الفهرس Only 14 pages are availabe for public view
 |  | from | 122 |  |  |
| | | from | 122 | | |
Abstract
Assessment of anterior segment structures is an integral part of ophthalmic examination. Objective quantitative assessment of anterior segment structures is limited and direct iridocorneal angle visualization can only be carried out with the use of diagnostic contact lenses.
OCT is a non-invasive optical imaging technique. It uses the property of optical reflectivity to give a cross-sectional imaging of biological tissue with a high resolution and micrometer scale (Hrynchak, 2000).
AS-OCT can detect quantitatively subtle changes to the eye caused during the early stages of ocular disease, such as glaucoma, and by procedures like cataract surgery. It can measure residual stromal thickness in LASIK patients who are candidates for re-treatment. This capability has made OCT an attractive imaging and measurement technique to aid photorefractive surgery for the correction of myopia, hyperopia and astigmatism. It is used to investigate and monitor post-op side-effects (Tomlins and Wang, 2005).
AS-OCT has also been used to measure intraocular dimensions, such as anterior chamber width, prior to phakic IOL implantation. Also it is used to study the dynamic nature of phakic IOLs during accommodation and to demonstrate contact of the IOL with the anterior surface of the crystalline lens (Konstantopoulos et al., 2007).
Such investigative tool performs a type of optical biopsy, with a micron-scale imaging of tissue morphology in-situ and in real time. Image information is available immediately without the need for excision and histological processing of a specimen. This allows pathology to be monitored on screen and stored on high-resolution video tape. Real-time imaging can enable real-time diagnosis, and coupling this information with surgery, it can enable surgical guidance (Fujimoto et al., 2000).
AS-OCT system provides clear, highly detailed, in-depth cross-sectional images of the anterior segment -including the angle- without the need for ocular anesthesia or a messy, time-consuming water bath. It is so easy to use and efficient to operate. This dramatically expands the potential for diagnostic confidence and therapeutic precision (Zeiss 1, website).