Assessment and In Vivo Scoring of Murine Experimental Autoimmune Uveoretinitis Using Optical Coherence Tomography

Abstract

Despite advances in clinical imaging and grading our understanding of retinal immune responses and their morphological correlates in experimental autoimmune uveoretinitis (EAU), has been hindered by the requirement for post-mortem histology. To date, monitoring changes occurring during EAU disease progression and evaluating the effect of therapeutic intervention in real time has not been possible. We wanted to establish whether optical coherence tomography (OCT) could detect intraretinal changes during inflammation and to determine its utility as a tool for accurate scoring of EAU. EAU was induced in C57BL/6J mice and animals evaluated after 15, 26, 36 and 60 days. At each time-point, contemporaneous Spectralis-OCT scanning, topical endoscopic fundal imaging (TEFI), fundus fluorescein angiography (FFA) and CD45-immunolabelled histology were performed. OCT features were further characterised on retinal flat-mounts using immunohistochemistry and 3D reconstruction. Optic disc swelling and vitreous opacities detected by OCT corresponded to CD45+ cell infiltration on histology. Vasculitis identified by FFA and OCT matched perivascular myeloid and T-cell infiltrates and could be differentiated from unaffected vessels. Evolution of these changes could be followed over time in the same eye. Retinal folds were visible and found to encapsulate mixed populations of activated myeloid cells, T-cells and microglia. Using these features, an OCT-based EAU scoring system was developed, with significant correlation to validated histological (Pearson r2 = 0.6392, P<0.0001, n = 31 eyes) and TEFI based scoring systems (r2 = 0.6784, P<0.0001). OCT distinguishes the fundamental features of murine EAU in vivo, permits dynamic assessment of intraretinal changes and can be used to score disease severity. As a result, it allows tissue synchronisation with subsequent cellular and functional assessment and greater efficiency of animal usage. By relating OCT signals with immunohistochemistry in EAU, our findings offer the opportunity to inform the interpretation of OCT changes in human uveitis.

Evaluation of mouse experimental autoimmune uveoretinitis by spectral domain optical coherence tomography

“…They reported that in the rat EAU model, severe anterior inflammation develops during the active phase, which impedes the acquisition of precise OCT images of individual retinal layers. Recently, the use of SD-OCT to evaluate mouse EAU has been reported by Chen et al 21 and Chu et al 22 These two investigations, together with the present study, establish that the wide range of retinal pathology detected by OCT matches the findings of histological sections and fundus imaging. Chen et al 21 examined the efficacy of SD-OCT in evaluating retinal pathology of EAU in B10RIII mice that differs in severity and time course to the EAU model of B6 mice.…”

“…Chen et al 21 examined the efficacy of SD-OCT in evaluating retinal pathology of EAU in B10RIII mice that differs in severity and time course to the EAU model of B6 mice. However, Chu et al 22 demonstrated the utility of SD-OCT to investigate retinal vasculitis and leukocyte infiltration into the retina during EAU developed in C57BL/6 mice, but changes in the retinal outer layers including granuloma formation was not shown. Furthermore, to distinguish our study from the paper by Chu et al , we have indicated the correlation between OCT grades of EAU developed in B6 mice based on the criteria we have established and conventional clinical and histopathological grades in the present study.…”

Doyne lecture 2016: intraocular health and the many faces of inflammation

“…35 The animal models, such as experimental autoimmune uveoretinitis (EAU), support a role for autoimmunity with clinical-pathological features bearing remarkable similarity to man. 7,8,36,37 The currently held notion is that of a CD4 + T helper cell-driven process and supported in man by the association of sympathetic ophthalmia and Vogt-Koyanagi-Harada disease with specific HLA class II alleles as well as the identification of ocular antigen-responsive T cells in both the peripheral blood and eyes of patients. [38][39][40] When T cells are activated, they assume different functional phenotypes directed through canonical transcription factors 41,42 and characterised by the secretion of signature cytokines.…”

Higher Numbers of Hyperreflective Foci Seen in the Vitreous on Spectral-Domain Optical Coherence Tomographic Images in Eyes with More Severe Diabetic Retinopathy

“…In experimental autoimmune uveoretinitis, the vitreous opacities detected by OCT corresponded to CD45+ cells that had infiltrated into the vitreous and were identified in histological sections [15] . Other groups have shown that similar foci of a size consistent with that expected from inflammatory cells were seen in eyes with posterior-segment inflammatory disease, such as ocular toxoplasmosis, during the active phases [10,16] .…”

“…Studies on an animal model of uveitis and on human eyes with uveitis concluded that the vitreal opacities seen in the OCT images, the same as the hyperreflective foci in the SD-OCT images, were most likely inflammatory cells [14,15] . In experimental autoimmune uveoretinitis, the vitreous opacities detected by OCT corresponded to CD45+ cells that had infiltrated into the vitreous and were identified in histological sections [15] .…”