Purpose
The Retinitis Pigmentosa Progression and Inflammatory Marker Registry (RP-PRIMARY) is intended as a prospective observational study aimed at establishing sensitive outcome measures to detect the efficacy of anti-inflammatory agents in future clinical trials. The following is the RP-PRIMARY study protocol.
Study Design
Prospective, multicenter study.
Methods
We will recruit 100 patients with typical RP (any genetic mutation) and the following characteristics: age 20–70 years; mean retinal sensitivity ≥ 10 dB at 12 central points on Humphrey 10-2 visual field tests; central foveal thickness ≤ 250 μm on optical coherence tomography (OCT); and no ocular complications unrelated to RP or serious systemic complications. Early Treatment Diabetic Retinopathy Study (ETDRS). visual acuity, Humphrey 10-2 visual field tests, OCT, and fundus autofluorescence imaging will be performed every 3 months for 2 years. Inflammatory indices such as aqueous flare values, high-sensitivity C-reactive protein (CRP), serum IL-8, and CD14/16 inflammatory monocyte proportion will be measured every year. The primary endpoint will be the progression rate of retinal sensitivity loss on the Humphrey 10-2 visual field tests. The secondary endpoints will be the rate of decline of each parameter and its association with inflammatory indices. Standard-operation-procedure documents were prepared for all study procedures, and consultations with the regulatory agency were conducted to ensure the data reliability for future use in clinical trials.
Conclusions
Detailed registry data on the natural history and inflammatory profile of RP will be useful in designing study protocols for anti-inflammatory therapy for RP and as natural history data for drug applications.