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Measurement of intraocular temperature in glaucoma: week-day and seasonal fluctuations
  1. Kaweh Mansouri1,2,
  2. Kevin Gillmann1,3,
  3. Harsha Laxmana Rao4,5,
  4. Peter Szurman6,
  5. Robert N Weinreb7
  6. ARGOS -2 Study Group
    1. 1 Swiss Visio, Montchoisi Clinic, Glaucoma Research Centre, Lausanne, Vaud, Switzerland
    2. 2 Department of Ophthalmology, University of Colorado School of Medicine, Denver, Colorado, USA
    3. 3 Glaucoma Department, Moorfields Eye Hospital NHS Foundation Trust, London, UK
    4. 4 Glaucoma, Narayana Nethralaya, Bangalore, India
    5. 5 University Eye Clinic Maastricht, University Medical Center, Maastricht, Netherlands
    6. 6 Department für Augenheilkunde, Universitätsklinikum Tübingen, Tubingen, Baden-Württemberg, Germany
    7. 7 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, Swiss Visio, Montchoisi Clinic, Glaucoma Research Centre, Lausanne 1006, Vaud, Switzerland; kwmansouri{at}


    Purpose To evaluate long-term intraocular temperature (IOT) variations in eyes with primary open-angle glaucoma (POAG) using an intraocular telemetric sensor.

    Methods This prospective, open-label, multicentre observational study analysed the IOT variations in 22 eyes of 22 patients with POAG. All enrolled patients underwent implantation of an intraocular pressure (IOP) sensor during cataract surgery. The telemetric system uses a built-in temperature sensor to control measured IOP for temperature. Each time a patient measures their IOP, both the IOP and IOT are recorded in the reader device. Patients were instructed to self-measure their IOP as often as desired, but at least four times daily. Recorded readings were retrieved and analysed using mixed effect models and pairwise comparisons using Bonferroni correction to assess the statistical significance of average IOT variations between each individual weekday and calendar month.

    Results The mean age of patients was 67.8±6.8 years and 36.4% were women. A total of 132 745 readings over 21 102 measurement-days were obtained. On average, IOT was significantly higher on Sundays (34.57°C; 95% CI 34.37 to 34.78) than on any other day of the week (p<0.001). Mean IOT on other weekdays ranged from 34.48°C to 34.51°C. Over the year, IOT followed a clear seasonal pattern, reaching its maximum in July (34.8°C; 95% CI 34.56 to 34.97) and its minimum in January (34.4°C; 95% CI 34.15 to 34.56; p<0.001).

    Conclusions This study demonstrates the feasibility of continual and long-term measurement of IOT using intraocular sensors. The results show significant short-term and long-term fluctuations of IOT. Research is warranted to understand the impact of IOT variations on IOP, ocular perfusion and glaucoma progression.

    • Glaucoma
    • Intraocular pressure
    • Diagnostic tests/Investigation
    • Physiology

    Data availability statement

    Data may be obtained from a third party and are not publicly available.

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    Data availability statement

    Data may be obtained from a third party and are not publicly available.

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    • Collaborators ARGOS-2 study group: Arno Haus, Eugen Reifschneider, Annekatrin Rickmann, Philip Wakili, Caroline Emmerich, Caroline Hoogmartens, Kristina Lambert, Kai Januschowski, Matthias Elling, Tim Schultz, Inga Kersten-Gomez, Katrin Lorenz, Bert GIers, Anna Beck, Matthias Nobl, Sigrid Freissinger.

    • Contributors KM, KG, HLR, PS, RNW—data interpretation, manuscript revision. KM, PS, RNW—research design and execution. KG—manuscript preparation, writing, illustrations. HLR—data analysis. KM—guarantor.

    • 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 KM: Santen (C), Sensimed (C), Topcon (S), Alcon (S), Allergan (S), Optovue (S), ImplanData (C); HLR: Santen (C), Carl-Zeiss Meditec (C), Allergan (C); RNW: Aerie Pharmaceuticals (C), Allergan (C), Bausch & Lomb (C), Eyenovia (C), ImplanData (C), Meditec-Zeiss (S), Centervue (S), Heidelberg Engineering (S), Konan (S), Unity Biosciences ©.

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

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