Abstract
Purpose :
Sensimed Triggerfish® contact lens sensor (CLS), a relatively new device, is designed to monitor 24-hour intraocular pressure (IOP) profile. Currently, the safety, tolerability and validity of triggerfish CLS remains controversial. We performed a prospective observational study (the first such study in the NHS UK) to evaluate the safety, tolerability of CLS in glaucoma patients and whether the CLS measurement can be correlated to IOP measured using Goldmann applanation tonometry (GAT).
Methods :
This was an observational single-facility study. 24 voluntary patients (9 females, 15 males) with glaucoma underwent 24-hour continuous measurement of IOP with a Triggerfish® CLS. Clinic letters and communications to the GP (general practitioner) were reviewed to identify any objective and subjective reports of eye symptoms during or after the usage of CLS.
IOP were measured immediately before and after CLS usage using GAT by ophthalmologists. We then compared the changes of IOP measurements (end-initial IOP in mVeq) from CLS and changes of IOP (end-initial IOP in mmHg) from GAT among the 24 patients to look for correlation.
Results :
All patients successfully completed the 24-hour measurement of IOP with CLS. The mean age was 69.83 (SD: 7.8). No patient needed emergency visit or discontinuation or removal of the CLS before the prescribed period.
The reporting rate of side effects, watering, redness, pain, blurring or discomfort was 0%. At the 3-week follow up clinic, the overall incidence of objective and subjective report of eye symptoms such as ocular pain and blurred vision was 0%. The Pearson correlation coefficient between the difference of IOP measurement from CLS and GAT was r=-0.173 (p=0.43), which represented a weak negative correlation.
Conclusions :
Our study showed that IOP measurement with 24-hour CLS is safe & well-tolerated in glaucoma patients. There were no short term or permanent complications or side effects reported. Our results showed a weak correlation between Triggerfish data changes and IOP measurements using the GAT. Though CLS cannot totally replace GAT for IOP measurement, this complements& adds useful insight on the innovative continuous 24 hour IOP profile and nocturnal measurements not covered by the static clinic GAT. Bigger, well-designed studies shall help in this exciting topic.
This is a 2021 ARVO Annual Meeting abstract.