has part has part has modifier Rod-cone dystrophy SNOMEDCT_US:28835009 HP:0007927 HP:0000510 HP:0007816 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. HP:0001127 UMLS:C0035334 Rod cone dystrophy HP:0000547 HP:0007826 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. HP:0007742 HP:0007635 HP:0007645 HP:0008036 Retinitis pigmentosa Retinal degeneration Retinal dystrophy Retinal atrophy quality abnormal