Two members of a family presented with loss of vision at night is diagnosed having retinitis pigmentosa. Which of the following is NOT true about retinitis pigmentosa?
Vision is retained till late stage
Central vision is lost early
Affects rods and cones
Tunnel vision may be seen
Retinitis Pigmentosa: It is a group of heterogeneous hereditary rod-cone dystrophies characterized by progressive dysfunction of the photoreceptors, associated with progressive cell loss and eventual atrophy of retinal layers. It occurs sporadically or in an autosomal recessive, dominant, or X-linked pattern. Hallmark symptoms are night blindness (nyctalopia) and gradually progressive peripheral visual field loss as a result of increasing and coalescing ring scotomas. Most characteristic fundoscopic findings: Attenuated retinal aerioles Waxy pale optic disk Mottling of the retinal pigment epithelium Peripheral retinal pigment clumping, referred to as "bone-spicule formation" Ref: Fletcher E.C., Chong N., Augsburger J.J., Correa Z.M. (2011). Chapter 10. Retina. In P. Riordan-Eva, E.T. Cunningham, Jr. (Eds), Vaughan & Asbury's General Ophthalmology, 18e.