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    24-Hour Monitoring: IOP and Daily Activities

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    Emotional stress and resistance training each caused a persistent rise in intraocular pressure (IOP) in open-angle glaucoma patients and glaucoma suspects, report researchers who used 24-hour telemetric monitoring to observe the effect of daily activities on IOP.1 The researchers caution, however, against drawing firm clinical recom­mendations from this small, exploratory study.

    “The important message this study conveys is that IOP is far from static,” said Kaweh Mansouri, MD, at Montchoisi Clinic in Lausanne, Switzerland. “IOP is highly dynamic and appears to be significantly affected by a wide range of day-to-day activities and lifestyle habits.”

    Minimal Impact?

    MINIMAL IMPACT? IOP rose slightly during cycling and walking.

    First of its kind. At the University of California, San Diego, 41 patients were fitted in one eye with a Triggerfish contact lens sensor (CLS; Sensimed), which continuously records subtle fluctuations in ocular volume.

    They were then instructed to return to their standard daily activities for a 24-hour period. This protocol was repeated twice.

    During the 24-hour time periods, the participants recorded the start and end times of their activities. Baseline was defined as CLS measurements tak­en 30 to 60 minutes prior to each event. Then IOP-related fluctuations were observed for 120 minutes from the start of each event.

    The study yielded 40 relevant events from 22 CLS recordings of 14 patients. The most surprising finding was the persistent effect of certain activities on IOP, Dr. Mansouri said.

    IOP fluctuations by activity. Record­ed events were divided into five types of activities by the researchers (other kinds of activity were disregarded):

    • Resistance training. This caused a rise in IOP-related profile from the onset of training through 120 minutes after the person stopped lifting weights.
    • Emotional stress. This was asso­ciated with a gradual elevation of the IOP-related profile from the start of the stressful stimulus; both early and late variations in IOP were statistically significant.
    • Walking/cycling. This caused a small, but significant, elevation of the IOP-related profile during the activity, followed by a nonsignificant decrease.
    • Yoga/meditation. This caused a sustained, but not significant, drop in the IOP-related profile through to 120 minutes.
    • Alcohol intake. Consumption of alcohol was associated with an initial significant decrease in IOP. Subsequent variations were not significant.

    Toward personalized care. “Recent studies have suggested IOP fluctuations may play an independent role in the pathophysiology of glaucoma,” said coauthor Kevin Gillmann, MD, also at Montchoisi Clinic.

    “Acknowledging these out-of-clinic variations may be key to understanding the broader picture and to addressing patient-specific risk factors for glauco­ma progression,” Dr. Gillman added.

    —Miriam Karmel


    1 Gillmann K et al. Sci Rep. 2021;11(1):6598.


    Relevant financial disclosures—Dr. Gillmann: None. Dr. Mansouri: Sensimed: C.

    For full disclosures and the disclosure key, see below.

    Full Financial Disclosures

    Dr. Crama None.

    Dr. Gillmann None.

    Dr. Mansouri Allergan: S; ImplanData: C; Santen: C; Sensimed: C.

    Dr. Ramanathan None.

    Dr. Wong None.

    Disclosure Category



    Consultant/Advisor C Consultant fee, paid advisory boards, or fees for attending a meeting.
    Employee E Employed by a commercial company.
    Speakers bureau L Lecture fees or honoraria, travel fees or reimbursements when speaking at the invitation of a commercial company.
    Equity owner O Equity ownership/stock options in publicly or privately traded firms, excluding mutual funds.
    Patents/Royalty P Patents and/or royalties for intellectual property.
    Grant support S Grant support or other financial support to the investigator from all sources, including research support from government agencies (e.g., NIH), foundations, device manufacturers, and/or pharmaceutical companies.


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