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GALILEI G2

Launched at ESCRS

September 04, 2010
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EVENTS

SOG 2010

Montreux, Switzerland

APAO Congress 2010

Beijing, China

AAO, Chicago

Joint Meeting of the AAO and the MEACO, Chicago, IL, USA

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Last Update: 08.09.2010
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Impressum

Intra-Ocular Pressure and Glaucoma

In routine eye examinations, Applanation Tonometry has been substantially relied upon as a screening tool – even though it can be now proven that this yields significant numbers of false negatives.  Dynamic Contour Tonometry as implemented in the PASCAL Dynamic Contour Tonometer is capable of measuring the "true IOP" directly. The pressure measured by the PASCAL is not influenced to any significant extent by corneal thickness, corneal geometry, or corneal biomechanics. PASCAL IOP has been demonstrated in clinical studies to reflect the true (intra-camerally measured) IOP more closely than classical applanation tonometers and air-puff tonometers.

A result of using PASCAL will be to see more glaucoma suspects earlier and to start them on therapy more timely.

 

IOP Measurement and Refractive Surgery

It is a well-established fact that Goldmann and non-contact "air-puff" tonometers fail when used for measuring IOP on post-refractive (e.g. post-LASIK or post-refractive) eyes (e.g.  Kaufmann et al, IOVS, 2004, Siganos et al, JCRS, 2004, or a recent review by Selim in Review of Ophthalmology, January 2004)). The cause of the systematic error inherent to such IOP measurements is that the biomechanical properties of the cornea are significantly altered by any corneal refractive procedure, affecting the force required to applanate the cornea. Hence, all tonometers functioning on the prinicple of measuring the force required to applanate the cornea will furnish low readings when used on post-refractive eyes.

The PASCAL Tonometer has been proven to provide more reliable IOP measurements on post refractive eyes. It is therefore the tonometer of choice for any refractive surgeon and any practitioner confronted with patients who had refractive surgery procedures.

Ziemer has therefore developed an IOP Pass for LASIK patients. Intended to be issued by refractive surgeons / refractive clinics to their patients, it helps improve awareness of this problem with patients as well as practitioners who see patients for IOP checkups after they had LASIK.

The IOP Pass is available as a free service to owners of the Ziemer FEMTO LDV Femtosecond Surgical Laser, helping them to provide that extra level of care to their premium Z-LASIK patients.

Read more about the Ziemer IOP Pass program.

 

 

 

Ocular Pulse Amplitude and Glaucoma

Because the PASCAL’® measures IOP 100 times per second, a pulse wave is generated, that is reflective of heart rate and the mean difference between diastolic and systolic IOP. This value is called Ocular Pulse Amplitude (OPA). OPA is reflective of the relative quality of ocular blood flow.
Investigators have shown that those individuals with lower than average OPA have a greater likelihood of being glaucomatous. This relationship seems to be particularly significant in patients with normal tension glaucoma.
This information may have value to the clinician in assessing the early onset of disease caused by compromised blood supply to the eye. In particular, patients who have normo-tensive glaucoma (NTG) may have insufficient blood perfusion. Studies have shown that OPA is lower in patients with glaucoma, which supports the hypothesis that vascular factors are associated with this disease. Low OPA has also been shown to correlate with Drance hemorrhage.
Effective January 1, 2009, Category III CPT Code 0198T (measurement of ocular blood flow by repetitive intraocular pressure sampling, with interpretation and report) has been assigned. Measuring the ocular pressure curve with the PASCAL DCT is therefore now a billable procedure in the U.S.A..