Imaging of the lens capsule with an ultrahigh-resolution spectral optical coherence tomography prototype based on a femtosecond laser

摘要

Aim To demonstrate the applicability of ultrahigh-speed, ultrahigh-resolution spectral optical coherence tomography (SOCT) to cross-sectional imaging of the capsular bag in vivo.Methods The ultrahigh-speed and ultrahigh-resolution SOCT prototype was designed and constructed at Nicolaus Copernicus University (Torun, Poland). To obtain an ultrahigh speed up to 100 000 lines/s a new spectrometer with fast CMOS line-scan camera was built. A femtosecond laser with a central wavelength of 780 nm and AX=160 nm enabled imaging with an axial resolution of 2.3 urn and lateral resolution of 10 |im in tissue. Lens capsules of two healthy eyes were examined with the aid of the instrument using two- and three-dimensional scanning protocols. Results The prototype provided ultrahigh-resolution tomograms composed of 8000 A-scans with an acquisition time of 0.16 s. The quality was sufficient to evaluate the capsular bag and to estimate its thickness. It was possible to visualise a separate layer of lens epithelium, to the authors' knowledge the first such visualisation. Three-dimensional data were used to produce lens-capsule thickness maps. Conculsions Ultrahigh-resolution, ultrahigh-speed SOCT based on a femtosecond laser allows two- and three-dimensional evaluation of a capsular bag and lens epithelium. The instrument provides new information of scientific and clinical value.