Abstract
Purpose: :
To develop and test a real time OCT technology that can image all the surfaces of the anterior segment of the eye simultaneously for the study of accommodation.
Methods: :
The system features two independent high speed OCT engines coupled together into the imaging system. The two OCT systems image different depths of the anterior segment simultaneously. The depth difference of the two simultaneous OCT images is accurately controlled by the path length difference of the reference arms in the two OCT engines. The two OCT images can thus be merged accurately into one cross sectional image of the whole anterior segment of the eye. By a novel design, the two light beams of the two OCTs are focused at different depth of the anterior segment, one of which is focused close to the cornea, the other is focused into the lens of the eye. This arrangement ensures high signal-to-noise ratio in the whole depth of the merged cross sectional image.
Results: :
The calibrated depth resolutions of the two OCT systems are 6 µm and 3 µm, respectively. The calibrated imaging depths of the two OCT systems are 5.2mm (OCT-A) and 2.5mm (OCT-B), respectively. OCT-A was aligned to image the cornea and the front surface of the lens. OCT-B was aligned to image the back surface of the lens. Both systems work at an A-line rate of 2400 lines/second. Normal eyes at different accommodation conditions were imaged with the system. The modification of the curvatures of the anterior and posterior surfaces of the crystalline lens and the dimensions of the anterior segment of the eye with accommodation is calculated. The results demonstrate the feasibility of this novel approach for the study of accommodation of the eye.
Keywords: accomodation • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical