Clinical Observation Of Corneal Nerve Fiber Morphology After Phacoemulsification In Diabetic Patients

Objective:To understand the changes of central corneal subepithelial nerve fiber morphology before and after phacoemulsification in diabetic patients with cataract and age-matched cataract,and to compare the differences between them.Method:We collected 60 patients(60 eyes)who had been diagnosed with cataracts and completed phacoemulsification in our hospital between March 2017 and March 2018.Among them,diabetic patients with cataract(diabetic group)and age-matched cataract patients(control group)Each of 30 cases.All cataract patients were performed by the same ophthalmologist.The corneal nerve fiber length(CNFL),corneal nerve fiber density(CNFD),corneal nerve fiber branching density(CNBD)and corneal nerve fiber tortuosity(CNFTo)were measured by in vivo confocal microscopy(IVCM)before operation,1 month after operation,3 months after operation and 6 months after operation.Confocal examinations were performed by the same experienced physician.SAS system software was used to establish a database for statistical analysis of data.Measured data were expressed as mean ±standard deviation(x ±S),and variance analysis and t-test of repeated measurement data were used.After testing,all measured data satisfy the normal distribution and variance test with homogeneity.The diabetes group and the control group were analyzed separately.Paired sample t-test was used to compare the samples.The samples from the diabetes group and the control group were tested by independent sample t test.P<0.05 was considered statistically significant.Result:1.There were significant differences in preoperative of CNFL,CNFD,CNBD and CNFTo parameters between 1 month,3 months and 6 months in the diabetic group(P<0.05).2.There were significant differences between preoperative of CNFD,CNBD,and CNFTo in the control group at 1 month,3 months,and 6 months(P<0.05).The CNFL difference between preoperative and postoperative of 6 months after surgery.No statistical significance(P>0.05).3.The four parameters,CNFL,CNFD,CNBD and CNFTo,were statistically different between the two groups before and after surgery in the diabetic group and the control group(P<0.05).Conclusion:Cataract phacoemulsification had effects on the corneal nerve fibers in both the diabetic group and the control group,but gradually recovered with the postoperative time,so the effect of phacoemulsification was reversible.In the control group,corneal nerve fiber length(CNFL)returned to preoperative baseline at 6 months postoperatively,and all parameters of the diabetic group did not reach preoperative baseline levels at 6 months postoperatively.Over all,the recovery of corneal nerve fibers in the diabetic group was slower than that of age-matched cataract patients alone.