Retinitis pigmentosa (RP) encompasses a group of inherited retinal dystrophies characterized
by the primary degeneration of rod and cone photoreceptors. RP is a leading cause
of visual disability, with a worldwide prevalence of 1:4000. Although the majority
of RP cases are non-syndromic, 20-30% of patients with RP also have an associated
non-ocular condition. RP typically manifests with night blindness in adolescence,
followed by concentric visual field loss, reflecting the principal dysfunction of
rod photoreceptors; central vision loss occurs later in life due to cone dysfunction.
Photoreceptor function measured with an electroretinogram is markedly reduced or even
absent. Optical coherence tomography (OCT) and fundus autofluorescence (FAF) imaging
show a progressive loss of outer retinal layers and altered lipofuscin distribution
in a characteristic pattern. Over the past three decades, a vast number of disease-causing
variants in more than 80 genes have been associated with non-syndromic RP. The wide
heterogeneity of RP makes it challenging to describe the clinical findings and pathogenesis.
In this review, we provide a comprehensive overview of the clinical characteristics
of RP specific to genetically defined patient subsets. We supply a unique atlas with
color fundus photographs of most RP subtypes, and we discuss the relevant considerations
with respect to differential diagnoses. In addition, we discuss the genes involved
in the pathogenesis of RP, as well as the retinal processes that are affected by pathogenic
mutations in these genes. Finally, we review management strategies for patients with
RP, including counseling, visual rehabilitation, and current and emerging therapeutic
options.