title: Differentiating drusen: Drusen and drusen-like appearances associated with ageing, age-related macular degeneration, inherited eye disease and other pathological processes.
abstract: Drusen are discussed frequently in the context of their association with age-related macular degeneration (AMD). Some types may, however, be regarded as a normal consequence of ageing; others may be observed in young age groups. They also occur in a number of inherited disorders and some systemic conditions. Whilst drusen are classically located external (sclerad) to the retinal pigment epithelium, accumulations of material internal (vitread to) this layer can display a drusen-like appearance, having been variously termed pseudodrusen or subretinal drusenoid deposits. This review first briefly presents an overview of drusen biogenesis and subclinical deposit. The (frequently overlapping) subtypes of clinically detectable deposit, seen usually in the context of ageing or AMD, are then described in more detail, together with appearance on imaging modalities: these include hard and soft drusen, cuticular drusen, reticular pseudodrusen and "ghost drusen". Eye disorders other than AMD which may exhibit drusen or drusen-like features are subsequently discussed: these include monogenic conditions as well as conditions with undefined inheritance, the latter including some types of early onset drusen such as large colloid drusen. A number of systemic conditions in which drusen-like deposits may be seen are also considered. Throughout this review, high resolution images are presented for most of the conditions discussed, particularly the rarer ones, providing a useful reference library for images of the range of conditions associated with drusen-like appearances. In the final section, some common themes are highlighted, as well as a brief discussion of some future avenues for research.
authors.affiliation: University College London, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; Medical Retina Service, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK; Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, University of Leeds, St James's University Hospital, Leeds LS9 7TF, UK. Electronic address: K.N.Khan@leeds.ac.uk.
authors.forename: Kamron N
authors.initials: KN
authors.lastname: Khan
authors.affiliation: University College London, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; Medical Retina Service, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK; Department of Ophthalmology, King's College London, St Thomas' Hospital Campus, Westminster Bridge Road, London SE1 7EH, UK; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK.
authors.forename: Omar A
authors.initials: OA
authors.lastname: Mahroo
authors.affiliation: Department of Ophthalmology, Calderdale & Huddersfield NHS Foundation Trust, Acre St, Huddersfield, West Yorkshire HD3 3EA, UK.
authors.forename: Rehna S
authors.initials: RS
authors.lastname: Khan
authors.affiliation: Department of Ophthalmology, Guys & St Thomas' NHS Foundation Trust, Westminster Bridge Road, London SE1 7EH, UK.
authors.forename: Moin D
authors.initials: MD
authors.lastname: Mohamed
authors.affiliation: Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, University of Leeds, St James's University Hospital, Leeds LS9 7TF, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: McKibbin
authors.affiliation: University College London, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; Medical Retina Service, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Bird
authors.affiliation: University College London, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; Medical Retina Service, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK.
authors.forename: Michel
authors.initials: M
authors.lastname: Michaelides
authors.affiliation: University College London, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; Medical Retina Service, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK.
authors.forename: Adnan
authors.initials: A
authors.lastname: Tufail
authors.affiliation: University College London, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; Medical Retina Service, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK; Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94143, USA.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Moore
mesh_terms: D000375:Aging; D000818:Animals; D015785:Eye Diseases, Hereditary / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis* / Q000235:genetics; D012160:Retina / Q000378:metabolism / Q000473:pathology; D015593:Retinal Drusen / Q000175:diagnosis* / Q000235:genetics; D055213:Retinal Pigment Epithelium / Q000378:metabolism / Q000473:pathology
keywords: Macular degeneration; Retinal drusen; Retinal dystrophy