Objective:Accurate intraocular pressure(IOP)measurement is a cornerstone of glaucoma diagnosis and management.While Goldmann applanation tonometry(GAT)remains the accepted gold standard,technological advancements have...Objective:Accurate intraocular pressure(IOP)measurement is a cornerstone of glaucoma diagnosis and management.While Goldmann applanation tonometry(GAT)remains the accepted gold standard,technological advancements have introduced alternative methods such as noncontact tonometry(NCT)and the dynamic Scheimpflug-based Corvis ST(CST).This study aims to conduct a rigorous comparative analysis of IOP measurements obtained by NCT,GAT,and CST across a wide spectrum of intraocular pressures.The primary objectives were to evaluate the performance of these devices in both healthy and glaucomatous eyes,assess their intra-and interobserver variability,and determine their level of agreement with the established reference.Methods:In this prospective,comparative study,a total of 212 eyes from 212 subjects were enrolled,comprising 137 eyes of patients with glaucoma and 75 eyes of healthy individuals.All participants underwent IOP measurement using the three devices in a randomized order to minimize bias.Based on the initial GAT readings,eyes were systematically classified into one of four predefined IOP levels:Level A(low,<10 mmHg),Level B(normal range,10-21 mmHg),Level C(moderately elevated,>21 to 40 mmHg),and Level D(severely elevated,>40 mmHg).A mixed-model analysis of variance(ANOVA)was employed to statistically analyze the differences in IOP measurements among the three tonometers at each distinct pressure level.The agreement between each pair of devices(CST vs.GAT,CST vs.NCT,and NCT vs.GAT)was meticulously assessed using Bland-Altman plots,which provide metrics for bias(mean difference)and the 95%limits of agreement(LoA).Results:CST and GAT exhibited better intra-and interobserver variability compared to NCT.Significant differences in IOP measurements were observed among CST,NCT,and GAT at levels A and D(P<0.001,P=0.030).Bland-Altman analysis revealed biases between CST and GAT,CST and NCT,and NCT and GAT at different levels(level A:-0.61,0.94,and-1.55 mmHg;level B:0.16,-0.7,and 0.8;level C:0.5,0.5,and-0.1;level D:0.83,-3.4,and 4.2).Notably,NCT tended to overestimate IOP more at higher levels(level D)and underestimate at lower levels(level A)compared to CST.CST demonstrated better agreement with GAT than NCT did.Conclusions:This study confirms that the Corvis ST(CST)shows superior agreement with the Goldmann applanation tonometer than noncontact tonometry,particularly at low and high IOP ranges.It also exhibits greater measurement consistency.While NCT remains a useful screening tool,its significant over-and underestimation at pressure extremes is a critical limitation.The findings strongly suggest that CST may serve as a more suitable and reliable alternative to NCT for measuring IOP across a broad clinical range.However,the results underscore that these three methods are not directly interchangeable.Clinicians must therefore exercise careful interpretation of IOP values,taking into account the specific tonometer used and the patient's probable pressure level for accurate diagnosis and management of glaucoma.展开更多
AIM： To explore the relationship between different parameters of Ocular Response Analyzer（ORA） and Corvis ST（CST） in a sample of healthy Iranian school-aged children and the relationship between parameters of the...AIM： To explore the relationship between different parameters of Ocular Response Analyzer（ORA） and Corvis ST（CST） in a sample of healthy Iranian school-aged children and the relationship between parameters of these 2 instruments against intraocular pressure（IOP）, measured by the Goldmann applanation tonometer（GAT-IOP）, age and gender, and find possible correlation between ORA and CST with GAT.METHODS： This cross-sectional study included 90 healthy children. A general interview and complete eye examination were performed. Following successful GATIOP measurement, ORA and CST were conducted. The CST parameters were A 1/2 length（A1 L, A2 L）, A 1/2 velocity（A1 V, A2 V）, highest concavity deformation amplitude（HCDA）, radius of curvature（Ro C）, peak distance（PD）, central corneal thickness（CCT） and IOP. The ORA parameters were corneal hysteresis（CH）, corneal resistance factor（CRF）, Goldmann-correlated IOP（IOP-G） and corneal compensated IOP（IOP-CC）. Extracted data was analyzed using the Statistical Package for Social Science software.RESULTS： Totally 39 males with age of 9.08±1.60（6-12）y and 51 females with age of 8.96±1.55（6-13）y were included. Many CST parameters were significantly correlated with CH, CRF, IOP-G and IOP-CC. Some CST parameters had a significant correlation with GAT-IOP, including IOP-CST in both eyes and HCDA, A2 L, PD, and RoC in the left eye, but none with age, except A2 L in the right eye. The CRF measurement showed a significant correlation with GAT-IOP in both eyes and CH in the right eye, yet, none with age. Among all CST and ORA parameters, CCT-CST in both eyes and A1 L in right eye had a significant correlation with gender, although this was a negligible negative correlation. Comparison of mean IOP values by different devices showed a significantly highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Also, IOP-G versus IOP-CST significantly had the lowest IOP overestimation among others. Overall, either low positive correlation or negligible correlation was found between IOP measurements by 3 instruments.CONCLUSION： The study finds the highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Overall, either low positive correlation or negligible correlation is found between IOP measurements by the 3 instruments.展开更多
AIM:To access the agreement of intraocular pressure(IOP)values obtained from biomechanically corrected tonometer[Corvis ST(CST)],non-contact tonometer(NCT),and Goldmann applanation tonometer(GAT)in children with NCT m...AIM:To access the agreement of intraocular pressure(IOP)values obtained from biomechanically corrected tonometer[Corvis ST(CST)],non-contact tonometer(NCT),and Goldmann applanation tonometer(GAT)in children with NCT measured-IOP(NCT-IOP)values of 22 mm Hg or more,and related factors.METHODS:A total of 51 eyes with NCT-IOP≥22 mm Hg in children aged 7 to 14y were examined and IOP was measured by CST,NCT,and GAT.Based on GAT measured IOP(GAT-IOP),ocular hypertension(OHT)group(≥22 mm Hg,24 eyes)and the non-OHT group(<22 mm Hg,27 eyes)were defined.We compared the agreement of the three measurements,i.e.,CST measured IOP(CST-IOP),GAT-IOP,and NCT-IOP,and further analyzed the correlation between the differences in tonometry readings,central corneal thickness(CCT),axial length(AL),optic disc rim volume,and age.RESULTS:Compared with the OHT group,thicker CCT,larger rim volume,and higher differences between NCTIOP and GAT-IOP,were found in the non-OHT group.The differences between CST-IOP and GAT-IOP were lower than the differences between NCT-IOP and GAT-IOP in both groups.The mean differences in CST-IOP and GAT-IOP were 1.26 mm Hg(95%limit of agreement ranged from 0.1 to 2.41 mm Hg,OHT group)and 1.20 mm Hg(95%limit of agreement ranged from-0.5 to 3.00 mm Hg,non-OHT group),and the mean differences in NCT and GAT were 3.90 mm Hg(95%limit of agreement ranged from-0.19 to 9.70 mm Hg,OHT group)and 6.00 mm Hg(95%limit of agreement ranged from 1.50 to 10.50 mm Hg,non-OHT group).The differences between CST-IOP and GAT-IOP were not related to CCT,age,and AL in both groups;while the differences between NCT-IOP and GAT-IOP were related to CCT in the OHT group(r=0.93,P<0.001)and to CCT and AL in the non-OHT group(r=0.66,P<0.001,r=-0.81,P<0.001).CONCLUSION:The accuracy of NCT in the diagnosis of pediatric OHT is low.The agreement of CST-IOP and GATIOP was significantly higher in children with and without OHT than in those with NCT-IOP and GAT-IOP.Therefore,CST can be used as a good alternative for IOP measurement in children.The impacts of CCT and AL on NCT measurement need to be fully considered when managing childhood IOP.展开更多
文摘Objective:Accurate intraocular pressure(IOP)measurement is a cornerstone of glaucoma diagnosis and management.While Goldmann applanation tonometry(GAT)remains the accepted gold standard,technological advancements have introduced alternative methods such as noncontact tonometry(NCT)and the dynamic Scheimpflug-based Corvis ST(CST).This study aims to conduct a rigorous comparative analysis of IOP measurements obtained by NCT,GAT,and CST across a wide spectrum of intraocular pressures.The primary objectives were to evaluate the performance of these devices in both healthy and glaucomatous eyes,assess their intra-and interobserver variability,and determine their level of agreement with the established reference.Methods:In this prospective,comparative study,a total of 212 eyes from 212 subjects were enrolled,comprising 137 eyes of patients with glaucoma and 75 eyes of healthy individuals.All participants underwent IOP measurement using the three devices in a randomized order to minimize bias.Based on the initial GAT readings,eyes were systematically classified into one of four predefined IOP levels:Level A(low,<10 mmHg),Level B(normal range,10-21 mmHg),Level C(moderately elevated,>21 to 40 mmHg),and Level D(severely elevated,>40 mmHg).A mixed-model analysis of variance(ANOVA)was employed to statistically analyze the differences in IOP measurements among the three tonometers at each distinct pressure level.The agreement between each pair of devices(CST vs.GAT,CST vs.NCT,and NCT vs.GAT)was meticulously assessed using Bland-Altman plots,which provide metrics for bias(mean difference)and the 95%limits of agreement(LoA).Results:CST and GAT exhibited better intra-and interobserver variability compared to NCT.Significant differences in IOP measurements were observed among CST,NCT,and GAT at levels A and D(P<0.001,P=0.030).Bland-Altman analysis revealed biases between CST and GAT,CST and NCT,and NCT and GAT at different levels(level A:-0.61,0.94,and-1.55 mmHg;level B:0.16,-0.7,and 0.8;level C:0.5,0.5,and-0.1;level D:0.83,-3.4,and 4.2).Notably,NCT tended to overestimate IOP more at higher levels(level D)and underestimate at lower levels(level A)compared to CST.CST demonstrated better agreement with GAT than NCT did.Conclusions:This study confirms that the Corvis ST(CST)shows superior agreement with the Goldmann applanation tonometer than noncontact tonometry,particularly at low and high IOP ranges.It also exhibits greater measurement consistency.While NCT remains a useful screening tool,its significant over-and underestimation at pressure extremes is a critical limitation.The findings strongly suggest that CST may serve as a more suitable and reliable alternative to NCT for measuring IOP across a broad clinical range.However,the results underscore that these three methods are not directly interchangeable.Clinicians must therefore exercise careful interpretation of IOP values,taking into account the specific tonometer used and the patient's probable pressure level for accurate diagnosis and management of glaucoma.
基金Supported by deputy dean in research of School of Medicine according to study project and deputy vice chancellor of Shiraz University of Medical Sciences
文摘AIM： To explore the relationship between different parameters of Ocular Response Analyzer（ORA） and Corvis ST（CST） in a sample of healthy Iranian school-aged children and the relationship between parameters of these 2 instruments against intraocular pressure（IOP）, measured by the Goldmann applanation tonometer（GAT-IOP）, age and gender, and find possible correlation between ORA and CST with GAT.METHODS： This cross-sectional study included 90 healthy children. A general interview and complete eye examination were performed. Following successful GATIOP measurement, ORA and CST were conducted. The CST parameters were A 1/2 length（A1 L, A2 L）, A 1/2 velocity（A1 V, A2 V）, highest concavity deformation amplitude（HCDA）, radius of curvature（Ro C）, peak distance（PD）, central corneal thickness（CCT） and IOP. The ORA parameters were corneal hysteresis（CH）, corneal resistance factor（CRF）, Goldmann-correlated IOP（IOP-G） and corneal compensated IOP（IOP-CC）. Extracted data was analyzed using the Statistical Package for Social Science software.RESULTS： Totally 39 males with age of 9.08±1.60（6-12）y and 51 females with age of 8.96±1.55（6-13）y were included. Many CST parameters were significantly correlated with CH, CRF, IOP-G and IOP-CC. Some CST parameters had a significant correlation with GAT-IOP, including IOP-CST in both eyes and HCDA, A2 L, PD, and RoC in the left eye, but none with age, except A2 L in the right eye. The CRF measurement showed a significant correlation with GAT-IOP in both eyes and CH in the right eye, yet, none with age. Among all CST and ORA parameters, CCT-CST in both eyes and A1 L in right eye had a significant correlation with gender, although this was a negligible negative correlation. Comparison of mean IOP values by different devices showed a significantly highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Also, IOP-G versus IOP-CST significantly had the lowest IOP overestimation among others. Overall, either low positive correlation or negligible correlation was found between IOP measurements by 3 instruments.CONCLUSION： The study finds the highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Overall, either low positive correlation or negligible correlation is found between IOP measurements by the 3 instruments.
基金Supported by Medical Science Research Project of Hebei Province in 2023(No.20231818).
文摘AIM:To access the agreement of intraocular pressure(IOP)values obtained from biomechanically corrected tonometer[Corvis ST(CST)],non-contact tonometer(NCT),and Goldmann applanation tonometer(GAT)in children with NCT measured-IOP(NCT-IOP)values of 22 mm Hg or more,and related factors.METHODS:A total of 51 eyes with NCT-IOP≥22 mm Hg in children aged 7 to 14y were examined and IOP was measured by CST,NCT,and GAT.Based on GAT measured IOP(GAT-IOP),ocular hypertension(OHT)group(≥22 mm Hg,24 eyes)and the non-OHT group(<22 mm Hg,27 eyes)were defined.We compared the agreement of the three measurements,i.e.,CST measured IOP(CST-IOP),GAT-IOP,and NCT-IOP,and further analyzed the correlation between the differences in tonometry readings,central corneal thickness(CCT),axial length(AL),optic disc rim volume,and age.RESULTS:Compared with the OHT group,thicker CCT,larger rim volume,and higher differences between NCTIOP and GAT-IOP,were found in the non-OHT group.The differences between CST-IOP and GAT-IOP were lower than the differences between NCT-IOP and GAT-IOP in both groups.The mean differences in CST-IOP and GAT-IOP were 1.26 mm Hg(95%limit of agreement ranged from 0.1 to 2.41 mm Hg,OHT group)and 1.20 mm Hg(95%limit of agreement ranged from-0.5 to 3.00 mm Hg,non-OHT group),and the mean differences in NCT and GAT were 3.90 mm Hg(95%limit of agreement ranged from-0.19 to 9.70 mm Hg,OHT group)and 6.00 mm Hg(95%limit of agreement ranged from 1.50 to 10.50 mm Hg,non-OHT group).The differences between CST-IOP and GAT-IOP were not related to CCT,age,and AL in both groups;while the differences between NCT-IOP and GAT-IOP were related to CCT in the OHT group(r=0.93,P<0.001)and to CCT and AL in the non-OHT group(r=0.66,P<0.001,r=-0.81,P<0.001).CONCLUSION:The accuracy of NCT in the diagnosis of pediatric OHT is low.The agreement of CST-IOP and GATIOP was significantly higher in children with and without OHT than in those with NCT-IOP and GAT-IOP.Therefore,CST can be used as a good alternative for IOP measurement in children.The impacts of CCT and AL on NCT measurement need to be fully considered when managing childhood IOP.
