Central retinal preservation in <italic>rdAc</italic> cats.

Abstract: Objective: Children with Leber congenital amaurosis (LCA) due to <italic>CEP290</italic> mutations show characteristic macular preservation. Spectral domain‐optical coherence tomography (SD‐OCT) is a noninvasive technique to investigate retinal structural changes. Loss of integrity of the ellipsoid zone (EZ) on OCT in people with retinal disease has been associated with loss of visual function and is a useful measure of retinal disease progression. We hypothesized that <italic>rdAc</italic> felines with <italic>Cep290</italic> mutation would have a similar pattern of degeneration, with relative central retinal preservation associated with maintenance of the EZ. Procedures: Fundus imaging, confocal scanning laser ophthalmoscopy, and SD‐OCT cross‐sectional imaging was performed on 11 <italic>rdAc</italic> cats ranging from 6 months to 10 years of age. Images were collected from the <italic>area centralis</italic>, visual streak, and the mid‐superior and mid‐inferior retina. Receptor plus (REC+, encompassing the entire length of photoreceptors) thicknesses were measured. Regional rates of degeneration were determined by regression analysis and compared using unpaired t‐tests. The EZ was evaluated for the presence, absence, or loss of definition. Results: <italic>RdAc</italic> cats showed REC+ thinning over time in all regions. The <italic>area centralis</italic> and visual streak had a slower rate of thinning than the mid‐peripheral retina. There was loss of integrity of the EZ initially in the more peripheral regions, while its integrity was maintained in the <italic>area centralis</italic> and visual streak at all ages studied. Conclusions: <italic>rdAc</italic> cats show preservation of the central retina with maintenance of EZ integrity, which recapitulates findings in human patients. [ABSTRACT FROM AUTHOR]