Prevalence and histopathological signatures of optic disc drusen based on microscopy of 1713 enucleated eyes

Abstract

Purpose Optic disc drusen (ODD) are calcified optic nerve head deposits. Objectives of this study were to examine the prevalence of ODD in eyes removed by enucleation and to describe related histopathological signatures of ODD and surrounding tissues. Methods The study was a retrospective observational case series study assessing and re‐evaluating enucleated eyes in Denmark from 1980 to 2015 by microscopy. Individual ODD were described based on size, number and location (superficial and/or deep) within the optic nerve. Optic nerve heads with ODD were assessed for elevated discs, retinal nerve fibre layer (RNFL) thickness, oedematous axons and presence of localized peripapillary axonal distension (LPAD) equivalent to the peripapillary hyperreflective ovoid mass‐like structures seen on optical coherence tomography. Results Microscopy of 1713 eyes revealed ODD in 31 eyes equivalent to a prevalence of 1.8%. Optic disc drusen (ODD) were seen as circular shapes of different sizes and varying number. Elevated discs were present in 15 (54%) of the cases. Thickening of the superficial RNFL was present in eyes with large deeply located ODD. For more superficial ODD of approximately same size, the RNFL was thinner. Oedematous axons were present in three eyes. Localized peripapillary axonal distension (LPAD) was seen in five eyes. Conclusions Prevalence of ODD in this study of histopathological signatures was higher than the prevalence found in clinical studies. Our results suggest that large, deep ODD might cause crowding and herniation of axons in the optic nerve head leading to a thickened superficial nerve fibre layer, pseudopapilledema and LPAD.

Multimodal Imaging Features of Optic Disc Drusen

“…10,13 PHOMS represent the distension of the crowded prelaminar peripapillary axons compressed by drusen. 23 The present cases demonstrated that the hypofluorescence of PHOMS coincided with the area loss of RPE cells containing intrinsic fluorophores. This can also explain a previous study demonstrating that PHOMS did not show autofluorescence.…”

“…Superficial ODD were defined as drusen located above Bruch's membrane opening (BMO), and deep ODD were defined as drusen located in line with or below BMO. 23 Eyes with ODD were divided into eyes with only superficial ODD, eyes with superficial and deep ODD, and eyes with only deep ODD. STATISTICAL ANALYSIS: Statistical analysis was performed using SPSS version 23.0 software (IBM, Armonk, New York, USA) for MacIntosh (New York City, New York, USA).…”

OCT Based Interpretation of the Optic Nerve Head Anatomy and Prevalence of Optic Disc Drusen in Patients with Idiopathic Intracranial Hypertension (IIH)

“…ODD are calcified deposits present from early childhood in the optic nerve head of about 2% of the background population [ 18 ]. ODD are slowly expanding in time and subsequently causing axonal damage [ 19 ]. There’s no known treatment and if one has ODD, they do not disappear.…”

Recent advances and future directions on the use of optical coherence tomography in neuro-ophthalmology

“…[ 13 ] EDI-OCT, however, has been shown to be superior compared to previous methods when evaluating ODD due to better resolution when imaging the deep ONH structures. [ 10 14 15 16 ] A primary limitation was that the majority of ODD are “buried” and difficult to visualize on examination and on B-scan ultrasound. For visible ODD, EDI-OCT and B-scan ultrasound have similar sensitivity, but there is recent evidence to suggest that EDI-OCT can identify buried ODD not seen on B-scan ultrasound.…”