IRDs

IRDs, or inherited retinal diseases, describe a broad group of genetically diverse disorders that cause progressive dysfunction and degeneration of retinal cells, primarily photoreceptors and the retinal pigment epithelium. They are typically bilateral and can affect night vision, peripheral vision, and central vision, with onset ranging from early childhood to adulthood.

Common conditions within IRDs include retinitis pigmentosa, cone-rod dystrophy, Leber congenital amaurosis, Stargardt disease, and Usher syndrome. The clinical presentation varies by condition and gene, leading to a spectrum from mild to severe vision loss.

Genetics: IRDs are usually inherited, with patterns including autosomal dominant, autosomal recessive, and X-linked transmission. Many cases result from mutations in one of more than 60 known retinal-disease genes, and new genes continue to be identified. Genetic testing can identify causative variants, inform prognosis, guide counseling, and determine eligibility for gene-based therapies.

Diagnosis: Evaluation typically includes a comprehensive ophthalmic examination, electroretinography (ERG), optical coherence tomography (OCT), fundus imaging, autofluorescence imaging, and visual field testing. Genetic testing panels or whole-exome/genome sequencing are used to confirm the underlying cause and to enable personalized management.

Management and treatment: There is no cure for most IRDs, but options include low-vision rehabilitation, assistive devices, and genetic counseling. Targeted therapies exist for a subset of conditions; for example, voretigene neparvovec (Luxturna) is approved for biallelic RPE65 mutation-associated retinal dystrophy. Ongoing research explores additional gene therapies, gene editing, stem cell–based approaches, and retinal prostheses.

Prognosis: Progression is highly variable and depends on genotype, residual retinal function, and access to supportive care. Some individuals maintain central vision for years, while others experience faster decline.