Age-Related Changes in Optic Disc Drusen Visibility and Their Anatomical Correlates.

Background: The visibility of optic disc drusen (ODD) increases with age, yet the anatomical changes related to this finding have not been established. Enhanced-depth imaging optical coherence tomography (EDI-OCT) provides a detailed imaging modality to evaluate the anatomical location of ODD within the optic nerve head. The aim of this study was to determine the factors contributing to the age-related increased visibility of ODD using EDI-OCT.

Methods: A retrospective observational study was conducted on patients who were diagnosed with ODD using EDI-OCT of the optic nerve head according to the Optic Disc Drusen Studies Consortium guidelines from November 2017 to December 2023. Data on ophthalmoscopic ODD visibility, OCT-based anatomical location, with superficial ODD being above and deep ODD being below Bruch Membrane Opening, peripapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell layer volume were collected and analyzed.

Results: A total of 411 eyes were included for analysis. ODD visibility increased significantly with age, with 6% being visible in the first decade of life and 90% being visible in patients >70 years of age based on fundus photography. The anatomical location of ODD was consistent across all age groups. RNFL thickness exhibited an age-related decline, with a mean thickness of 153 µm in the first decade decreasing to 70 µm in patients >70 years of age. In 17% of cases, ODD were classified as buried on fundus photography despite being superficial on OCT.

Conclusions: Our study revealed that with age, ODD become more visible, while their anatomical location in the optic nerve head remains stable and the peripapillary RNFL thickness decreases. This suggests that RNFL thinning is the primary contributor to the age-related increased ODD visibility.