Automatic measurements of choroidal thickness in EDI-OCT images

Enhanced Depth Imaging (EDI) optical coherence tomography (OCT) provides high-definition cross-sectional images of the choroid in vivo, and hence is used in many clinical studies. However, measurement of choroidal thickness depends on the manual labeling, which is tedious and subjective of inter-observer differences. In this paper, we propose a fast and accurate algorithm that could measure the choroidal thickness automatically. The lower boundary of the choroid is detected by searching the biggest gradient value above the retinal pigment epithelium (RPE) and the upper boundary is formed by finding the shortest path of the graph formed by valley pixels using dynamic programming. The average of Dice's Coefficient on 10 EDI-OCT images is 94.3%, which shows good consistency of the algorithm with the manual labeling. The processing time for each image is about 2 seconds.

[1]  J. Schuman,et al.  Optical coherence tomography. , 2000, Science.

[2]  J. Wallman,et al.  The circadian rhythm in intraocular pressure and its relation to diurnal ocular growth changes in chicks. , 1998, Experimental eye research.

[3]  Kim L. Boyer,et al.  Retinal thickness measurements from optical coherence tomography using a Markov boundary model , 2001, IEEE Transactions on Medical Imaging.

[4]  Ruikang K. Wang,et al.  Signal degradation by multiple scattering in optical coherence tomography of dense tissue: a Monte Carlo study towards optical clearing of biotissues. , 2002, Physics in medicine and biology.

[5]  R. Spaide,et al.  Enhanced depth imaging spectral-domain optical coherence tomography. , 2008, American journal of ophthalmology.

[6]  R. Spaide,et al.  A pilot study of enhanced depth imaging optical coherence tomography of the choroid in normal eyes. , 2009, American journal of ophthalmology.

[7]  H. Quigley,et al.  What's the choroid got to do with angle closure? , 2009, Archives of ophthalmology.

[8]  Y. Ikuno,et al.  Choroidal thickness in healthy Japanese subjects. , 2010, Investigative ophthalmology & visual science.

[9]  Joseph A. Izatt,et al.  Automatic segmentation of seven retinal layers in SDOCT images congruent with expert manual segmentation , 2010, Optics express.

[10]  Qi Yang,et al.  Automated layer segmentation of macular OCT images using dual-scale gradient information. , 2010, Optics express.

[11]  R. Spaide,et al.  Subfoveal choroidal thickness after treatment of central serous chorioretinopathy. , 2010, Ophthalmology.

[12]  Michael V. Boland,et al.  Choroidal thickness measured by spectral domain optical coherence tomography: factors affecting thickness in glaucoma patients. , 2011, Ophthalmology.

[13]  Se Woong Kang,et al.  Choroidal thickness in polypoidal choroidal vasculopathy and exudative age-related macular degeneration. , 2011, Ophthalmology.

[14]  Paul L. Rosin,et al.  Automated choroidal segmentation of 1060 nm OCT in healthy and pathologic eyes using a statistical model , 2011, Biomedical optics express.