Relationship between reticular pseudodrusen and choroidal thickness in intermediate age-related macular degeneration.

ImportanceReticular pseudodrusen (RPD) is strongly associated with late age-related macular degeneration (AMD) but their aetiology remains unknown. RPD have been associated with reduced choroidal thickness (ChT) but most studies are limited by small sample size and varying severity of AMD. BackgroundTo investigate the relationship between choroidal thickness and RPD in eyes with intermediate AMD (iAMD), controlling for variables known to influence ChT. DesignRetrospective cohort study. ParticipantsParticipants were recruited from Centre for Eye Research Australia. MethodsColour fundus photographs, fundus auto fluorescence, near-infrared and spectral-domain ocular coherence tomography (OCT) were graded for RPD. ChT was measured from enhanced-depth imaging OCT scans at the centre of fovea, 1500 and 3000m nasal, temporal, superior and inferior from centre of fovea. Main Outcome MeasuresChT between RPD and non-RPD group. ResultsA total of 297 eyes from 152 subjects were included. A total of 84 (28%) had RPD and were older than non-RPD group (75.1 5.4 years and 68.7 +/- 6.9 years, respectively; P < 0.001). In unadjusted analysis, the RPD group was significantly associated with thinner choroids across all measured locations (P 0.022). After adjustment for variables, the presence of RPD was no longer associated with ChT (P 0.132 for all locations) but age (P < 0.001) and refractive error (P = 0.002) remained significantly associated with ChT. Conclusions and RelevanceAge and refractive error, rather than RPD, was significantly associated with reduced ChT in eyes with iAMD. Choroidal insufficiency may be a less important variable in RPD aetiology than previously considered.