Abstract
Purpose:
To report our initial clinical results with a wireless ocular telemetry sensor (OTS) (Sensimed AG, Switzerland) for continuous intraocular pressure (IOP) monitoring in patients with open angle glaucoma.
Methods:
A prospective, observational study. We included 6 patients with clinical diagnosis of open angle glaucoma. All patients underwent a complete ophthalmologic examination, best corrected visual acuity, gonioscopic examination, intraocular pressure (Goldman applanation tonometer), visual field testing and optic nerve examination with stereoscopic photograph. We performed a conventional IOP 24-h monitoring with Goldman applanation tonometer during diurnal period (8:00 am to 5:00 pm) and Perkins applanation and Schiotz indentation tonometry in nocturnal period (8:00 pm to 6:00 am) The OTS is a disposable silicone contact lens with an embedded micro-electromechanical system, which measures changes in corneal curvature induced by variations in IOP. An antenna, mounted around the eye, receives the data and it is transmitted to a recorder. Patients were asked to fill a tolerability and comfort form in which they grade their level of ocular comfort an some symptoms on a 10 grade scale.
Results:
A successful signal was recorder in all of our patients. The mean age was 65.5 ± 7.3 years, 75% were female. The highest signals were recorded during the nocturnal period and we found that this peaks correlate with the time were the highest IOP values were measured in the conventional IOP monitoring. The mean of the mayor variation recorded was 55.5 aμ ± 8.8 aμ. Prolonges Peaks (>1 hr) were observed in all patient occurring outside office hours. No serious adverse events were reported. Average patient score for comfort was 6.5 and the most frequent symptoms were itching from the antenna patch, foreign body sensation, and redness.
Conclusions:
We found a positive correlation between the conventional 24-h IOP monitoring and the contact lens monitoring. Intraocular pressure fluctuations were detected and recorded successfully with the Triggerfish device. This OTS has the potential to improve clinical approach and assessment of glaucoma patients because static IOP measurements obtained in diurnal or nocturnal testing only estimates a portion of the 24-h IOP and do not reflect the dynamic nature of IOP.
Keywords: 568 intraocular pressure •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques