Macular Findings of Patients on Pentosan Polysulfate Sodium

In 2018, a unique maculopathy associated with chronic pentosan polysulfate sodium (PPS) use for the treatment of interstitial cystitis (IC) was described, where the authors detailed macular retinal pigment epithelial abnormalities in six patients. In this paper, a retrospective study of a larger patient pool at one large tertiary retina practice was undertaken to evaluate patients taking PPS and their macular findings.

A retrospective chart review was performed on all patients presenting to a single large retina practice between 2011 and 2019. Patient's macular diagnosis, findings, optical coherence tomography scans, and macular auto-fluorescent scans were assessed. This project was Institutional Review Board (IRB) approved by the St Luke's Hospital IRB board (St Louis, MO, USA).

Fifty-five patients were identified as taking PPS for IC. Fifty-three patients were found to have a diagnosis consistent with changes attributable to known macular diseases to include macular degeneration and pattern dystrophies. Two (4%) of fifty-five patients had macular findings suggestive of PPS toxicity. The first was a 58-year-old female with subtle retinal pigment epithelium (RPE) deposits on optical coherence tomography that exhibited hyper-autofluorescence. The second was a 72-year-old female with 14 years of PPS use who exhibited RPE excrescences and parafoveal areas of atrophy.

Pentosan polysulfate sodium may be the cause of macular findings in a small percentage of patients referred to a tertiary retina practice. Although causation of macular changes with PPS use has yet to be elucidated, clinicians should be aware of this possibility when assessing patients with atypical macular findings. Future longitudinal studies are necessary to evaluate a definitive relationship. This paper should remind all clinicians of the importance of a throughout review of the patient's medication list as novel toxicities may become apparent years after initial FDA trials. The strength of this study is the larger patient population compared to earlier studies, and the main weaknesses include the retrospective nature of the study, lack of family and genetic testing, and lack of multimodal imaging for all patients.