The objective of this study is to develop the comprehensive visual function evaluation method in severe visually impaired patient

This study is a prospective observational study which consists of 4 Parts; Part 1A, 1B, 2 and 3. Part 1A has been conducted on 6 subjects diagnosed with retinitis pigmentosa. Additional examination will be performed using alternative devices imported outside Japan on subjects who completed Part 1A and re-consented (Part 1B). Based on the interim result of Part 1A, Part 2 will be conducted on another 6 subjects with retinitis pigmentosa with improved methodology and the devices used in Part 1B. Part 3 will be conducted in 6 healthy volunteers to obtain comparative data using devices used in Part 1B.

Inclusion Criteria for patients with retinitis pigmentosa:

• Age: ≥ 20 years
• Subjects with severe visual disturbance (count-fingers or worse vision for severe eyes) at the time of obtaining the consent

Inclusion Criteria for healthy Volunteers:

• Age: ≥ 35 and ≤ 75 years
• Subjects with corrected visual acuity ≥ 1.0 with both eyes and without severe refractive error nor abnormal findings in slit-lamp microscopy, OCT, fundoscopy and pupillary function test at screening

Exclusion Criteria:

• Subjects who have participated in any other clinical trial or clinical study involving visual function evaluation within 6 months
• Subjects who have history of surgery, past history, and complications (cardiac/ hepatic/ renal/ respiratory/ hematological diseases, optic nerve diseases causing marked loss of visual field, and uveitis etc.) that potentially affect evaluation and safety of the study
• Pregnant women
• Subjects who are judged that continuation of the study is difficult during the study period
• Subjects who are employed by the company sponsoring this study, an organization or institution related to this study

Retinitis pigmentosa, healthy volunteers

Access to anonymized individual participant level data will not be provided for this trial. Further details on Astellas' data sharing policy can be found at https://www.clinicaltrials.astellas.com/transparency/.