Abstract
Purpose :
To establish SD-OCT quantification data in well-established canine models of inherited retinal dystrophies: PDE6B-rod-cone dysplasia 1(RCD1: early onset retinitis pigmentosa), PRCD-progressive rod-cone degeneration (PRCD: late onset retinitis pigmentosa), CNGB3-achromatopsia (ACHM), and RPE65-Leber congenital amaurosis (LCA).
Methods :
High resolution SD-OCT images (Spectralis, Heidelberg Engineering) of the retina were acquired in 5 planes: temporal (T); superotemporal (ST, including area centralis); superior (S); nasal (N); and inferior (I) in adult dogs with advanced disease: PDE6B-RCD1 (n=4 dogs, median age=1.5yrs); PRCD (n=2, 4.3yrs); RPE65-LCA (n=3, 5.2yrs); CNGB3-ACHM (n=3, 4.2yrs); and wild types (wt, n=6, 5.5yrs). Total, inner (from inner limiting membrane to inner plexiform layer-inner nuclear layer interface), and outer (from inner plexiform layer-inner nuclear layer interface to retinal pigment epithelium-choroid interface) retinal thicknesses and ellipsoid zone were analyzed with univariate ANOVA with post-hoc Tuckey test and Chi-square test, respectively.
Results :
Compared to wt the thickness of outer retinal layers was significantly decreased (p<0.01) in all imaging planes with RCD1 (decreased by 50.0%, 51.2%, 57.4%, 57.5%, and 60.6% in T, ST, S, N, and I, respectively), PRCD (35.2%, 12.6%, 22.8%, 44.7%, and 38.1%), and LCA (18.0%, 8.4%, 10.4%, 13.4%, and 19.5%) but not ACHM. Significantly more loss of the outer layer thickness was observed in the I and N planes than the ST and T planes, respectively (p<0.05). No significant thinning was observed in inner retinal layer thickness in any disease model. Dogs with RCD1, PRCD, and LCA had significantly more disrupted ellipsoid zone in the presumed area centralis than wt (p<0.01).
Conclusions :
We successfully demonstrated the use of SD-OCT to evaluate changes in the retinal morphology in representative canine models of inherited retinal dystrophies. Our findings are consistent with previously published histologic studies. We believe that SD-OCT will provide valuable in vivo outcome measures in the development of novel therapeutics of retinal disease using canine models. The well preserved inner retina in the late stages of disease bauds well for some of the novel therapeutic modalities.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.