Purpose: To determine the association and cumulative dose-response pattern between pentosan polysulfate sodium (PPS) use for interstitial cystitis (IC) and maculopathy.
Design: Large, multicenter, retrospective cohort study of commercially insured patients in the MarketScan database (Truven Health Analytics, San Jose, CA).
Participants: Two hundred twenty-seven thousand three hundred twenty-five patients with IC who were enrolled continuously in the MarketScan database.
Methods: Cox proportional hazards models (controlling for patient gender, age at index diagnosis of IC, and diagnosis with diabetes mellitus) followed up patients from index diagnosis of IC for 5 years, or until patients discontinued insurance coverage, or until patients' first diagnosis with a maculopathy. As a sensitivity analysis, we re-estimate all models after excluding all patients with diabetes. To assess for dose response, we calculated the total days of PPS prescriptions filled and created a categorical variable indicating total exposure.
Main outcome measures: The primary outcome measure was association between binary PPS exposure and any maculopathy. Secondary outcome measures included exposure between binary and categorical, time-dependent, exposure to PPS and to drusen, nonexudative age-related macular degeneration (AMD), exudative AMD, hereditary maculopathy, and toxic maculopathy.
Results: The most common diagnoses of maculopathy in patients with IC were exudative AMD (1.5%), drusen (0.8%), nonexudative AMD (0.3%), toxic maculopathy (0.1%), and hereditary dystrophy (0.04%). In unadjusted analyses, the percentage of patients who filled a PPS prescription and were diagnosed later with a maculopathy (2.37%) was very similar to the percentage of patients who did not fill a prescription (2.77%). Survival models using a binary variable indicating PPS exposure showed no significant associations between PPS exposure and diagnosis of drusen, nonexudative AMD, exudative AMD, toxic maculopathy, hereditary dystrophy, or an aggregate variable of any maculopathy. Similarly, there was no dose-dependent relationship between PPS exposure and diagnosis of any maculopathy. These findings remained stable in sensitivity analysis models that excluded patients with diabetes mellitus.
Conclusions: In this large, commercial claims database analysis, no association was found between PPS exposure and subsequent diagnosis of maculopathy.
Copyright © 2019 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.