Rod-cone dystrophy

Description

An inherited retinal disease subtype in which the rod photoreceptors appear to be more severely affected than the cone photoreceptors. Typical presentation is with nyctalopia (due to rod dysfunction) followed by loss of mid-peripheral field of vision, which gradually extends and leaves many patients with a small central island of vision due to the preservation of macular cones.; Retinitis pigmentosa is a group of hereditary diseases of the eye. However, the term retinitis pigmentosa has also been used to describe the retinal findings characteristic of these diseases but also seen on other diseases such as Usher syndrome. It is preferable to describe the findings precisely if possible, but this term is kept for convenience.