ABSTRACT
Objective:To investigate the effect of long-term application of prostaglandin analog drops on bulbar conjunctival thickness in rabbits.Methods:Twenty-four healthy New Zealand white rabbits were randomly divided into latanoprost group, carteolol group and blank control group using the random number table method, with 8 rabbits in each group.The left eyes of rabbits were taken as experimental eyes.The rabbits in the latanoprost group and carteolol group were given latanoprost eye drops or carteolol eye drops once a day for 2 months according to grouping.The bulbar conjunctival thickness of left eyes of the latanoprost group and carteolol group were measured by optical coherence tomography (OCT) at baseline and two months after administration, respectively.The conjunctival tissue of the three groups were extracted to investigate the protein and mRNA expression level of matrix metalloproteinases-1 (MMP-1) and MMP-3 by Western blot and real-time fluorescence quantitative polymerase chain reaction (PCR). The study protocol was approved by an Ethics Committee of Putuo Hospital Affiliated to Shanghai University of Traditional Chinese Medicine (No.2017-0014). The use and care of the experimental animals complied with the ARVO Statement.Results:In the latanoprost group, the conjunctival thickness was significantly reduced from baseline (178.88±5.23)μm to (124.19±11.29)μm at 2 months after administration ( P<0.01). In the carteolol group, there existed no significant difference in the conjunctival thickness between baseline (184.94±11.85)μm and (183.31±8.71)μm at 2 months after administration ( P>0.05). The conjunctival thickness at 2 months after administration of the latanoprost group was significantly thinner than that of the carteolol group ( P<0.01). The protein and mRNA expression levels of MMP-1 and MMP-3 in conjunctival tissue of the latanoprost group were significantly higher than those of the blank control group and carteolol group (all at P<0.01). Conclusions:The long-term topical use of prostaglandin analog drops can significantly reduce the bulbar conjunctival thickness in rabbits.The mechanism may be related to the elevated expression levels of MMP-1 and MMP-3 in the bulbar conjunctival tissue.