Incidence and Risk of Retinopathy in Patients With and Without Interstitial Cystitis and Pentosan Polysulfate Sodium Use

Abstract

Purpose: We investigated the potential for indication bias to be present in previous studies of pentosan polysulfate sodium (PPS) pigmentary retinopathy by comparing the incidence and risk of retinopathy in patients with interstitial cystitis (IC) to matched controls. Methods: Adult women with IC from a multicenter database of electronic medical record data were matched to non-IC controls at a 1:4 ratio. The IC cohort was subdivided according to duration of PPS use: never, <5 years, and ≥5 years. Incidence and risk (estimated by Cox proportional hazards models) of retinopathy (defined by 6 International Classification of Diseases, Ninth and Tenth Revision codes) were compared between groups. Results: There were 22 060 women with IC and 88 240 women without IC. Average age was 53.92 years (SD, 16.22 years), and 96 110 (87.14%) patients were non-Hispanic White. Incidence of retinopathy per 100 000 person-years was 173.88 (95% CI, 162.78-185.53) for patients without IC, 226.63 (95% CI, 197.73-258.56) for IC without PPS use, 293.02 (95% CI 230.86-366.75) for IC with <5 years of PPS use, and 558.91 (95% CI, 399.29-761.07) for IC with ≥5 years of PPS use. Adjusted hazard ratios were 1.31 (95% CI, 1.13-1.51, P < .001) for IC without PPS use, 1.70 (95% CI, 1.35-2.15, P < .001) for IC with <5 years of PPS use, and 3.10 (95% CI, 2.26-4.27, P < .001) for IC with ≥5 years of PPS use. Conclusions: Patients with IC had greater incidence and risk of retinopathy. PPS use further increased the incidence and risk of retinopathy.