Showing papers on "Optical coherence tomography published in 1992"

Optical Coherence Tomography

Abstract: Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described as the optical analogue to ultrasound. The inherent safety of the technology allows for in vivo use of OCT in patients. The main strength of OCT is the depth resolution. In dermatology, most OCT research has turned on non-melanoma skin cancer (NMSC) and non-invasive monitoring of morphological changes in a number of skin diseases based on pattern recognition, and studies have found good agreement between OCT images and histopathological architecture. OCT has shown high accuracy in distinguishing lesions from normal skin, which is of great importance in identifying tumour borders or residual neoplastic tissue after therapy. The OCT images provide an advantageous combination of resolution and penetration depth, but specific studies of diagnostic sensitivity and specificity in dermatology are sparse. In order to improve OCT image quality and expand the potential of OCT, technical developments are necessary. It is suggested that the technology will be of particular interest to the routine follow-up of patients undergoing non-invasive therapy of malignant or premalignant keratinocyte tumours. It is speculated that the continued technological development can propel the method to a greater level of dermatological use.

Measurement of corneal thickness by low-coherence interferometry

Abstract: A special interferometric technique, which uses light of low-coherence length and the Doppler principle, is applied to measurement of the thickness of the human cornea in vivo. The special construction of the instrument eliminates any influence from eye motions on the thickness results. With a superluminescent diode as a light source, a precision of ~ 1.5 microm is obtained. This is ~ 3-8 times better than the precision of existing instruments. Since interobserver and interinstrument variability are avoided by the measurement principle, the improvement in total accuracy, compared with that when existing instruments are used, should be even better.