Clinical trial NCT02759952: Clinical Characterization on PDE6A-related Retinitis Pigmentosa in Preparation to a Gene Therapy Trial
Official title: Clinical Characterization on PDE6A-related Retinitis Pigmentosa in Preparation to a Gene Therapy Trial: An Observational Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Retinitis Pigmentosa
Keywords: retinitis pigmentosa
PDE6A
gene therapy trial
Lead sponsor: STZ eyetrial
Sponsor class: OTHER
First posted: 2016-05-03
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Retinitis pigmentosa patients with genetically confirmed mutations in the PDE6A-gene

Brief summary: Mutations in the PDE6A gene - encoding the -subunit of the rod cGMP-phosphodiesterase - account for 1% of autosomal recessive retinitis pigmentosa (arRP) through impaired regulation of cGMP levels in the rod outer segment. This study aims for a detailed clinical characterization of patients with PDE6A mutations in preparation of a clinical gene replacement study (phase I/II safety trial).

Detailed description: Retinitis pigmentosa (RP) is a clinically and genetically heterogenous group of hereditary retinal disorders, being one of the most common types of retinal degenerations with a prevalence of 1:4000. More than 45 genes have been associated with RP so far, whose defects cause a progressive loss of rod photoreceptor function, followed by cone photoreceptor dysfunction often leading to complete blindness. Mutations in the PDE6A gene - encoding the -subunit of the rod cGMP-phosphodiesterase - account for 1% of autosomal recessive retinitis pigmentosa (arRP) through impaired regulation of cGMP levels in the rod outer segment.

With the help of improved genetic and functional diagnostic tools an early recognition and differentiation has become possible. Still, up to date no established therapy is available, therefore, social and professional consequences are essential tasks to deal with. The modern ophthalmological functional diagnostic tools enable a precise characterisation and early recognition of such retinal diseases. The detailed results and information can help to extend the understanding of the pathological mechanisms involved in these diseases.

In this study the investigators intend to investigate patients with a genetically confirmed diagnosis of Retinitis pigmentosa due to PDE6A mutations hereby assessing the function and structure of the retina with an extensive battery of tests.

Eligibility criteria: Inclusion Criteria:

* Retinitis pigmentosa patients with genetically confirmed mutations in the PDE6A-gene
* written informed consent

Exclusion Criteria:

* severe general disease, that would make longer examinations not possible
* patients who cannot give written informed consent independently

Primary outcomes:
measure: best corrected visual acuity in both eyes
timeFrame: 3 years
measure: kinetic visual field in both eyes
timeFrame: 3 years
measure: central retinal thickness in both eyes
timeFrame: 3 years
Secondary outcomes:
measure: multifocal ERG responses in both eyes
timeFrame: 3 years
measure: colour vision in both eyes
timeFrame: 3 years
Other outcomes:
Locations:
city: Tübingen
country: Germany
facility: Institute for Ophthalmic Research, University Tübingen, Germany
state: Baden-Württemberg
Study officials:
affiliation: Institute for Ophthalmic Research, University Tübingen, Germany
name: Ditta Zobor, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Institute for Ophthalmic Research, University Tübingen, Germany
name: Susanne Kohl, PhD
role: PRINCIPAL_INVESTIGATOR
References: