Evaluation Of Ocular Surface Before And After LASIK Surgery By Comprehensive Ocular Surface Analysis Combined With Lymphotoxin-alpha Detection

Objective:Lymphotoxin alpha(LT-α/LTA)detection reagent card(immunochrom atography)combined with Keratograph 5M ocular surface comprehensive analyzer were used for comparison the changes of LTA concentration and ocular surface related parameters before and one week after LASIK.The correlation between ocular surface parameters and between parameters and LTA was analyzed and evaluate the status of ocular surface before and after LASIK to provide effective guidance for the postoperative prognosis of patients with refractive errors.Method:Twenty-four patients who underwent LASIK in the First Affiliated Hospital of Nanchang University from March 2022 to July 2022 were selected.Tear samples were collected from the right eyes before and one week after LASIK(24 eyes).Fluorescence immunochromatography was used to detect the concentration of LTA in tears.Keratograph 5M was used to measure tear meniscus height(TMH),frist non-invasive tear film break-up time(NIBUTf),average non-invasive tear film break-up time(NIBUTav),automatic dry eye grading,first tear break-up location,bulbar conjunctival hyperemia,meibomian gland imaging and other ocular surface related signs(48 eyes).The data of gender,age,spherical diopter and spherical equivalent,intraocular pressure and corneal thickness before and after LASIK were collected.Finally,SPSS 25.0 was used to analyze the obtained data and reach conclusions.Results:1、The ocular surface parameters were compared before and after surgeryThere were significant differences in intraocular pressure,corneal thickness,spherical diopter,spherical equivalent and bulbar conjunctival hyperemia index before and after LASIK(P <0.05).Other indicators such as tear meniscus height(P =0.272),first break-up time(P =0.912),average break-up time(P = 0.312),the automatic dry eye classification(P = 0.361),number of break-up rings(P = 0.146),and the "cross quadrant" of the first break-up(P = 0.947),"X" quadrant of the first tear film break-up(P = 0.391),upper meibomian gland grade(P = 0.639),lower meibomian gland grade(P = 0.071),and meibomian gland morphological parameters between the two groups.2.Correlation analysis of ocular surface parametersCorneal thickness and intraocular pressure(R = 0.68,P<0.001),bulbar conjunctival hyperemia index(R = 0.35,P<0.001)showed a significant positive correlation,but with gender(R =-0.21,P = 0.041),spherical equivalent(R =-0.62,P<0.001),spherical diopter(R =-0.61,P<0.001)showed a significant negative correlation.The correlation between the automatic dry eye grading and the first tear break-up time(R =-0.67,P<0.001),average tear film break-up time(R =-0.75,P<0.001)showed a significant negative correlation.3.Comparison of tear LTA concentration before and after surgeryThe tear LTA concentration was 1.32±0.43ng/ml before surgery and0.69±0.41ng/ml at one week after surgery,and the difference was statistically significant(Z=-3.19,P < 0.05).4.Correlation analysis between LTA and ocular surface parametersLTA was positively correlated with corneal thickness(R = 0.33,P < 0.05),but negatively correlated with spherical diopter(R =-0.36,P < 0.05)and spherical equivalent(R =-0.37,P < 0.05).Conclusion:1.LASIK has a certain adverse effect on the homeostasis of ocular surface microenvironment,but has no significant effect on the state of meibomian glands.Keratograph 5M can accurately,easily and systematically evaluate the ocular surface and tear film of patients before and after LASIK surgery,and perioperative medication may be beneficial to patients.2.The measurement of corneal thickness before and after LASIK surgery has a certain guiding significance for monitoring the change of intraocular pressure.3.The concentration of LTA in tears decreases after LASIK,and LTA may have a regulatory effect on dry eye symptoms related to LASIK surgery and play a role in ocular surface homeostasis.