Longitudinal changes in quantitative autofluorescence during progression from intermediate to late age related macular degeneration.
PURPOSE To prospectively investigate the development of quantitative autofluorescence (qAF) during progression from intermediate to late age related macular degeneration (AMD) METHODS qAF images from patients with intermediate AMD were acquired every three months with a Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany) using a built in autofluorescence reference. The association between changes in longitudinal qAF and progression towards late AMD was assessed using Cox regression models with time dependent covariates. RESULTS One hundred twenty one eyes of 71 patients were included and 653 qAF images were acquired. Twenty one eyes of 17 patients converted to late AMD (median follow up: 21 months; 12 eyes: atrophic AMD; 9 eyes: neovascular AMD) The converting patients' mean age was 74.6 4.4 years. Eleven eyes in the converting group (52.4% were pseudophakic. The presence of an intraocular lens did not affect the qAF regression slopes (p>0.05) The median change for atrophic AMD was 2.34 qAF units/3 months and 0.78 qAF units/3 months for neovascular AMD. A stronger decline in qAF was significantly associated with an increased risk of developing atrophic AMD (HR=1.022, p<0.001) This association, however, was not present in the group progressing towards neovascular AMD (HR=1.001, p=0.875) CONCLUSION The qAF signal declines with progression to atrophy, contrary to developing neovascularization. qAF may allow identification of patients at risk of progressing to late AMD and benefits individualized patient care in intermediate AMD.
Retina