C1q enhances cone photoreceptor survival in a mouse model of autosomal recessive retinitis pigmentosa.

Retinitis pigmentosa (RP) is a degenerative retinal disease involving progressive loss of rod and cone photoreceptor function. It represents the most common form of registered blindness among the working aged populations of developed countries. Given the immense genetic heterogeneity associated with this disease, parameters influencing cone photoreceptor survival (preservation of daytime vision) that are independent of primary mutations are exceedingly important to identify from a therapeutic standpoint. Here we identify C1q, the primary component of the classical complement pathway, as a cone photoreceptor neuronal survival factor.