Abstract

In this article the ability of ultrahigh resolution ophthalmic optical coherence tomography (OCT) to image small choroidal blood vessels below the highly reflective and absorbing retinal pigment epithelium is demonstrated for the first time. A new light source (λc=1050 nm, Δλ=165 nm, Pout=10 mW), based on a photonic crystal fiber pumped by a compact, self-starting Ti:Al2O3 laser has therefore been developed. Ex-vivo ultrahigh resolution OCT images of freshly excised pig retinas acquired with this light source demonstrate enhanced penetration into the choroid and better visualization of choroidal vessels as compared to tomograms acquired with a state-of-the art Ti:Al2O3 laser (Femtolasers Compact Pro, λc=780 nm, Δλ=160 nm, Pout=400 mW), normally used in clinical studies for in vivo ultrahigh resolution ophthalmic OCT imaging. These results were also compared with retinal tomograms acquired with a novel, spectrally broadened fiber laser (MenloSystems, λc=1350 nm, Δλ=470 nm, Pout=4 mW) permitting even greater penetration in the choroid. Due to high water absorption at longer wavelengths retinal OCT imaging at ~1300 nm may find applications in animal ophthalmic studies. Detection and follow-up of choroidal neovascularization improves early diagnosis of many retinal pathologies, e.g. age-related macular degeneration or diabetic retinopathy and can aid development of novel therapy approaches.

© 2003 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |

  1. D. Huang, E.A. Swanson, C.P. Lin, J.S. Schuman, W.G. Stinson, W. Chang, M.R. Hee, T. Flotte, K. Gregory, C.A. Puliafito, J.G. Fujimoto, �??Optical coherence tomography,�?? Science 254, 1178-1181 (1991).
    [CrossRef] [PubMed]
  2. B. Bouma and J. Tearney (ed) Handbook of Optical Coherence Tomography (Marcel Dekker Inc., 2002).
  3. A.F. Fercher, �??Optical coherence tomography,�?? J. Biomed. Opt. 1, 157-173 (1996).
    [CrossRef] [PubMed]
  4. C.A Puliafito, M.R. Hee, J.S. Schuman, J.G. Fujimoto Optical coherence tomography of ocular disease (Thorofare, New Jersey: Slack Inc., 1995).
  5. W. Drexler, U. Morgner, R.K. Ghanta, J.S. Schuman, F. Kärtner, J.G. Fujimoto, �??Ultrahigh-resolution ophthalmic optical coherence tomography, �?? Nature Medicine 7, 502-507 (2001).
    [CrossRef] [PubMed]
  6. M.E. Boulton, F. Docchio, P. Dayhaw-Barker, R. Ramponi, R. Cubeddu, �??Age-related changes in the morphology, absorption and fluorescence of melanosomes and lipofuscin granules of the retinal pigment epithelium,�?? Vision Res. 30, 1291 (1990).
    [CrossRef] [PubMed]
  7. Schmitt, S.H. Xiang, K.M. Yung, �??Differential absorption imaging with optical coherence tomography,�?? J.Opt. Soc. Am. A, 15, 2288-2297 (1998).
    [CrossRef]
  8. G. M. Hale, M. R. Querry, �??Optical constants of water in the 200 nm to 200 µm wavelength region," Appl. Opt. 12, 555-563 (1973).
    [CrossRef] [PubMed]
  9. ANSI Standard Z136.1-2000
  10. Y. Wang, J. Nelson, Z. Chen, B. Reiser, R.S. Chuck, R. S. Windeler, "Optimal wavelength for ultra-high resolution optical coherence tomography," Opt. Express 11, 1411-1417 (2003).
    [CrossRef] [PubMed]
  11. B. Považay, K. Bizheva, A. Unterhuber, B. Herman, H. Sattmann, A. Fercher, W. Drexler, A. Apolonski, W.J. Wadsworth, J. C. Knight, P.St.J. Russel, M. Vetterlein, E. Scherzer, �??Sub-micrometer resolution optical coherence tomography,�?? Opt. Lett. 27, 1800-18024 (2002).
    [CrossRef]
  12. A. Apolonski, B. Považay, A. Unterhuber, T.A Birks, W.J. Wadsworth, P.St.J. Russel, W. Drexler, �??Spectral shaping of supercontinuum in a cobweb photonic-crystal fiber with sub-20-fs pulses,�?? J.Opt.Soc.Am. B 19, 2165-2170 (2002).
    [CrossRef]
  13. K. Bizheva, B. Považay, B. Hermann, H. Sattmann, W. Drexler, M. Mei, R. Holzwarth, T. Hoelzenbein, V. Wacheck, H. Pehamberger, �??Compact, broad bandwidth fiber laser for sub-2 µm axial resolution optical coherence tomography in the 1300 nm wavelength region," Opt. Lett. 28, 707-709 (2003).
    [CrossRef] [PubMed]
  14. I. Hartl, X.D. Li, C. Chudoba, R. K. Ghanta, T.H. Ko, J. G. Fujimoto, J. K. Ranka and R.S. Windeler, �??Ultrahigh resolution optical coherence tomography using continuum generation in an air-silica microsctructure optical fiber,�?? Opt. Lett. 26, 608-610 (2001).
    [CrossRef]
  15. A. Roggan, M. Friebel, K. Dörschel, A. Hahn and G. Müller, "Optical properties of circullating human blood in the wavelength range 400-2500 nm,�?? J. Biomed. Opt. 4, 36-46 (1999).
    [CrossRef] [PubMed]
  16. Q. Li, A.M Timmers, K. Hunter, C. Gonzalez-Pola, A.S. Lewin, D.H Reitze, W.W Hauswirth, �??Noninvasive imaging by optical coherence tomography to monitor retinal degeneration in the mouse," Invest. Ophthalmol. Vis. Sci. 42, 2981-2989 (2001).
    [PubMed]
  17. N.M. Bressler, S.B. Bressler, E.S. Gragoudas, �??Clinical characteristics of choroidal neovascular membranes,�?? Arch Ophthalmol 105, 209-213 (1987).
    [CrossRef] [PubMed]
  18. L. M. Aiello Principles and practice of ophthalmology: clinical practice (Saunders, Philadelphia, PA, 1994).
  19. W. Drexler, H. Sattmann, B. Hermann, T.H. Ko, M. Stur, A. Unterhuber, C. Scholda, O. Findl, M. Wirtitsch, J.G. Fujimoto, A.F. Fercher, �??Enhanced visualization of macula pathology using ultrahigh resolution optical coherence tomography, " Arch Ophthalmol-Chic 121, 695-706 (2003).

Appl. Opt.

Arch Ophthalmol

N.M. Bressler, S.B. Bressler, E.S. Gragoudas, �??Clinical characteristics of choroidal neovascular membranes,�?? Arch Ophthalmol 105, 209-213 (1987).
[CrossRef] [PubMed]

Arch Ophthalmol-Chic

W. Drexler, H. Sattmann, B. Hermann, T.H. Ko, M. Stur, A. Unterhuber, C. Scholda, O. Findl, M. Wirtitsch, J.G. Fujimoto, A.F. Fercher, �??Enhanced visualization of macula pathology using ultrahigh resolution optical coherence tomography, " Arch Ophthalmol-Chic 121, 695-706 (2003).

J. Biomed. Opt.

A. Roggan, M. Friebel, K. Dörschel, A. Hahn and G. Müller, "Optical properties of circullating human blood in the wavelength range 400-2500 nm,�?? J. Biomed. Opt. 4, 36-46 (1999).
[CrossRef] [PubMed]

A.F. Fercher, �??Optical coherence tomography,�?? J. Biomed. Opt. 1, 157-173 (1996).
[CrossRef] [PubMed]

J. Opt. Soc. Am. A

J. Opt. Soc. Am. B

Nature Medicine

W. Drexler, U. Morgner, R.K. Ghanta, J.S. Schuman, F. Kärtner, J.G. Fujimoto, �??Ultrahigh-resolution ophthalmic optical coherence tomography, �?? Nature Medicine 7, 502-507 (2001).
[CrossRef] [PubMed]

Ophthalmol.Vis. Sci.

Q. Li, A.M Timmers, K. Hunter, C. Gonzalez-Pola, A.S. Lewin, D.H Reitze, W.W Hauswirth, �??Noninvasive imaging by optical coherence tomography to monitor retinal degeneration in the mouse," Invest. Ophthalmol. Vis. Sci. 42, 2981-2989 (2001).
[PubMed]

Opt. Express

Opt. Lett

B. Považay, K. Bizheva, A. Unterhuber, B. Herman, H. Sattmann, A. Fercher, W. Drexler, A. Apolonski, W.J. Wadsworth, J. C. Knight, P.St.J. Russel, M. Vetterlein, E. Scherzer, �??Sub-micrometer resolution optical coherence tomography,�?? Opt. Lett. 27, 1800-18024 (2002).
[CrossRef]

I. Hartl, X.D. Li, C. Chudoba, R. K. Ghanta, T.H. Ko, J. G. Fujimoto, J. K. Ranka and R.S. Windeler, �??Ultrahigh resolution optical coherence tomography using continuum generation in an air-silica microsctructure optical fiber,�?? Opt. Lett. 26, 608-610 (2001).
[CrossRef]

Opt. Lett.

Science

D. Huang, E.A. Swanson, C.P. Lin, J.S. Schuman, W.G. Stinson, W. Chang, M.R. Hee, T. Flotte, K. Gregory, C.A. Puliafito, J.G. Fujimoto, �??Optical coherence tomography,�?? Science 254, 1178-1181 (1991).
[CrossRef] [PubMed]

Vision Res.

M.E. Boulton, F. Docchio, P. Dayhaw-Barker, R. Ramponi, R. Cubeddu, �??Age-related changes in the morphology, absorption and fluorescence of melanosomes and lipofuscin granules of the retinal pigment epithelium,�?? Vision Res. 30, 1291 (1990).
[CrossRef] [PubMed]

Other

ANSI Standard Z136.1-2000

B. Bouma and J. Tearney (ed) Handbook of Optical Coherence Tomography (Marcel Dekker Inc., 2002).

C.A Puliafito, M.R. Hee, J.S. Schuman, J.G. Fujimoto Optical coherence tomography of ocular disease (Thorofare, New Jersey: Slack Inc., 1995).

L. M. Aiello Principles and practice of ophthalmology: clinical practice (Saunders, Philadelphia, PA, 1994).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1.
Fig. 1.

In-vivo ultrahigh resolution OCT image (2700×830 pixels, 5 mm×2 mm) of human retina with areolar atrophy associated with foveomacular dystrophy, acquired with the Ti:Al2O3 light source. Solid arrows indicate intact RPE; dashed arrow indicates RPE with atrophy enabling visualization of choroidal vessels.

Fig. 2.
Fig. 2.

Output spectra (top): Ti:Al2O3 (blue line), PCF based source (green line) and fiber laser based light source (red line), overlaid with water absorption spectrum (black line). Corresponding fringe patterns produced by interfacing the light sources to the OCT system (bottom).

Fig. 3.
Fig. 3.

Ex-vivo OCT images of pig retinas, acquired with the Ti:Al2O3 source (top, at ~800 nm, SNR 105 dB, 2000×1000 pixels, 2×1 mm), PCF based source (middle, at ~1050 nm, SNR 98 dB, 2000×1010 pixels, 2×1 mm), and the fiber laser based source (bottom, at ~1350 nm, SNR 95 dB, 2000×888 pixels, 2×1 mm). Red arrows indicate choroidal blood vessels.

Fig. 4.
Fig. 4.

Ex-vivo OCT image of a pig retina, acquired with the PCF based source at ~1050 nm (2000×1010 pixels, 2 mm×1 mm). The red arrow marks a region in the choroid, where multiple small blood vessels partially filled with coagulated blood, positioned on top of each other are visible. Green arrow depicts a blood vessel on the retinal surface with reduced shadowing because of better penetration at the imaging wavelength.

Metrics