natural history of drusen morphology in agerelated macular degeneration using spectral domain optical coherence tomography purpose to characterize the natural history of drusen using spectraldomain optical coherence tomography sdoct imaging of eyes from patients with nonexudative agerelated macular degeneration amddesign prospective longitudinal natural history studyparticipants we included 143 eyes of 100 patients with at least 6 months of followupmethods patients with drusen secondary to nonexudative amd were scanned using the cirrus sdoct instrument eyes were imaged using the 200 200 ascan raster pattern contained within a 6 6 mm area custom software was used to quantify volumetric changes in drusen over a period of 6 months and for as long as 24 months drusen volume and drusen area were measured within circular regions centered at the fovea having diameters of 3 and 5 mm the measurements were analyzed using a suitable scale transformation for drusen volume a cube root transformation strategy was usedmain outcome measures change in drusen volume and area over timeresults we analyzed 143 eyes of 100 patients with 69 eyes followed for 6 months 106 eyes followed for 12 months 48 eyes followed for 18 months and 48 eyes followed for 24 months the 3 mm circle baseline drusen volume ranged from 00009 to 07479 mm3 or 010 to 091 mm using the cube root scale on average drusen volume and drusen area increased over time with the magnitude of the increase dependent on the length of followup p 0001 3 mm circle in the eyes with a decrease in drusen volume the magnitude of this decrease was dependent on the baseline drusen volume p 0001 3 mm circle and independent of the followup interval after 12 months drusen volume increased in 48 of eyes remained stable in 40 and decreased in 12conclusions imaging with sdoct revealed a dynamic undulating growth pattern for drusen with a tendency for drusen to increase in volume and area over time an appreciation of the quantitative changes in drusen volume over time using sdoct imaging provides a novel strategy for following normal disease progression and for identifying novel clinical trial end points to be used when investigating therapies for the treatment of nonexudative amdfinancial disclosures proprietary or commercial disclosure may be found after the references