In this work we demonstrate the potential of Vertical-Aligned Spatial Light Modulators in the simulation and correction of High Order Aberrations by testing visual acuity and contrast sensitivity function in a set of healthy subjects.
The potential of vertical-aligned spatial light modulators for use in adaptive-optics visual simulators is demonstrated. We performed visual acuity and contrast sensitivity tests in different subjects, with their eye’s optics corrected by the custom adaptive-optics system and with induced aberrations similar to those in severe keratoconus. We tested the system in a see-through configuration, achieving a total corrected field of view of ∼13 deg. The applicability of these modulation devices for a wearable visual adaptive optics system is discussed.
Swept source OCT was used to image crystalline lens of 100 eyes (age range: 9-78 years) and 3-dimensional lens suture structure was visualized in vivo for the first time. Lens suture patterns were extracted using average intensity projections (AIP) or cortical layers of crystalline lens. Our imaging system has capacity to extract complex star-sutures from cortical layers of lens and simple Y-sutures from fetal nucleus of crystalline lens. Age-related changes in lens and lens sutures were observed and were characterized quantitatively. The developed imaging system can be used to study growth of crystalline lens and its age-related diseases like cataract, presbyopia.
Transparency of ocular structures is an important factor determining contrast in the retinal image. Although opacities are most commonly formed in the crystalline lens of aging eye (cataract formation), visual function can be also altered by the opacities in the vitreous body. Therefore, macro- and micro-scale visualization of vitreous is clinically relevant since alterations of vitreous organization impact retinal diseases and affect vision. However, optical imaging of the vitreous body is challenging due to its transparency. We demonstrate visualization of vitreous and its opacities in vivo using optical coherence tomography (OCT). We developed a prototype long-depth-range Swept-Source OCT instrument operating at the speed of 30 kA-scans/second and at the central wavelength of 1 μm to perform high-resolution imaging through the entire vitreous depth. The interface with focus-tunable optics has been used to optimize the field of view. 2-D and 3-D OCT data sets of eyes with vitreous opacities were acquired and processed to obtain contrast-enhanced high-resolution images of vitreous. The results demonstrate the ability of the OCT imaging to characterize the opacities that cause floaters. In conclusion, long-depth-range SS-OCT enables volumetric visualization of in vivo microstructural changes in the vitreous body. This instrument might be a useful tool in high-resolution evaluation and surgical management of vitreous opacities.
Optical methods have been recently used to perform objective assessment of crystalline lens and corneal opacities. Swept-source optical coherence tomography (SS-OCT) enables measurements of the back-reflected or back-scattered photons from the internal objects. In this work, we present a long-depth range SS-OCT system, with a focus tunable lens, optimized for the visualization of large sections of the posterior segment of the eye, including the vitreous. The system was validated using an eye model.