Choroidal structure determined by binarizing optical coherence tomography images in eyes with reticular pseudodrusen

PURPOSE To compare the choroidal structure beneath the macular area in eyes with reticular pseudodrusen (RPD) and age-matched controls. METHODS This study was performed at Nara Medical University Hospital, Japan. Twenty eyes of 14 patients (82.3±4.2 years, mean ± standard deviation) with RPD and 35 eyes of 20 age-matched controls (81.5±6.0 years) were studied. The choroidal structure was determined by binarizing the images obtained by enhanced depth imaging optical coherence tomography in all patients and controls. The total, luminal, and stromal choroidal areas were quantified by the binarization method. RESULTS The total choroidal area of the eyes with RPD was significantly smaller than that of control eyes (P=0.001, unpaired t-test). Both the luminal and stromal areas in eyes with RPD were significantly smaller than that of control eyes (P=0.001, paired t-test), but there was no significant difference in the luminal/stromal ratio between eyes with RPD and control eyes. CONCLUSION The total, luminal, and stromal choroidal areas in eyes with RPD were smaller than those of the control eyes. The reduction of the choroidal luminal and stromal areas may be due to a loss of the oxygen demand of the choroid due to RPE dysfunction.