Researchers from Wills Eye Hospital recently explored risk factors for choroidal nevus transformation into melanoma, in a review published in Current Opinion in Ophthalmology. They found that the mnemonic ‘To Find Small Ocular Melanoma Doing IMaging’ (TFSOM-DIM) can assist in detecting factors that increase the risk of choroidal nevi transforming into small choroidal melanoma.

The TFSOM-DIM acronym encapsulates the following risk factors:

• Thickness >2 mm (on ultrasound)
• Fluid subretinal (on OCT)
• Symptoms of vision loss (by VA testing)
• Orange pigment (on autofluorescence)
• Melanoma hollow (on ultrasound)
• DIaMeter >5mm (by photography)

The authors note that a recent longitudinal study of 3,806 choroidal nevi images revealed that 5.8% had transformed into melanoma after five years and 13.9% after 10. Multivariate factors predictive of this transformation included: more than 2mm of thickness, subretinal fluid, vision loss, orange pigment, melanoma hollow and a diameter of more than 5mm. The team notes that the TFSOM-DIM can help detect each of these risk factors, giving clinicians an edge over the cancer. A five-year estimate of nevi growth into melanoma came out to 1.1% for patients with zero risk factors, 11% for those with one, 22% for those with two, 34% for those with three, 51% for those with four and 55% for those with five.

The review also found small choroidal melanoma management typically involves plaque radiotherapy with five- and 10-year rates of tumor recurrence at 7% and 11%, visual acuity loss (≥3 Snellen lines) at 39% and 49% and melanoma-related metastasis at 4% and 9%, respectively. Although plaque radiotherapy offers tumor control, it could also cause vision loss, the researchers note. Hoping to induce tumor regression while also minimizing vision loss, researchers are currently investigating an infrared, dye-conjugated, virus-like nanoparticle therapy using AU-011 to treat small choroidal melanoma.