AIM: To analyze the therapeutic effect of loratadine combined with diclofenac sodium eye drops in the treatment of allergic conjunctivitis, and the influence on tear film stability and tear-related indexes.

METHODS: A prospective study was conducted among 93 patients(186 eyes)with allergic conjunctivitis admitted to the hospital between January 2019 and January 2020. They were randomly divided into observation group(n=47, 94 eyes, treated with loratadine and diclofenac sodium eye drops)and control group(n=46, 48 eyes, treated with loratadine). All patients received 2wk of treatment. The improvement of ocular symptoms and signs after treatment was evaluated. Schirmer I test(SⅠt)and break up time(BUT)were used to evaluate the tear film stability. The height, depth and cross-sectional area of lacrimal rivus were measured by anterior segment related optical coherence tomography. Tear specimens were collected to detect changes in tear hyaluronic acid(HA), group ⅡA secretory phospholipase A2(sPLA2-Ⅱa and eosinophil cationic protein(ECP). The occurrence of adverse reactions was counted.

RESULTS: After 2wk of treatment, the scores of main symptoms and signs were reduced in the two groups(P<0.05), and the observation group had lower scores than the control group(P<0.05). SⅠt and BUT were increased in the two groups(P<0.05), which were longer in the observation group than in the control group(P<0.05). The height of lacrimal rivus increased, depth increased, and cross-sectional area were increased in the two groups(P<0.05). Besides, the above indexes in observation group were higher than those in the control group(P<0.05). Meanwhile, HA, ECP and sPLA2-Ⅱa were decreased in the two groups(P<0.05), which were lower in the observation group than in the control group(P<0.05). No significant differences were found between the 2 groups in the incidence of adverse reactions(12.8% vs 10.9%, P>0.05).

CONCLUSION: The overall effect of loratadine combined with diclofenac sodium eye drops is better than that of loratadine alone in the treatment of allergic conjunctivitis. The combined treatment can improve symptoms, signs and tear film stability, reduce inflammatory mediators in tears, and promote recovery of tear film function. Besides, it is safe and feasible.