Abstract
Purpose:
Although reticular pseudodrusen (RPD) are often first observed in the upper part of the macula, the reason remains unclear. Our purpose in the current study is to evaluate the relationship between the outer retinal layer and the choroid using divided thickness map in Japanese patients with RPD.
Methods:
Eighteen eyes of 14 patients (average 83 years old) in RPD, determined by color fundus photograph, were included. The eyes with exudative age-related macular degeneration were excluded because of indetermination. 3D-scan was taken using swept source optical coherence tomography (DRI-OCT, Topcon, Japan). Segmentation lines of outer retinal layer (superior border of outer plexiform layer to retinal pigment epithelium; RPE) and choroidal layer (RPE to chorioscleral interface; CSI) were drawn manually within 6mm at the macula. All areas were divided by 9 sectors according to ETDRS grid map style. The eyes in age-matched patients (18 eyes of 17 patients) without retinal and choroidal disorder were also examined as control.
Results:
Mean outer retinal layer thickness within ETDRS map was significantly thinner in RPD than control (133±12µm vs 143±8µm, P<0.01). Mean choroidal thickness within ETDRS map was also significantly thinner in RPD than control (125±39µm vs 216±77µm, P<0.01). The thicknesses of outer retinal layer and choroid in all areas of ETDRS map were correlated with each other (r=0.22, P<0.01). Especially, the significant correlation was reached at upper areas (inner and outer quadrant) of ETDRS map (r=0.37, P=0.03).
Conclusions:
Thinning of not only choroid but also outer retinal layer indicates the impairing of the photoreceptors in RPD. The correlations of thicknesses between outer retinal layer and choroid at upper quadrant area may elucidate the origin of RPD development.<br />