Stereo fundus photography in the diagnosis of optic disc melanocytoma

Abstract

Editor, O ptic disc melanocytoma is a benign, dark brown to black tumour that usually occurs on or adjacent to the optic nerve head. Although most tumours are asymptomatic, some patients may experience visual symptoms related to neural or vascular compression or tumour necrosis (Shields 2000). Here, we present the stereo photographic findings in a patient with a small optic disc melanocytoma. A 43-year-old asymptomatic woman was found on routine examination to have a pigmented optic nerve tumour in her left eye. Otherwise, both eyes were normal with a visual acuity of 6 ⁄6. Ophthalmoscopic evaluation of the left eye revealed a slightly elevated, darkly pigmented tumour located eccentrically over the inferior edge of the optic disc (Fig. 1). An anaglyph stereo fundus photograph that can be viewed with standard red ⁄ green glasses, readily available in the examination equipment of most ophthalmic departments, is shown in Fig. 2. This image illustrates the three dimensionality of the tumour and the scattering of fine pigment clumps into the adjacent retinal nerve fibre layer. The pigmented infiltration of the normally transparent retina leads to fibrillated tumour margins partially obscuring the retinal vessels. The tumour was undetectable on ultrasonography. By fluorescein angiography, pooling of dye was seen in a limited area of secondary disc oedema in the temporal part of the lesion. Optical coherence tomography revealed a Fig. 1. Conventional fundus photograph of the left eye showing a small melanocytoma involving the inferior part of the optic disc.