Comparison of Shape-based Analysis of Retinal Nerve Fiber Layer Data Obtained From OCT and GDx-VCC

Gunvant, Pinakin, Zheng, Yufeng, Essock, Edward A., Parikh, Rajul S., Prabakaran, Selvaraj, Babu, Jonnadula Ganesh, Shekar, Chandra G. and Thomas, Ravi (2009) Comparison of Shape-based Analysis of Retinal Nerve Fiber Layer Data Obtained From OCT and GDx-VCC. Journal of Glaucoma, 18 6: 464-471. doi:10.1097/IJG.0b013e31818c6f2b

Author Gunvant, Pinakin
Zheng, Yufeng
Essock, Edward A.
Parikh, Rajul S.
Prabakaran, Selvaraj
Babu, Jonnadula Ganesh
Shekar, Chandra G.
Thomas, Ravi
Title Comparison of Shape-based Analysis of Retinal Nerve Fiber Layer Data Obtained From OCT and GDx-VCC
Journal name Journal of Glaucoma   Check publisher's open access policy
ISSN 1057-0829
Publication date 2009-08
Sub-type Article (original research)
DOI 10.1097/IJG.0b013e31818c6f2b
Volume 18
Issue 6
Start page 464
End page 471
Total pages 8
Place of publication Hagerstown, MD, USA
Language eng
Subject 1103 Clinical Sciences
Abstract AB Purpose: To directly compare in 1 population: (1) the performance of Optical Coherence Tomograph (OCT) and GDx-Variable Corneal Compensator (VCC) when using Wavelet-Fourier Analysis (WFA) and Fast-Fourier Analysis (FFA), (2) the performance of these shape-based and standard metrics, and (3) the shape of the retinal nerve fiber layer (RNFL) temporal, superior, nasal, inferior, temporal (TSNIT) curves obtained by the 2 different devices. Methods: RNFL estimates were obtained from 136 eyes of 136 individuals (73 healthy and 63 mild glaucoma). WFA and FFA with and without asymmetry measures were performed on the TSNIT RNFL estimates to identify glaucoma from healthy eyes. Performance of WFA, FFA, and the standard metrics of OCT (Inferior Average) and GDX-VCC (Nerve Fiber Indicator) was evaluated by calculating receiver operating characteristic area. Measurements were obtained at a custom radius (33 to 41 pixels) for GDx-VCC to match the OCT radius (1.73 mm). Results: WFA and FFA shape analysis significantly improved performance of both OCT (0.937) and GDx-VCC (0.913) compared with Inferior Average and Nerve Fiber Indicator (0.852 and 0.833, respectively). With either shape-based or standard metrics, OCT performance was slightly, but not significantly, better than GDx-VCC performance. Comparison of RNFL curves revealed that the GDx-VCC curves were more jagged and the peaks shifted more nasally when compared with the OCT RNFL curves. Conclusions: Performance of both OCT and GDx-VCC devices are improved by shape-based analysis methods. Classification performance was greater when using WFA for the OCT, and greater with FFA for the GDx-VCC. Significant differences between the machines exist in the measured TSNIT thicknesses, possibly because of GDx-VCC's measurements being affected by polarization magnitude varying with angle. (C) 2009 Lippincott Williams & Wilkins, Inc.
Keyword Wavelet-Fourier analysis
Fourier analysis
optical coherence tomograph
retinal nerve fiber layer
Q-Index Code C1
Q-Index Status Provisional Code

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Medicine Publications
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Citation counts: TR Web of Science Citation Count  Cited 3 times in Thomson Reuters Web of Science Article | Citations
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Created: Fri, 04 Sep 2009, 10:21:16 EST