Abstract
Purpose::
To demonstrate very high-speed three-dimensional (3D) morphological retinal imaging by a spectral domain OCT (SD-OCT) with a novel optical configuration.
Methods::
Line field spectral domain OCT (LF-SDOCT), which uses the principles of conventional spectral domain OCT and an imaging system, was developed and employed for this study. In LF-SDOCT, line illumination and a two-dimensional (2D) area scan camera are employed for parallel detection of a single OCT B-scan. LF-SDOCT acquires a cross sectional image of the retina by a single shot of a CCD camera without mechanical scanning. In our system, B-scan image is obtained with only 311 us measurement time, and it corresponds to an A-scan rate of 823,151 A-scans/sec. For 3D imaging, only one additional mechanical scanning is employed. LF-SDOCT is capable of acquiring 201 B-scans/s where a single B-scan contains 256 A-lines. The measurement time is 1.3 seconds for the 3D tomogram with 256 B-scans. Due to limitation of the image acquisition speed of the camera, the achievable A-scans/s is 51.5 kHz for 3D imaging, and it corresponds to 2.6 times faster than conventional SD-OCT.Three normal subjects were examined. This examination was approved by the institutional board of University of Tsukuba.
Results::
In-vivo 3D OCT measurements of the maculae of healthy volunteers were achieved by our LF-SDOCT. Owing to faster measurement speed than conventional SD-OCT, the undesirable artifact due to the sample motion is suppressed. This is effective for eye motion and blinking. Moreover, this is useful for practical clinical uses, especially for patients who have difficulty to fix the eye even with fixation target by ages, diseases and so on.
Conclusions::
LF-SDOCT visualized a 3D structure of in-vivo retina at more than twice faster speed than conventional SD-OCT.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: non-clinical • retina