Abstract
Purpose: :
To report evaluate the echographic features of optic nerve head melanocytoma as detected by standard 10mHz and high–resolution 20mHz ophthalmic ultrasound.
Methods: :
Retrospective review of 33 patients with melanocytoma of the optic nerve head studied with echography. All patients were evaluated with standard ophthalmic A–scan and B–scan ultrasound and 20 (61%) underwent high–resolution ultrasound at baseline and on repeat examination.
Results: :
Forty–four percent (44%) of patients had dome–shaped lesions on ultrasound, 44% had only mild elevations, and 11% appeared flat. The maximum elevation of any lesion was 3.5 mm. The vast majority of lesions had high internal reflectivity (97%) and avascularity (85%), but there were exceptions. Mean follow–up for all patients was 9 years. High resolution ultrasound enabled enhanced accuracy for detection of lesion dimensions and exact location with respect to the optic nerve. Specific cases in which high–resolution ultrasound only was able to delineate important tumor features will be highlighted.
Conclusions: :
Recent research has indicated that a significant percentage of optic nerve head melanocytomas grow if followed long–term (32% growth at 10 years), and that risk factors for growth include: tumor thickness, intrinsic vascularization, and shape. In this study, we demonstrate a new and important role for the use of ultrasound in this disease in identifying and following patients with these high–risk characteristics for growth. These tumor characteristics can be accurately detected with 10mHz ultrasound and most reliably followed with the 20mHz technology. Use of these modalities can aid in distinguishing the melanocytomas that grow from choroidal melanomas and in avoiding unnecessary treatments.
Keywords: tumors • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • oncology