What is the primary characteristic of retinitis pigmentosa?

Retinitis pigmentosa is primarily characterized by progressive vision loss, which occurs due to the degeneration of photoreceptor cells in the retina, specifically the rods and cones. The condition typically begins with night blindness and the inability to see in low light conditions as the rods, responsible for peripheral and night vision, are affected first. As the disease progresses, tunnel vision may develop, leading to further central vision loss.

This progressive nature of vision loss is a distinct hallmark of retinitis pigmentosa, differentiating it from other ocular conditions that may present with more acute symptoms or different patterns of visual impairment. The gradual deterioration reflects the typical course of this hereditary retinal dystrophy, making it crucial for diagnosis and management within ophthalmology.