  Given the capacity of Optical Coherence Tomography (OCT) imaging to display
symptoms of a wide variety of eye diseases and neurological disorders, the need
for OCT image segmentation and the corresponding data interpretation is
latterly felt more than ever before. In this paper, we wish to address this
need by designing a semi-automatic software program for applying reliable
segmentation of 8 different macular layers as well as outlining retinal
pathologies such as diabetic macular edema. The software accommodates a novel
graph-based semi-automatic method, called ''Livelayer'' which is designed for
straightforward segmentation of retinal layers and fluids. This method is
chiefly based on Dijkstra's Shortest Path (SPF) algorithm and the Live-wire
function together with some preprocessing operations on the to-be-segmented
images. The software is indeed suitable for obtaining detailed segmentation of
layers, exact localization of clear or unclear fluid objects and the ground
truth, demanding far less endeavor in comparison to a common manual
segmentation method. It is also valuable as a tool for calculating the
irregularity index in deformed OCT images. The amount of time (seconds) that
Livelayer required for segmentation of ILM, IPL-INL, OPL-ONL was much less than
that for the manual segmentation, 5s for the ILM (minimum) and 15.57s for the
OPL-ONL (maximum). The unsigned errors (pixels) between the semi-automatically
labeled and gold standard data was on average 2.7, 1.9, 2.1 for ILM, IPL-INL,
OPL-ONL, respectively. The Bland-Altman plots indicated perfect concordance
between the Livelayer and the manual algorithm and that they could be used
interchangeably. The repeatability error was around one pixel for the OPL-ONL
and < 1 for the other two. The dice scores for comparing the two algorithms and
for obtaining the repeatability on segmentation of fluid objects were at
acceptable levels.
