Mapping of photoreceptor dysfunction using high resolution, three‐dimensional spectral optical coherence tomography

Abstract

Abstract Purpose To introduce a novel method of 3‐D Spectral Optical Coherence Tomography (SOCT) data analysis called reflectivity maps. Methods We introduced new software to perform segmentation of the junction between photoreceptor inner and outer segments (IS/OS) at 2‐D tomograms. After segmentation, each cross‐sectional image is transformed in such a fashion that posterior contour of the retina becomes a straight line but all radial distances within each cross section are preserved. It enables us to display the distribution of a back‐reflected intensity taken only from individual retinal layers located at specific distance from the reference plane and create reflectivity maps. We analysed the reflectivity maps of the IS/OS layer of 56 patients with photoreceptor dysfunction in course of age‐related macular degeneration, central serous chorioretinopathy, macular holes, retinal detachment, acute zonal occult outer retinopathy, multiple evanescent white dot syndrome, acute posterior multifocal placoid pigment epitheliopathy, drug‐induced retinopathy and congenital disorders. Results The reflectivity maps of the IS/OS layer displayed the areas of photoreceptor dysfunction. Conclusion Subtle changes in the IS/OS reflectivity can be detected and presented as SOCT reflectivity maps. The maps reveal the areas of photoreceptor dysfunction and can be correlated with standard techniques like fluorescein angiography and electrophysiological examination. We believe that the use of 3‐D analysis of segmented IS/OS layer in larger number of retinal pathologies may help in better understanding of photoreceptor dysfunction and allow for more accurate interpretation of the IS/OS layer on SOCT images.