Efficacy and safety of transient receptor potential channel modulators for dry eye: A systematic review and meta-analysis.

Purpose: To investigate the efficacy and safety of transient receptor potential (TRP) channel modulators for dry eye.

Methods: A thorough search for randomized clinical trials was conducted in seven databases up to February 16, 2024. Suitable studies were identified according to inclusion and exclusion criteria, extracted data were synthesized and analyzed using Review Manager 5.4, and risk of bias and quality of evidence were assessed using recommended tools.

Results: Six trials with 884 patients using two kinds of TRP channel modulators (TRPV1 antagonist and TRPM8 agonist) were included. TRP channel modulators were effective in reducing subjective symptom scores (standardized mean differences [SMD], -0.41; 95 % confidence interval [CI], -0.75 to -0.07), corneal fluorescence staining (mean differences [MD], -0.19; 95 % CI, -0.37 to -0.02), impact on quality of life and daily function, and increasing the non-anesthetic Schirmer's test score (MD, 11.71; 95 % CI, 9.59 to 13.83), instant tear meniscus height (MD, 245.52; 95 % CI, 14.02 to 477.02), improvement in conjunctival hyperemia (risk ratio [RR], 2.08; 95 % CI, 1.07 to 4.06). There was no increased incidence of adverse events with TRP modulators compared to vehicle solution controls.

Conclusions: TRP channel modulators have shown positive therapeutic effects in reducing the symptoms and signs of dry eye and improving the quality of life associated with the disease without raising the risk of adverse events. These modulators are expected to become a new therapy for dry eye.