Purpose:
Spectral domain optical coherence tomography (OCT) can provide high resolution imaging of the living retina in experimental murine disease models. This study documents the findings of OCT in murine experimental autoimmune uveitis (EAU).
Methods:
Ten B10 RIII mice were immunized with 25µg of IRBP peptide 161-180 (SGIPYIISYLHPGNTILHVD), emulsified 1:1 v/v in complete Freund’s adjuvant. Mice were injected with a total of 0.3ml of the emulsion subcutaneously. OCT examinations were obtained of both eyes on the day of immunization and 18 days following immunization immediately prior to euthanasia. A single eye of five animals was enucleated, fixed in 4% formaldehyde solution, and paraffin embedded sections were stained with haematoxylin and eosin. The remaining eyes were prepared for other histologic and immunologic studies to be reported elsewhere.
Results:
Histology of five eyes (day 18) demonstrated typical findings of EAU, ranging from normal anatomy to severe papillitis, full-thickness retinitis, choroiditis, pars planitis and serous retinal detachment. Baseline OCT images (day 0) were obtained and unremarkable in all 20 eyes. OCT images (day 18) were successfully obtained in 9 eyes of 5 animals. OCT of 4 eyes in 2 animals were unremarkable. The five remaining eyes demonstrated irregular contour of the internal retina, retinal thickening, multifocal intraretinal hyper-reflective foci (including peripapillary foci), subretinal fluid, thickened hyper-reflective retinal pigment epithelium, and pigment epithelial detachment.
Conclusions:
In affected animals with EAU, disruption of normal retinal architecture including retinal infiltration and increased retinal thickness can be confirmed by OCT. Further studies need to define the limiting factors in obtaining adequate OCT images, the utility of retinal thickness quantification, the direct correlation of OCT with histopathology in specific eyes, and the anatomic changes in EAU over time. OCT may prove to be an important in vivo assay of EAU.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • uveitis-clinical/animal model • microscopy: light/fluorescence/immunohistochemistry