Longitudinal analysis of reticular drusen associated with age-related macular degeneration using combined confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography imaging

Purpose: To evaluate longitudinal variations of reticular drusen (RDR) in age-related macular degeneration using confocal scanning laser ophthalmoscopy (cSLO), near-infrared reflectance (NIR) and spectral-domain optical coherence tomography (SD-OCT) imaging. Methods: Eighteen eyes of 12 patients with RDR (median observational time 5 months, range 3-10) were included. Changes over time in the en face cSLO NIR images, the identical SD-OCT B scan (simple approach) and the dense SD-OCT volume scans (11 µm between B scans, detailed approach) for 5 preselected RDR lesions were analysed, respectively. Results: Nineteen of 90 (21%) lesions were no longer detectable at the follow-up examination with the simple SD-OCT approach (increase 7/decrease 48/unchanged 15/not gradable 1). By contrast, no disappearance of single lesions was noted for both cSLO (3/8/61/18) and detailed SD-OCT image analysis (67/22/1/0). Within the dense SD-OCT volume scan, a median change of individual lesion height of 10 µm/year was determined. Conclusions: The findings indicate a recordable progression of RDR lesions in lateral and vertical dimensions. Using dense SD-OCT volume scans, individual RDR lesion progression can be quantified and may be applied in future longitudinal studies.