This looks like winter injury or leaf burn on your camellia. There is nothing you need to do now. Affected leaves will drop in the spring and you should see new growth. You will have to wait and see if the flower buds are affected.
Water the shrub deeply during dry periods this growing season.
Make sure it goes into the winter well-watered, as the desiccation or drying out of leaves of broad-leaved evergreens or winterburn, is common.
Placing stakes around the plant and wrapping them with a winter protection like burlap can also help. You can also fill the spaces within the burlap with fallen leaves or straw for extra insulation
Here is our website on winter injury http://extension.umd.edu/hgic/winter-damage-trees-and-shrubs