RESUMO
Cone-rod dystrophy [CRD] is an inherited retinal dystrophy with initial loss of cone mediated functions followed by rod dystrophy. We report the case a young male affected by CRD. Case report: The case of a 27-year-old male patient is presented. He was hospitalized for decreased vision of both eyes and hemeralopia. The eye fundus examination showed bilateral lesions of retinitis pigmentosa in the supero temporal sector and macular cystoid oedema. Both photopic and scotopic full field ERG amplitudes were reduced, showing involvement of both photoreceptor systems. However, cone response was reduced more than that of rod response suggesting CRD diagnosis. His mother was diagnosed with age-related macular degeneration and his brother with CRD. The patient refused genetic analysis. Based on family history and clinical diagnosis, the disease was classified as cone-rod dystrophy. Discussion and Cone-rod dystrophy [CRD] is a particular form of retinitis pigmentosa [RP] which characteristically lead to early impairment of vision, usually from the first or second decade of life. CRD patients suffer from hemeralopia, loss of visual acuity and peripheral visual fields and show reduced ERG responses. In later life, vision may be reduced to a bare perception of light. Ophthalmoscopic abnormalities in CRD patients ranged from minor granular pigmentary changes in the posterior pole to widespread atrophy. Genetic analysis revealed various mutations in many genes may lead to CRD. There's no treatment available for this condition. Genetic advice is the most effective mean for preventing this inherited disease