Amy C. Schefler, MD (Miami, FL), Brandy Hayden (Miami, FL), David H. Abramson, MD (New York, NY), Timothy G. Murray, MD (Miami, FL)

PURPOSE:

This study characterizes the echographic features of optic nerve head melanocytoma as detected by standard 10mHz and high-resolution 20 mHz ophthalmic ultrasound.

METHODS:

A retrospective chart review of all patients diagnosed with melanocytoma of the optic nerve head was performed for all patients seen at two different institutions from January, 1990 through January, 2005. All patients who had undergone standard ophthalmic A-scan and Bscan echography at the initial visit were included in the study. A prospective arm of the study was then performed in which as many patients as possible (17 patients, 61%) were reevaluated
with high resolution 20mHz ultrasound in order to determine whether these lesions could be better characterized with this modality.

RESULTS:

Forty-four percent (46%) of patients had dome-shaped lesions on ultrasound, 43% had only mild elevations, and 11% appeared flat. The maximum elevation of any lesion was 4.0 mm. The vast majority of lesions had high internal reflectivity and avascularity. Four lesions (14%) demonstrated interval growth during the study period. Mean follow-up for all patients was nearly 9 years. High resolution ultrasound enabled enhanced accuracy for detection of lesion dimensions and risk factors for growth and malignant transformation.

CONCLUSION:

This study demonstrates a new and important role for the use of echography in optic nerve head melanocytoma. Ultrasound is particularly useful for identifying high-risk growth characteristics and following the lesions over time. These tumor characteristics can be most reliably followed with the 20 mHz technology. Use of echography can aid in diagnosing early malignant transformation and can prevent unnecessary treatments in stable lesions.