Abstract
Purpose:
Conditional Notch1 knockout mice spontaneously develop corneal scarring, neovascularization and keratinization which characteristically predominates on the nasal side of the cornea. We were interested in determining the basis for this finding. We hypothesized that the nictitating membrane which is located nasally (and slides across the cornea with every blink), might be a contributing factor to the nasal predominance of the corneal disease in our model.
Methods:
In order to determine the contribution of the nictitating membrane, we proceeded to excise the membrane from one eye of Notch1flox/flox, K14-Cre-ERT mice prior to Notch1 deletion. One week later, Notch1 was deleted by intraperitoneal injection of 4-hydroxy tamoxifen. The mice were evaluated by slit lamp at 3 weeks after Notch1 deletion to compare the pattern and severity of corneal changes between the two eyes of each mouse.
Results:
The results indicated that all the eyes with intact nictitating membrane developed significantly more severe disease compared to the eyes where the nictitating membrane had been removed (N = 4). Further studies are underway to confirm these findings in a larger sample size.
Conclusions:
Trauma from the nictitating membrane might be responsible for the nasal predominance of the corneal disease in conditional Notch1 -/- mice. The nictitating membrane should be considered in other mouse models where the corneal findings are more prominent nasally.
Keywords: 480 cornea: basic science •
482 cornea: epithelium