Three-dimensional Imaging of the Foveal Photoreceptor Layer in Central Serous Chorioretinopathy Using High-speed Optical Coherence Tomography

Abstract

To describe the 3-dimensional (3-D) imaging of the pathologic changes in the foveal photoreceptor layer in eyes with central serous chorioretinopathy (CSC) using high-speed optical coherence tomography (OCT). Prospective observational case series. Twenty-seven eyes of 27 consecutive patients with various stages of CSC. A prototype high-speed OCT system was fabricated for patient examinations based on Fourier domain OCT. The system had a sensitivity of 98 dB, a tissue axial resolution of 4.3 mum, and an acquisition rate of approximately 18700 axial scans per second. Three-dimensional imaging was performed based on a raster-scan protocol. Anatomic features of CSC distinguished by 3-D OCT. A line corresponding to backreflection from the external limiting membrane (ELM) was visible in images from eyes with all stages of CSC, including 6 in the acute, 5 in the chronic, and 9 in the recurrent phase of retinal detachment and 11 examined in the quiescent phase (including 4 reexamined after reattachment). Backreflection from the photoreceptor inner and outer segment junction (IS/OS) was missing before but present after reattachment. The ELM line bordered the photoreceptor nuclear and inner segment layers, clearly showing that CSC primarily alters the outer segment (OS) layer. Punctate areas of intense reflectivity were observed more frequently in the OS layer of detached retinas in cases of chronic or recurrent versus acute CSC (P<0.05, chi-square test). Of 11 eyes with reattached macula, 3 eyes with large defects in the subfoveal IS/OS had poor visual acuity (VA), and 8 eyes with small or no defects had good VA (P<0.05 and P<0.001, chi-square test). Decreases in foveal full and outer thickness were associated with VA loss (P<0.05 and P<0.001, Spearman rank correlation test). Three-dimensional OCT imaging delineates the microstructural changes that occur within the photoreceptor layers and demonstrates the spatial relationship between the laterally spreading or scattering microstructures and the fovea in eyes with CSC. Visualization of the 3-D relationship between the ELM and each photoreceptor layer before and after macular reattachment facilitates understanding of anatomic and vision changes that result from CSC.