Involvement of circulatory disturbance in optic disk melanocytoma with visual dysfunction

This study aims to examine the relationship between ocular circulation changes and visual field defects in optic disk melanocytoma (ODM).

Five eyes of five patients were enrolled in this study. All patients were diagnosed with ODM in the Department of Ophthalmology, Hokkaido University Hospital from March 2009 to November 2017. Ophthalmological data including optical coherence tomography angiography (OCTA) and laser speckle flowgraphy (LSFG) findings were retrospectively analyzed.

The five ODM cases consisted of two females and three males. Ages of the patients ranged from 47 to 82 years (mean 54 years). Follow-up periods were from 4 to 105 months. Fluorescein angiography showed hypo-fluorescence throughout the examination in all four eyes examined with this modality. OCTA detected dense blood vessel networks in the tumor in two out of the five eyes. Nasal visual field defects were found in two other eyes, which were correlated with locations of tumors free of vessel networks. One ODM eye without marked visual field defects and pigmentations showed lower mean blur rates determined by LSFG in optic disk vessels and tissue circulations than those in the contralateral eye. During follow-up, there was no tumor enlargement in any case.

This study showed the relationship between the deficit of blood vessel networks and visual field defects in ODM patients. LSFG demonstrated reduced blood flow in the tumor, suggesting that circulatory disorder caused by the optic disk tumor might be correlated with visual field defect.