Investigation of a novel implantable suprachoroidal pressure transducer for telemetric intraocular pressure monitoring

Siegfried Mariacher; Martina Ebner; Kai Januschowski; José Hurst; Sven Schnichels; Peter Szurman

doi:10.1016/j.exer.2016.07.016

Investigation of a novel implantable suprachoroidal pressure transducer for telemetric intraocular pressure monitoring

Exp Eye Res. 2016 Oct:151:54-60. doi: 10.1016/j.exer.2016.07.016. Epub 2016 Jul 25.

Authors

Siegfried Mariacher¹, Martina Ebner², Kai Januschowski³, José Hurst⁴, Sven Schnichels⁴, Peter Szurman³

Affiliations

¹ Knappschaft Eye Clinic Sulzbach, Knappschaft Hospital Saar, An der Klinik 10, 66280, Sulzbach, Germany. Electronic address: siegfried.mariacher@gmail.com.
² Knappschaft Eye Clinic Sulzbach, Knappschaft Hospital Saar, An der Klinik 10, 66280, Sulzbach, Germany.
³ Knappschaft Eye Clinic Sulzbach, Knappschaft Hospital Saar, An der Klinik 10, 66280, Sulzbach, Germany; Centre for Ophthalmology, University Eye Hospital Tuebingen, Schleichstr. 12, 72076, Tuebingen, Germany.
⁴ Centre for Ophthalmology, University Eye Hospital Tuebingen, Schleichstr. 12, 72076, Tuebingen, Germany.

PMID: 27456134
DOI: 10.1016/j.exer.2016.07.016

Abstract

Intraocular Pressure (IOP) is an important and modifiable risk factor for glaucoma progression. IOP fluctuations and spikes often remain undetected despite clinical routine examinations. Therefore telemetric IOP measurement systems with continuous IOP monitoring can provide major advantages in glaucoma surveillance. To the best of our knowledge, this is the first study to investigate implantable telemetric suprachoroidal IOP sensors. Six novel telemetric pressure transducers were implanted in the suprachoroidal space of 6 eyes from 6 New Zealand White rabbits. Functionality of each microsensor was verified 1, 4, 8, 12 and 30 weeks after implantation. After cannulation of the anterior chamber different intracameral pressure levels were generated using a height adjustable water column. Telemetric assessed IOP and intracameral pressure were analysed using scatter plots and Bland-Altman analysis (95% CI). Mean bias (limits of agreement) 1, 4, 8, 12 and 30 weeks after implantation was 0.14 mmHg (-2.04 to 2.31 mmHg), 0.01 mmHg (-2.83 to 2.86 mmHg), 0.62 mmHg (-2.08 to 3.32 mmHg), 0.47 mmHg (-3.04 to 3.98 mmHg) and 0.33 mmHg (-2.75 to 3.42 mmHg) respectively. Ophthalmological examinations showed no signs of conjunctival, scleral, choroidal or retinal lesions. Histological analyses revealed a small band of fibrosis next to the implantation site but showed no signs of inflammation, necrosis or other pathologies. Implantable telemetric suprachoroidal pressure sensors provided promising concordance between telemetric and intracameral IOP values. Clinical and histological examinations revealed good biocompatibility 30 weeks after implantation. A major advantage of the suprachoroidal approach is that the anterior chamber stays unaffected during implantation. Therefore the procedure can be performed regardless of the lens status and any anterior chamber pathologies.

Keywords: IOP; Intraocular pressure; Suprachoroidal implant; Suprachoroidal space; Telemetric pressure monitoring; Telemetric pressure sensor.

MeSH terms

Animals
Anterior Chamber
Biosensing Techniques / instrumentation*
Choroid
Equipment Design
Female
Glaucoma, Open-Angle / diagnosis*
Glaucoma, Open-Angle / physiopathology
Intraocular Pressure / physiology*
Male
Rabbits
Reproducibility of Results
Telemetry / instrumentation*
Tonometry, Ocular / instrumentation*