Field guide: optic disc drusen

Lorcan Butler’s August 27, 2024 review in *Ophthalmology Times Europe* set out a practical guide to optic disc drusen, a finding that can resemble true optic-nerve swelling and complicate triage in glaucoma and neuro-ophthalmology clinics. Butler described optic disc drusen as hyaline-like fatty and protein deposits within the optic nerve head and said the condition is often labelled pseudopapilloedema when it elevates the disc. The article focused on how clinicians can separate drusen from papilloedema and from other causes of disc edema using targeted imaging rather than a single test. Butler wrote that the distinction can be difficult even for experienced clinicians. ### Why are optic disc drusen easy to mistake for papilloedema? Butler wrote that optic disc drusen can produce a “lumpy-bumpy” optic disc appearance that is especially misleading in children, where it may mimic suspected papilloedema. The review said 60% of drusen are buried below the disc surface, where they may be non-calcified, and 70% are bilateral. (europe.ophthalmologytimes.com) EyeWiki and other ophthalmic references describe the same diagnostic problem from another angle: true papilledema usually shows vascular congestion and other signs of swelling, while drusen can elevate the disc without the same edema pattern. Visual-field defects can also occur with drusen, which means an abnormal field test does not by itself settle the diagnosis. (europe.ophthalmologytimes.com) ### Which imaging tests did the review say matter most? Fundus autofluorescence, B-scan ultrasonography and optical coherence tomography were the main imaging tools discussed in the review and related ophthalmic literature. Butler wrote that fundus autofluorescence can help visualize surface drusen but is less useful for buried drusen. He said enhanced depth imaging, or EDI, has superseded autofluorescence for buried lesions and is regarded by the Optic Disc Drusen Society as the optimal drusen imaging method. (eyewiki.org) B-scan ultrasonography remains useful because calcified drusen appear highly reflective and can cast posterior acoustic shadowing, according to EyeWiki, Medscape and the University of Iowa’s EyeRounds atlas. Those sources also describe OCT findings that help distinguish drusen from edema, including deeply located signal-poor cores with hyperreflective borders on enhanced-depth scans. (modernretina.com) ### What clues point toward true optic-nerve edema instead? Medscape says swelling of the peripapillary retinal nerve fiber layer is almost always evident in true papilledema or papillitis, making OCT a useful adjunct when edema is the concern. Review articles on differentiating disc drusen from papilledema also point to globe contour and Bruch’s membrane shape as clues on imaging, with edema more likely to produce smooth, uniform elevation and secondary signs linked to raised intracranial pressure. (eyewiki.org) EyeWiki says clinicians should also look for whether the disc is hyperemic and whether there is leakage on fluorescein angiography when the diagnosis remains uncertain. Those features support true edema rather than pseudopapilloedema from drusen. ### Why does the distinction matter in everyday practice? Butler framed the issue as a triage problem: missing true papilloedema can delay work-up for raised intracranial pressure, while overcalling edema can send patients into unnecessary neurologic testing. (emedicine.medscape.com) The review’s emphasis on choosing the right modality reflects that buried drusen are common and that no single exam finding is definitive in every patient. (eyewiki.org) EyeWiki says optic disc drusen are often asymptomatic but can be associated with gradual visual-field loss, enlarged blind spots and, more rarely, central visual loss or anterior ischemic optic neuropathy. That overlap with glaucoma and neuro-ophthalmic complaints helps explain why imaging interpretation matters as much as image acquisition. ### Where can clinicians find the full guide and related material? (europe.ophthalmologytimes.com) *Ophthalmology Times Europe* listed Butler’s article in its July/August 2024 issue under the subtitle “Clinical associations, imaging strategies and establishing a differential diagnosis from pseudopapilloedema.” The article page and the issue archive were both available as of May 18, 2026. (eyewiki.org) The broader literature Butler’s review sits alongside includes multimodal imaging papers in the *American Journal of Ophthalmology* and a 2025 systematic review in *Diagnostics*, both of which describe OCT, autofluorescence, near-infrared reflectance and ultrasound as complementary rather than interchangeable tools. (ajo.com) (europe.ophthalmologytimes.com)