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 affects contrast in the retinal image and has an impact on visual quality. Vitreous constitutes the largest volumetric component of the human eye, thus it contributes to the intraocular scattering. The vitreous can contain subtle opacifications causing an increase in scattering and a reduction in vision. We report three-dimensional enhanced depth imaging of the anterior vitreous with SS-OCT. We show visualization of anterior vitreous opacities (floaters). We also demonstrate the quantification of vitreal opacities with respect to the age of the subjects.
Photothermal optical coherence tomography (PT-OCT) employs a secondary intensity-modulated photothermal laser to create modulated thermal strains that cause variations of the refractive index in the proximity of absorbing chromophores. These variations are directly detected with phase-sensitive OCT and offer insight to the molecular composition and thermo-elastic properties of the sample. Here, we define optimal PT laser modulation parameters by investigating the effect of PT laser power and modulation frequency on the ensuing thermal waves and thermal waves’ impact on the spatial resolution of PT-OCT imaging based on numerical simulations of PT-OCT and samples containing point absorbers.