Pentosan polysulfate maculopathy

Pentosan polysulfate sodium (PPS), a semisynthetic sulfated polysaccharide, is the only FDA-approved oral therapy for interstitial cystitis. Recent studies have described a progressive, vision-threatening macular condition associated with long-term PPS use. We reviewed all publications concerning PPS maculopathy to consolidate known clinical features and to evaluate the strength of this association. Current literature supports a strong dose-dependent association between PPS exposure and a progressive maculopathy impacting the retinal pigment epithelium (RPE) and RPE-photoreceptor interface that may worsen even after drug cessation. Initial symptoms may include prolonged dark adaptation and difficulty reading with relative visual acuity preservation. Fundus examination often shows macular pigment clumps corresponding to lesions of focal RPE thickening. Fundus autofluorescence most clearly depicts the condition, with a distinctive pattern of hypo- and hyperautofluorescent spots in the posterior pole that sometimes extends to the retinal periphery. Many cases also show a characteristic peripapillary hypoautofluorescent halo. Near infrared reflectance may aid in early detection. RPE atrophy, cystoid macular edema, and macular neovascularization may also occur, potentially resulting in loss of central acuity. This newly described association implies significant public health risk. Ophthalmologists should screen PPS users with multimodal retinal imaging, and prescribers should minimize dose and duration of PPS use.

Update on maculopathy secondary to pentosan polysulfate toxicity

PURPOSE OF REVIEW

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

RECENT FINDINGS

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%.

SUMMARY

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.