scholarly journals Comparison of IOL Power Calculated by Preoperative Biometry versus Intraoperative Wavefront Aberrometry in Thai Cataract Patients.

2020 ◽  
Author(s):  
Bharkbhum Khambhiphant ◽  
Sribenjapanon Thanyaporn

Abstract Background: As people now are expecting more precise and predictable results from cataract surgery. We need to find agreement between the calculated intraocular lens (IOL) power from using the SRK/T based preoperative biometry and the intraoperative wavefront aberrometry (ORA®) in Thai cataract patients. Methods: Eyes that underwent cataract surgery with monofocal or multifocal IOL implantation were enrolled in this prospective study. All eye biometry was measured preoperatively and the ORA intraoperatively. The SRK/T suggested IOL from the preoperative biometry was chosen in all cases. The suggested power and the estimated refraction (EST) from both devices were collected. Bland Altman analysis was used to find the agreement between them. The predicted EST of implanted IOL from both devices were compared with the one-month postoperative SE. Results: The study comprised 97 eyes (79 patients). Of these, 38 eyes (39.2%) had the same suggested IOL power, 36 eyes (37.1%) were within ±0.5D, 20 eyes (20.6%) were within ±1.0D and 3 eyes were beyond ±1.0D. Bland-Altman analysis found the mean difference between IOL power calculated from both devices was 0.39 with LoA of -0.54 to 1.31. The correlation was 98.50% (95%CI 98%- 99.10%). In the same suggested IOL power group, the median difference of EST by preoperative biometry and ORA compared with one-month postoperative SE were -0.08 (95%CI: -0.08, 1.11), and -0.14 (95%CI: -0.88, 1.2), respectively. Conclusions:The ORA and preoperative biometry results were in concordance with each other. The result of preoperative biometry was more accurate than ORA in this study.

2020 ◽  
Author(s):  
Bharkbhum Khambhiphant ◽  
Sribenjapanon Thanyaporn

Abstract Background: To find agreement between the calculated intraocular lens (IOL) power from using the SRK/T based preoperative biometry and the intraoperative wavefront aberrometry (ORA®) in Thai cataract patients, and to compare the accuracy of each method with the postoperative refraction results.Methods: Eyes that underwent cataract surgery with monofocal or multifocal IOL implantation were enrolled in this prospective study. All eye biometry was measured preoperatively and the ORA intraoperatively. The SRK/T suggested IOL from the preoperative biometry was chosen in all cases. The suggested power and the estimated refraction (EST) from both devices were collected. Bland Altman analysis was used to find the agreement between them. The predicted EST of implanted IOL from both devices were compared with the one-month postoperative SE. Results: The study comprised 97 eyes (79 patients). Of these, 38 eyes (39.2%) had the same suggested IOL power, 36 eyes (37.1%) were within ±0.5D, 20 eyes (20.6%) were within ±1.0D and 3 eyes were beyond ±1.0D. Bland-Altman analysis found the mean difference between IOL power calculated from both devices was 0.39 with LoA of -0.54 to 1.31. The correlation was 98.50% (95%CI 98%- 99.10%). In the same suggested IOL power group, the median difference of EST by preoperative biometry and ORA compared with one-month postoperative SE were -0.08 (95%CI: -0.08, 1.11), and -0.14 (95%CI: -0.88, 1.2), respectively. Conclusions:The ORA and preoperative biometry results were in concordance with each other. The result of preoperative biometry was more accurate than ORA in this study. Trial Registration: The thai clinical trial registration number: TCTR20171005001Registration Date: October 3rd, 2017First Enrollment: November 10th, 2017


2020 ◽  
Author(s):  
Bharkbhum Khambhiphant ◽  
Sribenjapanon Thanyaporn

Abstract Background: To find agreement between the calculated intraocular lens (IOL) power from using the SRK/T based preoperative biometry and the intraoperative wavefront aberrometry (ORA®) in Thai cataract patients, and to compare the accuracy of each method with the postoperative refraction results.Methods: Eyes that underwent cataract surgery with monofocal or multifocal IOL implantation were enrolled in this prospective study. All eye biometry was measured preoperatively and the ORA intraoperatively. The SRK/T suggested IOL from the preoperative biometry was chosen in all cases. The suggested power and the estimated refraction (EST) from both devices were collected. Bland Altman analysis was used to find the agreement between them. The predicted EST of implanted IOL from both devices were compared with the one-month postoperative SE. Results: The study comprised 97 eyes (79 patients). Of these, 38 eyes (39.2%) had the same suggested IOL power, 36 eyes (37.1%) were within ±0.5D, 20 eyes (20.6%) were within ±1.0D and 3 eyes were beyond ±1.0D. Bland-Altman analysis found the mean difference between IOL power calculated from both devices was 0.39 with LoA of -0.54 to 1.31. The correlation was 98.50% (95%CI 98%- 99.10%). In the same suggested IOL power group, the median difference of EST by preoperative biometry and ORA compared with one-month postoperative SE were -0.08 (95%CI: -0.08, 1.11), and -0.14 (95%CI: -0.88, 1.2), respectively. Conclusions:The ORA and preoperative biometry results were in concordance with each other. The result of preoperative biometry was more accurate than ORA in this study. Trial Registration: The thai clinical trial registration number: TCTR20171005001Registration Date: October 3rd, 2017First Enrollment: November 10th, 2017


2020 ◽  
Author(s):  
Bharkbhum Khambhiphant ◽  
Sribenjapanon Thanyaporn

Abstract Background : To find agreement between the calculated intraocular lens (IOL) power from using the SRK/T based preoperative biometry and the intraoperative wavefront aberrometry (ORA ® ) in Thai cataract patients, and to compare the accuracy of each method with the postoperative refraction results. Methods : Eyes that underwent cataract surgery with monofocal or multifocal IOL implantation were enrolled in this prospective study. All eye biometry was measured preoperatively and the ORA intraoperatively. The SRK/T suggested IOL from the preoperative biometry was chosen in all cases. The suggested power and the estimated refraction (EST) from both devices were collected. Bland Altman analysis was used to find the agreement between them. The predicted EST of implanted IOL from both devices were compared with the one-month postoperative SE. Results : The study comprised 97 eyes (79 patients). Of these, 38 eyes (39.2%) had the same suggested IOL power, 36 eyes (37.1%) were within ±0.5D, 20 eyes (20.6%) were within ±1.0D and 3 eyes were beyond ±1.0D. Bland-Altman analysis found the mean difference between IOL power calculated from both devices was 0.39 with LoA of -0.54 to 1.31. The correlation was 98.50% (95%CI 98%- 99.10%). In the same suggested IOL power group, the median difference of EST by preoperative biometry and ORA compared with one-month postoperative SE were -0.08 (95%CI: -0.08, 1.11), and -0.14 (95%CI: -0.88, 1.2), respectively. Conclusions :The ORA and preoperative biometry results were in concordance with each other. The result of preoperative biometry was more accurate than ORA in this study. Trial Registration: The clinical trial registration number: TCTR20171005001 Registration Date October 3 rd , 2017 First Enrollment November 1 st , 2017


2021 ◽  
Author(s):  
Qiong Lei ◽  
Haixia Tu ◽  
Xi Feng ◽  
Yong Wang

Abstract Background: To create an anterior chamber depth (ACD) regression model for adult cataract surgery candidates from China, and to evaluate the distribution of their ocular biometric parameters.Methods: The ocular biometric records of 28,709 right eyes of cataract surgery candidates who were treated at Aier Eye Hospitals in nine cities from 2018 to 2019 were retrospectively analyzed. All measurements were taken with IOLMaster 700. We included patients who were at least 40 years old and were diagnosed with cataract.Results: The mean age of the patients was 68.6 ± 11.0 years. The mean values recorded were as follows: axial length (AL), 24.17 ± 2.47 mm; mean keratometry (Km) value, 44.09 ± 3.25 D; corneal astigmatism (CA), 1.06 ± 0.98 D; ACD, 3.02 ± 0.45 mm; lens thickness (LT), 4.52 ± 0.45 mm; central corneal thickness (CCT), 0.534 ± 0.04 mm; and white to white (WTW) corneal diameter, 11.64 ± 0.46 mm. The proportion of patients with long axial length (AL >25 mm) decreased with age. ACD, LT, AL, Km, WTW, and age were correlated. In the multivariate regression analysis of ACD, which included LT, AL, WTW, sex, Km, CCT, and age, there was a reasonable prediction with adjusted R2 = 0.629.Conclusions: The results show that high myopes are inclined to schedule cataract surgery at a younger age. LT and AL were found to be important factors that affect ACD. This study provides reference data for cataract patients from China.


2016 ◽  
Vol 17 (4) ◽  
pp. 294-299 ◽  
Author(s):  
Mohammad Y Hajeer ◽  
Ahmad L Maroua ◽  
Mowaffak Ajaj

ABSTRACT Objective To evaluate the accuracy and reproducibility of linear measurements made on cone-beam computed tomography (CBCT)-derived digital models. Materials and methods A total of 25 patients (44% female, 18.7 ± 4 years) who had CBCT images for diagnostic purposes were included. Plaster models were obtained and digital models were extracted from CBCT scans. Seven linear measurements from predetermined landmarks were measured and analyzed on plaster models and the corresponding digital models. The measurements included arch length and width at different sites. Paired t test and Bland–Altman analysis were used to evaluate the accuracy of measurements on digital models compared to the plaster models. Also, intraclass correlation coefficients (ICCs) were used to evaluate the reproducibility of the measurements in order to assess the intraobserver reliability. Results The statistical analysis showed significant differences on 5 out of 14 variables, and the mean differences ranged from −0.48 to 0.51 mm. The Bland–Altman analysis revealed that the mean difference between variables was (0.14 ± 0.56) and (0.05 ± 0.96) mm and limits of agreement between the two methods ranged from −1.2 to 0.96 and from −1.8 to 1.9 mm in the maxilla and the mandible, respectively. The intraobserver reliability values were determined for all 14 variables of two types of models separately. The mean ICC value for the plaster models was 0.984 (0.924–0.999), while it was 0.946 for the CBCT models (range from 0.850 to 0.985). Conclusion Linear measurements obtained from the CBCTderived models appeared to have a high level of accuracy and reproducibility. How to cite this article Maroua AL, Ajaj M, Hajeer MY. The Accuracy and Reproducibility of Linear Measurements Made on CBCT-derived Digital Models. J Contemp Dent Pract 2016;17(4):294-299.


Author(s):  
Mera Usman Muhammed ◽  
Mayaki Abubakar Musa ◽  
Gambo Abdulrahman Abdullahi

This study was carried out to compare the digital rectal (DR) thermometer with non-contact infrared thermometer (IRT) measurements at two locations on the face in some large animal species. Two hundred and forty (240) animals comprising of equal numbers of three species (cattle, camel and horses) of varying age and either sex was used. The IR temperature was taken from two sites [frontal (FIRT) and temporal (TIRT) region] on the animal face. The mean IR temperatures (FIRT and TIRT) were higher than the RT in all the animal species. The two thermometers correlate poorly in all the animal species. Bland-Altman analysis showed high biases and limits of agreement not acceptable for clinical purposes. In conclusion, IRT seems to offer a quick and easy way to determine the animal temperature but clinically it cannot be used interchangeably with DR thermometer at the moment for body temperature measurement in these animal species.


2021 ◽  
Author(s):  
Dan Liu ◽  
Cong Fan ◽  
Chunyan Li ◽  
Jian Jiang

Abstract Background: Multifocal intraocular lenses (IOLs) is very intolerant to residual corneal astigmatism and patients with more than 1.0 D of residual corneal astigmatism are not suitable candidates for implantation of multifocal IOLs. The purpose of this study was to evaluate the efficacy of a single clear corneal incision (CCI) or an opposite clear corneal incision (OCCI) made on a steep meridian for correction of low to moderate corneal astigmatism during implantation of multifocal IOLs.Methods: This is a retrospective cohort study. A total of 50 patients with pre-operative total corneal astigmatism, ranging between 0.5 and 2.0 diopters (D), who underwent cataract surgery and received multifocal IOLs were included. Correction of corneal astigmatism was done via single CCIs on steep meridians in patients with 0.5–1.2 D total corneal astigmatisms, and OCCIs in patients with 1.3–2.0 D total corneal astigmatisms. Visual acuity, corneal astigmatism, ocular aberrations, corneal aberrations, and subjective vision quality were evaluated after surgery.Results: At 12-weeks post-surgery, the mean uncorrected distance vision (UCDV) was 0.06±0.09 logarithm of the minimum angle of resolution (logMAR) and 0.03±0.09 logMAR, and the mean uncorrected near vision (UCNV) was 0.08±0.11 logMAR and 0.09±0.09 logMAR in the CCI and OCCI groups, respectively. The change in corneal astigmatism was 0.52 ± 0.22D and 1.06 ± 0.23D in the CCI and OCCI groups, respectively (P<0.001). Total corneal higher-order aberrations (HOAs) and trefoil increased in both groups (P<0.05); however, there was no difference in the change in total corneal HOAs between the two groups (P>0.05). Conclusions: CCI and OCCI made on a steep axis could be an option for correction of mild-to-moderate astigmatism during cataract surgery with multifocal IOL implantation.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ziming Liu ◽  
Emmanuel Eric Pazo ◽  
Hong Ye ◽  
Cui Yu ◽  
Ling Xu ◽  
...  

Purpose. To assess the repeatability and agreement of refractive measurements using 2WIN-S photoscreening with the gold-standard cycloplegic retinoscope refraction. Design. Single centre, cross-sectional study. Methods. Spherical, cylindrical, axis, and spherical equivalent of 194 bilateral eyes of 97 children were assessed using a retinoscope and 2WIN-S. One week later, another operator repeated the 2WIN-S measurements. The primary outcome measures were to assess the repeatability and agreement between spherical equivalent, J0, and J45 readings of 2WIN-S. The repeatability of measurements was assessed by the within-subject standard deviation (2.77 Sw) and intraclass correlation coefficient (ICC). The agreement between devices was assessed using 95% limits of agreement. The extent of the agreement between cycloplegic retinoscopy and noncycloplegic 2WIN-S measurements was assessed using Bland–Altman analysis. Results. The mean age ± SD was 10.3 ± 2.46 year (range, 4–14 years). The sphere, cylinder, and spherical equivalent measurements were found to be consistent with both apparatus (r value >0.86). ICC for SE, J0, and J45 was 0.900, 0.666, and 0.639, respectively; Sw for SE, J0, and J45 was 0.61D, 0.30D, and 0.31D, respectively; Bland–Altman analysis of retinoscopy with cycloplegia and 2WIN-S for SE was 184/194 (95%) in 95% confidence interval, and the mean value was 0.46. J0 was 184/194 (95%), and the mean value is −0.04. J45 was 181/194 (93%), and the mean value is −0.15. Conclusion. The objective refractive measurement of 2WIN-S had good reliability and high agreement with the gold-standard retinoscopy refraction in children and adolescents. While consistency was observed, it is essential to take into consideration that it is a screening tool.


2021 ◽  
Vol 12 (9) ◽  
pp. 126-129
Author(s):  
Kabindra Bajracharya ◽  
Anjita Hirachan ◽  
Kriti Joshi ◽  
Bimala Bajracharya

Background: In congenital and developmental cataract primary undercorrection of intraocular lens (IOL) power is a common practice. However, long-term refractive status of these children is largely unknown. Aims and Objective: To analyse refractive status after cataract surgery with undercorrected IOL power implantation in congenital and developmental cataract. Materials and Methods: This study was descriptive, retrospective conducted for three years from 1st January 2013 to 31st December 2015. The children (> 6 months to <=7 years of age) who underwent cataract surgery for congenital and developmental cataract with a primary IOL implantation and had reached the age of 8 years were studied. The data were collected in terms of demography, axial length, biometry, IOL implanted, hyperopic correction and postoperative refractive status at 8 years. Results: Total numbers of children operated were 181 with total eyes 288. Unilateral cases were 74 (40.88%) and bilateral 107 (59.12%). Male were 121 (66.85%) and female were 60 (33.15%) with male is to female ratio of 2:1. Right eye was involved in 152 (52.8%) and left eye 136 (47.2%). The mean axial length at the age of one year was 20.75 mm, and gradually increased as age increased which was 22.47 mm at 6 years. The mean biometry was 27.9 diopter (D) at the age of one year which gradually decreased as age increased. Of the total 288 congenital cataract operated, complete follow-up documents were available for 77 (26.74%) eyes up to 8 years which showed emmetropia achieved in 25.97%, myopia in 28.57% and hypermetropia in 45.45%. Conclusion: Primary IOL implantation with hyperopic correction is accepted practice in congenital and developmental cataract. Emmetropia can be achieved however some hyperopic or myopic refractive status at the age of 8 years is not a surprise. Myopic shift continues as the age increases. Parent awareness for early detection and surgery, optical correction and regular follow-up are essential for good outcome.


2019 ◽  
Vol 43 (6) ◽  
pp. 379-384
Author(s):  
Qi Zhang ◽  
Feng Zhuang ◽  
Qichen Fan ◽  
Wenyan Yu ◽  
Feng Ding

Aim: This study aimed to investigate whether effluent ionized calcium was an appropriate indicator to assess anticoagulant effect in continuous renal replacement therapy with regional citrate anticoagulation instead of post-filter ionized calcium. Methods: In total, 48 paired samples of effluent fluid and post-filter blood were obtained from critically ill patients who required continuous renal replacement therapy. All samples were taken for ionized calcium measurements and were assessed by point-of-care analyzer. Correlations and agreements between two methods were performed by Pearson linear analysis and Bland–Altman analysis accordingly. Results: The mean post-filter ionized calcium was 0.42 ± 0.12 mmol/L, and mean ionized calcium level of effluent fluid was 0.39 ± 0.11 mmol/L. The ionized calcium level of effluent fluid was significantly correlated with post-filter ionized calcium in all continuous renal replacement therapy patients. Bland–Altman analysis showed that the mean difference of ionized calcium between two sampling sites in all continuous renal replacement therapy patients was −0.02 mmol/L with 95% confidence interval ranging from −0.09 to 0.04 mmol/L. The significant correlations and agreements were also demonstrated in continuous veno-venous hemofiltration, continuous veno-venous hemodialysis, and continuous veno-venous hemodiafiltration modalities separately. Conclusion: The effluent ionized calcium could be a considerable substitute for post-filter ionized calcium to monitor the validity of regional citrate anticoagulation in continuous renal replacement therapy with less blood loss.


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