Abstract
Purpose: :
The intraocular pressure (IOP) measurement is the mainstay of investigation in the management of patients with glaucoma. Single IOP tonometry only represents snapshots, while circadian IOP fluctuations are not detected. A circadian IOP pattern is usually determined in hospitalized patients by about 5 to 6 measurements. In our explorative clinical study, we compared Triggerfish®, designed for 24-hour continuous IOP monitoring, to golden standard for IOP measurement, the Goldmann-Applanationtonometry (GAT), and monitored its use and tolerability.
Methods: :
Twenty-two patients with POAG underwent 24-hour IOP monitoring in our clinic. Patients were randomized to either compare GAT between eyes on the first day and Triggerfish® and GAT in the fellow eye on the consecutive day, or vice versa. A correlation of 70% between the GAT IOP of both eyes was considered appropriate and in agreement with literature. GAT was not performed during the night.Triggerfish® (Sensimed AG, Lausanne, Switzerland) is a device that monitors the 24-hour IOP fluctuations by wireless sensor contact lens placed on the eye that sends its signal via a periorbital antenna to a recorder worn by the patient. The recorded data can be read in arbitrary units and visualized on a computer.
Results: :
All 22 eligible patients with POAG completed the study. Mean age was 62 ±7 years and 8 were male and 14 female. The overall mean correlation between GAT IOP of both eyes was 56% (± 36%) and only 10 patients (45%) had a high correlation (mean: 87% (± 10%)) for GAT IOP of both eyes. As expected, a high proportion of patients (18 out of 22, 81%) displayed a nocturnal (supine position) increase in Triggerfish® output.Overall, 76% of the patients were satisfied with the Triggerfish® as compared to GAT (subjective acceptance scale). Triggerfish® was easy to handle and was safe and well tolerated for use.
Conclusions: :
Overall, the Triggerfish® is an advance in the management of glaucoma, as it provides a non-invasive continuous monitoring of the IOP behavior during 24 hours, both during sleep and normal daily activities. Given the low mean correlation between GAT IOP of both eyes, direct comparison between GAT and Triggerfish® may not be meaningful. The Triggerfish® sensor however does not replace conventional GAT IOP measurement, but may provide complementary useful information for the management of glaucoma.
Keywords: intraocular pressure