Choroidal nevi are a common differential for choroidal melanoma; while most often benign, these melanocytic tumors can become malignant—about one in every 500 will transform within a 10-year follow-up.¹ ODs can follow the vast majority of nevi, and new data now provides some pointers on what to watch for.

Researchers at Wills Eye Hospital and the Mayo Clinic found subretinal fluid (SRF) is a common association with choroidal nevi,  and it can cause progressive changes in photoreceptor morphology.²

This retrospective observational study used OCT to evaluate 232 choroidal nevi that presented with or developed SRF. The images helped the researchers assess nevus and SRF features and photoreceptor morphology over time.²

The team classified photoreceptor morphology at presentation as normal (26%), shaggy/elongated (31%), retracted/stalactite appearance (33%) or absent (10%). They noted that photoreceptor morphology progressed with increasing SRF chronicity.²

For nevi presenting with normal photoreceptors that later developed SRF, the study authors discovered that photoreceptors became shaggy in 48% after 15 months of chronic SRF, retracted in 40% by month 19 and absent in 12% after 22 months. They add that for nevi with both SRF and shaggy photoreceptors, progression to retracted photoreceptors occurred in 42% after a mean follow-up of 22 months; for nevi with SRF and retracted photoreceptors, progression to absent photoreceptors occurred in 25% after a mean follow-up of 34 months.²

They also found that SRF chronicity, as indicated by photoreceptor morphology on presentation, did not correlate with nevus growth to melanoma.²