Retinitis Pigmentosa Clinical Measures and Repeatability Testing of Potential Outcome Measures

Background: Retinitis pigmentosa (RP) is a group of blinding eye diseases. It is caused mostly by mutations in photoreceptor-expressed genes. RP affects about 2 million people globally. There is no cure, but treatment and diagnosis can be guided by certain tests. Researchers want to see how well these tests capture stages of RP. Objectives: To find out how well certain tests track changes in retinitis pigmentosa. Eligibility: People ages 12 and older with RP Healthy volunteers ages 18 and older with no evidence of RP Design: Participants will be screened in another protocol. Participants will have 2 visits about 6 weeks apart. Both will include all the tests below. Each visit will last 5-6 hours, or a visit can be split into 2 days. Participants will give their medical and eye history. Participants will have an eye exam. Their pupils will be dilated with eye drops. Participants will give blood samples. Pictures of participants retinas will be taken. Their retinas will be measured. Participants will take several eye tests. They will: Sit in a dark room and press a button when they see lights. View a bright background then press a button when they see lights. Look into a bowl and press a button when they see lights. Sit in the dark with their eyes patched. Then they will take eye-numbing drops and wear contacts as lights flash. A small electrode taped to their forehead will record signals from their retinas. Minors will give written consent to stay in the study when they turn 18. After the study ends, they may also be asked to give consent for researchers to continue to use their study information.