A-scan rate of 100 kHz). However, commercial SD-OCT systems suffer significant drops in sensitivity, and thus image quality, beyond 2mm of penetration depth. Therefore, if used sequentially to image an eye from the cornea to the choroid, commercial SD-OCT systems would probably produce images with unacceptably inconsistent quality across the depth of the eye. Furthermore, commercial SD-OCT devices also produce mirror image artifacts around the zero delay position. Although this is infrequently distracting in posterior segment imaging, it can be quite confusing when imaging near the iris plane. Swept Source OCT (SS-OCT) The development of short external cavity tunable laser technology has made SS-OCT biomicroscopy possible by combining high speed acquisition with long coherence length and consistently high image quality across the depth of the eye. It is now feasible that properly designed SS-OCT systems could acquire full OCT biomicroscopic data from both eyes of a subject in less than 20 seconds. As with SD-OCT, mirror image artifacts must be removed from SS-OCT systems. Exam Components Lids, Lashes, Lacrimal Glands Although traditionally used for imaging of the retina and, more recently, the iris and angle of the eye, SS-OCT systems have also been demonstrated to be capable of imaging the lid margins and eyelashes. Although it is possible that future SS-OCT systems might also be capable of imaging a majority of visible eyelid tissue, it is unlikely that OCT biomicroscopic systems will be capable of imaging the lacrimal gland. Conjunctiva High speed SS-OCT systems focused on the anterior segment have been demonstrated to be capable of imaging the bulbar conjunctiva within the palpebral fissure.(see Gora et al.) The remaining bulbar conjunctiva and palpebral conjunctiva cannot currently be imaged while the eyelids are in their natively relaxed position. The use of eyelid retractors as well as eyelid eversion may enable more comprehensive examinations of these conjunctival regions. Cornea In addition to recent work with SS-OCT, (see Gora et al.) numerous investigators have demonstrated the ability of OCT systems to depict pathology within the cornea as well as disorders of corneal topography. References External links Eye Examination with the Slit Lamp (article by Zeiss) Medical ultrasonography Eye procedures Laser medicine