Outcome, influence factor and development of CLS measurement in continuous IOP monitoring: A narrative review

Abstract

A large fluctuation in intraocular pressure (IOP) and a high peak IOP remain the risk factors for progressive visual field loss in patients with glaucoma, which is a leading cause of irreversible blindness. However, IOP measurements during working time cannot provide sufficient information on IOP to guide clinicians in setting IOP target values. Contact lenses are extensively used in ophthalmology to correct the refractive error, and recently, they are serving as platforms for detection and drug delivery. Contact lens sensor (CLS) is a feasible and promising approach to continuously monitor IOP, with superior tolerance, non-invasiveness, and without sleep disturbance. The present work reviewed the associations between progressive course and Triggerfish® CLS outputs as well as the relationship between treatments and Triggerfish® CLS outputs. Moreover, it further summarized state-of-the-art CLS devices of the past decade.

Advancements in Wearable and Implantable Intraocular Pressure Biosensors for Ophthalmology: A Comprehensive Review

“…One of the prominent advances in the field of IOP monitoring was the FDA approval of the Sensimed Triggerfish contact lens sensor in 2016 (Triggerfish CLS, Sensimed AG, Lausanne, Switzerland) [111][112][113]. The Triggerfish CLBS is a silicone contact lens that detects changes in the corneoscleral limbus curvature due to changes in IOP variations [114]. The sensor records at 5 min intervals over the 24 h period, giving the user 288 readings a day [115].…”

“…The CLBS has been tested for possible influences of electromagnetic radiation on its measurement behavior [117] and has been used to predict the visual field loss [44,118,119]. Overall, it has been concluded by a recent narrative review of all studies involving Triggerfish that the device is a promising tool that, while undeniably beneficial, still has to be further refined and improved [114].…”

“…All in all, the Triggerfish presents numerous advantages. However, it can also lead to a few adverse effects, especially over a long period of wearing time-such as causing transient myopia [114]. With further iterations, these adverse events can be reduced, increasing the benefit-risk ratio of the device.…”

“…Accuracy data for IOP biosensors are summarized in Figure 10. On the supply side, recent innovations in both CLS [114,[145][146][147][148][149][150][151] and hydrogel contact lens technology [96,152,153] have enabled advanced biosensors to engage in accurate, safe, and clinically actionable 24 h monitoring of IOP in both normal and glaucomatous eyes. With respect to the fungibility of CLS data with GAT measurements, Szurman and colleagues [133] measured a mean difference in IOP of −0.2 mmHg between patients using an implantable CLS and those subject to GAT measurement, which the authors categorized as "excellent" and in excess of the instrumental agreement between non-biosensorbased IOP measurement modalities such as GAT as compared to rebound tonometry.…”

“…Consequently, advanced biosensors offer an exciting new instrument by which to interrogate IOP in way that is vastly more comprehensive than GAT. Numerous studies demonstrate how CLS are enabling clinicians to (i) better identify individuals with normal in-office pressures but who actually experience IOP spikes nocturnally [119,136,143,144,150,151,[164][165][166][167][168] and thus better risk-stratify and treat patients, (ii) document changes in IOP in response to both surgical [125,133,156,169] and pharmacological [114,143,150,170,171] glaucoma treatment, and (iii) triangulate IOP trends with other concurrent biometric data such as blood pressure and sleep position [151,172] for clinical research purposes.…”