Efficacy and safety of a vectored thermal pulsation system (Lipiflow®) in the treatment of meibomian gland dysfunction: a systematic review and meta-analysis

Purpose To investigate the efficacy and safety of a vectored thermal pulsation system (Lipiflow®) in the treatment of dry eye disease resulting from meibomian gland dysfunction (MGD). Methods We searched for randomized clinical trials (RCTs) in Embase, MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Web of Science, and ClinicalTrials.gov up to 4 January 2021. The subjective symptoms, objective tests of dry eye, meibomian gland function, and the incidence of adverse events were evaluated. Results Ten qualified RCTs incorporating 761 patients were analyzed. In the comparison of Lipiflow® treatment and lid hygiene, the subgroup with inconsistent units of randomization and analysis showed that the Lipiflow® treatment brought slight improvement in corneal fluorescein staining (mean difference (MD), − 0.42; 95% CI, − 0.75 to − 0.1), significant improvements in ocular surface disease index (OSDI) score (MD, − 7.4; 95% CI, − 11.06 to − 3.74), Standard Patient Evaluation of Eye Dryness (SPEED) score (MD, − 2.7; 95% CI, − 3.95 to − 1.45), meibomian glands yielding liquid secretion (MGYLS) (MD, 1.3; 95% CI, 0.78 to 1.82), and meibomian glands yielding secretion score (MGYSS) (MD, 4.09; 95% CI, 1.18 to 6.99). Meanwhile, significant improvements were detected in OSDI score, SPEED score, MGYLS, and MGYSS with patients who received Lipiflow® treatment compared with those who received nontreatment. The adverse events were comparable in the two control groups. Conclusions Lipiflow® treatment can improve the subjective and objective outcomes of MGD and does not increase the incidence of adverse events. The improper choice of units of analysis may be the leading cause of heterogeneity, which should be noted in the design of future ophthalmology research. Additional well-designed, large-scale RCTs are required to reach a firmer conclusion.