Common-path fourier-domain optical coherence tomography in ophthalmology applications

We have demonstrated in vivo three-dimensional imaging and estimated localized and quantitative hemoglobin oxygen saturation (SO₂) of blood vessel by using a simple, easy to operate common-path Fourier-domain optical coherence tomography (OCT) system. The common-path OCT system can be easily integrated with various surgical tools and we demonstrated its usefulness by imaging outer and inner intraocular tissues such as cornea and neurosensory retinal layers as well as detecting SO₂ level from a chicken embryo. The system uses 800 nm near infrared broadband light sources and has axial resolution as low as 3 mum in air. Self-adaptive scanning mechanism with real-time surface recognition and feedback control was also applied to the probe where the scanning probe tracks the sample surface variance and effective imaging depth was largely extended to the probe's free-moving range.