Researchers in California recently discovered that, even 20 years after ceasing Plaquenil (hydroxychloroquine (HCQ), Sanofi-Aventis) usage, patients with severe retinopathy, characterized by retinal pigment epithelial (RPE) damage, can have steady progression. This suggests a metabolic insult that chronically destabilizes rather than destroys cellular function, with a clinical course resembling that of genetic dystrophies, they said in the study published in Retina.

The team reviewed findings from 13 patients with initial HCQ retinopathy classified as early (patchy photoreceptor damage), moderate (ring of photoreceptor thinning or scotoma) or severe (RPE damage). Participants had been off the drug for as long as 14 years at initial examination and were followed for five to eight years with repeated fundus autofluorescence and spectral domain optical coherence tomography.

They found that early and moderate cases showed stable fundus autofluorescence appearance, foveal thickness, ellipsoid zone line length and visual acuity for up to nine years after discontinuing HCQ. Severe cases, on the other hand, demonstrated a continual loss of these parameters for up to 20 years post-HCQ. They add that the presence of RPE damage at initial examination predicted progressive retinopathy over many years.

These findings stress the importance of early detection to minimize this observed progression and visual loss, the study concludes.