Search PubMed⌕ Search

PubMed · 16832671

[Dynamic contour tonometry].

Abstract

Dynamic contour tonometry (DCT) is a new technology for noninvasive and direct measurement of intraocular pressure (IOP); its results are thought to be influenced less than those of other methods by structural characteristics of the eye. The curvature of the pressure sensing device is concave and only slightly flatter than that of the human cornea. The cornea adapts to the curvature of the transducer head, and the sensor in the centre of the adapted area measures the pressure on the other side of the cornea in the force-free range. Studies published so far suggest that DCT is less heavily dependent than applanation tonometry on the biomechanical properties of the cornea . A further advantage of DCT over other forms of tonometry is the capability of dynamic measurements over time. It is also possible to measure both the diastolic and the systolic IOD and determine the difference between the two, i.e. the ocular pulse amplitude (OPA). OPA is an indirect indicator of choroidal perfusion and reflects the condition of the arterial vascular system and the action of the heart. It could be important in the diagnosis and treatment of glaucoma.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C Kniestedt, H E Kanngiesser. 2006. [Dynamic contour tonometry].. https://doi.org/10.1007/s00347-006-1387-7

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Dual-pump coherent anti-Stokes-Raman scattering microscopy.

We introduce dual-pump coherent anti-Stokes-Raman scattering (dual-CARS) microscopy. This new technique permits simultaneous imaging of two species characterized by different molecular vibrations, as well as the removal of nonresonant background. This is achieved by using three synchronized laser pulses probing two different vibrations. We demonstrate the virtues of the method by imaging a mixture of nondeuterated and deuterated lipids, clearly distinguishing the individual components and their organization in the mixed arrangement. Further, dual-CARS images of lipid stores in living Caenorhabditis elegans nematodes show that the suppression of the nonresonant background results in significantly enhanced image contrast.

Equipment Design↗

Application of a portable nuclear magnetic resonance surface probe to porous media.

A portable nuclear magnetic resonance (NMR) surface probe was used to determine the time-dependent self-diffusion coefficient D(t) of water molecules in two fluid-filled porous media. The measuring equipment and the inhomogeneous magnetic fields in the sensitive volume of the probe are described. It is discussed how to evaluate D(t) using a surface probe from the primary and stimulated echoes generated in three-pulse experiments. Furthermore, the evaluation of D(t) allows one to determine the geometrical structure of porous materials.

Equipment Design↗

I can C clearly now the rail has gone!

Accurate intra-operative imaging is vital in orthopaedic pelvic surgery in order to achieve precise reduction of fractures and correct positioning of osteotomies. Radiological assessment is carried out, in most centres, using standard C-arm fluoroscopy. A limitation of this technique is that it is not always possible to obtain accurate images in all planes due to the presence of radiopaque materials on the operating table. One such example is the 45 degrees oblique view, which is frequently obscured by the presence of a metal rail on the operating table. We report on a practical solution; the development of a unique 360 degrees radiolucent table by placing a sheet of Perspex material between two standard operating tables, which allows for perfect radiological exposure of the pelvis in all planes.

Equipment Design↗