| Objective: Keratoconus is a blinding eye disease that occurs in adolescents and is characterized by a thinned cornea and a tapered tilting forward.Early detection and early intervention can prevent corneal enlargement.In this study,Pentacam and Corvis ST examinations were performed on healthy eyes,keratoconus,subclinical and clinical keratoconus,respectively,and 15 parameters of two devices were changed for statistical analysis.The diagnostic value in the diagnosis of subclinical keratoconus and mitral keratoconus provides theoretical basis and basis for early diagnosis of keratoconus.Methods: A total of 217 eyes of keratoconus patients attending the Ningxia Eye Hospital were collected.The experimental components were the keratoconus group in the frustration phase,the keratoconus group in the clinical phase and the keratoconus group in the clinical phase.Among the patients and volunteers,a normal group was randomly selected as a control group according to the exclusion conditions of the study,for a total of four groups.Using Pentacam and Corvis ST to measure the cornea to obtain 15 related parameters such as CBI,TBI,BAD D value,DA ratio,SP-A1 hardness parameter,comprehensive radius,ARTh,etc.,measured three times per eye,the measurement was performed by the same experienced doctor,Patients in each group were compared with each other,and the data were compared and analyzed.The receiver operating curve(ROC)was drawn.The diagnostic threshold of each parameter was explored according to the receiver operating characteristic curve(ROC),and then evaluated based on the area under the curve(AUC).The diagnostic value of each parameter,the sensitivity and specificity of each parameter of keratoconus were diagnosed by Pentacam + Corvis ST combined diagnosis,the best diagnostic boundary was determined,and the diagnostic value of each parameter was evaluated.P <0.05 was considered statistically significant.Results:(1)The normal group,keratoconus group,subclinical keratoconus group,and keratoconus group were enrolled in 44,50,34,and 89 eyes,respectively.Statistical analysis revealed that only TP was included in all the parameters included,SPA1,ARTh,and bIOP belonged to the normal distribution,and only bIOP was normally distributed with uniform variance.Comparison of parameters between the four groups: The parameters included in this study were statistically significant except for bIOP(all P <0.001).(2)Comparing the normal group with the clinical keratoconus group,it was found that all the parameters included in this study were statistically significant(P <0.05),among which the parameters of the keratoconus group were higher than those of the CBI,BAD-D,TBI,and DA Ratio.Normal group(P <0.001),but TP,ARTh,SPA1,and bIOP were lower than the normal group.ROC curve analysis found that all parameters except bIOP,DA Ratio,and Integrated radius(AUC> 0.8),the AUC values of other parameters were greater than 0.9.(3)Comparing the normal group with the subclinical keratoconus group,it was found that except for bIOP(AUC = 0.57,P = 0.1877),the AUC curve P values of other parameters were less than 0.01.Among the parameters included,AUC> 0.9 included BAD-D,Da,Dt,TP,TBI,CBI,ARTh,and Integrated radius.The other parameters AUC were greater than 0.8,indicating that the bIOP parameter has no diagnostic efficacy for keratoconus in the subclinical stage,while The parameters have better diagnostic performance.Among them,the parameter with the strongest diagnostic efficacy was TBI,with AUC of 0.980,sensitivity of 96.00%,specificity of 98.88%,95% confidence interval of 95.53% to 98%,Z = 54.952,P <0.001.(4)Comparing the normal group with the keratoconus group in the stagnation phase,it was found that the parameter with the strongest diagnostic efficacy was the BAD-D value,the sensitivity was 64.71%,the specificity was 84.27%,the AUC was 0.781,and the 95% confidence interval was 69.8% To 85.1%,Z = 5.650,P <0.001,Youden index is 0.8063,followed by TBI with a sensitivity of 67.65%,specificity of 75.28%,AUC of 0.774,95% confidence interval of 65.2% to 81.5%,Z = 4.639,P <0.001,Youden index is 0.4293.(5)Analysis of multiparameter ROC curve:(1)Normal corneal group and keratoconus group in the setback period: The first 6 parameters of the ROC curve area are BAD-D,TBI,dp,Kmax,dt,integrated radius,and the P values of the ROC curve are compared in pairs.More than 0.05,so the above 5 parameters and 1 index have no significant difference in the diagnosis of keratoconus in the stagnation phase.(2)Comparison of the normal group and subclinical keratoconus group,the index and parameters of the top 6 are TBI,BAD-D,dt,da,ARTh,and CBI.Among them,TBI,BAD-D and CBI compare the ROC surface area TBI and BADD parameters were not statistically different(P = 0.667),TBI and CBI were statistically different(P <0.005),and BAD and CBI were not statistically different(P = 0.109).(3)Normal group and clinical keratoconus group: The first 6 parameters of diagnostic efficacy are TBI,BAD-D,Da,TP,CBI,Kmax,and P between all the above parameters is greater than 0.05.These parameters are used in the clinical diagnosis of keratoconus There was no statistical difference in these.Conclusion: The TBI and CBI indexes are highly sensitive and specific for the diagnosis of subclinical keratoconus,and have a high diagnostic ability,which can be used to assist screening and early diagnosis of keratoconus.Among various parameters,BAD-D has better diagnostic ability for keratoconus in each stage of progression compared to other parameters,especially for the keratoconus group in the setback stage,which has the highest diagnostic ability.For the diagnosis of subclinical keratoconus,with the exception of bIOP,the other 14 indices or parameters have AUC greater than 0.8,and TBI,CBI,BAD-D,ARTh,Integrated Radius,Da,Dp,Dt,and TP have excellent diagnostic capabilities(AUC > 0.9),the highest sensitivity and specificity is the TBI index(sensitivity 96.0%,specificity 98.88%),although the specificity of CBI,Dt,TP is as high as TBI,but the sensitivity is significantly lower than the TBI index,and Although the specificity of BAD-D index is slightly lower(97.75%),it is more sensitive than others.For the diagnosis of subclinical keratoconus,with the exception of bIOP,the other 14 indices or parameters AUC are greater than 0.8,of which TBI,CBI,BAD-D,ARTh,integration radius,Da,Dp,Dt,TP have excellent diagnostic capabilities AUC> 0.9).The sensitivity and the best are the TBI index(sensitivity 96.0%,specificity 98.88%).Although the specificity of CBI,Dt,TP can be 98.88% as the TBI,but the sensitivity is significantly lower than the TBI index,so TBI can be used as the best diagnostic index of subclinical corneal keratoconus.All the parameters or indexes included in this study have low diagnostic ability for keratoconus in stagnation.Therefore,no optimal index for diagnosing keratoconus in stagnation has been found.All parameters for the diagnosis of keratoconus in subclinical stage are available.Excellent diagnostic ability,among which TBI's diagnostic ability is significantly higher than other parameters or indexes,so the TBI value can be used as the optimal index for diagnosing keratoconus in the subclinical stage;for the diagnosis of keratoconus in the clinical stage,the top 6 parameters included in this study Or the index has an ideal ROC curve area,so these parameters or indexes have excellent diagnostic ability for keratoconus in clinical stage,and there is no significant difference between each parameter.For the diagnosis of early keratoconus According to the statistical results of this study,if patients with suspicious keratoconus are encountered in clinical work in combination with the patient's topographic map and various parameters or indexes,if TBI ? 0.32,BAD-D ? 1.59 can be considered as frustration Keratoconus;when CBI ? 0.4,TBI ? 0.68,and BAD-D ? 2.17,it is highly suspected that the patient is a subclinical keratoconus. |
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