Baseline Relationships between Visual Function and Inflammatory Markers in the Registry of Moderated-Stage Retinitis Pigmentosa

Purpose: To analyze the association between visual function and inflammatory markers in the baseline data of a prospective natural history registry of patients with typical retinitis pigmentosa (RP) (Retinitis Pigmentosa Progression and Inflammatory Marker Registry Study [RP-PRIMARY Study]). Design: A cross-sectional observational study using baseline data from the RP-PRIMARY study. Participants: A total of 67 patients with moderate-stage typical RP who were treated between October 2021 and October 2022 in 1 of 3 participating hospitals consented to participate and met the inclusion criteria. Methods: Visual functions were ETDRS best-corrected visual acuity (BCVA), Humphrey Field Analyzer 10-2 program (mean deviation value, and the mean sensitivity within the central 1° area [central 4 points, RS Cent 1’] and the 4° area [central 12 points, RS Cent 4’]), ellipsoid zone (EZ) length, central foveal thickness (CFT), hyper-autofluorescence (AF) ring area, and inflammatory markers were aqueous flare and blood test measurements. Main Outcome Measures: Association between visual function and inflammatory markers. Results: The median age of participants was 51 (interquartile range: 43–60) years. Spearman rank correlation coefficient demonstrated that aqueous flare values were negatively correlated with ETDRS BCVA (ρ = –0.35; P = 0.004), RS Cent 1’ (ρ = –0.32; P = 0.008), EZ length (ρ = –0.28; P = 0.023), and hyper-AF ring area (ρ = –0.31; P = 0.016). There was no significant correlation between systemic inflammatory markers and visual function. Eyes with intraocular lens (IOL) had significantly lower values of ETDRS BCVA (P = 0.004), RS Cent 1’ (P = 0.005), RS Cent 4’ (P = 0.010), CFT (P = 0.001), and EZ length (P = 0.011), in addition to higher values of aqueous flare (P < 0.001). Multiple linear regression analysis revealed that eyes with IOL (β = 0.262; P < 0.001) were significantly associated with aqueous flare. Conclusions: In the baseline data of the RP-PRIMARY study, aqueous flare, an ocular inflammatory marker, was negatively associated with visual function, and IOL implantation was most strongly associated with an increase in aqueous flare in patients with moderate-stage RP. The association between inflammatory markers and disease progression will be evaluated in the ongoing RP-PRIMARY study. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.