Einfluss der Hornhautdicke auf die Tonometrie

Zusammenfassung

Die Hornhautdicke hat einen Einfluss auf die Messung des Augeninnendrucks und ist gleichzeitig ein unabhängiger Risikofaktor für die Entstehung eines Glaukoms. Die Messwerte aller gängigen Tonometer, insbesondere des Goldmann-Applanationstonometers, der Non-Contact-Tonometer und der Rebound-Tonometer, werden von der Hornhautdicke beeinflusst. Es wurden Nomogramme zur Korrektur der Messwerte für die unterschiedlichen Tonometer entwickelt. Diese Nomogramme bewirken auf Patientengruppen bezogen eine Annäherung der gemessenen Augeninnendruckwerte an den tatsächlichen Augeninnendruck. Im Einzelfall kann es aber zu Fehlbestimmungen in der Art kommen, dass der korrigierte Augeninnendruck weiter vom realen Augeninnendruck abweicht als der eigentliche Messwert. Dessen muss man sich bewusst sein, wenn man eine Korrektur der IOD-Messwerte mit Nomogrammen durchführt. Die dynamische Konturtonometrie und der IOD_cc des Ocular-Response-Analyzers werden nur vernachlässigbar gering durch die Hornhautdicke beeinflusst. Die Hornhautdicke ist ein wichtiger Parameter im Management von Glaukompatienten und sollte bei der Beurteilung der gemessenen Augeninnendruckwerte berücksichtigt werden. Dies kann entweder durch die Korrektur der Messwerte mithilfe von Nomogrammen oder bei der Festlegung des individuellen Zieldrucks erfolgen.

Abstract

Central corneal thickness (CCT) affects IOP measurements and is an independent risk factor for the development of glaucoma. IOP measurements of all common tonometers, such as the Goldmann applanation tonometer, non-contact tonometer and rebound tonometer, are affected by CCT. Nomograms to correct IOP measurements according to CCT have been established. These nomograms lead to a reduction of the measurement error caused by CCT in groups of patients. However, one has to be aware of the fact that, in individuals, the correction of IOP measurements can even increase the deviation of the IOP measurement from the actual IOP. The effect of CCT on dynamic contour tonometry and IOP_cc measured by ORA is negligible. CCT is an important parameter in glaucoma management and needs to be considered when interpreting IOP measurements. This can be done by using nomograms or by implementing CCT in the calculation of the individual target pressure.

Schlüsselwörter

Glaukom - Kornea - Tonometrie

Key words

glaucoma - cornea - tonometry

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