Low-level light therapy and intense pulse light therapy in meibomian gland dysfunction. A systematic review and meta-analysis.

Background: Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease, affecting over a third of the global population. This disease is associated with ocular discomfort, reduced visual quality, and quality of life. Novel treatments like Intense Pulse Light (IPL) therapy and Low-Level Light Therapy (LLLT) have been reported to be useful in refractory MGD treatment. However, no systematic review has explored the utility of combining these two therapies.

Methods: Medline, Embase, and CENTRAL databases were searched for articles on LLLT + IPL therapy in MGD. A meta-analysis of single means was conducted to assess clinical endpoints.

Results: Analysis of 12 studies showed that LLLT + IPL therapy in MGD patients led to a significant decrease in Ocular Surface Disease Index score (MD: -22.8, 95 %CI: -29.1 to -16.5, I² = 97.5 %, p < 0.001), and a significant increase in both Tear Break-up Time (MD: 2.2 s, 95 %CI: 0.9 s to 3.4 s, I² = 98.6 %, p < 0.001) and Schirmer test (MD: 1.5 mm, 95 %CI: 0.6 mm to 2.5 mm, I² = 0.0 %, p = 0.001) at ≤ 3 months post treatment. These improvements were sustained in a sensitivity analysis at endpoints ≥ 6 months post treatment. While the percentage of loss of meibomian gland area (n = 4, MD: -3.8 %, 95 %CI: -7.2 % to -0.4 %, I² = 40.0 %, p = 0.031) was reported to be significantly reduced, this was not found to be sustained at endpoints ≥ 6 months post treatment (n = 2, MD: 5.9 %, 95 %CI: 1.8 % to 10.0 %, I² = 0.0 %, p = 0.005) in two studies.

Conclusions: This meta-analysis provides quantitative evidence supporting the clinical efficacy of LLLT + IPL therapy in MGD. Future research should evaluate its long-term safety and efficacy and compare it with alternative treatments.