Abstract
Purpose :
To create optical coherence tomography (OCT) Endothelium/Descemets membrane complex (En/DM) three dimensional 6 mm thickness maps and evaluate distribution of En/DM thickness in the normal maps of the subjects.
Methods :
First, we validated our methods using phantom eye model. We obtained 6 mm radial cuts for central region of the phantom eye. We used graph-based segmentation method to automatically segment the anterior and posterior layers of each radial cut of the phantom eye model. Then, we constructed the surfaces for the anterior and posterior layers from the segmented layers. We reconstructed the surfaces using bi-cubic interpolation without any assumption about the surface shape. Then, we measured the thickness of the central cornea based on the perpendicular distance between the two surfaces. Created maps were compared to pre-known thickness map of the phantom eye. We applied same procedure on OCT images of 5 normal eyes to automatically segment, 3 dimensional (3D) optical correction and creating the 3D En/DM layer map. Bullseye maps were created and divided into central region that is 1 mm around the center of the cornea, paracentral region that extends from 1 to 2 mm from the center and peripheral regions that extends 2-3 mm from the center of the cornea.
Results :
En/DM 3D thickness maps and bullseye maps were created successfully in all examined eyes. En/DM mean thickness in normal subjects was 16.19 µm. En/DM showed thickening towards the peripheral cornea. The mean thickness of the central En/DM was 11±2 µm (Mean and SD), paracentral En/DM region was 12±2.75 µm and the peripheral En/DM was 15.5±4.75 µm. The 3D En/DM maps showed that the thickest En/DM region is 22 µm while the thinnest is 8 µm.
Conclusions :
Endothelium/Descemets membrane Complex 3D thickness maps can be created from OCT images. In Normal Subjects, En/DM showed thickening towards the peripheral cornea.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.