Autologous Serum Eye Drops for Dry Eye: Systematic Review

BACKGROUND: Dry eye is a common condition with serious implications worldwide. The unique composition of autologous serum (AS) eye drops has been hypothesized as a possible treatment. OBJECTIVES: This study aimed to review the effectiveness and safety of AS. DATA SOURCES: We searched five databases and three registries up to September 30, 2022. STUDY ELIGIBILITY: We included randomized controlled trials (RCTs) comparing AS with artificial tears, saline, or placebo for participants with dry eye. STUDY APPRAISAL AND SYNTHESIS METHODS: We adhered to Cochrane methods for study selection, data extraction, risk-of-bias assessment, and synthesis. We used the Grading of Recommendations Assessment, Development and Evaluation framework to evaluate the certainty of evidence. RESULTS: We included six RCTs with 116 participants. Four trials compared AS with artificial tears. We found low-certainty evidence that AS may improve symptoms (0- to 100-point pain scale) after 2 weeks of treatment compared with saline (mean difference, −12.00; 95% confidence interval, −20.16 to −3.84; 1 RCT, 20 participants). Ocular surface outcomes (corneal staining, conjunctival staining, tear breakup time, Schirmer test) were inconclusive. Two trials compared AS with saline. Very low-certainty evidence suggested that Rose Bengal staining (0- to 9-point scale) may be slightly improved after 4 weeks of treatment compared with saline (mean difference, −0.60; 95% confidence interval, −1.11 to −0.09; 35 eyes). None of the trials reported outcomes of corneal topography, conjunctival biopsy, quality of life, economic outcomes, or adverse events. LIMITATIONS: We were unable to use all data because of unclear reporting. CONCLUSIONS: The effectiveness of AS is uncertain based on current data. Symptoms improved slightly with AS compared with artificial tears for 2 weeks. Staining scores improved slightly with AS compared with saline, with no benefit identified for other measures. IMPLICATIONS OF KEY FINDINGS: High-quality, large trials enrolling diverse participants with varying severity are needed. A core outcome set would allow for evidence-based treatment decisions consistent with current knowledge and patient values.