Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO

Kari V. Vienola, Boy Braaf, Christy K. Sheehy, Qiang Yang, Pavan Tiruveedhula, Johannes F. de Boer, Austin Roorda

Research output: Contribution to ConferencePosterOther research output

Abstract

Purpose
To remove the eye motion and stabilize the optical frequency domain imaging (OFDI) system for obtaining high quality images of the optic nerve head (ONH) and the pore structure of the lamina cribrosa.

Methods
An optical coherence tomography (OCT) instrument was combined with an active eye tracking system to compensate for eye motion in OCT imaging. The OCT system was a phase-stabilized deeply penetrating OFDI system operating at center wavelength of 1040 nm and the eye tracker was an 840 nm scanning laser ophthalmoscope (SLO). Retinal tracking was performed using real-time analysis of the distortions within SLO frames. OFDI had axial resolution of 4.8 µm (6.5 µm in air) and the theoretical spot-size on the retina was 13.7 µm. Eye motion was reported at a rate of 960 Hz and motion signals were inverted to correction signals and used to keep the OCT scanning grid locked on the same retinal area throughout the measurement. In the case of a tracking lock failure (e.g. blink or large saccade), the tracker signaled the OFDI system to rescan corrupted B-scans immediately stepping back 10 B-scans and holding the position until signal was valid again. The achieved tracking bandwidth was 32 Hz due to an internal time lag of the hardware. The ONH of a healthy volunteer was imaged over an area of 2.7 × 2.7 mm (8.8°) using 700 A-scans/B-scan. To visualize the benefit of the tracking, each acquired B-scan in a volume dataset (total of 700 B-scans) was integrated over depth to create an enface image of the ONH.

Results
The ONH was successfully imaged with negligible artifacts from eye motion (Fig. 1). On the left side, the whole dataset is seen including the duplicate corrupted B-scans. The corrupted B-scans were then removed in post-processing, thus leaving the undistorted duplicates untouched. The measured residual motion in the OCT B-scans was 0.32 arcmin (~1.6 µm) in a human eye. Four volumes from the same location were registered together to visualize the lamina cribrosa throughout the different depth slices of the eye (Fig. 2). The pore structure was clearly visible up to 430 um from the bottom of the ONH cup.

Conclusions

It is possible to obtain high quality OCT images from ONH and lamina cribrosa by compensating the eye motion during the measurements.
Original languageEnglish
Pages1452
Number of pages1
Publication statusPublished - 5 May 2013
EventThe Association for Research in Vision and Ophthalmology Annual Meeting 2013 - The Washington State Convention Center, Seattle, United States
Duration: 5 May 20139 May 2013
http://www.arvo.org/Conferences_and_Courses/Past_Conferences/

Conference

ConferenceThe Association for Research in Vision and Ophthalmology Annual Meeting 2013
Abbreviated titleARVO 2013
CountryUnited States
CitySeattle
Period5/05/139/05/13
Internet address

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Optical tomography
Pore structure
Optics
Scanning
Imaging techniques
Lasers
Imaging systems
Eye movements
Image quality
Hardware
Bandwidth
Wavelength
Processing
Air

Keywords

  • optical coherence tomography
  • retinal imaging
  • scanning laser ophthalmoscope
  • optic nerve head

Cite this

Vienola, K. V., Braaf, B., Sheehy, C. K., Yang, Q., Tiruveedhula, P., de Boer, J. F., & Roorda, A. (2013). Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO. 1452. Poster session presented at The Association for Research in Vision and Ophthalmology Annual Meeting 2013, Seattle, United States.
Vienola, Kari V. ; Braaf, Boy ; Sheehy, Christy K. ; Yang, Qiang ; Tiruveedhula, Pavan ; de Boer, Johannes F. ; Roorda, Austin. / Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO. Poster session presented at The Association for Research in Vision and Ophthalmology Annual Meeting 2013, Seattle, United States.1 p.
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abstract = "PurposeTo remove the eye motion and stabilize the optical frequency domain imaging (OFDI) system for obtaining high quality images of the optic nerve head (ONH) and the pore structure of the lamina cribrosa.MethodsAn optical coherence tomography (OCT) instrument was combined with an active eye tracking system to compensate for eye motion in OCT imaging. The OCT system was a phase-stabilized deeply penetrating OFDI system operating at center wavelength of 1040 nm and the eye tracker was an 840 nm scanning laser ophthalmoscope (SLO). Retinal tracking was performed using real-time analysis of the distortions within SLO frames. OFDI had axial resolution of 4.8 µm (6.5 µm in air) and the theoretical spot-size on the retina was 13.7 µm. Eye motion was reported at a rate of 960 Hz and motion signals were inverted to correction signals and used to keep the OCT scanning grid locked on the same retinal area throughout the measurement. In the case of a tracking lock failure (e.g. blink or large saccade), the tracker signaled the OFDI system to rescan corrupted B-scans immediately stepping back 10 B-scans and holding the position until signal was valid again. The achieved tracking bandwidth was 32 Hz due to an internal time lag of the hardware. The ONH of a healthy volunteer was imaged over an area of 2.7 × 2.7 mm (8.8°) using 700 A-scans/B-scan. To visualize the benefit of the tracking, each acquired B-scan in a volume dataset (total of 700 B-scans) was integrated over depth to create an enface image of the ONH.ResultsThe ONH was successfully imaged with negligible artifacts from eye motion (Fig. 1). On the left side, the whole dataset is seen including the duplicate corrupted B-scans. The corrupted B-scans were then removed in post-processing, thus leaving the undistorted duplicates untouched. The measured residual motion in the OCT B-scans was 0.32 arcmin (~1.6 µm) in a human eye. Four volumes from the same location were registered together to visualize the lamina cribrosa throughout the different depth slices of the eye (Fig. 2). The pore structure was clearly visible up to 430 um from the bottom of the ONH cup.ConclusionsIt is possible to obtain high quality OCT images from ONH and lamina cribrosa by compensating the eye motion during the measurements.",
keywords = "optical coherence tomography, retinal imaging, scanning laser ophthalmoscope, optic nerve head",
author = "Vienola, {Kari V.} and Boy Braaf and Sheehy, {Christy K.} and Qiang Yang and Pavan Tiruveedhula and {de Boer}, {Johannes F.} and Austin Roorda",
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Vienola, KV, Braaf, B, Sheehy, CK, Yang, Q, Tiruveedhula, P, de Boer, JF & Roorda, A 2013, 'Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO' The Association for Research in Vision and Ophthalmology Annual Meeting 2013, Seattle, United States, 5/05/13 - 9/05/13, pp. 1452.

Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO. / Vienola, Kari V.; Braaf, Boy; Sheehy, Christy K.; Yang, Qiang; Tiruveedhula, Pavan; de Boer, Johannes F.; Roorda, Austin.

2013. 1452 Poster session presented at The Association for Research in Vision and Ophthalmology Annual Meeting 2013, Seattle, United States.

Research output: Contribution to ConferencePosterOther research output

TY - CONF

T1 - Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO

AU - Vienola, Kari V.

AU - Braaf, Boy

AU - Sheehy, Christy K.

AU - Yang, Qiang

AU - Tiruveedhula, Pavan

AU - de Boer, Johannes F.

AU - Roorda, Austin

PY - 2013/5/5

Y1 - 2013/5/5

N2 - PurposeTo remove the eye motion and stabilize the optical frequency domain imaging (OFDI) system for obtaining high quality images of the optic nerve head (ONH) and the pore structure of the lamina cribrosa.MethodsAn optical coherence tomography (OCT) instrument was combined with an active eye tracking system to compensate for eye motion in OCT imaging. The OCT system was a phase-stabilized deeply penetrating OFDI system operating at center wavelength of 1040 nm and the eye tracker was an 840 nm scanning laser ophthalmoscope (SLO). Retinal tracking was performed using real-time analysis of the distortions within SLO frames. OFDI had axial resolution of 4.8 µm (6.5 µm in air) and the theoretical spot-size on the retina was 13.7 µm. Eye motion was reported at a rate of 960 Hz and motion signals were inverted to correction signals and used to keep the OCT scanning grid locked on the same retinal area throughout the measurement. In the case of a tracking lock failure (e.g. blink or large saccade), the tracker signaled the OFDI system to rescan corrupted B-scans immediately stepping back 10 B-scans and holding the position until signal was valid again. The achieved tracking bandwidth was 32 Hz due to an internal time lag of the hardware. The ONH of a healthy volunteer was imaged over an area of 2.7 × 2.7 mm (8.8°) using 700 A-scans/B-scan. To visualize the benefit of the tracking, each acquired B-scan in a volume dataset (total of 700 B-scans) was integrated over depth to create an enface image of the ONH.ResultsThe ONH was successfully imaged with negligible artifacts from eye motion (Fig. 1). On the left side, the whole dataset is seen including the duplicate corrupted B-scans. The corrupted B-scans were then removed in post-processing, thus leaving the undistorted duplicates untouched. The measured residual motion in the OCT B-scans was 0.32 arcmin (~1.6 µm) in a human eye. Four volumes from the same location were registered together to visualize the lamina cribrosa throughout the different depth slices of the eye (Fig. 2). The pore structure was clearly visible up to 430 um from the bottom of the ONH cup.ConclusionsIt is possible to obtain high quality OCT images from ONH and lamina cribrosa by compensating the eye motion during the measurements.

AB - PurposeTo remove the eye motion and stabilize the optical frequency domain imaging (OFDI) system for obtaining high quality images of the optic nerve head (ONH) and the pore structure of the lamina cribrosa.MethodsAn optical coherence tomography (OCT) instrument was combined with an active eye tracking system to compensate for eye motion in OCT imaging. The OCT system was a phase-stabilized deeply penetrating OFDI system operating at center wavelength of 1040 nm and the eye tracker was an 840 nm scanning laser ophthalmoscope (SLO). Retinal tracking was performed using real-time analysis of the distortions within SLO frames. OFDI had axial resolution of 4.8 µm (6.5 µm in air) and the theoretical spot-size on the retina was 13.7 µm. Eye motion was reported at a rate of 960 Hz and motion signals were inverted to correction signals and used to keep the OCT scanning grid locked on the same retinal area throughout the measurement. In the case of a tracking lock failure (e.g. blink or large saccade), the tracker signaled the OFDI system to rescan corrupted B-scans immediately stepping back 10 B-scans and holding the position until signal was valid again. The achieved tracking bandwidth was 32 Hz due to an internal time lag of the hardware. The ONH of a healthy volunteer was imaged over an area of 2.7 × 2.7 mm (8.8°) using 700 A-scans/B-scan. To visualize the benefit of the tracking, each acquired B-scan in a volume dataset (total of 700 B-scans) was integrated over depth to create an enface image of the ONH.ResultsThe ONH was successfully imaged with negligible artifacts from eye motion (Fig. 1). On the left side, the whole dataset is seen including the duplicate corrupted B-scans. The corrupted B-scans were then removed in post-processing, thus leaving the undistorted duplicates untouched. The measured residual motion in the OCT B-scans was 0.32 arcmin (~1.6 µm) in a human eye. Four volumes from the same location were registered together to visualize the lamina cribrosa throughout the different depth slices of the eye (Fig. 2). The pore structure was clearly visible up to 430 um from the bottom of the ONH cup.ConclusionsIt is possible to obtain high quality OCT images from ONH and lamina cribrosa by compensating the eye motion during the measurements.

KW - optical coherence tomography

KW - retinal imaging

KW - scanning laser ophthalmoscope

KW - optic nerve head

M3 - Poster

SP - 1452

ER -

Vienola KV, Braaf B, Sheehy CK, Yang Q, Tiruveedhula P, de Boer JF et al. Imaging of optic nerve head pore structure with motion corrected deeply penetrating OCT using tracking SLO. 2013. Poster session presented at The Association for Research in Vision and Ophthalmology Annual Meeting 2013, Seattle, United States.