Study On The Correlation Between Eye Rubbing And Keratoconus

Background:Keratoconus（KC）is a progressive,bilateral corneal disease characterized by dilatation of the corneal with a central thinning protruding forward cone.Keratoconus often results in myopia and irregular astigmatism,and later edema and scarring of the corneal can lead to a significant loss of visual acuity that ultimately requires a corneal transplant.Previous reports suggested that eye rubbing may lead to the occurrence of keratoconus and accelerate the development of keratoconus,but there is a lack of effective clinical data,which is controversial.Objective:In this study,through a large-scale clinical retrospective study,Pentacam and Corvis ST instruments were used to evaluate the morphological and biomechanical changes of the corneal,compare the differences of each parameter between the eye rubbing group and the no eye rubbing group,and analyze the correlation between eye rubbing and keratoconus,so as to provide clinical basis for the prevention and treatment of keratoconus.METHODS:Patients diagnosed with keratoconus in our hospital between October 2018 and August 2020 and controls to undergo refractive surgery between July 2020 and August 2020 were included as the research subjects,with 256 eyes for each and matched according to gender and age.General data such as gender,age,visual acuity and intraocular pressure were collected for statistical analysis,and information such as eye rubbing was obtained through questionnaire survey.Pentacam and Corvis ST were used to collect topographic maps and biomechanical parameters,and the keratoconus group and the normal control group were divided into the eye rubbing group and the no eye rubbing group according to whether or not eye rubbing was performed for comparative analysis.SPSS 23.0 statistical software package was used for data analysis and processing.Chi-square test and Logistic regression were used to analyze the correlation between eye rubbing and keratoconus.The independent sample t test and non-parametric test were used to compare the parameters of the kneading group and the non-kneading group.Results:The proportion of eye rubbing in keratoconus group was 70.7%,and the difference was statistically significant compared with 20.7%in the control group.In unifactorial logistic regression analysis,only eye rubbing and atopic disease were risk factors,and the odds ratio（OR）was 10.046（P<0.001）and 6.351（P<0.001）,respectively.In multivariate logistic regression analysis,eye rubbing and atopic disease were still risk factors(OR _{eye rubbing}=9.971,P<0.001,OR _{atopic disease}=6.274,P<0.001).There were statistically significant differences in spherical scope,cylindrical scope,corrected visual acuity,axial length,anterior chamber depth and corneal endothelial cell count between keratoconus group and control group（P<0.05）,while there were no statistically significant differences in other items（P>0.05）.In the control group,the axis of scattered light in the eye-rubbing group 65（0,177.5）was significantly higher than that in the no-eye-rubbing group 10（0,170）,and the difference was statistically significant（P<0.05）.Keratoconus group of rubbing eyes,group and don’t rub eyes Corvis ST parameters comparison,there was no statistically significant difference（P>0.05）,the control of rubbing eyes set first flatten deformation amplitude（A1DA）,first flatten deformation amplitude（A2DA）,Peak distance（PD）less rubbing eyes group is low,the difference was statistically significant（P<0.05）,compared the parameters had no statistical significance.The results showed that Mean Keratometry（Km）and the variation of corneal curvature force（KPD）in the kneading group was greater than that in the non-kneading group（P<0.05）,while the parameters in the kneading group and the non-kneading group were not statistically significant（P>0.05）.Conclusion:Eye rubbing is an important risk factor for keratoconus and a long-term habit of eye rubbing may accelerate the onset of the disease in susceptible populations.No significant statistical difference was found in corneal parameters between the control group and the keratoconus group in the eye rubbing group and no eye rubbing group.Therefore,further study with a large sample of multiple centers is needed to investigate the relationship between eye rubbing and keratoconus.