Abstract
Purpose:
To characterize a chorioretinal coloboma occurring in the JF1 mouse line.
Methods:
Indirect ophthalmoscopy with a 90D lens was performed on JF1 mice. Mice with chorioretinal colobomas had either optical coherence tomography (OCT) performed, followed by sacrifice and histologic preparation of the eyes, or were bred. Select mice fundi were photographed. Offspring of affected mice were examined for presence or absence of coloboma by indirect ophthalmoscopy.
Results:
60 eyes of 30 JF1 mice were examined. 19 were female, 11 were male. 11 of 30 mice demonstrated chorioretinal (CR) coloboma. 10/11 were unilateral. 6 were right eye, while 4 were left eye. 6 of 11 affected mice were female. All colobomas were adjacent to the optic nerve but none involved the nerve itself. On both OCT and histologic examination, the retinal layers adjacent to the colobomatous defect appeared to deviate course toward the sclera. The retinal pigment epithelium (RPE) ended abruptly on either side of the retinal defect. Rather than bare sclera, the base of the coloboma has a layer of collagen above sclera. Trichrome stain revealed collagen infiltrate into the retina. Based on pedigrees, this CR coloboma may be inherited in an autosomal dominant or autosomal recessive manner with variable expressivity.
Conclusions:
We describe a mouse model of chorioretinal coloboma. The retinal defect appears to be complex, with disruption of normal retinal layers, and replacement of some tissue rather than simply a localized deficiency of retinal tissue. Variable expressivity is the norm, similar to human CR colobomas.
Keywords: 688 retina •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
698 retinal development