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Identifier

000382416

Title

Έλεγχος αξιοπιστίας και επαναληψιμότητας συσκευής μη επεμβατικής ελαστομετρίας

Alternative Title

Audit of reliability and repeatability of the non-invasive device of elastometer

Author

Δούκα, Χρυσούλα

Thesis advisor

Τσιλιμπάρης, Μιλτιάδης

Reviewer

Γκίνης, Χαρίλαος
Δετοράκης, Ευστάθιος

Abstract

Purpose Various instruments and methods applied for the measurement of intraocular pressure (IOP), mostly on the basis of the applied force-deformation region. The ocular regitity is a parameter expressing the elastic properties of the eye and is defined mathematically as the ratio of the change in intraocular pressure to the change of the volume of the eye. Ocular rigidity coefficient, which according to the Friedenwald, is the measure of resistance of the eye to the forces that tend to deform it, is represented by the slope of the line of intraocular pressure versus volume of deformation of the eye. However, the measurement of ocular rigidity remains problematic due to the lack of accurate, clinically viable, non-invasive measurement technique. The purpose of this study was to present a new device for the measurement of IOP and ocular rigidity. Methods-device The apparatus consists of an opto-mechanical head, which comprises a sensor and a deformation force sensor, a camera and a microstepping motor. The deformation sensor is a device consisting of two optoelectronics beamsplitter, a plano lens, a fiber and a light receiver fiber. Carry sensor alignment with the tested eye through a camera is mounted on the axis of the instrument. The alignment is based on the superposition of the reflection of the light source from the optics of the instrument and the first Purkinje image of the cornea and the eye under examination focuses on the source. This ensures that the plane defined by the edge flattening is perpendicular to the axis of the instrument. This study examined 118 of eyes (right and left) in which IOP was measured with the new device after measuring with a tonometer Goldmann (GAT). Results The mean age of participants was 60,42 years (±18,53 years). IOP was measured with the device was 12,995 mmHg (±5,997 mmHg), while GAT IOP was 14,120 mmHg (±2,56 mmHg). The absolute mean difference between the two devices 4,40 mmHg (± 3,56 7 mmHg) and the correlation index between the two devices was p=0,992. The coefficient of ocular rigidity measurements were 0,017μl−1 (±0,026 μl−1 ). Conclusions The non-invasive method is described and evaluated in this study is theoretically a way of measuring intraocular pressure. Comparative measurements done using the commonly used device Goldman exhibiting at this stage statistically significant deviations, which is obvious by the low correlation index (p = 0,002) for 95% significance level. Further measurements and modifications need to be made to this device to eliminate errors, and their agreement with the measurements of the tonometer Goldman.

Language

Greek

Subject

Non invasive elastometer

Reliability

Repeatability

Αξιοπιστία

Επαναληψιμότητα

Μη επεμβατικό ελαστόμετρο

Issue date

2013-07-16

Collection