Shape Decomposition of Foveal Pit Morphology using Scan Geometry Corrected OCT.

The fovea is an important structure that allows for the high acuity at the center of our visual system. While the fovea has been well studied, the role of the foveal pit in the human retina is still largely unknown. In this study we analyze the shape morphology of the foveal pit using a statistical shape model to find the principal shape variations in a cohort of 50 healthy subjects. Our analysis includes the use of scan geometry correction to reduce the error from inherent distortions in OCT images, and a method for aligning foveal pit surfaces to remove translational and rotational variability between the subjects. Our results show that foveal pit morphology can be represented using less than five principal modes of variation. And we find that the shape variations discovered through our analysis are closely related to the main metrics (depth and diameter) used to study the foveal pit in current literature. Lastly, we evaluated the relationship between the first principal mode of variation in the cohort and the axial length from each subject. Our findings showed a modest inverse relationship between axial length and foveal pit depth that can be confirmed independently by existing studies.