FIGURE 1.

Optical coherence tomography (OCT) schematics: time-domain OCT (TD-OCT), spectral-domain OCT (SD-OCT), swept-source OCT (SS-OCT), and the adaptive optics system that can be added into a SD-OCT system (AO-OCT). Light signals are split and exchanged through the fiber coupler. The scanning mirror scans the beam across to make a B-scan. The dispersion correction of SD-OCT and SS-OCT corrects for light dispersion through the length of the eye and can be done through software after acquisition or through a material like a cuvette of distilled water approximately the length of the eye to compensate. The collimator in SD-OCT collects the light to shine it through a diffraction grating that spreads the different frequencies of light across the charge-coupled device (CCD) camera.