Advances in telemetric continuous intraocular pressure assessment

Kakaday, Tarun; Hewitt, Alex W.; Voelcker, Nicolas H.; Li, Jim S. Jimmy; Craig, Jamie E

doi:10.1136/bjo.2008.144261

Cited by 41 publications

(26 citation statements)

References 24 publications

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“…As 24-hour IOP measurements are impractical for the majority of patients and clinicians, the identification of appropriate surrogate measures of circadian fluctuation is important. The currently emerging continuous IOP monitoring technologies 22,44,78 may soon offer important contributions to the study of IOP rhythms. Once telemetric technologies become validated and widely available for clinical use, they may provide an invaluable tool towards a better understanding of long-and shortterm IOP fluctuations during a patient's undisturbed daily routine.…”

Section: Discussionmentioning

confidence: 99%

24-hour Intraocular Pressure and Ocular Perfusion Pressure in Glaucoma

Quaranta

Katsanos

Russo

et al. 2013

Survey of Ophthalmology

137

147

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Abstract. This review analyzes the currently available literature on circadian rhythms of intraocular pressure (IOP), blood pressure, and calculated ocular perfusion pressure (OPP) in patients with openangle glaucoma. Although adequately powered, prospective trials are not available. The existing evidence suggests that high 24-hour IOP and OPP fluctuations can have detrimental effects in eyes with glaucoma. The currently emerging continuous IOP monitoring technologies may soon offer important contributions to the study of IOP rhythms. Once telemetric technologies become validated and widely available for clinical use, they may provide an important tool towards a better understanding of longand short-term IOP fluctuations during a patient's daily routine. Important issues that need to be investigated further include the identification of appropriate surrogate measures of IOP and OPP fluctuation for patients unable to undergo 24-hour measurements, the determination of formulae that best describe the relationship between systemic blood pressure and IOP with OPP, and the exact clinical relevance of IOP and OPP fluctuation in individual patients. Despite the unanswered questions, a significant body of literature suggests that OPP assessment may be clinically relevant in a significant number of glaucoma patients. (Surv Ophthalmol 58:26--41, 2013. Ó 2013 Elsevier Inc. All rights reserved.) Key words. glaucoma circadian rhythm intraocular pressure blood pressure ocular perfusion pressure I. Physiological ConsiderationsThe principal physiological entities that affect intraocular pressure (IOP) and its characteristics are the aqueous humor (AH) dynamics in healthy and glaucomatous eyes.The production of AH involves two consecutive processes. First, a portion of the plasma that reaches the vascular plexus of the ciliary processes is filtered through the fenestrated capillaries into the interstitial space between the vessels and the ciliary epithelia. Next, a portion of the filtrate is actively secreted by the ciliary epithelial cells into the posterior chamber.In humans, these processes are affected by age, circadian rhythm, topical and systemic medications, and the presence of glaucoma. 63,64,70,109,121 The rate of AH formation decreases with age: by 15--35% between age 20 and 80 years. 15,30 The rate of AH production in humans is significantly lower at night, 99,119 attributed to decreased endogenous circulating catecholamine levels, which may partly explain the decreased nocturnal efficacy of topical 26

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Section: Discussionmentioning

confidence: 99%

24-hour Intraocular Pressure and Ocular Perfusion Pressure in Glaucoma

Quaranta

Katsanos

Russo

et al. 2013

Survey of Ophthalmology

137

147

View full text Add to dashboard Cite

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“…Kakaday et al [62] present a much more in depth viewpoint on intraocular pressure measurements and the clinical need. Accepting that the approach is valid, the questions of practicality, medical demand, and persuasive reimbursement arguments are challenging.…”

Section: Other Recent Reviewsmentioning

confidence: 99%

Recent Advances in Translational Work on Implantable Sensors

Black

2011

IEEE Sensors J.

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This review evaluates example technologies from the point-of-view of likely translation into human use, including regulatory clearance, insertion into common medical practice and reimbursability. The intent is to highlight recent innovations in implantable sensors with a focus on the translational process itself in a holistic fashion. As well as looking at success stories, this review will also examine several seemingly promising technologies that have failed for reasons having nothing to do with the operational aspects of the sensors and systems involved. Innovation must be viewed as a multifaceted process, all segments of which must be fully addressed to achieve success. No party to the process can work in isolation and expect to achieve the end goal of providing new advances to patients. This review will have succeeded if it provides the reader with a better appreciation of the complex environment in which implantable sensor discoveries that seek to be translated into human medicine must navigate.Index Terms-Implantable sensors, sensor systems, in vivo medical devices.

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“…Examples include the use of contact lenses, 11,12 implants with telemetric pressure transducers, [13][14][15][16] and other devices based on optical principles. [17][18][19][20] Recently, a special configuration has demonstrated the ability to sense remote speech signals, heart beats, and vibrations from remote objects using reflected secondary speckle patterns.…”

Section: Introductionmentioning

confidence: 99%

New method for remote and repeatable monitoring of intraocular pressure variations

et al. 2014

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We present initial steps toward a new measurement device enabling high-precision, noncontact remote and repeatable monitoring of intraocular pressure (IOP)-based on an innovative measurement principle. Using only a camera and a laser source, the device measures IOP by tracking the secondary speckle pattern trajectories produced by the reflection of an illuminating laser beam from the iris or the sclera. The device was tested on rabbit eyes using two different methods to modify IOP: via an infusion bag and via mechanical pressure. In both cases, the eyes were stimulated with increasing and decreasing ramps of the IOP. As IOP variations changed the speckle distributions reflected back from the eye, data were recorded under various optical configurations to define and optimize the best experimental configuration for the IOP extraction. The association between the data provided by our proposed device and that resulting from controlled modification of the IOP was assessed, revealing high correlation (R2=0.98) and sensitivity and providing a high-precision measurement (5% estimated error) for the best experimental configuration. Future steps will be directed toward applying the proposed measurement principle in clinical trials for monitoring IOP with human subjects.

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Advances in telemetric continuous intraocular pressure assessment

Cited by 41 publications

References 24 publications

24-hour Intraocular Pressure and Ocular Perfusion Pressure in Glaucoma

24-hour Intraocular Pressure and Ocular Perfusion Pressure in Glaucoma

Recent Advances in Translational Work on Implantable Sensors

New method for remote and repeatable monitoring of intraocular pressure variations

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