Optical coherence tomography angiography findings of an optic disc melanocytoma in a glaucoma eye

To determine the optical coherence tomography angiography (OCTA) characteristics of a case of optic disc melanocytoma (ODM) associated with glaucomatous visual field and retinal nerve fiber layer (RNFL) defects in normal tension glaucoma.

The left eye of a 37-year-old female patient followed for a stable ODM for 10 years was investigated with OCT, OCTA, fluorescein (FA), and indocyanine green (ICGA) angiography. The ODM was unchanged, but a previously unknown inferotemporal neuroretinal rim loss and inferotemporal and superotemporal wedge shape glaucomatous RNFL thinning were seen with corresponding glaucomatous visual field defects. The intraocular pressure was 12 mmHg without treatment.

In the area of the ODM, FA showed minimal vasculature, and week staining in the late phase, while ICGA showed no signal. In contrast, OCTA showed a dense vasculature in both the superficial and deep layers of the melanocytoma, which was clearly separated from the capillaries of the peripapillary retina. OCTA also showed reduced peripapillary perfusion in the areas of the glaucomatous RNFL bundle defects.

In the presented case of a stable ODM and newly detected normal tension glaucoma, OCTA provided more information on perfusion than FA and ICGA which are limited by the heavy pigmentation of the ODM. OCTA also showed a similarly decreased capillary perfusion in both RNFL bundle defects suggesting that the structural damage was related to glaucoma and not compression by ODM. These results suggest that OCTA may be a method preferred over conventional angiography in ODM cases.