Serum eye drops for the treatment of ocular surface diseases. a systematic review and meta-analysis

Background. The use of blood-derived eye drops for topical treatment of ocular surface diseases has progressively increased in recent years.Materials and methods. To evaluate the use of serum eye drops in ocular surface disorders, we performed a systematic search of the literature.Results. In this systematic review, we included 19 randomised controlled trials ( RCTs) investigating the use of serum eye drops in 729 patients compared to controls. For the quantitative synthesis, we included only 10 RCTs conducted in patients with dry eye syndrome comparing autologous serum to artificial tears. At 2-6 weeks, no clear between-group differences in Schirmer test ( MD 1.05; 95% CI: -0.17-2.26) and in fluorescein staining ( MD -0.61; 95% CI: -1.50-0.28) were found ( very lowquality evidence, down-graded for inconsistency, serious risk of biases, and serious imprecision). Slightly higher increase in tear film break-up time ( TBUT) scores in autologous serum compared to control ( MD 2.68; 95% CI: 1.33-4.03), and greater decrease in ocular surface disease index ( OSDI) in autologous serum compared to control ( MD -11.17; 95% CI: -16.58- -5.77) were found ( low quality evidence, down-graded for serious risk of bias, and for inconsistency). For the Schirmer test, fluorescein staining and TBUT, data were also available at additional follow-up timing ( 2-12 months): no clear between-group differences were found, and the quality of the evidence was graded as low/very-low.Conclusions. In patients with dry eye syndrome, it is unclear whether or not the use of autologous serum compared to artificial tears increases Schirmer test and fluorescein staining scores at short-term and medium-/long-term follow up. Some benefit at short-term follow up for the outcome of TBUT and OSDI was observed, but the quality of the evidence was low.