Session Title: AMD I
Session Date/Time: Thursday 26/09/2013 | 08:30-10:30
Paper Time: 09:58
Venue: Hall 1 (Level 2)
First Author: M.Fleckenstein GERMANY
Co Author(s): A. Boker C. Brinkmann S. Schmitz-Valckenberg R. Fimmers
In eyes with advanced dry age-related macular degeneration (geographic atrophy - GA) the fovea may be spared for some time despite atrophy enlargement. The purpose of this study was to determine directional spread in the context of a natural history study in eyes with foveal sparing.
In the context of the Fundus Autofluorescence in Age-related Macular Degeneration (FAM) Study (NCT00393692), patients with GA and foveal sparing were examined longitudinally.
Retinal imaging included confocal scanning-laser-ophthalmoscopy (cSLO) fundus autofluorescence (FAF, exc. 488nm, em. > 500nm) and near-infrared reflectance (IR) imaging (Spectralis HRA+OCT or HRA2, Heidelberg Engineering). Peripheral vs. central spread was analyzed based on measurements in processed cSLO images. Linear mixed effect models were used to model the development of the area of GA and the sparing of the central macula over time. In addition, a similar model was used to describe the development of the radius of both areas.
A total of 46 eyes of 42 patients aged 77.4 ± 9.1 years were analyzed over a median follow-up time of 11.6 months (min 2.5, max 71.9 months). The mean size of the entire atrophic lesions was 13.3 ± 6.0 mm2 and of the residual foveal islands was 0.82 ± 0.61 mm2 at baseline, respectively. Mean enlargement of the area of GA was 2.36 ± 0.22 mm2/year while the area of the preserved foveal retina showed a mean regression of -0.23 ± 0.05 mm2/year. Analysis of the radius of both areas revealed a peripheral progression of 0.17 ± 0.02 mm/year and a central regression of -0.08 ± 0.01 mm/year.
The results indicate that centrifugal vs. centripetal spread of GA can be quantified based on standardized image analysis and that the directional extension over time differs significantly. Although protective factors underlying the foveal sparing phenomenon are yet unknown, the kinetics suggests that local factors are operative in topographic atrophy progression. Natural history data on the preservation of a residual foveal island are helpful to model the disease process and to design interventional clinical trials aiming at prolonging foveal survival and, thus, central visual acuity.