Retinitis Pigmentosa
Overview
Plain-Language Overview
Retinitis Pigmentosa is a group of inherited eye disorders that affect the retina, the light-sensitive tissue at the back of the eye. It primarily causes a gradual loss of vision, starting with difficulty seeing at night and loss of peripheral vision. Over time, this can lead to tunnel vision and eventually significant visual impairment. The condition affects the photoreceptor cells, which are responsible for detecting light and sending visual signals to the brain. Because it progresses slowly, many people notice symptoms only in adolescence or adulthood. The disease impacts the ability to perform daily activities that require good vision, such as driving or reading.
Clinical Definition
Retinitis Pigmentosa is a genetically heterogeneous group of progressive retinal dystrophies characterized by the degeneration of rod and cone photoreceptors. The primary pathology involves mutations in genes such as RHO, RPGR, and USH2A that disrupt phototransduction or retinal cell maintenance, leading to photoreceptor apoptosis. Clinically, it presents with night blindness (nyctalopia), progressive peripheral visual field loss, and eventual central vision decline. Fundoscopic examination reveals bone spicule pigmentation, attenuated retinal vessels, and optic disc pallor. Electroretinography shows reduced or absent rod and cone responses, confirming photoreceptor dysfunction. The condition is a major cause of inherited blindness and has variable inheritance patterns including autosomal dominant, autosomal recessive, and X-linked forms.