Ocular coherence tomography image data of the retinal laminar structure in a mouse model of oxygen-induced retinopathy.

The data presented in this article are related to the research paper entitled "Norrin treatment improves ganglion cell survival in an oxygen-induced model of retinal ischemia" (Dailey et al., 2017) [1] This article describes treatment with the human Norrin protein, an atypical Wnt-protein, to improve the survival of retinal ganglion cells in a murine model of Oxygen-Induced Retinopathy (OIR). That study utilized Optical coherence tomography (OCT) to visualize retinal layers at high resolution in vivo, and to quantify changes to nerve fiber layer thickness. Organization of the laminar structure of other retinal layers in this model in vivo, were not known because of uncertainties regarding potential artifacts during the processing of tissue for traditional histology. The OCT image data provided here shows researchers the retinal laminar structural features that exist in vivo in this popular mouse OIR model. Traditional H&E stained retinal tissue sections are also provided here for comparison.

Norrin treatment improves ganglion cell survival in an oxygen-induced retinopathy model of retinal ischemia.

Treatment of a mouse model of oxygen-induced retinopathy (OIR) with recombinant human Norrin (Norrie Disease Protein, gene: NDP) accelerates regrowth of the microvasculature into central ischemic regions of the neural retina, which are generated after treatment with 75% oxygen. While this reduces the average duration and severity of ischemia overall, we do not know if this accelerated recovery of the microvasculature results in any significant survival of retinal ganglion cells (RGCs). The purpose of this study was to investigate ganglion cell survival with and without the intravitreal injection of Norrin in the murine model of oxygen induced retinopathy (OIR), using two strains of mice: C57BL/6J and Thy1-YFP mice. Intravitreal injections of Norrin or vehicle were done after five days of exposure to 75% oxygen from ages P7 to P12. The C57BL/J mice were followed by Spectral-Domain Optical Coherence Tomography (SD-OCT), and the average nerve fiber layer (NFL) and inner-plexiform layer (IPL) thicknesses were measured at twenty-four locations per retina at P42. Additionally, some C57BL/J retinas were flat mounted and immunostained for the RGC marker, Brn3a, to compare the population density of surviving retinal ganglion cells. Using homozygous Thy1-YFP mice, single intrinsically fluorescent RGCs were imaged in live animals with a Micron-III imaging system at ages P21, 28 and P42. The relative percentage of YFP-fluorescent RGCs with dendritic arbors were compared. At age P42, the NFL was thicker in Norrin-injected OIR eyes, 14.4 µm, compared to Vehicle-injected OIR eyes, 13.3 µm (p = 0.01). In the superior retina, the average thickness of the IPL was greater in Norrin-injected OIR eyes, 37.7 µm, compared to Vehicle-injected OIR eyes, 34.6 µm (p = 0.04). Retinas from Norrin injected OIR mice had significantly more surviving RGCs (p = 0.03) than vehicle-injected mice. Based upon NFL thickness and counts of RGCs, we conclude that Norrin treatment, early in the ischemic phase, increased the relative population density of surviving RGCs in the central retinas of OIR mice.

Effects of anti-VEGF treatment on the recovery of the developing retina following oxygen-induced retinopathy.

PURPOSE: Inhibition of VEGF is widely used in patients to control neovascularization and decrease vascular permeability. To date, the effect of VEGF inhibition has not been evaluated in the developing retina such as that seen in premature infants. The goal of this study was to address the effect of anti-VEGF treatment on retinal development of a mouse model of retinopathy. METHODS: C57BL/6J mice were evaluated using a model of oxygen-induced retinopathy. Test animals were treated at postnatal day (P) 14 with intravitreal injections of the VEGF inhibitor aflibercept (2.5 or 10 µg) in one eye. Control animals were treated with injection of PBS in one eye. The noninjected fellow eyes were used as internal controls. Areas of avascular retina and neovascular tufts in injected (treated) eyes and noninjected fellow eyes were determined at P17, and the difference related to these characteristics was obtained among them. To evaluate the effect of VEGF inhibition on neurogenesis, focal ERG was performed at P21 and P42. Histologic evaluation of the retinal structure was also evaluated at P42. RESULTS: Aflibercept treatment reduced the amount of neovascular tufts but significantly increased the area of avascular retina (low dose and high dose) at P17. The delayed vascular growth corresponded to decreased ERG amplitudes (at P21 and P42) and structural changes in the retinal layers that persisted (at P42), despite vascular recovery. CONCLUSIONS: Inhibition of VEGF in developing eyes has the short-term effect of delayed vascular growth and the long-term effects of decreased function with persistent changes in the neuroretinal structures.