Evaluation Of Corneal Changes On The Eyes Long-time Wearing Contact Lens By Confocal Microscope Analyzer

Objective: To analyze corneal changes on the eyes long-time wearing contact lens(CL) by confocal microscope in order to provide an objective data for the clinic to instruct patients to wear contact lens reasonably.Methods: 52 patients with a history of long-time contact lens wearing from 1 month to 18 years were collected in the study. The age was ranging from 17 to 60 years old. The average wearing time for CL was above 8 hours daily. The diopter is–1.75D- -10.00D. Three distinct time-based subject groups were involved: CL wearers with wearing time less than 5 years (including 5 years,G 1 ), with wearing time from 5 to 10 years(including 10 years,G 2), and with wearing time over 10 years(G 3). A confocal microscope was used to examine all patients.Results:①The density of Langerhans cells of limbal cornea was 220±75cells/μ㎡,276±53.9cells/μ㎡,361±83.6cells/μ㎡ respectively among the three subject groups and the density of Langerhans cells of central cornea was 176±119.3cells/μ㎡, 229±28cells/μ㎡,251±50.8cells/μ㎡ respectively. There were significant difference among the three groups(p<0.05).②The epithelial thickness was 51±4.3μm, 45.6±2.7μm , 43.5±4.9μm respectively among the three subject groups and the density of anterior stroma keratocytes was 1150±146.8cells/μ㎡, 1094±103cells/μ㎡, 1011±197.8cells/μ㎡ respectively. There were significant difference among the three groups(p<0.05).③The percentage of endothelial polymorphology was 36±1.62%; 33.7±1.71%; 32.8±1.47% respectively among the three subject groups and the percentage of endothelial pleomorphism was 56±3.39%,63±3.67%,64±7.06% respectively . There were significant difference among the three groups(p<0.05).④There were no significant changes in the thickness of the cornea , the density of the posterior stromal cells orthe endothelial cells. For the evaluation of the regenerating vein of limbal corneas and distribution of corneal nerves no statistically significant differences were found. Many microdots and regenerating vas were found in the posterior stromal.Conclusions: 1. The different wearing time of CL can cause evident effect on the corneal tissue . 2. Long-term CL wearing can induce corneal tissue remarkable changes(especially above 10 years). Including following changes:①The epithelial thickness decreased gradually among the three subject groups and the density of anterior stroma keratocytes decreased significantly.②The percentage of endothelial polymorphology decreased gradually among the three subject groups and the percentage of endothelial pleomorphism increases gradually.③The density of Langerhans cells of limbal and central corneas increased gradually among the three subject groups.