Relationship Between The Levels Of Tumor Necrosis Factor-alpha In Tears And Tear Film Stability After LASIK

Objective:LASIK treatment of myopia because of the scope, predictability, stability and security advantage of the strong, the world has become the most popular method of correction of myopia. With the extensive application of the surgery, whether doctors or patients are no longer concerned only about postoperative visual acuity, but rather on postoperative comfort increasingly attention. In clinical work, we found that a large part in the postoperative patients with a dry eye symptoms, which to some extent affected the surgical results. Dry eye is a result of inadequate or tear secretion tear film stability caused by the decline in ocular surface damage. Cause symptoms of dry eye after LASIK in the exact mechanism is unclear, and some scholars believe that the ocular surface inflammation affecting the dry eye condition is very important factors. Most scholars tend to this inflammatory response, as various types of dry eye common pathogenesis, which play an important role in the interaction of various inflammatory cytokines. In this experiment through the collection before and after LASIK patients with tears, double-antibody sandwich ELISA tear was detected in the concentration of TNF-α, while observation of corneal epithelial damage and the stability of the tear film. To investigate the concentration of tumor necrosis factor-alpha (TNF-α) in tears before LASIK and postoperatively, to identify the short term changes.And to study the mechanism of tumor necrosis factor-alpha (TNF-α)in the dry eye after LASIK.Methods:TNF-αlevels in the tears of 38 Patients aged from 18 to 45(male 18 eyes,female 20 eyes) were studied with a monoclonal antibody based ELISA before LASIK and 1 day, 7 days, 14 days, and 30 days after LASIK. Tear film stability and fluorescence staining were examined during the same visits. And then study the relationship with the levels of TNF-αin tears and corneal epithelial damage and the tear film stability in the eyes of pre and postoperative LASIK patients.Results:Compared the TNF-αmean values at Different Age and different sex pre and post-operation, there were no statistically significant differences (P<0.05); The TNF-αmean value before LASIK was (10.96±8.06) pg/ml and mean values at 1 day, 7 days, 14 days, and 30 days after LASIK were (826.38±141.64) pg/ml,(558.72±101.26) pg/ml,(248.48±62.14) pg/ml,(54.34±23.68) pg/ml , respectively. The TNF-αlevels in tears at the four visits post-operation were significantly different from levels in the pre-operative group (P<0. 05). Tear film stability before LASIK was(12.62±1.99)seconds,and at 1 day,2 days,10 days and 30days after LASIK,it was(4.68±1.77)seconds,(5.84±1.92)seconds,(7.36±1.53)seconds,and(8.82±3.08)seconds,respectively.Tear film stability at the time of the four visits after surgery was significantly different from the preoperative level(P<0.05).TNF-αcontent and tear in the tear film break-up time is a negative correlation (r = -0.420, P <0.01). TNF-αwas not detected in the tears of eyes before LASIK.The concentration of TNF-αwas significantly higher in the tear samples from patients whose clinical scores were two or three points compared with patients whose scores were zero or one point(P<0.05). There was a positive correlation between tear film content and tear in the corneal epithelial damage after LASIK (r=0.484,P<0.01).Conclusion:The TNF-αmean value in the tears has no relativity with sex and it also has no relativity with age in certain range of age. Tear after LASIK TNF-αby the content of the existence is a dynamic process of change from higher to lower the dynamic process of change. The onset of dry eye after LASIK are related to the level of TNF-α. Dry eye after LASIK for the pathogenesis and clinical studies provide the basis for anti-inflammatory treatment.