Followup of a Peripaillary Choroidal Nevus

Approximately 1 choroidal nevus per 5000 per year converts to a choroidal melanoma. To monitor for this, it is typical to take periodic photographs, often once per year. Not all nevi receive this attention, especially small ones (e.g., < 1 disc diameter in greatest diameter). In this example, a fairly large nevus adjacent to the optic disc has not changed in size over 10 years of observation. Drusen can change on the surface of the nevus. For example, a druse has appeared at the yellow arrow, and disappeared at the blue arrow. This is normal, and not a concern. One should note that conditions of photography change from year to year, and such differences in lighting, contrast, and cameras need to be taken into account in interpreting the photographs. In this example, the photograph from 2003 is brighter than the one from 2013, which will artifactitiously change the appearance of the border of the nevus. The most relaible method of comparison is checking lesion borders against unchanging landmarks, such as blood vessel crossings.