Update on maculopathy secondary to pentosan polysulfate toxicity

The aim of the present review is to provide a comprehensive summary of available knowledge regarding toxic maculopathy secondary to pentosan polysulfate sodium (PPS).

PPS toxicity was described in 2018, and additional studies characterize it as dysfunction of the retinal pigment epithelium centered on the posterior pole, which can progress despite drug cessation. Requisite exposure can be as little as 0.325 kg and 2.25 years but averages closer to 1-2 kg and 10-15 years. Multimodal imaging should include near-infrared reflectance, optical coherence tomography, and fundus autofluorescence. Cross-sectional studies demonstrate evidence correlating cumulative dosing and the likelihood/severity of maculopathy. Early estimates of prevalence range from 12.7 to 41.7% depending on dosing, with overall rates around 20%.

Reasonable evidence associates maculopathy with extended exposure to PPS, with an average reported incidence of around 20% in patients with long-term exposures. Patients with unexplained retinal pigment epithelium changes and difficulty with dark adaptation should be questioned regarding PPS exposure, and patients with known exposure to PPS should be examined. Further research is needed to refine screening protocols. Currently, providers should consider baseline examination and examination at 5 years and/or 500 g of exposure followed by yearly screening.