Optic Nerve Head Anatomy and Vascular Risk Factors in Patients With Optic Disc Drusen Associated Anterior Ischemic Optic Neuropathy

Abstract

Optic disc drusen (ODD) is an anatomical risk factor for nonarteritic anterior ischemic optic neuropathy (NA-AION). This study aimed to investigate the anatomical and vascular risk factors of patients with ODD-AION (ODD-associated NA-AION) and compare them with similar data from patients with nODD-AION (NA-AION without ODD). Case-control study. Thirty-four ODD-AION and 34 nODD-AION patients who had all been systematically optical coherence tomography scanned using a standardized ODD scanning protocol were retrospectively analyzed and compared regarding demographics, vascular risk factors, clinical characteristics, and specific optic nerve head anatomical characteristics. In patients with ODD-AION, the ODD were predominantly deeply located (82%) but with no significant difference in size (52% large, 48% small). When compared with nODD-AION patients, ODD-AION patients were significantly younger at the time of diagnosis (P=.012) and had fewer vascular risk factors (P=.015). The ODD-AION patients had significantly more peripapillary hyperreflective ovoid mass-like structures (PHOMS) (P < .001) and prelaminar hyperreflective lines (P < .001) as well as smaller Bruch's membrane opening diameters (P=.017) compared with nODD-AION patients. No significant differences were found between ODD-AION and nODD-AION patients regarding visual acuity, refraction, lamina cribrosa position, ganglion cell layer volume, or retinal nerve fiber layer thickness. In ODD-AION, location of the ODD within the optic nerve head is important, while the size of the ODD is not. The ODD-AION and nODD-AION patients presented with distinctly different vascular risk factors and anatomical characteristics, establishing ODD and potentially also PHOMS as independent risk factors for developing NA-AION.