En face optical coherence tomography transillumination for evaluation of retinal pigment epithelium alteration in central serous chorioretinopathy: correlation with multimodal imaging

Purpose To study optical coherence tomography (OCT) en face imaging approach to evaluate retinal pigment epithelium (RPE) alteration in central serous chorioretinopathy (CSC). Methods Forty eyes with CSC were imaged with structural en face OCT, fluorescein angiography (FA), and fundus autofluorescence (FAF). Structural en face OCT projections were generated using a 200-mu m slab with the inner limit at the outer choroid to register choroidal hypertransmission signal in transillumination manner. Two masked graders independently defined the area of RPE alteration on resultant images. Agreement between graders and correlation between imaging modalities was assessed by kappa coefficients (k) and intraclass correlation coefficients (ICC), respectively. Results The measurements derived from three methods were highly correlated with ICC of 0.99 (95% CI 0.99 to 1.0) for OCT and FA, 0.97 (95% CI 0.93 to 0.99) for OCT and FAF, and 0.98 (95% CI 0.95 to 0.99) for FA and FAF. For the measurement of the area of RPE alteration, kappa value for inter-grader agreement was 0.94 for OCT, 0.89 for FA, and 0.92 for FAF. Conclusion En face OCT proved a reliable tool for the noninvasive evaluation of RPE status in CSC.