The MOLES system to guide the management of melanocytic choroidal tumours: can optometrists apply it?

Although melanocytic choroidal tumours of the choroid are a common eye pathology, no standardised protocol exists for their management in the community.

Choroidal naevi are found in approximately 6% of the adult White population, whereas choroidal melanomas are rare, with an annual incidence of 5-10/million/year. Multimodal imaging has advanced the understanding of malignancy imaging biomarkers, but distinguishing between a small melanoma and naevus remains difficult and an algorithm for their management by community practitioners has not been uniformly adopted. One of the authors (BD) devised the MOLES scoring system, which indicates malignancy likelihood according to mushroom shape, orange pigment, large size, enlargement, and subretinal fluid. When applied by ocular oncologists, the system accurately distinguishes choroidal naevi from melanomas. The aim of this study was to evaluate whether community optometrists can appropriately manage patients with melanocytic choroidal tumours using this system.

Clinical images of 25 melanocytic choroidal tumours were presented in an online survey, including colour fundus photographs, fundus autofluorescence, optical coherence tomography, and B-scan ultrasound images. Using the MOLES system, 39 optometrists diagnosed tumours as naevus or probable melanoma and decided between community monitoring and ophthalmologist referral. Responses were compared to MOLES grading of the same clinical images by ocular oncologists.

Using MOLES, optometrists correctly identified 389/406 probable melanomas (95.8% sensitivity) and 331/516 choroidal naevi (64.1% specificity); correctly referred 773/778 tumours to an ophthalmologist (99.4% sensitivity); and correctly managed 80/144 lesions (55.6% specificity) in the community.

Optometrists safely applied the MOLES scoring system in this survey. Further measures are indicated to reduce choroidal naevi over-referral and evaluate MOLES system usage in clinical optometric practice, where some imaging modalities may not be readily available.