Therapeutic effectiveness of different machines in intense pulsed light treatment of meibomian gland dysfunction

Purpose: This study aimed to determine the therapeutic effectiveness of different machines in intense pulsed light (IPL) treatment of meibomian gland dysfunction (MGD). Methods: 213 subjects diagnosed with MGD underwent three sessions of IPL treatment in a control (M22) treatment group or experimental (OPL-I) treatment group and were followed up three to four weeks after each session. Tear breakup time (TBUT), meibomian gland secretion scores (MGSS), meibomian gland meibum scores (MGMS), corneal fluorescein staining (CFS) scores, and the Standard Patient Evaluation of Eye Dryness (SPEED) was used to assess eye dryness signs and symptoms at baseline and follow-up visits. Results: Two machines had the same working principles except that experimental (OPL-I) group consist of a dual filter system. Both groups showed significant improvements (P < 0.0001) in TBUT, MGSS, MGMS, CFS scores and SPEED scores. Non-inferiority analysis showed no statistically significant differences in any result between the two groups. Various defects appeared on the filter with the extension of usage time. Spectrophotometry showed that light intensity decreased to 93.5% f 0.46% past the first filter. Conclusions: IPL treatment completed with different machines have the same effect on improving the symptoms and signs of MGD. The dual filter system in the IPL machine reduces light intensity by approximately 6.5% without affecting its therapeutic effect. It is a feasible measure to ensure double safety and has the significance of popularization not only for MGD but also in other IPL treatment scenarios.