부산대학교 도서관

Intraocular light scattering affects the contrast of the image created on the retina thus reducing the vision quality. Although one can consider the ocular components transparent, the microstructural changes (that are associated with aging or other factors) lead to the increase in intraocular light scattering. Therefore, the opacification of ocular structures is associated with vision‐affecting diseases such as corneal dystrophies, crystalline lens cataracts, vitreous floaters etc. Optical coherence tomography (OCT) is a non‐invasive imaging modality enabling generation of micrometre resolution, two‐dimensional (2‐D) cross‐sectional images and three‐dimensional (3‐D) volumetric data presenting internal structure of optically scattering tissues. OCT detects light that is back‐scattered/back‐reflected at the optical in homogeneities within the ocular structures. Due to its high sensitivity, OCT enables detection of ultralow scattered light levels obtained from weakly scattering tissues such as the vitreous body. In this talk, we will demonstrate in vivo enhanced three‐dimensional visualization of vitreous and lens opacities in normal subjects and cataract patients of different ages using a swept source OCT (SS‐OCT) system deployed to the Laboratory of Optics at the University of Murcia, Spain. The instrument operated at the central wavelength of 1050 nm and was optimized to image the anterior segment of the eye. Volumetric images were used to effectively map the opacities and to generate en‐face projection images of opacities. The results revealed the changes in the transparency of the crystalline lens showing lens micro‐ and macro‐scale features related to cataract such as cortical spokes, water clefts and enhanced scattering in the lens nucleus. On the other hand, vitreous imaging with SS‐OCT allowed for visualization of gel vitreous, liquefied lacunae, Berger's space, retrolental laminae and fibrous opacifications. Volumetric OCT data of the lens and retrolental vitreous were used to perform quantitative analysis of light scattering (transparency). We introduced indices describing transparency and optical homogeneity of ocular structures. Later on, we showed that those biomarkers correlate with age. Finally, statistical association between transparency of crystalline lens / vitreous and degradation of visual function was performed. The proposed imaging platform can be a new‐generation ophthalmic diagnostic tool in the fundamental studies as well as for objective clinical evaluation and management of eye diseases. [ABSTRACT FROM AUTHOR]