed, either intact or with the retinal pigment epithelial (RPE) cell layer removed, for imaging by either QFDE or cTEM. QFDE images were correlated with cTEM cross-sections and en face images through the outer retina. Nicely preserved outer retinal architecture was observed with both methods, however, QFDE provided excellent high magnification imaging, with greater detail, of the apical, central, and basal planes of the RPE. Furthermore, key landmarks within Bruch's membrane, choriocapillaris, choroid and sclera were characterized and identified. In this study we developed methods for preparing the outer retina of the mouse for evaluation with QFDE and provide a map of the ultrastructure and cellular composition of the outer posterior pole. This technique should be applicable for morphological evaluation of mouse models, in which detailed visualization of subtle ocular structural changes is needed or in cases where post-processing methods introduce unacceptable artifacts.
Tian B, Al-Moujahed A, Bouzika P, Hu Y, Notomi S, Tsoka P, Miller JW, Lin H, Vavvas DG. Atorvastatin Promotes Phagocytosis and Attenuates Pro-Inflammatory Response in Human Retinal Pigment Epithelial Cells. Sci Rep 2017;7(1):2329.Abstract
Phagocytosis of daily shed photoreceptor outer segments is an important function of the retinal pigment epithelium (RPE) and it is essential for retinal homeostasis. RPE dysfunction, especially impairment of its phagocytic ability, plays an essential role in the pathogenesis of age-related macular degeneration (AMD). Statins, or HMG CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitors, are drugs with multiple properties that have been extensively used to treat hyperlipidemia. However, their effect on RPE cells has not been fully elucidated. Here we report that high dose atorvastatin increased the phagocytic function of ARPE-19 cells, as well as rescue the cells from the phagocytic dysfunction induced by cholesterol crystals and oxidized low-density lipoproteins (ox-LDL), potentially by increasing the cellular membrane fluidity. Similar effects were observed when evaluating two other hydrophobic statins, lovastatin and simvastatin. Furthermore, atorvastatin was able to block the induction of interleukins IL-6 and IL-8 triggered by pathologic stimuli relevant to AMD, such as cholesterol crystals and ox-LDL. Our study shows that statins, a well-tolerated class of drugs with rare serious adverse effects, help preserve the phagocytic function of the RPE while also exhibiting anti-inflammatory properties. Both characteristics make statins a potential effective medication for the prevention and treatment of AMD.
PURPOSE: Fibrovascular contraction and tractional retinal detachment (TRD) are recognized complications associated with the use of anti-vascular endothelial growth factor agents in vasoproliferative vitreoretinopathies. The authors characterize TRDs that developed after intravitreal bevacizumab or ranibizumab therapy for vascularly active retinopathy of prematurity. METHODS: This is an international, multicenter, interventional, retrospective, case series. Thirty-five eyes from 23 infants were included. Inclusion required anti-vascular endothelial growth factor treatment of Type 1 retinopathy of prematurity with progression to TRD. RESULTS: Mean gestational age was 26 ± 2 weeks, and mean birth weight was 873 ± 341 g. Mean postmenstrual age on the day of injection was 35 ± 2 weeks. Retinal detachment was noted a mean of 70 days (median, 34; range, 4-335) after injection. Eleven percent detached within 1 week, 23% within 2 weeks, and 49% within 4 weeks. The highest stage of retinopathy of prematurity noted was 4A in 29%, 4B in 37%, and 5 in 34% of eyes. Time to RD negatively correlated with postmenstrual age at the time of injection (Rho = -0.54; P < 0.01). Three TRD configurations were observed: 1) conventional peripheral elevated ridge or volcano-shaped Stage 5 detachment, 2) midperipheral detachment with tight circumferential vectors, and 3) very posterior detachment with prepapillary contraction. Full or partial reattachment was achieved with surgical intervention in 86% of eyes. CONCLUSION: Progressive atypical TRD may occur after anti-vascular endothelial growth factor injections for retinopathy of prematurity. The configuration of the detachment varies with the extent of primary retinal vascularization present at the time of treatment.
Olivares AM, Han Y, Soto D, Flattery K, Marini J, Molemma N, Haider A, Escher P, Deangelis MM, Haider NB. The Nuclear Hormone Receptor Gene Nr2c1 (Tr2) is a Critical Regulator of Early Retina Cell Patterning. Dev Biol 2017;Abstract
Nuclear hormone receptors play a major role in the development of many tissues. This study uncovers a novel role for testicular receptor 2 (Tr2, Nr2c1) in defining the early phase of retinal development and regulating normal retinal cell patterning and topography. The mammalian retina undergoes an overlapping yet biphasic period of development to generate all seven retinal cell types. We discovered that Nr2c1 expression coincides with development of the early retinal cells. Loss of Nr2c1 causes a severe vision deficit and impacts early, but not late retina cell types. Retinal cone cell topography is disrupted with an increase in displaced amacrine cells. Additionally, genetic background significantly impacts phenotypic outcome of cone photoreceptor cells but not amacrine cells. Chromatin-IP experiments reveal NR2C1 regulates early cell transcription factors that regulate retinal progenitor cells during development, including amacrine (Satb2) and cone photoreceptor regulators thyroid and retinoic acid receptors. This study supports a role for Nr2c1 in defining the biphasic period of retinal development and specifically influencing the early phase of retinal cell fate.