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Weekly and seasonal changes of intraocular pressure measured with an implanted intraocular telemetry sensor
  1. Kaweh Mansouri1,2,
  2. Kevin Gillmann1,
  3. Harsha Laxmana Rao3,
  4. Robert N Weinreb4
  5. On behalf of ARGOS–2 Study Group
  1. 1 Glaucoma Research Centre, Swiss Visio, Montchoisi Clinic, Lausanne, Switzerland
  2. 2 Department of Ophthalmology, University of Colorado School of Medicine, Denver, Colorado, USA
  3. 3 Narayana Nethralaya, Bangalore, India
  4. 4 Hamilton Glaucoma Center, Shiley Eye Institute and Department of Ophthalmology, University of California San Diego, La Jolla, California, USA
  1. Correspondence to Professor Kaweh Mansouri, Glaucoma Research Centre, Swiss Visio, Montchoisi Clinic, Lausanne, Switzerland; kwmansouri{at}


Background/Aims To better understand seasonal and weekday intraocular pressure (IOP) variations, long-term daily IOP measurements were assessed in patients with glaucoma using an intraocular telemetric sensor.

Methods This prospective, open-label, multicentre observational study analysed the IOP variation patterns in 22 eyes of 22 patients with primary open-angle glaucoma (67.8±6.8 years, 36.4% female) who had undergone placement of an intraocular telemetric sensor at the time of cataract surgery. The telemetric system combines an implantable IOP sensor with a hand-held reading device. Patients were instructed to self-measure their IOP as often as desired, but at least four times daily. Analysis of variance and Tukey multiple-comparison correction were used to assess the statistical significance of average and peak IOP variations between individual weekdays and months.

Results Each enrolled patient recorded daily IOP measurements for an average duration of 721 days. On average, IOPs were highest on Wednesdays and lowest on Fridays (p=0.002). There were significant variations of IOP throughout the year, and IOP showed a seasonal pattern. Between mid-winter (December–January) and mid-summer months, there was a reduction in mean IOP of 8.1% (-1.55 mm Hg, p<0.05).

Conclusion This study confirms previously observed seasonal variations of IOP. IOP was significantly higher in winter compared with summer months. Moreover, IOP was lower on Friday than on other days. The explanation for these results is not known.

  • glaucoma
  • intraocular pressure
  • diagnostic tests/investigation
  • physiology

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  • Contributors KM: idea, supervision, review. KG: writing, revision. HLR: analysis. RNW: idea, supervision, review.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval The study adhered to the tenets of the Declaration of Helsinki, received EC/IRB approval at each study site and was registered at (NCT02434692).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Deidentified participant data are property of Implandata Ophthalmic Products GmbH and may be available on reasonable request.

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