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

PURPOSE: 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).

DESIGN: Case-control study.

METHODS: 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.

RESULTS: 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.

CONCLUSION: 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.