It is a heterogeneous group of ocular pathologies, genetically determined, in which the involvement of different genes and etiopathogenetic mechanisms leads to the progressive degeneration of retinal photoreceptors (cones and rods). They are divided into two large categories depending on whether rods (rod-cone dystrophies, improperly called peripheral forms) or cones (cone-rod dystrophies, improperly called macular dystrophies) are initially and mainly affected.
The symptoms of onset are different: the rod-cone forms are characterized by night blindness and reduction of the visual field, while in the cone-rod forms there is an earlier central visual decrease, acquired deficit of the chromatic vision, glare. In the terminal stages, if the damage has spread to all the photoreceptors, the shapes can be superimposable and difficult to distinguish even with instrumental examinations. In some cases retinal changes are a sign in the context of syndromic diseases (i.e. involving multiple districts of the organism) and in these cases the patient’s polispeciastic framework (in particular otolaryngologist, neurologist, clinical geneticist) is necessary.
Hereditary retinal dystrophies can be transmitted in any transmission mode (autosomal recessive, autosomal dominant, X linked, mitochondrial). The main pathologies include peripheral forms: retinitis pigmentosa (typical and atypical forms) and central forms: macular dystrophy of Stargardt, macular dystrophy of Best, X linked retinoschisis, progressive dystrophy of cones.
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