AIM: To evaluate the clinical effects and safety of Loratadine combined with Diclofenac sodium eye drops in the treatment of allergic conjunctivitis by system review.

METHODS:Using “Loratadine” “Diclofenac sodium” and “allergic conjunctivitis” as keywords, a randomized controlled trial of Loratadine combined with diclofenac sodium in the treatment of allergic conjunctivitis was searched in Embase, Cochrane library, Pubmed, CNKI, Wanfang database, VIP and SionMed. The retrieval time is from the establishment of the database to July 2021. The risk bias tool provided by the Cochrane cooperation scale was used to assess the risk bias of included studies of RCTs. The publication bias of the included studies was assessed by the Egger's test. Meta-analysis of clinical efficiency, incidence of adverse effects, ocular itch score, and discharge score were using RevMan 5.3. Descriptive analysis were performed on the results with high heterogeneity.

RESULTS:A total of 19 articles were included, all of which were Chinese literatures, including 1 931 patients(2 044 eyes). The control group was treated with Loratadine, and the experimental group was treated with Loratadine combined with Diclofenac sodium eye drops. The Meta-analysis showed that the clinical effect of experimental group was better than control group(OR=4.43, 95%CI:3.26-6.03,P<0.00001).The incidence of adverse reaction was lower than control group(OR=0.32, 95%CI:0.2-0.52,P<0.00001). The Score of ocular itching(MD=-0.36, 95%CI:-0.39 to -0.33,P<0.00001)and discharge(MD=-0.24,95%CI: -0.31 to -0.18,P<0.00001)in experimental group was lower than control group. All the studies on hyperemia and edema of conjunctiva, conjunctival papilla or follicle proliferation and foreign body sensation in patients with allergic conjunctivitis showed that the experimental group could significantly reduce the above symptoms(all P<0.05). Egger's test was performed on the total effective rate, the incidence of adverse reaction. The results showed that there was publication bias in the total effective. Trim and fill method showed that the publication bias did not affect the results.

CONCLUSION: On the basis of the oral Loratadine, combined with Diclofenac sodium eye drops has a certain clinical efficacy in the treatment of allergic conjunctivitis, which can improve the clinical symptoms such as ocular itching, foreign body sensation, hyperemia and edema of conjunctiva, and the incidence of adverse reactions is low, which can provide evidence-based basis for the drug treatment of allergic conjunctivitis in the future. However, due to the low intensity of the included research evidence, more multicenter, randomized double-blind clinical trials are needed in the future, so that to improve the evidence intensity.