Abstract
Purpose: :
X-linked juvenile retinoschisis (XLRS) has been shown to affect the retina in both human patients and mice deficient for retinoschisin ( Rs1h-/-). Here we report a structural and functional comparison of the retinal phenotype in Rs1h-/- mice and patients with XLRS.
Methods: :
The functional assessment of patients and animals (Rs1h-/-, C57BL/6) was based on the ISCEV standard for electroretinographic testing (ERG). Retinal imaging was performed using confocal scanning laser ophthalmoscopy (cSLO) for en face visualization and Spectral Domain OCT (SD-OCT) for cross-sectional imaging of retinal structures using the SpectralisTM HRA+OCT.
Results: :
Affected patients showed characteristic retinal lesions including macular schisis. Splitting occurred within the inner nuclear layer and led to an elevation of central retinal thickness to 515±42µm. The functional deficits, a central loss in multifocal ERG, and a decreased b-/a amplitude ratio in Ganzfeld-ERG, correlated well with previous studies. Despite the lack of a macula, a ubiquitous punctuate retinal schisis was detected with cSLO and SD-OCT in the Rs1h-/- but not in wildtype mice. The schisis was associated with a similar ERG pattern as in human patients.
Conclusions: :
We compared patients with XLRS and Rs1h-deficient mice using standard functional and state-of-the-art structural diagnostic tools. In both organisms, we found a similar formation of schisis in the INL, which was more evenly distributed in mice and more centered within the macula and the periphery in human patients. The uniformity of the functional outcome supports the view that XLRS is a disease of the entire retina. The use of SD-OCT in animal models will further facilitate the evaluation of putative therapeutic effects following experimental interventions and promote translational research in the wake of upcoming clinical trials in patients with hereditary retinal disorders.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retinal degenerations: hereditary • transgenics/knock-outs