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

BACKGROUND: Dry eye syndrome (DES) is a prevalent multifactorial condition characterized by tear film instability and meibomian gland dysfunction (MGD). Warm compress therapy remains a cornerstone for improving lipid layer function. However, very limited comparative data exist on newer USB-powered devices vs. self-heating masks in Middle Eastern populations. METHODS: This randomized crossover clinical trial compared USB-powered and self-heating masks in 15 participants aged 18-40 years with meibomian gland dysfunction (MGD) associated eye (tear break-up time ≤10 s). Each intervention was scheduled for five consecutive days, separated by a two-week washout. The prespecified primary outcome was non-invasive TBUT measured with the OCULUS Keratograph 4M; tear meniscus height (TMH) and symptom scores were secondary outcomes. A two-way ANOVA and Post-hoc Bonferroni tests adjusted for multiple comparisons were used for analysis. The trial was registered at ClinicalTrials.gov (NCT07618169). RESULTS: All 15 participants contributed data to both intervention phases. Across observed visits, the USB-powered device was associated with higher TBUT (likelihood-ratio χ2(1) = 7.43, p = 0.006) and TMH (χ2(1) = 4.49, p = 0.034). Day 5 descriptive means with USB-Powered compress and self-heating mask were 9.53 ± 2.18 s versus 7.21 ± 2.90 s for TBUT, and 0.200 ± 0.020 mm versus 0.188 ± 0.016 mm for TMH, respectively. No significant between-device difference was observed in SPEED scores, although mean scores showed a mild improvement, and no adverse events were reported. CONCLUSIONS: USB-powered warm compresses provided superior outcomes in enhancing tear film stability and volume compared to self-heating masks. Consistent temperature control and reusability make them a promising at-home therapy for patients with MGD. USB-powered devices may be preferred for patients requiring sustained thermal therapy, particularly in arid climates with variable indoor cooling. Further large-scale trials are warranted to confirm these findings. CLINICAL TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov under registration number: NCT07618169.