USB compresses improved tear film in 15-person MGD crossover trial

A USB-powered warm compress was associated with better short-term measures of tear film stability and volume than a self-heating mask in a prospective randomized crossover trial involving 15 adults with meibomian gland dysfunction. The participants were 18 to 40 years old and had meibomian gland dysfunction associated with an eye whose tear break-up time was no more than 10 seconds. Each participant used both devices in separate phases, with each intervention scheduled for five consecutive days and a two-week washout period between phases.

All 15 participants contributed data to both phases of the trial. The prespecified primary outcome was non-invasive tear break-up time, measured with an OCULUS Keratograph 4M. Tear meniscus height and symptom scores were secondary outcomes.

Researchers analyzed the results using two-way analysis of variance and post-hoc Bonferroni tests to adjust for multiple comparisons. The trial was registered at ClinicalTrials.gov under the identifier NCT07618169. Across the observed visits, the USB-powered device was associated with a likelihood-ratio chi-square value of 7.43 for tear break-up time, with p = 0.006.

It also had a significantly higher tear meniscus height, with a chi-square value of 4.49 and p = 0.034. On day 5, descriptive mean tear break-up time was 9.53 ± 2.18 seconds with the USB-powered compress and 7.21 ± 2.90 seconds with the self-heating mask. Mean tear meniscus height was 0.200 ± 0.020 millimeters and 0.188 ± 0.016 millimeters, respectively.

SPEED symptom scores showed mild improvement in mean values but no significant difference between devices, and no adverse events were reported. The investigators concluded that USB-powered warm compresses provided superior results for tear film stability and volume compared with self-heating masks, describing temperature control and reusability as advantages of the powered devices. However, the evidence comes from a small cohort of young adults treated for two five-day periods.

The study was not designed to establish longer-term effectiveness, and larger trials would be needed to confirm whether the observed differences are reproducible in broader populations. The findings support further investigation of USB-powered compresses as an at-home treatment for meibomian gland dysfunction, rather than definitive conclusions about their clinical superiority.

Subject of Research: Comparative effects of USB-powered and self-heating warm compresses on tear film measures in adults with meibomian gland dysfunction

Article Title: USB-powered vs. self-heating warm compresses for meibomian gland dysfunction: A prospective randomized crossover clinical trial

Article References: Al Saqr, A. M., Alharbi, M. F., Alrumizan, M., & Abusharha, A. (2026). USB-powered vs. self-heating warm compresses for meibomian gland dysfunction: A prospective randomized crossover clinical trial. PLOS One, 21(10), e0360762. https://doi.org/10.1371/journal.pone.0360762

Image Credits: AI Generated

DOI: 10.1371/journal.pone.0360762

Keywords: meibomian gland dysfunction, dry eye, warm compress therapy, tear break-up time, tear meniscus height, USB-powered device, self-heating mask, randomized crossover trial, eye health, USB-powered, self-heating, warm