Development of a novel noninvasive system for measurement and imaging of the arterial phase oxygen density ratio in the retinal microcirculation

  • Shinichiro Ishikawa
  • Yukiyasu Yoshinaga
  • Daichi Kantake
  • Daisuke Nakamura
  • Noriko Yoshida
  • Toshio Hisatomi
  • Yasuhiro Ikeda
  • Tatsuro Ishibashi
  • Hiroshi EnaidaEmail author
Retinal Disorders



This study was conducted in order to develop a novel noninvasive system for measurement and imaging of the arterial oxygen density ratio (ODR) in the retinal microcirculation.


We developed a system composed of two digital cameras with two different filters, which were attached to a fundus camera capable of simultaneously obtaining two images. Actual measurements were performed on healthy volunteer eyes (n = 61). A new algorithm for ODR measurement and pixel-level imaging of erythrocytes was constructed from these data. The algorithm was based on the morphological closing operation and the line convergence index filter. For system calibration, we compared and verified the ODR values in arterioles and venules that were specified in advance for 56 eyes with reproducibility. In 10 additional volunteers, ODR measurements and imaging of the arterial phase in the retinal microcirculation corresponding to changes in oxygen saturation of the peripheral arteries at normal breathing and breath holding were performed.


Estimation of incident light to erythrocytes and pixel-level ODR calculation were achieved using the algorithm. The mean ODR values of arterioles and venules were 0.77 ± 0.060 and 1.02 ± 0.067, respectively. It was possible to separate these regions, calibrate at the pixel level, and estimate the arterial phase. In each of the 10 volunteers, changes in the arterial phase ODR corresponding to changes in oxygen saturation of the peripheral arteries were observed before and after breath holding on ODR images. The mean ODR in 10 volunteers was increased by breath holding (p < 0.05).


We developed a basic system for arterial phase ODR measurement and imaging of the retinal microcirculation. With further validation and development, this may provide a useful tool for evaluating retinal oxygen metabolism in the retinal microcirculation.


Retinal microcirculation region Oxygen density ratio Arterial phase Morphological closing operation Line convergence index filter 



We thank Mr. Tokio Ueno (Nidek Co., Ltd.) for technical support for hardware and Edanz Group ( for editing a draft of this manuscript.


This work was supported in part by the Translational Research Network Program (# 08061012) funded by the Japan Agency for Medical Research and Development (AMED) and by grants-in-aid (#18K09451) for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology, and the Public Interest Incorporated Foundation Research Foundation of Elderly Eye Disease. We asked Nedek Co., Ltd. to create a prototype as a joint research project.

Compliance with ethical standards

Conflicts of interest

Hiroshi Enaida has received the instrument lease used in this research from Nidek Co., Ltd. Hiroshi Enaida, Yukiyasu Yoshinaga, and Tatsuro Ishibashi developed algorithms for measurement of this system and submitted patent applications (Japanese Patent Nos. 4544891, 4951757, and 4951758). The remaining authors declare no conflicts of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This clinical study is registered with UMIN Clinical Trials Registry (UMIN000017580).

Informed consent

Informed consent was obtained from all of the subjects before participating in the study.

Supplementary material

417_2018_4211_Fig7_ESM.png (16 kb)
Online Resource 1

Algorithm for measuring the oxygen density ratio (ODR) for verification of separation ability of the major arterioles and venules. The algorithm for verification of separation ability of the major arterioles and venules differs from the normal program (Fig. 4a) in that the parameters of the morphological closing (MC) operation are for major blood vessels, and that the line convergence index filter (LCF) is used for extraction of the ODR. (PNG 15 kb)

417_2018_4211_MOESM1_ESM.tif (82 kb)
High Resolution Image (TIF 82 kb)


  1. 1.
    Hickam JB, Frayser R, Ross JC (1963) A study of retinal venous blood oxygen saturation in human subjects by photographic means. Circulation 27:375–385CrossRefGoogle Scholar
  2. 2.
    Beach JM, Schwenzer KJ, Srinivas S, Kim D, Tiedeman JS (1999) Oximetry of retinal vessels by dual-wavelength imaging: calibration and influence of pigmentation. J Appl Physiol 86:748–758CrossRefGoogle Scholar
  3. 3.
    Hardarson SH, Harris A, Karlsson RA, Halldorsson GH, Kagemann L, Rechtman E, Zoega GM, Eysteinsson T, Benediktsson JA, Thorsteinsson A, Jensen PK, Beach J, Stefánsson E (2006) Automatic retinal oximetry. Invest Ophthalmol Vis Sci 47:5011–5016CrossRefGoogle Scholar
  4. 4.
    Hardarson SH, Stefánsson E (2010) Oxygen saturation in central retinal vein occlusion. Am J Ophthalmol 150:871–875CrossRefGoogle Scholar
  5. 5.
    Blondal R, Sturludottir MK, Hardarson SH, Halldorsson GH, Stefánsson E (2011) Reliability of vessel diameter measurements with a retinal oximeter. Graefes Arch Clin Exp Ophthalmol 249:1311–1317CrossRefGoogle Scholar
  6. 6.
    Hardarson SH, Stefánsson E (2012) Retinal oxygen saturation is altered in diabetic retinopathy. Br J Ophthalmol 96:560–563CrossRefGoogle Scholar
  7. 7.
    Geirsdottir A, Hardarson SH, Olafsdottir OB, Stefánsson E (2014) Retinal oxygen metabolism in exudative age-related macular degeneration. Acta Ophthalmol 92:27–33CrossRefGoogle Scholar
  8. 8.
    Tayyari F, Khuu LA, Flanagan JG, Singer S, Brent MH, Hudson C (2015) Retinal blood flow and retinal blood oxygen saturation in mild to moderate diabetic retinopathy. Invest Ophthalmol Vis Sci 56:6796–6800CrossRefGoogle Scholar
  9. 9.
    Eysteinsson T, Hardarson SH, Bragason D, Stefánsson E (2014) Retinal vessel oxygen saturation and vessel diameter in retinitis pigmentosa. Acta Ophthalmol 92:449–453CrossRefGoogle Scholar
  10. 10.
    Türksever C, Valmaggia C, Orgül S, Schorderet DF, Flammer J, Todorova MG (2014) Retinal vessel oxygen saturation and its correlation with structural changes in retinitis pigmentosa. Acta Ophthalmol 92:454–460CrossRefGoogle Scholar
  11. 11.
    Van Keer K, Abegão Pinto L, Willekens K, Stalmans I, Vandewalle E (2015) Correlation between peripapillary choroidal thickness and retinal vessel oxygen saturation in young healthy individuals and glaucoma patients. Invest Ophthalmol Vis Sci 56:3758–3762CrossRefGoogle Scholar
  12. 12.
    Olafsdottir OB, Eliasdottir TS, Kristjansdottir JV, Hardarson SH, Stefánsson E (2015) Retinal vessel oxygen saturation during 100% oxygen breathing in healthy individuals. PLoS One 10:e0128780CrossRefGoogle Scholar
  13. 13.
    Yang W, Fu Y, Dong Y, Lin L, Huang X, Li Y, Lin X, Gao Q (2016) Retinal vessel oxygen saturation in a healthy young Chinese population. Acta Ophthalmol 94:373–379CrossRefGoogle Scholar
  14. 14.
    Willerslev A, Hansen MM, Klefter ON, Bjerrum OW, Hasselbalch HC, Clemmensen SN, Larsen M, Munch IC (2017) Non-invasive imaging of retinal blood flow in myeloproliferative neoplasms. Acta Ophthalmol 95:146–152CrossRefGoogle Scholar
  15. 15.
    Nitta E, Hirooka K, Shimazaki T, Sato S, Ukegawa K, Nakano Y, Tsujikawa A (2017) Retinal oxygen saturation before and after glaucoma surgery. Acta Ophthalmol 95:e350–e353CrossRefGoogle Scholar
  16. 16.
    Stefánsson E, Olafsdottir OB, Einarsdottir AB, Eliasdottir TS, Eysteinsson T, Vehmeijer W, Vandewalle E, Bek T, Hardarson SH (2017) Retinal oximetry discovers novel biomarkers in retinal and brain diseases. Invest Ophthalmol Vis Sci 58:BIO227–BIO233CrossRefGoogle Scholar
  17. 17.
    Salem SA, Salem NM, Nandi AK (2007) Segmentation of retinal blood vessels using a novel clustering algorithm (RACAL) with a partial supervision strategy. Med Biol Eng Comput 45:261–273CrossRefGoogle Scholar
  18. 18.
    Matsopoulos GK, Mouravliansky NA, Delibasis KK, Nikita KS (1999) Automatic retinal image registration scheme using global optimization techniques. IEEE Trans Inf Technol Biomed 3:47–60CrossRefGoogle Scholar
  19. 19.
    Laliberté F, Gagnon L, Sheng Y (2003) Registration and fusion of retinal images—an evaluation study. IEEE Trans Med Imaging 22:661–673CrossRefGoogle Scholar
  20. 20.
    Kobatake H, Yoshinaga Y (1996) Detection of spicules on mammogram based on skeleton analysis. IEEE Trans Med Imaging 15:235–245CrossRefGoogle Scholar
  21. 21.
    Jin XC, Ong SH, Jayasooriah J (1995) A domain operator for binary morphological processing. IEEE Trans Image Process 4:1042–1046CrossRefGoogle Scholar
  22. 22.
    Kobatake H, Hashimoto S (1999) Convergence index filter for vector fields. IEEE Trans Image Process 8:1029–1038CrossRefGoogle Scholar
  23. 23.
    Hammer M, Vilser W, Riemer T, Schweitzer D (2008) Retinal vessel oximetry-calibration, compensation for vessel diameter and fundus pigmentation, and reproducibility. J Biomed Opt 13:054015. CrossRefGoogle Scholar
  24. 24.
    Türksever C, Orgül S, Todorova MG (2015) Reproducibility of retinal oximetry measurements in healthy and diseased retinas. Acta Ophthalmol 93:e439–e445CrossRefGoogle Scholar
  25. 25.
    Told R, Boltz A, Schmetterer L, Garhöfer G, Sacu S, Schmidt-Erfurth U, Pollreisz A (2018) Method comparison of two non-invasive dual-wavelength spectrophotometric retinal oximeters in healthy young subjects during normoxia. Acta Ophthalmol.

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Shinichiro Ishikawa
    • 1
  • Yukiyasu Yoshinaga
    • 2
  • Daichi Kantake
    • 1
  • Daisuke Nakamura
    • 3
  • Noriko Yoshida
    • 4
  • Toshio Hisatomi
    • 5
  • Yasuhiro Ikeda
    • 5
  • Tatsuro Ishibashi
    • 6
  • Hiroshi Enaida
    • 1
    Email author
  1. 1.Department of Ophthalmology, Faculty of MedicineSaga UniversitySagaJapan
  2. 2.Graduate School of DesignKyushu UniversityFukuokaJapan
  3. 3.Graduate School of Information Science and Electrical EngineeringKyushu UniversityFukuokaJapan
  4. 4.Section of Ophthalmology, Department of MedicineFukuoka Dental CollegeFukuokaJapan
  5. 5.Department of Ophthalmology, Graduate School of Medical SciencesKyushu UniversityFukuokaJapan
  6. 6.Kyushu UniversityFukuokaJapan

Personalised recommendations