| Objective:To investigate the effect of corneal cross-linking(CXL)combined with voriconazole on fungal keratitis of rabbits under different ultraviolet A(UVA)parameters.Methods:Thirty-two male New Zealand white rabbits(2.5-3.0kg)were selected and fed in standard environment.Fungal keratitis was induced by injecting 50μL concentration of 10~6 colony forming units(CFU)/ml of Aspergillus fumigatus suspension(right eye injection).The model was completed if the mycelium was discovered with the confocal microscopy after72 hours.,and the day after the model was completed was remembered as the first day of treatment.The experimental rabbits were randomly divided into four groups,Group A:blank group,n=8;group B:drug group,n=8;group C:drug combined with conventional CXL group,n=8;group D:drug combined with rapid CXL group,n=8.The treatment of each group was as follows:(1)blank group:no antifungal treatment was given;(2)drug group,1%voriconazole eye drops were given 3 hours a time and 4 times a day;(3)drug combined with conventional CXL group:on the day the model was completed,UVA with intensity of 3 mw/cm~2 and riboflavin with 0.1%were used for CXL,the irradiation time was 30 minutes.From the first day of treatment,1%voriconazole eye drops were applied,3 hours/time,4 times a day.(4)drug combined accelerate CXL group:on the day the model was completed,UVA with intensity of 9 mw/cm~2and riboflavin with 0.1%were used for CXL,the irradiation time was 10 minutes.From the first day of treatment,1%voriconazole eye drops were applied,3 hours/time,4 times a day.Slit-lamp microscopy and photography of the anterior segment,fluorescein sodium staining(FL),corneal turbidity and neovascularizationscore,optical coherence tomography(OCT),corneal ulcer depth grading and corneal confocal microscopy(IVCM)were performed in sequence before the treatment and on the 1st,4th,7th,14th,21st and 28th day.After 28 days of treatment,all rabbits were sacrificed and their eyeballs were removed.The cornea was stained with hematoxylin-eosin(HE)and periodic acid-silver metheramine(PASM).Univariate analysis of variance(anova)with multiple comparisons was used for comparison among data sets,paired t-test was used for comparison within groups,and independent sample kruskal-wallis test was used for comparison of grade data.Results:Before the treatment,there was no significant difference in ulcer area,ulcer depth,corneal turbidity score and corneal neovascularization score(P>0.05).At the end of the study,there was no statistical difference in ulcer area between group A and B(P>0.05),group C was smaller than group A(P<0.05),but there was no statistical difference compared with group B(P>0.05),group D was smaller than group A and B(P<0.05).At the end of the study,the score of ulcer depth in group C and D was lower than that in group A and B,the difference was statistically significant(P<0.05),but there was no statistical difference between group A and group B(P>0.05).At the end of the study,the score of corneal neovascularization and turbidity score in group C and D were lower than that in group A(P<0.05),but there was no significant difference between group A and group B(P>0.05).The results of confocal microscopy demonstrated that there was no significant difference in the duration of infection between groups A and B(P>0.05).The duration of infection in group C was shorter than that in group A and B(P<0.05),while the duration of infection in group D was shorter than that in groups A,B and C(P<0.05).The healing rates of four groups of A,B,C and D were 12.5%,12.5%,62.5%,87.5%respectively,and there was no significant difference in the healing rate between group A,B and C(P>0.05),but the healing rate in D group was higher than group B(P<0.05).The corneal perforation rates in the four groups of A,B,C and D were 62.5%,37.5%,12.5%and 0%respectively.There was no significant difference in perforation rate between the group A and B(P>0.05),while the puncture rate in group C and D was lower than group A(P<0.05).HE staining showed that the corneal ulcer in group A did not heal after 28 days of intervention.Under the microscope,almost all of them were necrotic tissue.The whole structure was destroyed with diffuse thickening and a large number of inflammatory cells infiltrating.The corneal epithelium was not obvious,the fibroblasts in stroma layer proliferated,and neovascularization was seen locally.In group B,the corneal ulcer did not heal,necrosis was about 1/2 of the thickness of the cornea.The whole layer of the cornea was diffuse thickening with a large number of inflammatory cells infiltrating.In group C,the ulcer was smaller and the depth was less than 1/4 of the thickness of the cornea.The proliferation of neovascularization and fibroblasts was found,and the inflammatory cells were less than group A and B.In group D,ulcer almost healed,but inflammatory cell infiltration was still observed.Neovascularization and fibroblast proliferation were also seen.PASM showed that fungal hyphae were still visible in group A and B after 28 days of treatment,but not in group C and d after 28 days of treatment.Conclusions:It is easy to establish fungal keratitis by corneal matrix injection.CXL combined with medicine is effective in the treatment of fungal keratitis.In addition,the overall effect of drug combined with accelerate CXL is better than that of drug combined with conventional CXL. |
