Abstract
Purpose :
To assess fluorescence lifetime characteristics of different areas within peripapillary atrophy and to correlate with high resolution optical coherence tomography.
Methods :
Mean fluorescence lifetimes in specific areas of peripapillary atrophy (α- and β-Zone) were measured using fluorescence lifetime imaging ophthalmoscopy (FLIO, Heidelberg Engineering, Germany). Autofluorescence of the posterior pole was excited by 473nm excitation wavelength and the decay time (lifetime) of the emitted fluorescence was detected in two spectral channels (498-560nm and 560-720nm). Additionally, High-Res-OCT (Heidelberg Engineering, Germany with axial resolution of up to 3 µm) was performed through the peripapillary atrophy and the optic nerve head. Structural correlation between FLIO and High-Res-OCT was performed. Fluorescence lifetimes of the fovea, retina and the optic nerve head were measured as reference.
Results :
A total of 30 eyes of 19 subjects (5 female, 14 male) with peripapillary atrophy were included. α-Zone atrophy was identified in all 30 eyes, whereas β-Zone atrophy was found in 22 eyes. Fluorescence lifetimes in the short spectral channel (498-560nm) showed a mean (± standard deviation) of 580ps (±104) in the α-Zone and 1347ps (±242) in the β-Zone compared to 364 ps in the foveal center, 439 ps in the perifoveal retina and 1280 ps in optic nerve head. The long spectral channel (560-720nm) showed a mean lifetime of 538ps (±79) in the α-Zone and 1067ps (±228) in the β-Zone compared to 451 ps in the foveal center, 483 ps in the perifoveal retina and 1168 ps in optic nerve head. Areas of different fluorescence lifetimes correlated with structural findings in the High-Res-OCT. Detailed analysis of the β-Zone revealed specific lifetimes corresponding to individual retinal layer structures.
Conclusions :
This study shows a characteristic fluorescence lifetime distribution pattern of peripapillary atrophy. The α-Zone showed slightly elongated lifetimes compared to retinal lifetimes possibly due to irregularities of the retinal pigment epithelium (RPE). The β-Zone was characterized by long lifetimes corresponding to the absence of the RPE, similar to lifetimes originating from the optic nerve. Fluorescence lifetime analysis of the peripapillary atrophy reveals details of specific retinal layers and structures.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.