Drusen and Age-Related Scattered Hypofluorescent Spots on Late-Phase Indocyanine Green Angiography, a Candidate Correlate of Lipid Accumulation

Purpose: Age-related scattered hypofluorescent spots on late-phase indocyanine green angiography (ASHS-LIA) might represent fundus aging and neutral lipid accumulation. The present study was conducted to determine the association between drusen and ASHS-LIA and to provide further evidence for our hypothesis. Methods: Patients who underwent indocyanine green angiography (ICGA), fundus fluorescein angiography (FFA), and spectral-domain optical coherence tomography (SD-OCT) at the Zhongshan Ophthalmic Center from January 2014 to March 2018 were reviewed. Patients with soft drusen or ASHS-LIA in the fellow eyes were included in this study. Results: A total of 345 patients aged 33 to 87 years (mean: 66.1 ± 8.4 years) were included in this study. Results showed that all patients had ASHS-LIA, among them, 70 patients (20.3%) had concurrent soft drusen, while 156 patients (45.2%) had concurrent hard drusen. Furthermore, the incidence of soft drusen was 8.9% (10/112), 21.2% (41/193), and 47.5% (19/40), respectively, in the different grades of ASHS-LIA and significantly increased with the grade of ASHS-LIA (all P < 0.01). In addition, soft drusen were located inside the ASHS-LIA in all cases and both soft drusen and ASHS-LIA presented as hypofluorescence on late-phase ICGA, while hard drusen were located outside the ASHS-LIA and presented as hyperfluorescence on late-phase ICGA. Conclusions: Soft drusen might occur in the presence of ASHS-LIA, and were correlated with the grade of ASHS-LIA. Based on the association between drusen and ASHS-LIA and their ICGA characteristics, we hypothesized that ASHS-LIA might be a candidate correlate of lipid accumulation in Bruch's membrane.