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Ruth Lapidgortzak - One of the best experts on this subject based on the ideXlab platform.
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ascrs calculator formula accuracy in multifocal intraocular lens implantation in hyperopic corneal refractive Laser Surgery eyes
Journal of Cataract and Refractive Surgery, 2019Co-Authors: Violette Vrijman, Jan Willem Van Der Linden, Ivanka J E Van Der Meulen, Maarten P Mourits, Adi Abulafia, Ruth LapidgortzakAbstract:Purpose To evaluate the accuracy of different intraocular lens (IOL) power calculation formulas available on the American Society of Cataract and Refractive Surgery calculator in calculating multifocal IOL power in eyes with previous hyperopic corneal refractive Laser Surgery. Design Retrospective case series. Setting Amsterdam University Medical Center, University of Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. Methods This study compared the accuracy of 3 formulas using historical refractive data (ie, Masket, modified Masket, and Barrett True-K) and 3 formulas using no previous refractive data (ie, Shammas, Haigis-L, and Barrett True-K no-history). Results Sixty-four eyes were included. The variance of the prediction error of the various formulas was similar and ranged from 0.27 D2 to 0.33 D2 (P = .99). The modified Masket formula had a significantly higher median absolute prediction error than the Masket formula, Barrett True-K formula, and mean value of all formulas (P Conclusion All formulas showed comparable accuracy in predicting IOL power in eyes after hyperopic corneal refractive Laser Surgery except for the modified Masket formula, which performed less accurately than the Masket formula, Barrett True-K formula, and mean value of all formulas.
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evaluation of different iol calculation formulas of the ascrs calculator in eyes after corneal refractive Laser Surgery for myopia with multifocal iol implantation
Journal of Refractive Surgery, 2019Co-Authors: Violette Vrijman, Jan Willem Van Der Linden, Ivanka J E Van Der Meulen, Maarten P Mourits, Adi Abulafia, Ruth LapidgortzakAbstract:PURPOSE: To compare the accuracy of different intraocular lens (IOL) calculation formulas available on the American Society of Cataract and Refractive Surgery (ASCRS) post-refractive Surgery IOL power calculator for the prediction of multifocal IOL power after previous corneal refractive Laser Surgery for myopia. METHODS: An analysis and comparison were performed of the accuracy of three methods using surgically induced change in refraction (ie, Masket, Modified Masket, and Barrett True-K formulas) and three methods using no previous data (ie, Shammas, Haigis-L, and Barrett True-K No History formulas). The average of all formulas was also analyzed and compared. RESULTS: Thirty-six eyes of 36 patients were included. All formulas, except for the Masket, Modified Masket, and Barrett True-K formulas, had myopic mean numerical errors that were significantly different from zero (P ≤ .01). The median absolute error of the Shammas formula (0.52 diopters [D]) was significantly higher compared to all of the other formulas (P < .05), except for the Haigis-L formula (P = .09). Comparing the formulas using no previous data, the Barrett True-K No History formula had the lowest median absolute error (0.33 D, P < .001). CONCLUSIONS: The Shammas formula showed the least accuracy in predicting IOL power in eyes with multifocal IOL implantation after previous corneal refractive Laser Surgery for myopia. In eyes with all available data, all formulas performed equally except for the Shammas formula, whereas in eyes lacking historical data, the Barrett True-K No History formula performed best.
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multifocal intraocular lens implantation after previous corneal refractive Laser Surgery for myopia
Journal of Cataract and Refractive Surgery, 2017Co-Authors: Violette Vrijman, Jan Willem Van Der Linden, Ivanka J E Van Der Meulen, Maarten P Mourits, Ruth LapidgortzakAbstract:Purpose To describe the refraction and visual acuity outcomes of multifocal intraocular lens (IOL) implantation in patients with previous corneal refractive Laser Surgery for myopia. Setting Academic Medical Center, University of Amsterdam, Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. Design Retrospective cohort study. Methods The 3-month results after implantation of a multifocal IOL (Acrysof Restor) in patients who had corneal refractive Laser Surgery for myopia were analyzed. The primary outcome measures were corrected distance visual acuity, uncorrected distance visual acuity (UDVA), and refraction. The secondary outcome measures were number of Laser enhancements, corneal irregularity, pre-Laser magnitude of myopia, and posterior capsule opacification (PCO) rate. Results Seventy-seven eyes of 43 patients were included. Twenty-nine eyes had lens extraction because of cataract, and 48 eyes had a refractive lens exchange. The mean postoperative UDVA was 0.14 logarithm of minimum angle of resolution ± 0.22 (SD). The mean postoperative spherical equivalent was −0.38 ± 0.78 diopter (D). Fifty-seven percent of eyes were within ±0.50 D of emmetropia, and 86% were within ±1.0 D. Sixteen eyes (20.8%) had Laser enhancement because of residual refraction. Fourteen eyes (18.2%) had a neodymium:YAG Laser capsulotomy because of PCO. Eyes with pre-Laser myopia greater than 6.0 D had a less predictable outcome than eyes with pre-Laser myopia less than 6.0 D (P = .026). Conclusions Multifocal IOL implantation after corneal refractive Laser Surgery for myopia resulted in good visual acuity and refraction. Results were less predictable with myopia greater than 6.0 D.
Violette Vrijman - One of the best experts on this subject based on the ideXlab platform.
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ascrs calculator formula accuracy in multifocal intraocular lens implantation in hyperopic corneal refractive Laser Surgery eyes
Journal of Cataract and Refractive Surgery, 2019Co-Authors: Violette Vrijman, Jan Willem Van Der Linden, Ivanka J E Van Der Meulen, Maarten P Mourits, Adi Abulafia, Ruth LapidgortzakAbstract:Purpose To evaluate the accuracy of different intraocular lens (IOL) power calculation formulas available on the American Society of Cataract and Refractive Surgery calculator in calculating multifocal IOL power in eyes with previous hyperopic corneal refractive Laser Surgery. Design Retrospective case series. Setting Amsterdam University Medical Center, University of Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. Methods This study compared the accuracy of 3 formulas using historical refractive data (ie, Masket, modified Masket, and Barrett True-K) and 3 formulas using no previous refractive data (ie, Shammas, Haigis-L, and Barrett True-K no-history). Results Sixty-four eyes were included. The variance of the prediction error of the various formulas was similar and ranged from 0.27 D2 to 0.33 D2 (P = .99). The modified Masket formula had a significantly higher median absolute prediction error than the Masket formula, Barrett True-K formula, and mean value of all formulas (P Conclusion All formulas showed comparable accuracy in predicting IOL power in eyes after hyperopic corneal refractive Laser Surgery except for the modified Masket formula, which performed less accurately than the Masket formula, Barrett True-K formula, and mean value of all formulas.
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evaluation of different iol calculation formulas of the ascrs calculator in eyes after corneal refractive Laser Surgery for myopia with multifocal iol implantation
Journal of Refractive Surgery, 2019Co-Authors: Violette Vrijman, Jan Willem Van Der Linden, Ivanka J E Van Der Meulen, Maarten P Mourits, Adi Abulafia, Ruth LapidgortzakAbstract:PURPOSE: To compare the accuracy of different intraocular lens (IOL) calculation formulas available on the American Society of Cataract and Refractive Surgery (ASCRS) post-refractive Surgery IOL power calculator for the prediction of multifocal IOL power after previous corneal refractive Laser Surgery for myopia. METHODS: An analysis and comparison were performed of the accuracy of three methods using surgically induced change in refraction (ie, Masket, Modified Masket, and Barrett True-K formulas) and three methods using no previous data (ie, Shammas, Haigis-L, and Barrett True-K No History formulas). The average of all formulas was also analyzed and compared. RESULTS: Thirty-six eyes of 36 patients were included. All formulas, except for the Masket, Modified Masket, and Barrett True-K formulas, had myopic mean numerical errors that were significantly different from zero (P ≤ .01). The median absolute error of the Shammas formula (0.52 diopters [D]) was significantly higher compared to all of the other formulas (P < .05), except for the Haigis-L formula (P = .09). Comparing the formulas using no previous data, the Barrett True-K No History formula had the lowest median absolute error (0.33 D, P < .001). CONCLUSIONS: The Shammas formula showed the least accuracy in predicting IOL power in eyes with multifocal IOL implantation after previous corneal refractive Laser Surgery for myopia. In eyes with all available data, all formulas performed equally except for the Shammas formula, whereas in eyes lacking historical data, the Barrett True-K No History formula performed best.
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multifocal intraocular lens implantation after previous corneal refractive Laser Surgery for myopia
Journal of Cataract and Refractive Surgery, 2017Co-Authors: Violette Vrijman, Jan Willem Van Der Linden, Ivanka J E Van Der Meulen, Maarten P Mourits, Ruth LapidgortzakAbstract:Purpose To describe the refraction and visual acuity outcomes of multifocal intraocular lens (IOL) implantation in patients with previous corneal refractive Laser Surgery for myopia. Setting Academic Medical Center, University of Amsterdam, Amsterdam, and Retina Total Eye Care, Driebergen, the Netherlands. Design Retrospective cohort study. Methods The 3-month results after implantation of a multifocal IOL (Acrysof Restor) in patients who had corneal refractive Laser Surgery for myopia were analyzed. The primary outcome measures were corrected distance visual acuity, uncorrected distance visual acuity (UDVA), and refraction. The secondary outcome measures were number of Laser enhancements, corneal irregularity, pre-Laser magnitude of myopia, and posterior capsule opacification (PCO) rate. Results Seventy-seven eyes of 43 patients were included. Twenty-nine eyes had lens extraction because of cataract, and 48 eyes had a refractive lens exchange. The mean postoperative UDVA was 0.14 logarithm of minimum angle of resolution ± 0.22 (SD). The mean postoperative spherical equivalent was −0.38 ± 0.78 diopter (D). Fifty-seven percent of eyes were within ±0.50 D of emmetropia, and 86% were within ±1.0 D. Sixteen eyes (20.8%) had Laser enhancement because of residual refraction. Fourteen eyes (18.2%) had a neodymium:YAG Laser capsulotomy because of PCO. Eyes with pre-Laser myopia greater than 6.0 D had a less predictable outcome than eyes with pre-Laser myopia less than 6.0 D (P = .026). Conclusions Multifocal IOL implantation after corneal refractive Laser Surgery for myopia resulted in good visual acuity and refraction. Results were less predictable with myopia greater than 6.0 D.
Enrico Lopriore - One of the best experts on this subject based on the ideXlab platform.
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histologic chorioamnionitis and funisitis after Laser Surgery for twin twin transfusion syndrome
Obstetrics & Gynecology, 2016Co-Authors: Depeng Zhao, Danielle Cohen, Monique E De Paepe, Erik W Van Zwet, Dick Oepkes, Johanna M. Middeldorp, Enrico LoprioreAbstract:OBJECTIVE:To estimate the incidence of histologic chorioamnionitis and funisitis after fetoscopic Laser Surgery for the management of twin–twin transfusion syndrome.METHODS:A case–control study was performed at the Leiden University Medical Center from 2013 to 2014. All patients with twin–twin trans
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operator competence in fetoscopic Laser Surgery for twin twin transfusion syndrome validation of a procedure specific evaluation tool
Ultrasound in Obstetrics & Gynecology, 2016Co-Authors: Suzanne H P Peeters, Enrico Lopriore, Johanna M. Middeldorp, Jan Deprest, Joost Akkermans, J Bustraan, Roland Devlieger, Liesbeth Lewi, Dick OepkesAbstract:OBJECTIVES Fetoscopic Laser Surgery for twin-twin transfusion syndrome is a procedure for which no objective tools exist to assess technical skills. To ensure that future fetal surgeons reach competence prior to performing the procedure unsupervised, we developed a performance assessment tool. The aim of this study was to validate this assessment tool for reliability and construct validity. METHODS We made use of a procedure-specific evaluation instrument containing all essential steps of the fetoscopic Laser procedure, which was previously created using Delphi methodology. Eleven experts and 13 novices from three fetal medicine centers performed the procedure on the same simulator. Two independent observers assessed each Surgery using the instrument (maximum score: 52). Interobserver reliability was assessed using Spearman correlation. We compared the performance of novices and experts to assess construct validity. RESULTS The interobserver reliability was high (Rs = 0.974, P < 0.001). Checklist scores for experts and novices were significantly different; the median score for novices was 28/52 (54%), whereas that for experts was 47.5/52 (91%) (P < 0.001). The procedure time and fetoscopy time were significantly shorter (P < 0.001) for experts. Residual anastomoses were found in 1/11 (9%) procedures performed by experts and in 9/13 (69%) procedures performed by novices (P = 0.005). Multivariable analysis showed that the checklist score, independent of age and gender, predicted competence. CONCLUSIONS The procedure-specific assessment tool for fetoscopic Laser Surgery shows good interobserver reliability and discriminates experts from novices. This instrument may therefore be a useful tool in the training curriculum for fetal surgeons. Further intervention studies with reassessment before and after training may increase the construct validity of the tool. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
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learning curve for fetoscopic Laser Surgery using cumulative sum analysis
Acta Obstetricia et Gynecologica Scandinavica, 2014Co-Authors: S. H. P. Peeters, Frans J.c.m. Klumper, Erik W Van Zwet, Enrico Lopriore, Dick Oepkes, Johanna M. MiddeldorpAbstract:Objective. To identify a learning curve and monitor operator performance for fetoscopic Laser Surgery for twin-to-twin transfusion syndrome using cumulative sum analysis. Design. Retrospective cohort study. Setting. National tertiary referral center for invasive fetal therapy. Population. A total of 340 consecutive monochorionic pregnancies with twin-to-twin transfusion syndrome treated with fetoscopic Laser coagulation between August 2000 and December 2010. Methods. A learning curve was generated using learning curve cumulative sum analysis and cumulative sum methodology to assess changes in double survival across the case sequence. Laser Surgery was initially performed by two operators, joined by a third and fourth operator after 1 and 2 years, respectively. Main outcome measures. Individual operator performance, double perinatal survival at 4 weeks. Results. Overall survival of both twins occurred in 59% (201/340), median gestational age at birth was 32.0 weeks. Cumulative sum graphs showed that level of competence for double survival for the operators was reached after 26, 25, 26, and 35 procedures, respectively. Two operators kept their competence level and continued to improve after completing the initial learning process; two others went out of control at one point in time, according to the cumulative sum boundaries. A difference in learning effect was associated with number of procedures performed annually and previous experience with other ultrasound-guided invasive procedures. Conclusions. This study shows that all operators reached a level of competence after at least 25 fetoscopic Laser procedures and confirms the value of using the cumulative sum method both for learning curve assessment and for ongoing quality control.
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risk factors for neurodevelopment impairment in twin twin transfusion syndrome treated with fetoscopic Laser Surgery
Obstetrics & Gynecology, 2009Co-Authors: Enrico Lopriore, Dick Oepkes, Johanna M. Middeldorp, Els Ortibus, Ruthy Acostarojas, Saskia Le Cessie, Eduard Gratacos, Frank P H A Vandenbussche, Jan Deprest, Frans J WaltherAbstract:OBJECTIVE:To estimate the risk factors for adverse long-term neurodevelopment outcome in twin–twin transfusion syndrome treated with Laser Surgery.METHODS:Twin–twin transfusion syndrome cases treated with Laser Surgery at three European centers from August 2000 to December 2005 were included in this
Giacomo Savini - One of the best experts on this subject based on the ideXlab platform.
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results of the barrett true k formula for iol power calculation based on scheimpflug camera measurements in eyes with previous myopic excimer Laser Surgery
Journal of Cataract and Refractive Surgery, 2020Co-Authors: Giacomo Savini, Kenneth J Hoffer, Graham D BarrettAbstract:Purpose To compare the refractive results of 4 different options for the Barrett True-K formula in eyes with previous myopic excimer Laser Surgery. Setting IRCCS-Fondazione Bietti, Rome, Italy. Design Retrospective case series. Methods Biometric measurements obtained with a rotating Scheimpflug camera (Pentacam) were entered into the Barrett True-K formula. Clinical history (Laser-induced refractive change) and the measured posterior corneal curvature were entered as optional. Four variants of the Barrett True-K formula were investigated: (1) with history and measured posterior corneal power, (2) with history and predicted posterior corneal power, (3) no history with measured posterior corneal power, and (4) no history with predicted posterior corneal power. The prediction error (PE) was calculated as the difference between the measured and predicted postoperative refraction values. Results In 50 eyes (50 patients), the Barrett True-K formula with history and measured posterior corneal power resulted in the lowest standard deviation of the PE (0.52 diopters [D]), lowest median (0.245 D) and mean (0.413 D) absolute errors, and highest percentage of eyes with a PE within ±0.25 D (54%), ±0.50 D (70%), and ±0.75 D (84%). The Barrett True-K no-history formula with predicted posterior corneal power yielded the worst refractive outcomes. When the 4 options were compared, statistically significant differences were detected among the median absolute errors (P = .0017) and the percentage of eyes with a PE within ±0.25 D (P Conclusions Using historical data and measured posterior corneal power improved the refractive accuracy of the Barrett True-K formula in eyes with previous myopic excimer Laser Surgery.
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corneal ray tracing versus simulated keratometry for estimating corneal power changes after excimer Laser Surgery
Journal of Cataract and Refractive Surgery, 2014Co-Authors: Giacomo Savini, Antonio Calossi, Massimo Camellin, Francesco Carones, Marco Fantozzi, Kenneth J HofferAbstract:Purpose To evaluate whether the refractive changes induced by excimer Laser Surgery can be accurately measured by corneal ray tracing performed by a combined rotating Scheimpflug camera–Placido-disk corneal topographer (Sirius). Setting Private practices. Design Evaluation of diagnostic test. Methods This multicenter retrospective study comprised patients who had myopic or hyperopic excimer Laser refractive Surgery. Preoperatively and postoperatively, 2 corneal power measurements—simulated keratometry (K) and mean pupil power—were obtained. The mean pupil power was the corneal power calculated over the entrance pupil by ray tracing through the anterior and posterior corneal surfaces using Snell's law. Agreement between the refractive and corneal power change was analyzed according to Bland and Altman. Regression analysis and Bland-Altman plots were used to evaluate agreement between measurements. Results The study evaluated 72 eyes (54 patients). The difference between the postoperative and preoperative simulated K values underestimated the refractive change after myopic correction and overestimated it after hyperopic correction. Agreement between simulated K changes and refractive changes was poor, especially for higher amounts of correction. A proportional bias was detected ( r = −0.77; P r 2 = 0.98). The mean pupil power did not overestimate or underestimate the refractive change. The 95% LoA ranged between −0.97 D and +0.56 D. Conclusion Corneal ray tracing accurately measured corneal power changes after excimer Laser refractive Surgery. Financial Disclosures Dr. Calossi is consultant to Costruzione Strumenti Oftalmici. Dr. Carones is consultant to Wavelight Laser Technologie AG. No other author has a financial or proprietary interest in any material or method mentioned.
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scheimpflug analysis of corneal power changes after myopic excimer Laser Surgery
Journal of Cataract and Refractive Surgery, 2013Co-Authors: Giacomo Savini, Michele Carbonelli, Kenneth J Hoffer, Piero BarboniAbstract:Purpose To assess the ability of corneal power measurements by a rotating Scheimpflug camera to measure the refractive change induced by myopic excimer Laser Surgery. Setting G.B. Bietti Foundation-IRCCS, Rome, Italy. Design Evaluation of diagnostic test. Methods The following corneal power measurements by the Pentacam Scheimpflug camera were analyzed: average keratometry (K), true net power (calculated by Gaussian optics formula), and total corneal refractive power (TCRP) at 2.0 mm, 3.0 mm, and 4.0 mm, calculated by ray tracing on a ring and as the average of the zone inside the ring. The difference between the preoperative and postoperative values was compared with the subjective surgically induced refractive change (SIRC) and with the difference between the preoperative and the postoperative anterior corneal power measured by Placido corneal topography (Keratron). Results In 36 consecutive eyes, the average K significantly underestimated the SIRC as determined by subjective refraction (−4.47 diopters [D] ± 1.81 [SD]) and corneal topography (−4.38 ± 1.81 D). The 3.0 mm and 4.0 mm ring total corneal refractive power significantly overestimated the SIRC. The remaining values did not show statistically significant differences with respect to the SIRC. The 3.0 mm zone TCRP and the 2.0 mm ring TCRP provided the lowest median difference compared with the SIRC (−0.07 D and −0.17 D, respectively) and the closest agreement. Conclusions The corneal power values provided by the Scheimpflug camera accurately reflected the SIRC after myopic excimer Laser Surgery. The best options seem to be the 3.0 mm zone TCRP and the 2.0 mm ring TCRP. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
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corneal power measurements with the pentacam scheimpflug camera after myopic excimer Laser Surgery
Journal of Cataract and Refractive Surgery, 2008Co-Authors: Giacomo Savini, Piero Barboni, Vincenzo Profazio, Maurizio Zanini, Kenneth J HofferAbstract:Purpose To evaluate corneal power measurements by a rotating Scheimpflug camera (Pentacam, Oculus) in eyes that have had myopic excimer Laser Surgery. Setting Private practice, Bologna, Italy. Methods This prospective comparative interventional case series comprised 16 eyes of 16 patients who had myopic excimer Laser Surgery and for whom all perioperative data were available. Four corneal power measurements obtained with the Pentacam (simulated keratometry, true net power, equivalent K reading, and BESSt formula) were analyzed and compared with values derived using the clinical history method and 2 other formulas for calculating corneal power after refractive Surgery (modified keratometric refractive index according to Savini et al. and separate consideration of the anterior and posterior corneal curvatures according to Speicher). Results Analysis of variance showed a statistically significant difference between all methods (P Conclusions The Pentacam device gave corneal power measurements that did not statistically significantly had differ from those predicted by the clinical history method in eyes that had previous myopic excimer Laser Surgery. Wide LoA are a potential source of error in intraocular lens power calculation in such patients.
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correlation between attempted correction and keratometric refractive index of the cornea after myopic excimer Laser Surgery
Journal of Refractive Surgery, 2007Co-Authors: Giacomo Savini, Piero Barboni, Maurizio ZaniniAbstract:PURPOSE Given that the standard keratometric refractive index of 1.3375 is no longer valid after excimer Laser Surgery, we aimed to investigate how this value changes postoperatively and if any correlation to the attempted correction exists. METHODS The pre- and postoperative data of 98 patients who underwent either myopic photorefractive keratectomy (PRK) or LASIK were reviewed. Using postoperative videokeratography, the corneal radius (r) was obtained; the corrected corneal power (Pc) was measured by separately calculating the dioptric power of the anterior and posterior corneal surfaces. The postoperative index of refraction (n(post)) was derived from these values using the formula: n(post) = (rPc) +1. RESULTS As the amount of refractive change increases, n(post) progressively decreases (P < .0001, r = 0.9581). Linear regression provided the subsequent formula to calculate the postoperative index of refraction: n(post) = 1.338 + 0.0009856 x attempted correction. CONCLUSIONS Myopic PRK and LASIK induce a decrease in the keratometric refractive index. This reduction correlates to the amount of attempted correction. When the latter is known, calculating n(post) may enable the measurement of corneal power and thus provide an additional method for calculating intraocular lens power in eyes that have undergone myopic PRK or LASIK.
Johanna M. Middeldorp - One of the best experts on this subject based on the ideXlab platform.
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histologic chorioamnionitis and funisitis after Laser Surgery for twin twin transfusion syndrome
Obstetrics & Gynecology, 2016Co-Authors: Depeng Zhao, Danielle Cohen, Monique E De Paepe, Erik W Van Zwet, Dick Oepkes, Johanna M. Middeldorp, Enrico LoprioreAbstract:OBJECTIVE:To estimate the incidence of histologic chorioamnionitis and funisitis after fetoscopic Laser Surgery for the management of twin–twin transfusion syndrome.METHODS:A case–control study was performed at the Leiden University Medical Center from 2013 to 2014. All patients with twin–twin trans
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operator competence in fetoscopic Laser Surgery for twin twin transfusion syndrome validation of a procedure specific evaluation tool
Ultrasound in Obstetrics & Gynecology, 2016Co-Authors: Suzanne H P Peeters, Enrico Lopriore, Johanna M. Middeldorp, Jan Deprest, Joost Akkermans, J Bustraan, Roland Devlieger, Liesbeth Lewi, Dick OepkesAbstract:OBJECTIVES Fetoscopic Laser Surgery for twin-twin transfusion syndrome is a procedure for which no objective tools exist to assess technical skills. To ensure that future fetal surgeons reach competence prior to performing the procedure unsupervised, we developed a performance assessment tool. The aim of this study was to validate this assessment tool for reliability and construct validity. METHODS We made use of a procedure-specific evaluation instrument containing all essential steps of the fetoscopic Laser procedure, which was previously created using Delphi methodology. Eleven experts and 13 novices from three fetal medicine centers performed the procedure on the same simulator. Two independent observers assessed each Surgery using the instrument (maximum score: 52). Interobserver reliability was assessed using Spearman correlation. We compared the performance of novices and experts to assess construct validity. RESULTS The interobserver reliability was high (Rs = 0.974, P < 0.001). Checklist scores for experts and novices were significantly different; the median score for novices was 28/52 (54%), whereas that for experts was 47.5/52 (91%) (P < 0.001). The procedure time and fetoscopy time were significantly shorter (P < 0.001) for experts. Residual anastomoses were found in 1/11 (9%) procedures performed by experts and in 9/13 (69%) procedures performed by novices (P = 0.005). Multivariable analysis showed that the checklist score, independent of age and gender, predicted competence. CONCLUSIONS The procedure-specific assessment tool for fetoscopic Laser Surgery shows good interobserver reliability and discriminates experts from novices. This instrument may therefore be a useful tool in the training curriculum for fetal surgeons. Further intervention studies with reassessment before and after training may increase the construct validity of the tool. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
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learning curve for fetoscopic Laser Surgery using cumulative sum analysis
Acta Obstetricia et Gynecologica Scandinavica, 2014Co-Authors: S. H. P. Peeters, Frans J.c.m. Klumper, Erik W Van Zwet, Enrico Lopriore, Dick Oepkes, Johanna M. MiddeldorpAbstract:Objective. To identify a learning curve and monitor operator performance for fetoscopic Laser Surgery for twin-to-twin transfusion syndrome using cumulative sum analysis. Design. Retrospective cohort study. Setting. National tertiary referral center for invasive fetal therapy. Population. A total of 340 consecutive monochorionic pregnancies with twin-to-twin transfusion syndrome treated with fetoscopic Laser coagulation between August 2000 and December 2010. Methods. A learning curve was generated using learning curve cumulative sum analysis and cumulative sum methodology to assess changes in double survival across the case sequence. Laser Surgery was initially performed by two operators, joined by a third and fourth operator after 1 and 2 years, respectively. Main outcome measures. Individual operator performance, double perinatal survival at 4 weeks. Results. Overall survival of both twins occurred in 59% (201/340), median gestational age at birth was 32.0 weeks. Cumulative sum graphs showed that level of competence for double survival for the operators was reached after 26, 25, 26, and 35 procedures, respectively. Two operators kept their competence level and continued to improve after completing the initial learning process; two others went out of control at one point in time, according to the cumulative sum boundaries. A difference in learning effect was associated with number of procedures performed annually and previous experience with other ultrasound-guided invasive procedures. Conclusions. This study shows that all operators reached a level of competence after at least 25 fetoscopic Laser procedures and confirms the value of using the cumulative sum method both for learning curve assessment and for ongoing quality control.
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risk factors for neurodevelopment impairment in twin twin transfusion syndrome treated with fetoscopic Laser Surgery
Obstetrics & Gynecology, 2009Co-Authors: Enrico Lopriore, Dick Oepkes, Johanna M. Middeldorp, Els Ortibus, Ruthy Acostarojas, Saskia Le Cessie, Eduard Gratacos, Frank P H A Vandenbussche, Jan Deprest, Frans J WaltherAbstract:OBJECTIVE:To estimate the risk factors for adverse long-term neurodevelopment outcome in twin–twin transfusion syndrome treated with Laser Surgery.METHODS:Twin–twin transfusion syndrome cases treated with Laser Surgery at three European centers from August 2000 to December 2005 were included in this