Figure 1.
Comparison of OCT images with fundus and histological findings of the retina in EAU.
EAU was induced in B10RIII mice by immunization with 8 ug IRBP in CFA. A, Normal retinal layers in a healthy eye assessed by cross-sectional OCT image in comparison with histological section of murine retina. Note ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer nuclear layer (ONL), IS/OS of photoreceptor layer (PRL), retinal pigment epithelium (RPE) and choroid (CH). B (a–f), Comparison of cross-sectional OCT images of retina with histological sections of the same eyes at different stages of EAU: a–b, early onset of EAU (13 days post immunization). Note largely normal retinal morphology on OCT and histology, but a moderate degree of cellular infiltrates is apparent in the vitreous near the optic nerve head (arrow); c, acute phase of EAU (14 days post immunization). Note retinal pathology including vitritis, retinal edema, retinal folds (arrow), subretinal hemorrhage (asterisk), retinal and choroidal inflammation. Heavy cellular infiltration in the anterior chamber (not shown) and vitreous limit OCT resolution of retinal layers. In correlation with the pathological findings, OCT shows cellular infiltrates in the vitreous, retinal vasculitis and edema, and retinal folds; d–f, resolution phase of EAU (21–28 days post immunization), partial clearing of ocular media facilitate OCT visualization of cellular infiltration in the vitreous (d), retinal folds (e, arrow), choroiditis (e, yellow arrow) as well as degenerating PRL (f). Eighteen mice were included for histological examination, and eyes of 2–3 mice were harvested at individual time point.
Figure 2.
Comparison of OCT images with color fundus photographs.
Horizontal-sectional 2D-view OCT images of GCL-IPL, INL-ONL-PRL, or RPE-CH in comparison with color fundus photographs at different stages of EAU: a, normal retinal structure; b, onset of EAU (13 days post immunization), horizontal-sectional OCT images showed swelling vessels and peri-vascular exudates (green arrows) in the layer of GCL-IPL; c, acute phase of EAU (18 days post immunization), peri-vascular exudates in GCL-IPL layer, retinal folds (yellow arrows) and subretinal hemorrhage (asterisk) seen in INL-ONL-PRL layer were detected by OCT 3D-view rectangle scanning; d, resolution phase of EAU (28 days post immunization), OCT detected a ring-like retinal thinning (yellow arrows) around the optic nerve head formed through INL-ONL-PRL; e, late phase of EAU (8 weeks post immunization), extensive ring-like retinal atrophy (arrows) in INL-ONL-PRL. Note parallel clinical features in the fundus images. Data are representative of 13 mice from two individual experiments.
Figure 3.
Longitudinal OCT imaging of the retina during the course of EAU.
EAU was induced in B10RIII mice by immunization with 8 ug IRBP in CFA. Cross (A) and horizontal (B) sections of OCT images were captured at the indicated time points post immunization. A, Cross-section of OCT image showed normal retinal morphology before immunization for EAU (day 0). The retinal layers were slightly less distinguishable than normal at the pre-peak phase of disease (day 13 post immunization), when retinal edema with increase of retinal thickness appears along with few cell infiltrates around the optic nerve head. On day 14, low OCT signal was detected. Abnormal retinal architecture including perivascular exudates (green arrow) and retinal edema appeared. At 18–21 days after immunization, when the cell infiltrates were reduced in the vitreous, the OCT signal was partially restored. Prominent vasculitis (green arrow), retinal folds (yellow arrow), and vitreal hemorrhage (red arrow) were detected. At late phase of EAU, OCT revealed degenerating retinal layers (particularly in photoreceptor layer) with reduced retinal thickness, retinal folds, as well as choroid inflammation (blue arrow) that formed a ring like retinal lesion around the optic nerve in EAU mice on 28 and 35 days post immunization. B, Horizontal section of OCT images revealed pathological lesions in different retinal layers of the same eye. Data are representative of 13 mice from two individual experiments.
Table 1.
Morphologic and functional changes of retinal lesions distinguished by OCT imaging, fundus photography, histology and ERG during EAU in B10RIII mice.
Figure 4.
Serial ERG response after dark and light adaptation in comparison to disease severity and fold change of retinal thickness obtained by OCT imaging.
EAU was induced in B10RIII mice by active immunization with IRBP161–180 in CFA. Mice were monitored and followed up at the indicative time points by standard fundoscopy, OCT and ERG. A, EAU clinical scores as determined by clinical examination using standard fundoscopy. B, Fold change of retinal thickness measured by OCT. C, Dark- and light-adapted ERGs during EAU. Data are present as mean ± SEM of 13 mice from two individual experiments. Statistical analyses of retinal thickness are performed using the Mann-Whitney test. *, p<0.05; **, p<0.01.