Study of SAR421869 in Participants With Retinitis Pigmentosa Associated With Usher Syndrome Type 1B

Inclusion Criteria: * Clinical and molecular diagnosis of Retinitis Pigmentosa associated with Usher Syndrome type 1B, caused by at least one pathogenic myosin 7a gene (MYO7A) mutation on both alleles, confirmed by direct sequencing and co-segregation analysis within the participant's family. * Suitable verbal/auditory and/or tactile sign language communication (in the opinion of the investigator) as to allow written informed consent to be obtained. * Women of childbearing potential had a negative pregnancy test at screening and at baseline, and agree to use an effective form of contraception such as the contraceptive pill or intra uterine device for at least three months following SAR421869 administration, or be surgically sterile or postmenopausal, with the last menstrual period being over two years prior to enrolment. * Males of reproductive potential agreed with their partner to use two forms of contraception, including one barrier method for at least three months following SAR421869 administration if their partner was of childbearing capacity, or must be surgically sterile. * Participants agreed to not donate blood, organs, tissues or cells for at least three months following SAR421869 administration. Exclusion Criteria: * Presence of significant ocular abnormalities in the study eye that in the opinion of the investigator would preclude the planned surgery, effective safety follow-up, or interfere with the interpretation of study outcome measures (e.g., glaucoma, cor…