Optical Coherence Tomography and Autofluorescence Findings in Areas with Geographic Atrophy Due to Age-Related Macular Degeneration

Abstract

To analyze outer retinal changes within the atrophic lesion in patients with geographic atrophy (GA) secondary to age-related macular degeneration. Twenty-one simultaneously obtained fundus autofluorescence (FAF, excitation, 488 nm; emission, 500-700 nm) and spectral-domain optical coherence tomography (SD-OCT) scans (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany) of 21 GA patients (mean age, 75.1 ± 7.4 years) were included and separately exported. Two readers independently graded the following parameters: width of the atrophic lesion on the FAF image at the site where the SD-OCT scan had been placed; and on the SD-OCT image, widths of the linear disruption of the outer nuclear layer, the external limiting membrane, and the inner and outer segments of the photoreceptor layer (IPRL) and width of the disruption of choroidal signal enhancement. Results. The mean width of the atrophic lesion by FAF imaging was 2.83 mm (95% confidence interval, 2.37-3.29). The linear disruption of choroidal hyperreflectivity showed the closest agreement with 2.83 mm (2.37-3.28), whereas the linear width of disrupted IPRL was larger (3.10 mm; 2.65-3.55). Overall, the width of the atrophic lesion correlated significantly with all five SD-OCT parameters (P < 0.0001, r = 0.96-0.99). These findings demonstrate that the atrophic lesions identified with FAF represent irreversible underlying outer retinal damage. The observation that the width of the atrophic lesion identified with FAF, although significantly correlated but not identical with the width of disruption within the cellular layers of the retina, is consistent with the dynamic nature of the disease. (ClinicalTrials.gov numbers, NCT00393692, NCT00599846.).