Retinitis pigmentosa is a collective term for a group of inherited retinal dystrophies characterized by loss of rod photoreceptors, followed by loss of cone photoreceptors. It is a disease with a... Show moreRetinitis pigmentosa is a collective term for a group of inherited retinal dystrophies characterized by loss of rod photoreceptors, followed by loss of cone photoreceptors. It is a disease with a variable clinical and genetic presentation, with regards to age at onset, severity, and disease progression. For many patients, no treatment is available at the moment, but promising advances are made in genomic medicine. In preparation for these novel therapies, this thesis focuses on the clinical characteristics and natural course of candidate genes, in order to define optimal clinical endpoints. Additionally, this thesis investigates current treatment modalities, as retinitis pigmentosa is associated with ocular comorbidities such as cataract and cystoid macular edema, which can significantly impact a patient's quality of life when left untreated. Show less
Retinal dystrophies comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in... Show moreRetinal dystrophies comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, e.g. retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, as well as the rate of vision decline, may vary widely per disease group and even within families. For most IRD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several IRD subtypes, and recently the first retinal gene therapy has been approved by the United States Food and Drug Administration for RPE65-associated IRDs: voretigene neparvovec-rzyl (Luxturna®). With these rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course becomes crucial. The vast clinical heterogeneity presents an important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This thesis responds to these challenges, providing detailed clinical descriptions of several forms of IRD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Show less
