title: Drusen volume development over time and its relevance to the course of age-related macular degeneration.
abstract: OBJECTIVE
  To quantify the change in drusen volume over time and identify its prognostic value for individual risk assessment.
  
  
  METHODS
  A prospective observational study over a minimum of 3 years and maximum of 5 years and follow-up examination every 3 months was conducted at the ophthalmology department of the Medical University of Vienna. 109 patients presenting early and intermediate age-related macular degeneration (AMD) were included, of which 30 patients concluded a regular follow-up for at least 3 years. 50 eyes of 30 patients were imaged every 3 months using spectral-domain and polarisation-sensitive optical coherence tomography (OCT). Drusen volume was measured using an automated algorithm. Data of a 6-month follow-up were segmented manually by expert graders.
  
  
  RESULTS
  Gradings from 24 000 individual B-scans showed solid correlation between manual and automated segmentation with an initial mean drusen volume of 0.17 mm3. The increase in drusen volume was shown to be comparable among all eyes, and a model for long-term drusen volume development could be fitted as a cubic polynomial function and an R2=0.955. Spontaneous drusen regression was observed in 22 of 50 eyes. In this group, four eyes developed choroidal neovascularisation and three geographic atrophy.
  
  
  CONCLUSIONS
  Drusen volume increase over time can be described by a cubic function. Spontaneous regression appears to precede conversion to advanced AMD. OCT might be a promising tool for predicting the individual risk of progression of AMD.
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Ferdinand G
authors.initials: FG
authors.lastname: Schlanitz
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Baumann
authors.affiliation: Institute of Environmental Health, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Kundi
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Sacu
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Baratsits
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Scheschy
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Abtin
authors.initials: A
authors.lastname: Shahlaee
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Tamara J
authors.initials: TJ
authors.lastname: Mittermüller
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Alessio
authors.initials: A
authors.lastname: Montuoro
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Roberts
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Pircher
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Christoph K
authors.initials: CK
authors.lastname: Hitzenberger
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D018450:Disease Progression; D005260:Female; D005451:Fluorescein Angiography; D057092:Geographic Atrophy / Q000473:pathology; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D015593:Retinal Drusen / Q000175:diagnosis*; D041623:Tomography, Optical Coherence / Q000379:methods
keywords: Degeneration; Imaging; Retina