Clinical presentation: A middle-aged male presented with longstanding visual field loss secondary to bilateral optic nerve head drusen (ONHD) since childhood. His medical history was significant for hypertension and T2DM non-insulin dependent and positive family history of ONHD (M) and DM (F). On examination, the BCVA was 20/20-2 OU with a trace rAPD OD. Biomicroscopy of the anterior segment was unremarkable and ocular pressure was within normal limits OU. Dilated fundus examination revealed extensive optic nerve disc drusen OU and retinal hemorrhages and exudates in the inferonasal macula adjacent to the disc margin.
Imaging Findings: Optical coherence tomography angiography (OCT-A) identified a small juxtapapillary choroidal neovascular membrane (CNVM) inferonasal to the macula correlating with the area of retinal hemorrhage and exudates. Traditional intravenous angiography methods showed late leakage on fluorescein angiography (inferonasal macula) consistent with a juxtapapillary CNVM OD. The optic disc drusen are striking on both the fundus photos (Fig. 1) and particularly the autofluorescence (Fig. 2). Swept Source OCT (Triton, Topcon) also nicely illustrated both the juxtapapillary subretinal fluid and optic disc drusen.
Discussion Points: Approximately 3.4 per 1000 have clinically evident ONHD while 10-20 per 1000 were reported in autopsy studies. ONHD are acellular, calcified bodies usually located anterior to the lamina cribosa and formed early in life. There is a higher prevalence in Caucasians and genetic predisposition has been implicated in its pathogenesis. ONHD is associated with several complications including retinal vascular occlusion, anterior ischemic optic neuropathy, and CNVM. OCT-A imaging allows for precise in vivo localization of the retinal and choroidal vasculatures, including the peripapillary network. Thus, it can be a valuable and noninvasive tool for the detection of ONHD bur also for its complications and prognosis.