The Utilization Of The Fourth Generation Fourier Domain Anterior Segment OCT (FD-OCT) In The Measurement Of Tear Meniscus And The Diagnosis Of Dry Eye

Dry eye is caused by a variety of reasons,as well as tear deficiency,corneal or conjunctival epithelial damage as chronic disorders.The cause is more complex, clinically misdiagnosed easily.The reproducibility of dry eye diagnostic criteria is not satisfied and there are many factors to interfere the results.So it is very important to search for a rapid and reliable method for diagnosis of dry eye.With the development of optical coherence tomography(optical coherence tomography,OCT) and further application in anterior segment,the fourth-generation Fourier domain(Fourier domain) OCT has beyond the characteristics of the previous time-domain(Time domain) OCT with high resolution and high speed.It has led to widespread concern researchers with a high-resolution functional imaging of anterior segment of tear meniscus.However, there is no research on the effectiveness of the Fourier-domain OCT in the diagnosis of dry eye and normal tear meniscus area.Therefore,this study will probe on the diagnostic effectiveness and tear meniscus imaging of fourth-generation Fourier domain OCT.We enroll in different ages,different types of dry eye patients,as well as normal controls to explore diagnostic effectiveness of Fourier domain OCT,in order to identify the type of dry eye which has a higher diagnostic effect.At the same time,we make the normal control group into Sub-groups in accordance with age to investigate age-related variations of human tear meniscus in Chinese.The results show that the fourth generation Fourier domain OCT can clearly image and measure the cross-sectional tear meniscus.It also has a good consistency with clinical diagnosis of dry eye examination(BUT,Schirmer test).As a non-invasive,non-contact,simple screening method,the fourth generation Fourier-domain OCT has a good application prospects in the diagnosis of dry eye,especially in aqueous tear deficiency. PartⅠResearch on the tear meniscus imaging and measurement of the anterior segment Fourier domain OCTObjective To discuss the utilization of the fourth generation anterior segment Fourier domain optical coherence tomography in the imaging and measurement of tear meniscusMethods We enrolled 146 cases(146 eyes) and 160 controls(160 eyes) in this study. The tear meniscus height(TMH),tear meniscus depth(TMD) and tear meniscus area (TMA) of each participant were measured by Fourier domain OCT(RTVue-100).We also estimated the tear break up time(BUT),performed the cornea fluorescein staining and Schirmer test,and recorded score of the dry eye questionnaire.The variability of the fourth generation anterior segment Fourier domain OCT in tear meniscus imaging and measurement was discussed.Results The average values of TMH,TMD and TMA in the patient group were 232.319±17.549(μm),151.494±12.811(μm),0.024428±0.003712(mm2), comparing with 328.113±19.036(μm),220.906±12.935(μm),0.045618±0.005623(mm2) in the control group,the difference of which reached significant (TMH t=12.2646,P=0.0000,TMD t=12.0567,P=0.0000,TMA t=10.1556, P=0.0000).The individual variability of the TMH,TMD and TMA in the patient group was less than the control group.The repeatability analysis showed a small variation in measurement.The OCT images of the bound and cross section area of the tear meniscus and the clarity of the tear fluid in the patient group were obviously different from those in the control group.Conclusion The fourth generation Fourier domain anterior segment optical coherence tomography can clearly image and measure the cross section of tear meniscus,the result of which showed a good coherence with the traditional diagnostic test(BUT,Schirmer test) and directly reflect features of the tear meniscus. PartⅡAge-Related Variations of Human Tear Meniscus in ChineseObjective To investigate age-related variations of human tear meniscus in Chinese and diagnosis of dry eye using Fourier domain anterior segment OCT.Methods.We enrolled 146 cases(146 eyes) and 160 controls(160 eyes) in this study.All the subjects in these two groups were divided into four subgroups according to different ages,respectively,group A(0～19),group B(20～39),group C (40～59) and group D(over 60).Dry eye patients have 6,60,60,20 in each group, normal controls have 6,60,60,20 in each group.The tear meniscus height(TMH),tear meniscus depth(TMD) and tear meniscus area(TMA) of each participant were measured by Fourier domain OCT(RTVue-100).We also estimated the tear break up time(BUT),performed the cornea fluorescein staining and Schirmer test,and recorded score of the dry eye questionnaire.The relativity of the clinical examinations was tested,the tear meniscus of the two groups were measured and ROC curves were drawn.Results There is a significant correlation among tear meniscus values,individual syndrome and clinical diagnoses.The mean TMH,TMD,TMA for dry-eye patients were significantly lower than those for control groups.There was negative correlation between tear meniscus values and age for Chinese healthy subjects(TMH r=-0.0649,p=0.000,TMD r=-0.0299,p=0.0024,TMA r=-0.0320,p=0.0017).The accuracy of the diagnosis of dry eye by Fd-OCT was TMH 68.95%,TMD 70.59%,TMA 70.92%.It's different between the age sub-groups.Area under the ROC curve (AUC) showed that overall,TMH to 0.7337,TMD is 0.7477,TMA is 0.7461.AUC of all ages there are some differences between.TMH Diagnostic value of the overall community for the 259(μm),TMD for 165.6667(μm),TMA was 0.024(mm2),the diagnosis of all ages increase community values decline with age.Conclusions Fd-OCT could instantly imply the age-related variations of human tear meniscus and has good consistency with the clinical diagnose examinations.It has different diagnostic accuracy in each age sub-group. PartⅢThe utilization of the fourth generation Fourier domain anterior segment OCT(FD-OCT) in the diagnosis of dry eyeObjective To discuss the utilization of the fourth generation anterior segment Fourier domain OCT in the diagnosis of different types of dry eye patients.Methods We enrolled 146 cases(146 eyes)of dry eye patients(DE group),102 cases(102 eyes)of aqueous tear deficiency patients(ATD group),81 cases(81 eyes)of lipid tear deficiency patients(LTD group),53 cases(53 eyes)of Sj(o|¨)gren syndrome patients(SS group)and 160 controls(160 eyes) in this study.The tear meniscus height (TMH),tear meniscus depth(TMD) and tear meniscus area(TMA) of each participant were measured by Fourier domain OCT(RTVue-100).We also estimated the tear break up time(BUT),performed the cornea fluorescein staining and Schirmer test,and recorded score of the dry eye questionnaire.The relativity of the clinical examinations was tested,the tear meniscus of the two groups were measured and ROC curves were drawn.Results The average values of clinical measurements in the patient group were quite different.The results of the diagnostic effectiveness for each group showed,SS group had the highest diagnostic effectiveness,TMH 91.19%,TMD 92.51%,TMA 92.51%; LD group had the lowest,TMH 45.49%,TMD 67.06%,TMA 46.27%.DE group was almost the same with ATD group.The area under the ROC curve(AUC) of TMA showed,DE group was 0.7855,AD group was 0.7110,LD group was 0.5279,SS group was 0.9706.Conclusion The fourth generation Fourier domain anterior segment optical coherence tomography can accurately measure all types of dry eye tears meniscus,, the result of which showed a good coherence with the traditional diagnostic test(BUT, Schirmer test) and directly reflect features of the tear meniscus.As a non-traumatic and non-contact technique,the fourth generation Fourier domain anterior segment OCT has a favorable prospect in the diagnosis of dry eye,especially in aqueous tear deficiency.