This study aimed to determine the therapeutic effectiveness of different machines in intense pulsed light (IPL) treatment of meibomian gland dysfunction (MGD). 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.

Inclusion Criteria:

1. Fitzpatrick skin type I-IV according to sun sensitivity and skin appearance
2. A Standard Patient Evaluation of Eye Dryness (SPEED) score of ≥6
3. Tear breakup time (TBUT) of ≤10 s in the studied eye
4. Corneal fluorescein staining (CFS) score of ≥1 (it is not necessary to consider this criterion if the TBUT is ≤5 s)
5. Meibomian gland secretion score (MGSS) of ≥6 in the studied eye.

Exclusion Criteria:

1. Use of prescription eye drops (excluding artificial tears) within 48 hours of recruitment
2. Facial IPL treatment within the prior 12 months
3. Any surgery of the eye or eyelids within the prior six months
4. Ocular surface and eyelid abnormalities
5. Any systemic condition that might cause eye dryness
6. Use of photosensitive drugs within the prior three months
7. Precancerous lesions
8. Skin cancer or pigmented lesions in the treatment area
9. Overexposure to the sun within the previous month
10. Ocular infections within the previous six months
11. Uncontrolled infections or immunosuppressive diseases

For patients' privacy reasons

Patients receiving IPL treatment were masked.