Background:The accuracy of using total keratometry(TK)value in recent IOL power calculation formulas in highly myopic eyes remained unknown.Methods:Highly myopic patients who underwent uneventful cataract surgery were...Background:The accuracy of using total keratometry(TK)value in recent IOL power calculation formulas in highly myopic eyes remained unknown.Methods:Highly myopic patients who underwent uneventful cataract surgery were prospectively enrolled in this prospective comparative study.At one month postoperatively,standard deviation(SD)of the prediction errors(PEs),mean and median absolute error(MedAE)of 103 highly myopic eyes were back-calculated and compared among ten formulas,including XGboost,RBF 3.0,Kane,Barrett Universal II,Emmetropia Verifying Optical 2.0,Cooke K6,Haigis,SRK/T,and Wang-Koch modifications of Haigis and SRK/T formulas,using either TK or standard keratometry(K)value.Results:In highly myopic eyes,despite good agreement between TK and K(P>0.05),larger differences between the two were associated with smaller central corneal thickness(P<0.05).As to the refractive errors,TK method showed no differences compared to K method.The XGBoost,RBF 3.0 and Kane ranked top three when considering SDs of PEs.Using TK value,the XGboost calculator was comparable with the RBF 3.0 formula(P>0.05),which both presented smaller MedAEs than others(all P<0.05).As for the percentage of eyes within±0.50 D or±0.75 D of PE,the XGBoost TK showed comparable percentages with the RBF 3.0 TK formula(74.76%vs.66.99%,or 90.29%vs.87.38%,P>0.05),and statistically larger percentages than the other eight formulas(P<0.05).Conclusions:Highly myopic eyes with thinner corneas tend to have larger differences between TK and K.The XGboost enhancement calculator and RBF 3.0 formula using TK showed the most promising outcomes in highly myopic eyes.展开更多
AIM:To analyze the differences,agreements,and correlation among total corneal power parameters generated by different instruments after myopic keratorefractive surgery.METHODS:The prospective cross-sectional study inc...AIM:To analyze the differences,agreements,and correlation among total corneal power parameters generated by different instruments after myopic keratorefractive surgery.METHODS:The prospective cross-sectional study included patients who underwent myopic keratorefractive surgery and received measurements of corneal power 3mo after surgery.Automated keratometer was used for the measurement of simulated keratometry(Sim K),sweptsource optical coherence tomography(SS-OCT)based biometer for total keratometry(TK),anterior segment-OCT for real keratometry(RK),and Scheimpflug keratometer for the true net power(TNP),the total corneal refractive power(TCRP)and equivalent K-readings(EKR).The differences among these parameters were analyzed,and the agreements and correlation between Sim K and other total corneal power parameters were investigated.RESULTS:A total of 70 eyes of 70 patients after myopic keratorefractive surgery were included.The evaluated corneal power parameters were as follows:Sim K 38.32±1.93 D,TK 37.54±2.12 D,RK 36.64±2.09 D,TNP 36.56±1.97 D,TCRP 36.70±2.01 D,and EKR 37.55±2.00 D.Pairwise comparison showed that there were significant differences(P<0.001)among all parameters except for between TK and EKR,RK and TNP,RK and TCRP(P=1.000,1.000,1.000,respectively).The limits of agreement between Sim K and TK,RK,TNP,TCPR,and EKR were 1.08,1.08,1.43,1.48,and 1.73 D,respectively.All parameters showed good correlation with Sim K,and the correlation coefficients were 0.995,0.994,0.983,0.982,and 0.975.CONCLUSION:Among the corneal power parameters after myopic keratorefractive surgery,the value of Sim K is the largest,followed by TK and EKR,with TCRP,RK,and TNP being the smallest.The differences among the parameters may be attributable to the different calculation principles.Correct understanding and evaluation of corneal power parameters can provide a theoretical basis for taking advantage of the total corneal power to improve the accuracy of intraocular lens calculation after keratorefractive surgery.展开更多
基金supported by research grants from the National Natural Science Foundation of China(Grant Nos.82122017,81870642,81970780 and 81670835)Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission(Grant Nos.19441900700 and 21S31904900)+1 种基金Clinical Research Plan of Shanghai Shenkang Hospital Development Center(Grant Nos.SHDC2020CR4078 and SHDC12019X08)the Fudan University“Outstanding 2025”Program.
文摘Background:The accuracy of using total keratometry(TK)value in recent IOL power calculation formulas in highly myopic eyes remained unknown.Methods:Highly myopic patients who underwent uneventful cataract surgery were prospectively enrolled in this prospective comparative study.At one month postoperatively,standard deviation(SD)of the prediction errors(PEs),mean and median absolute error(MedAE)of 103 highly myopic eyes were back-calculated and compared among ten formulas,including XGboost,RBF 3.0,Kane,Barrett Universal II,Emmetropia Verifying Optical 2.0,Cooke K6,Haigis,SRK/T,and Wang-Koch modifications of Haigis and SRK/T formulas,using either TK or standard keratometry(K)value.Results:In highly myopic eyes,despite good agreement between TK and K(P>0.05),larger differences between the two were associated with smaller central corneal thickness(P<0.05).As to the refractive errors,TK method showed no differences compared to K method.The XGBoost,RBF 3.0 and Kane ranked top three when considering SDs of PEs.Using TK value,the XGboost calculator was comparable with the RBF 3.0 formula(P>0.05),which both presented smaller MedAEs than others(all P<0.05).As for the percentage of eyes within±0.50 D or±0.75 D of PE,the XGBoost TK showed comparable percentages with the RBF 3.0 TK formula(74.76%vs.66.99%,or 90.29%vs.87.38%,P>0.05),and statistically larger percentages than the other eight formulas(P<0.05).Conclusions:Highly myopic eyes with thinner corneas tend to have larger differences between TK and K.The XGboost enhancement calculator and RBF 3.0 formula using TK showed the most promising outcomes in highly myopic eyes.
基金Supported by the Hospital Founding of Beijing Tongren Hospital(No.2021-YJJ-PY-002)。
文摘AIM:To analyze the differences,agreements,and correlation among total corneal power parameters generated by different instruments after myopic keratorefractive surgery.METHODS:The prospective cross-sectional study included patients who underwent myopic keratorefractive surgery and received measurements of corneal power 3mo after surgery.Automated keratometer was used for the measurement of simulated keratometry(Sim K),sweptsource optical coherence tomography(SS-OCT)based biometer for total keratometry(TK),anterior segment-OCT for real keratometry(RK),and Scheimpflug keratometer for the true net power(TNP),the total corneal refractive power(TCRP)and equivalent K-readings(EKR).The differences among these parameters were analyzed,and the agreements and correlation between Sim K and other total corneal power parameters were investigated.RESULTS:A total of 70 eyes of 70 patients after myopic keratorefractive surgery were included.The evaluated corneal power parameters were as follows:Sim K 38.32±1.93 D,TK 37.54±2.12 D,RK 36.64±2.09 D,TNP 36.56±1.97 D,TCRP 36.70±2.01 D,and EKR 37.55±2.00 D.Pairwise comparison showed that there were significant differences(P<0.001)among all parameters except for between TK and EKR,RK and TNP,RK and TCRP(P=1.000,1.000,1.000,respectively).The limits of agreement between Sim K and TK,RK,TNP,TCPR,and EKR were 1.08,1.08,1.43,1.48,and 1.73 D,respectively.All parameters showed good correlation with Sim K,and the correlation coefficients were 0.995,0.994,0.983,0.982,and 0.975.CONCLUSION:Among the corneal power parameters after myopic keratorefractive surgery,the value of Sim K is the largest,followed by TK and EKR,with TCRP,RK,and TNP being the smallest.The differences among the parameters may be attributable to the different calculation principles.Correct understanding and evaluation of corneal power parameters can provide a theoretical basis for taking advantage of the total corneal power to improve the accuracy of intraocular lens calculation after keratorefractive surgery.
