After examining 1,713 eyes to describe related histopathological signatures of optic disc drusen (ODD), researchers in Denmark noted a prevalence of 1.8% within their study cohort. They determined that large, deep ODD might cause crowding and herniation of axons in the optic nerve head; this may in turn lead to a thickened superﬁcial retinal nerve ﬁber layer (RNFL), pseudopapilledema and localized peripapillary axonal distension (LPAD). OCT data showed that, in older patients with large, superficial ODD, disc elevation often disappears and RNFL thickness decreases.
The retrospective observational case series study assessed and re-evaluated eyes enucleated between 1980 and 2015. Researchers found ODD of different sizes in the 31 eyes, with elevated discs in 15 (54%), edematous axons in three and LPAD in five.
The study concluded that continuous calciﬁcation of ODD might be sustained in otherwise healthy optic nerve head tissue as the growing ODD results in further crowding and herniation of the axons in the optic nerve head, leading to pseudopapilledema and LPAD. Crowding of nerve ﬁbers might also lead to visual ﬁeld defects and visual loss as the ODD progresses in time.
|Skougaard M, Heegaard S, Malmqvist L, Hamann S. Prevalence and histopathological signatures of optic disc drusen based on microscopy of 1713 enucleated eyes. Acta Ophthalmol. July 1, 2019. [Epub ahead of print].|