New clinical ultrahigh-resolution SD-OCT using A-scan matching algorithm
A new clinical ultrahigh-resolution spectral domain optical coherence tomography (UHR-SD-OCT) system using an original averaging technique named “A-scan matching algorithm” was developed. The aim of this study was to determine whether our new UHR-SD-OCT system can obtain clearer sectional images of the retina than conventional standard resolution SD-OCT systems (SR-SD-OCT).
We recorded horizontal B-scan images of 42 normal eyes using our new UHR-SD-OCT device (Bi-μ, Kowa) and a conventional SR-SD-OCT (Spectralis, Heidelberg). To evaluate the clarity of the interdigitation zone (IZ) subjectively, the integrity of IZ was divided into three types by two raters. To evaluate the clarity of the IZ objectively, a peak height score (PHS) was calculated at five different points of the macula using the longitudinal reflectivity profile.
The mean (± SD) of the subjective visibility score of the IZ in the UHR-SD-OCT images was 2.64 ± 0.54 which was significantly higher than the 2.46 ± 0.46 in the SR-SD-OCT images (P = 0.02). The PHS was also significantly higher for the UHR-SD-OCT than for the SR-SD-OCT images at all five locations (all P < 0.01).
The results indicate that the newly developed clinical UHR-SD-OCT instrument using the A-scan matching algorithm can obtain clearer images of the IZ, and they suggest that this device should be clinically useful in detecting finer structural abnormalities of the outer retina.
KeywordsUltrahigh-resolution Spectral domain Optical coherence tomography (OCT) Interdigitation zone Retina
We thank Professor Duco I. Hamasaki of the Bascom Palmer Eye Institute of the University of Miami and Professor Artur V. Cideciyan of the Scheie Eye Institute of the University of Pennsylvania for critical discussion and final manuscript revisions. We also thank Masaharu Mizuochi and Toshiaki Nakagawa of Kowa Company for technical support.
We thank the Grant-in-Aid for Scientific Research C (MK, 17K19721) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (http://www.jsps.go.jp/).
Compliance with ethical standards
Conflict of interest
YM received honoraria from Alcon, Bayer, Hoya, Kowa, Novartis, Santen, and Senju. MK is a consultant to Senjyu and Bayer, and received financial research support from Alcon, AMO Japan, Hoya, Kowa, Nidek, Novartis, Otsuka, Pfizer, Santen, and Senju, and honoraria from Alcon, Bayer, Hoya, Kowa, Nidek, Novartis, Otsuka, Pfizer, Sanofi, Santen, Sanwa, and Senju. HM received financial research support from Novartis and honoraria from Alcon, Bayer, Novartis, and Santen. Other authors have no financial disclosures.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study.
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