LAUSR

INTRODUCTION Drusen and pigmentary abnormality are found as the hallmark to predict progression of age-related macular degeneration (AMD). In Asian populations, exudative AMD often appears in the absence of drusen but are rather accompanied by pigmentary abnormality. Recently, shallow irregular retinal-pigment-epithelium (RPE) elevations (SIRE) has been shown as a sign of subclinical non-exudative macular neovascularization. In this study, we aimed to investigate the characteristics of optical coherence tomography (OCT) findings including SIRE before the appearance of exudative AMD. METHODS We retrospective reviewed 32 cases of exudative AMD that occurred in the fellow eye within the 5-years-observation period. Color fundus photography, OCT, and fluorescein/indocyanine green angiography at the beginning of observation and at the time when exudative AMD appeared were examined to diagnose SIRE and the subtype of exudative AMD. RESULTS Exudative AMD were found in 19 eyes with large drusen and 13 eyes without large drusen. Mean sub-foveal choroidal thickness without large drusen were significantly thicker than those with large drusen (336 ± 109 and 220 ± 96 μm, respectively; mean± SD). Six eyes with pachychoroid neovasculopathy, 4 eyes with Type 1 macular neovascularization, and 3 eyes with PCV had occurred in the fellow eye without large drusen. Among those, 6 eyes had been accompanied by SIRE with a greatest transverse linear dimension of 1 mm or more at the beginning of observation-period. Besides, small RPE elevations with a longest diameter of less than 1 mm had been observed in other 5 eyes. Three cases of polypoidal choroidal vasculopathy had originated from small RPE elevations. Moreover, pachyvessels, choriocapillaris thinning, or choroidal hyperpermeability were observed with SIRE or small RPE elevation. CONCLUSIONS There is a non-drusen type of exudative AMD that originates from small RPE elevations as well as SIRE.