Interstitial cystitis has another, more pedestrian name: painful bladder syndrome. It’s a chronic problem that simultaneously has patients running for and dreading trips to the bathroom. One way to bring these patients relief is the use of pentosan polysulfate sodium (PPS). But new research is showing that 20% of patients who took a PPS drug faced significant risk of macular toxicity, particularly if they’ve been exposed to greater than 1,500g of PPS altogether.

The investigators recommended optometrists obtain an initial baseline eye exam that includes OCT, near-infrared reflectance (NIR) and fundus autofluorescence (FAF) as well as annual retinal imaging, especially as cumulative dosages approach 500g.

The research, based out of UCLA, looked into the cases of 50 patients who were treated with PPS. Ten of them developed maculopathy. Both the average duration of PPS therapy and the average cumulative dosage were significantly lower in those who were unaffected than those who were. NIR illustrated early characteristic punctate retinal pigment epithelium (RPE) macular lesions. FAF was useful in exposing speckled autofluorescence in the posterior pole with peripapillary extension. Colocalization with OCT displayed focal RPE thickening and, in more severe cases, RPE atrophy in both the macula and periphery.