Purpose
To analyze choroidal thickness maps (CMs) and fundus autofluorescence (FAF) in patients with non-exudative age-related macular degeneration (AMD) using swept source optical coherence tomography (Swept-OCT).
Methods
CMs imaging were obtained using Swept-OCT (Topcon Medical Systems, Oakland, NJ). A standardized imaging protocol was performed in all patients: radial diameter 9.0 mm scans through the foveal center with automated ETDRS choroidal thickness map (9 sectors). FAF images obtained using Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany) were overlay with Swept-OCT. Eyes were divided in: Group 1, early non-exudative AMD with at least one large soft drusen (>125 µm); Group 2, early non-exudative AMD with intermediate distribution of reticular pseudodrusen; Group 3, late non-exudative AMD / Geographic atrophy (GA); and Group 4, control subjects with no ocular diseases The mean thickness was automatically measured in the “center” sector within 1 mm from the center of the fovea, in 4 “inner ring” sectors (superior, inferior, nasal, and temporal; 1 to 2 mm from the center of the fovea), and in 4 “outer ring” sectors (superior, inferior, temporal, and nasal; 2 to 3 mm from the center of the fovea).
Results
A total of 72 eyes of 72 consecutive patients with non-exudative AMD (56 females; mean age 79.1±8.1 years) were included in the analysis. The mean whole choroidal thickness were 157 ± 55 µm, 126 ± 52 µm, 114 ± 38 µm et 18 8± 74 µm (in group 1,2,3 and 4 respectively). The CMs were significantly reduced in Group 2, and 3 compared with group 1 and 4 (p <0.05). A similar reduction in CMs were found in Group 3, compared with group 2. (p 0.001).<br /> On the basis of FAF features in Group 3, a total of 70 ETDRS sectors were categorized as hypo-FAF (sectors characterized by > 50% absence of FAF), and 83 ETDRS sectors were categorized as hyper/iso-FAF (sectors characterized by ≤ 50% absence of FAF). No statistical differences in CMs were found among ETDRS sectors with >50% and <50% atrophic (HypoFAF) or preserved retina (Hyper/IsoFAF) in GA group (p 0.07).
Conclusions
CMs reveal a thinner choroid in eyes with GA and Pseudodrusen AMD patients compared with drusen and control subjects on swept OCT. CM in the different ETDRS sectors was not associated with FAF features in eyes with GA.