Ciliary Defects in Inherited Retinal Diseases

Abstract

Inherited retinal diseases (IRDs) are a heterogeneous group of disorders characterized by progressive photoreceptor degeneration that frequently results in severe vision loss. A major cause of IRDs is attributed to structural or functional defects of the photoreceptor cilium that arise from mutations in ciliary genes. The photoreceptor outer segment is a highly specialized sensory cilium composed of hundreds of stacked, flattened, membranous discs. This complex membrane architecture constitutes the primary site of phototransduction, in which light stimuli are converted into biochemical signaling cascades that ultimately generate electrical signals. In this review, the structure and function of photoreceptors are systematically described, major classes of IRDs caused by mutations in ciliary genes are summarized, and the therapeutic potential of emerging ciliary gene-targeted strategies is critically evaluated in the context of recent advances in IRD treatment.