Evaluation Of Corneal Changes After Collagen Cross-Linking For The Treatment Of Keratoconus Using Pentacam

Objective:Corneal collagen cross-linking therapy was performed in progressive keratoconus patients.Examination data of Pentacam were analyzed and evaluated before and after corneal collagen cross-linking therapy.Method:In this study,patients were selected from Bright Eye hospital in Hefei from January 2016 to December 2017,diagnosed as keratoconus and treated with corneal collagen cross-linking.51 eyes(32 patients)including24 males(75%)and 8 females(25%)were taken into the research.The patients mean age was 22.39±6.29 years.The ocular examinations including Pentacam and other investigations were done to assess the state of the cornea before and after operation.In cases with corneal thickness below 400μm the cornea was expanded by hypertonic solution and then up to 400μm made corneal collagen cross-linking.KXL system was used for rapid corneal collagen cross-linking in cases with corneal thickness over 400μm.The patients were followed up at 1 month,2 months,3months and 6 months after operation,and the data were recorded using Pentacam examination.SPSS 21 software was used to do statistical analysis of the data.ANOVA and comparisons were performed for multiple sets of measurement data that met the test of homogeneity of variance.P<0.05 was assumed that the difference was statistically significant.Results:The data of K1,K2,Km,Kmax,thinnest local,cornea volume,ACV(anterior chamber volume),ACA(anterior chamber angle)and ACD(anterior chamber depth)before and after surgery were compared.There was no significant difference in statistics.The mean value of K2,Km and Kmax were decreases at 2m,3m and 6m,ACV trends to 200mm~3 and ACD trend to 3.42mm.Two month after the operation,the mean value of ACV was found to be higher in patients with age less than 18 years(P=0.036).And the average ACA value of the male patients,3 months after operation was lower than that of the female patients(P=0.011).The mean ACA value of patients was lower in patients with age below 18 years before operation(P=0.015).Average ACD values of patients below 18 years old,2 months after operation and 3 months after operation,were higher(P=0.019,P=0.005).Conclusion:1.CXL operation can control and prevent further deterioration at least to a certain degree in the development of progressive keratoconus and reduce the probability of keratoplasty.2.The significant difference between sex and age before and after treatment is statistically significant.It suggests that sex and age play an important role in the pathogenesis along with development of keratoconus,and is worthy of further study.3.Pentacam can comprehensively,systematically and truly reflect the effect of CXL on keratoconus,and provide evidence for further clinical treatment.