Characterization of Pentosan Polysulfate Sodium Maculopathy With Fluorescence Lifetime Imaging

Long-term use of pentosan polysulfate sodium (PPS) for interstitial cystitis, has been associated with a sight-threatening pigmentary maculopathy. This study evaluated fluorescence lifetime imaging ophthalmoscopy (FLIO) in PPS maculopathy patients and correlated findings with fundus autofluorescence (FAF) and optical coherence tomography (OCT).

This prospective study included patients with confirmed PPS maculopathy at the University of California, San Diego. All patients underwent same-day multimodal imaging (FLIO, fundus photography, FAF, OCT). Disease severity was graded using updated PPS maculopathy criteria. FLIO data were compared to age-, sex- and lens-status-matched controls.

Nineteen eyes from 10 PPS patients (mean age 71.2) and 19 eyes from 11 age-sex matched normal controls (mean age 71.5) were included. Both groups had seven pseudophakic (PP) and four phakic (P) patients. PPS maculopathy patients showed characteristic FAF changes and RPE hypertrophy. Disease severity did not significantly differ within or between phakic and pseudophakic groups. Mean FLIO lifetimes in PPS eyes were significantly longer than in controls (P: 905 ps v.s 500 ps, p<0.019), PP: 557 ps vs. 371 ps, p<0.044). Lifetimes also varied significantly with maculopathy severity (p<0.05). In 11 eyes, parafoveal foci with very short lifetimes (273-394 ps) were detected and differed significantly from central values (p=0.030).

FLIO detected significant differences in fluorescence lifetimes between PPS maculopathy patients and controls. Discrete very short lifetime foci may represent early or distinct disease features. FLIO is a promising non-invasive tool for diagnosing and monitoring PPS maculopathy.