Predictability of formulae for intraocular lens power calculation according to the age of implantation in paediatric cataract

2018 ◽  
Vol 103 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Byung Joo Lee ◽  
Sang-Mok Lee ◽  
Jeong Hun Kim ◽  
Young Suk Yu
Keyword(s):  
Linear Regression ◽  
Intraocular Lens ◽  
Congenital Cataract ◽  
Linear Regression Analysis ◽  
Final Analysis ◽  
Absolute Error ◽  
Posterior Chamber ◽  
Power Calculation ◽  
Age Group ◽  
Iol Implantation

AimsTo analyse the predictability of diverse intraocular lens (IOL) power calculation formulae in paediatric patients with congenital cataract.MethodsThe medical records of patients who underwent cataract surgery and posterior chamber IOL implantation (in-the-bag) for congenital cataract before 17 years of age were reviewed retrospectively. Target refractions calculated by Sanders-Retzlaff-Kraff (SRK)/II, SRK/T and Hoffer-Q formulae were compared with the actual refraction. Patients were subgroup according to the age at IOL implantation (age group 0–24 months, 25–60 months, 61–120 months, 121–203 months), and we compared mean prediction error (PE) and mean absolute error (AE) for each formula. Corrected AE was obtained by linear regression analysis.ResultsTotally 481 eyes were included in the final analysis. Both SRK/II and SRK/T yielded the lowest mean AE in the age group 0–24 months and SRK/II yielded the lowest mean AE in the age group 25–60 months. For every formula, the mean PE was positive during the first five years of age, which converged to zero according to age as IOL implantation increases. The tendency for immediate postoperative overcorrection in younger patients (<6 years) could be improved by corrected formulae based on the linear regression equation.ConclusionsPatients with congenital cataract who underwent IOL implantation within 5 years of age showed higher AE than the older ones did. Among the three formulae evaluated, SRK/II consistently provided the best predictive result in these patients. For patients aged >10 years, all three formulae showed favourable predictive abilities.

scholarly journals Prediction accuracy of conventional and total keratometry for intraocular lens power calculation in femtosecond laser-assisted cataract surgery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soyoung Ryu ◽  
Ikhyun Jun ◽  
Tae-im Kim ◽  
Kyoung Yul Seo ◽  
Eung Kweon Kim
Keyword(s):  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Intraocular Lens ◽  
Intraclass Correlation ◽  
Absolute Error ◽  
Power Calculation ◽  
Prediction Errors ◽  
Intraocular Lens Power Calculation ◽  
Iol Power Calculation ◽  
Severance Hospital

AbstractThis study evaluated the accuracy of total keratometry (TK) and standard keratometry (K) for intraocular lens (IOL) power calculation in eyes treated with femtosecond laser-assisted cataract surgery. The retrospective study included a retrospective analysis of data from 62 patients (91 eyes) who underwent uneventful femtosecond laser-assisted cataract surgery with Artis PL E (Cristalens Industrie, Lannion, France) IOL implantation by a single surgeon between May 2020 and December 2020 in Severance Hospital, Seoul, South Korea. The new IOLMaster 700 biometry device (Carl Zeiss Meditec, Jena, Germany) was used to calculate TK and K. The mean absolute error (MAE), median absolute error (MedAE), and the percentages of eyes within prediction errors of ± 0.25 D, ± 0.50 D, and ± 1.00 D were calculated for all IOL formulas (SRK/T, Hoffer-Q, Haigis, Holladay 1, Holladay 2, and Barrett Universal II). There was strong agreement between K and TK (intraclass correlation coefficient = 0.99), with a mean difference of 0.04 D. For all formulas, MAE tended to be lower for TK than for K, and relatively lower MAE and MedAE values were observed for SRK/T and Holladay 1. Furthermore, for all formulas, a greater proportion of eyes fell within ± 0.25 D of the predicted postoperative spherical equivalent range in the TK group than in the K group. However, differences in MAEs, MedAEs, and percentages of eyes within the above prediction errors were not statistically significant. In conclusion, TK and K exhibit comparable performance for refractive prediction in eyes undergoing femtosecond laser-assisted cataract surgery.

scholarly journals Accuracy of theoretical IOL formulas for Panoptix intraocular lens according to axial length

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ayoung Choi ◽  
Hyunggoo Kwon ◽  
Sohee Jeon
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Mean Absolute Error ◽  
Visual Quality ◽  
Absolute Error ◽  
Fort Worth ◽  
Iol Implantation ◽  
Multifocal Iol ◽  
Study Results ◽  
Study Population

AbstractThe accuracy of intraocular lens (IOL) calculations is suboptimal for long or short eyes, which results in a low visual quality after multifocal IOL implantation. The purpose of the present study is to evaluate the accuracy of IOL formulas (Barrett Universal II, SRK/T, Holladay 1, Hoffer Q, and Haigis) for the Acrysof IQ Panoptix TFNT IOL (Alcon Laboratories, Inc, Fort Worth, Texas, United States) implantation based on the axial length (AXL) from a large cohort of 2018 cases and identify the factors that are associated with a high mean absolute error (MAE). The Barrett Universal II showed the lowest MAE in the normal AXL group (0.30 ± 0.23), whereas the Holladay 1 and Hoffer Q showed the lowest MAE in the short AXL group (0.32 ± 0.22 D and 0.32 ± 0.21 D, respectively). The Haigis showed the lowest MAE in the long AXL group (0.24 ± 0.19 D). The Barrett Universal II did not perform well in short AXL eyes with higher astigmatism (P = 0.013), wider white-to-white (WTW; P < 0.001), and shorter AXL (P = 0.016). Study results suggest that the Barrett Universal II performed best for the TFNT IOL in the overall study population, except for the eyes with short AXL, particularly when the eyes had higher astigmatism, wider WTW, and shorter AXL.

Linear Regression Software for Intraocular Lens Implant Power Calculation

1986 ◽  
Vol 101 (5) ◽  
pp. 597-599 ◽  
Author(s):  
Edmond H. Thall ◽  
William J. Reinhart ◽  
Deborah Sabol
Keyword(s):  
Linear Regression ◽  
Intraocular Lens ◽  
Power Calculation

scholarly journals Contralateral Posterior Chamber Phakic Intraocular Lens Implantation as Rehabilitation of Refractive Lens Exchange with a Monofocal Intraocular Lens in a Young, Nonpresbyopic, Bilateral Highly-Myopic Patient

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Kepa Balparda ◽  
Claudia Marcela Vanegas-Ramírez ◽  
Laura Segura-Muñoz ◽  
Manuela Gómez-Londoño
Keyword(s):  
Intraocular Lens ◽  
Crystalline Lens ◽  
Posterior Chamber ◽  
Phakic Intraocular Lens ◽  
Short Term ◽  
Corneal Surgery ◽  
Iol Implantation ◽  
Refractive Lens Exchange ◽  
Patient’S Satisfaction ◽  
Refractive Lens

Background. Refractive errors are widespread in the human population; nowadays, numerous surgical options allow for efficient and safe correction them. One of the main elements to ensure success in this kind of intervention will depend on the careful patient and surgical approach selection. Excimer laser corneal surgery is considered by most for low to moderate ametropias. Another option, which has been suggested may be safer, is to cut a small corneal lenticule with femtosecond laser, and then extracting it through a small incision. Nevertheless, in some specific cases, such as patients with high refractive error or those with some corneal abnormality, laser corneal ablations are considered unsafe from either a biomechanical or refractive standpoint. In this kind of particular cases, Phakic Intraocular Lens (P-IOL) implantation constitutes attractive, highly predictable and safe option. Objective. The authors want to show the case of a young high-myopic woman, already pseudophakic in one eye, where the P-IOL implantation in the fellow eye yielded excellent short-term visual results, and high patient’s satisfaction, is presented. Materials. The authors present the case of a 32-years-old, highly myopic female patient underwent a Refractive Lens Exchange (RLE) with a monofocal Intraocular Lens (IOL) implantation in her left eye elsewhere, and developed severe visual issues, especially regarding near-work. Symptoms resolved through the implantation of a posterior chamber P-IOL in the contralateral eye. Results. The postoperative course was unremarkable, inflammation was mild, and visual recovery was quick. There was no need to perform any procedure on her left eye or to use any reading glasses, as unilateral effective near vision through her right eye was enough for all her daily tasks. Conclusions. RLE in young pre-presbyopic highly myopic patients may not be an advisable alternative in most cases, because of the high risks of retinal complications observed. In addition, eliminating accommodation will cause significant limitations, and multifocal IOLs currently available are far from the quality of vision that a young human crystalline lens yields. On the other hand, implantation of a P-IOL is a good option if eye conditions are optimal, as it preserves natural accommodation. In this case an EyeCryl Phakic Toric® IOL showed excellent short-term refractive predictability and safety.

scholarly journals Cataract Surgery following Sequential Myopic and Hyperopic LASIK

2018 ◽  
Vol 9 (2) ◽  
pp. 264-268
Author(s):  
Tao Ming Thomas Chia ◽  
Hoon C. Jung
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Calculation Method ◽  
Cataract Extraction ◽  
Power Calculation ◽  
Iol Implantation ◽  
Patient Dissatisfaction ◽  
Iol Power Calculation ◽  
Iol Power

We report a case of patient dissatisfaction after sequential myopic and hyperopic LASIK in the same eye. We discuss the course of management for this patient involving eventual cataract extraction and intraocular lens (IOL) implantation with attention to the IOL power calculation method used.

scholarly journals A-scan biometry, phacoemulsification, and foldable intraocular lens implantation in a young orangutan (Pongo pygmaeus)

2021 ◽  
Vol 11 (1) ◽  
pp. 121-127
Author(s):  
Natthanet Sritrakoon ◽  
Winyu Karntip ◽  
Sirirat Niyom ◽  
Susadee Khemton ◽  
Panuwat Pakpiboon ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Standard Technique ◽  
Pongo Pygmaeus ◽  
Power Calculation ◽  
Iol Implantation ◽  
Ocular Biometry ◽  
Normal Behavior ◽  
Almost All

Background: Cataracts are the major cause of visual impairment in animals which can be curable by surgical treatment. Phacoemulsification is the standard technique for cataract treatment that is applied to almost all species with a high success rate. Case Description: A 2-year-old intact female orangutan (Pongo pygmaeus) was presented for the study having bilateral opacity of the lenses, for 2 weeks. Ophthalmic examination revealed mature cataract OU. Ocular biometry measurements using A-scan ultrasonography for appropriate intraocular lens (IOL) refractive power calculation were carried out. Electroretinography was applied to ensure retinal function is intact. The orangutan underwent phacoemulsification OU and +24 diopter IOL implantation OS to restore vision. IOL implantation was not carried out OD because of a posterior capsular tear. Retinoscopy after 3 weeks postoperatively revealed +2.0 diopters OS. The outcome of the cataract surgery was successful during 3 years follow-up. The orangutan lived with other orangutans and was alert with normal behavior such as catching food, climbing trees, and swinging hand over hand from one branch to another. Conclusion: Cataract surgery with phacoemulsification OU and adjusted IOL implantation OD was successful with few complications in this orangutan. Vision was restored with normal behavior, even though an adjusted IOL was inserted in only one eye.

scholarly journals Improving the prediction of effective lens position for intraocular lens power calculations

2020 ◽  
Vol 17 (2) ◽  
pp. 233-242
Author(s):  
Juanita Noeline Chui ◽  
Keith Ong
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Sagittal Plane ◽  
Anterior Chamber Depth ◽  
Posterior Chamber ◽  
Power Calculation ◽  
Iol Power Calculation ◽  
Lens Position ◽  
Iol Power ◽  
Corneal Apex

Purpose: Achieving the desired post-operative refraction in cataract surgery requires accurate calculations for intraocular lens (IOL) power. Latest-generation formulae use anterior-chamber depth (ACD)—the distance from the corneal apex to the anterior surface of the lens—as one of the parameters to predict the post-operative IOL position within the eye, termed the effective lens position (ELP). Significant discrepancies between predicted and actual ELP result in refractive surprise. This study aims to improve the predictability of ELP. We hypothesise that predictions based on the distance from the corneal apex to the mid-sagittal plane of the cataractous lens would more accurately reflect the position of the principal plane of the non-angulated IOL within the capsular bag. Accordingly, we propose that predictions derived from ACD + ½LT (length thickness) would be superior to those from ACD alone. Design: Retrospective cohort study, comparing ELP predictions derived from ACD to aproposed prediction parameter. Method: This retrospective study includes data from 162 consecutive cataract surgery cases, with posterior-chamber IOL (AlconSN60WF) implantation. Pre- and postoperative biometric measurements were made using the IOLMaster700 (ZEISS, Jena, Germany). The accuracy and reliability of ELP predictions derived from ACD and ACD + ½LT were compared using software-aided analyses. Results: An overall reduction in average ELP prediction error (PEELP) was achieved using the proposed parameter (root-mean-square-error [RMSE] = 0.50 mm), compared to ACD (RMSE = 1.57 mm). The mean percentage PEELP, comparing between eyes of different axial lengths, was 9.88% ± 3.48% and −34.9% ± 4.79% for predictions derived from ACD + ½LT and ACD, respectively. A 44.10% ± 5.22% mean of differences was observed (p < 0.001). Conclusion: ACD + ½LT predicts ELP with greater accuracy and reliability than ACD alone; its use in IOL power calculation formulae may improve refractive outcomes.

scholarly journals Microperipheral Iridectomy for Troublesome Posterior Synechiolysis in Secondary Intraocular Lens Implantation

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Wu Xiang ◽  
Jing Li ◽  
Wan Chen ◽  
Haotian Lin ◽  
Weirong Chen
Keyword(s):  
Intraocular Lens ◽  
Pediatric Patients ◽  
Posterior Chamber ◽  
Intraoperative Bleeding ◽  
Iol Implantation ◽  
Secondary Iol Implantation ◽  
Peripheral Iridectomy ◽  
Surgical Incisions ◽  
Posterior Synechiae ◽  
Secondary Intraocular Lens Implantation

Purpose. To introduce an effective method for separating extensive posterior synechiae and those located under or adjacent to surgical incisions. Methods. Pediatric patients who had been subjected to cataract surgery and developed troublesome posterior synechiae requiring secondary intraocular lens (IOL) implantation were recruited. All patients underwent microperipheral iridectomy at the 12 o’clock position. Then, an ophthalmic viscosurgical device was injected into the posterior chamber through the iris fistula to mechanically separate the posterior synechiae, using scissors to cut robust posterior synechiae if necessary. The results of posterior synechiolysis and the position of the implanted IOL were analyzed. Results. Sixteen patients (median age, 51.56 months; range, 28–80 months) were included. The scope of posterior synechia in clock was 4.42 (range, 1–10). All troublesome posterior synechiae were successfully separated using the microperipheral iridectomy method, and all patients underwent IOL implantation in the ciliary sulcus. There was one case of peripheral iridectomy-related early intraoperative bleeding; no bleeding was observed at the end of surgery. Conclusions. Microperipheral iridectomy is a useful method for the management of troublesome posterior synechiae during secondary IOL implantation in pediatric patients, which makes secondary IOL implantation an easier and safer method in some challenging cases.

scholarly journals Correlation of Handprints and Footprints with respect to Stature: Study on Maharashtrians of Mumbai

2020 ◽  
Vol 10 (1) ◽  
pp. 91-96
Author(s):  
Deepika Bhandari ◽  
Sonali Patil ◽  
Vivek Sahajpal
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Age Group ◽  
Microsoft Excel ◽  
Physical Evidence ◽  
Males And Females ◽  
Forensic Scientists ◽  
Positive Significant Correlation ◽  
Indian Male

Identification of an individual is an important aspect in forensic investigations. Stature estimation is of interest to forensic scientists for its importance in human identification. The present study was an attempt to deduce the stature from footprints as well as the hand prints and hence to determine whether there is any correlation between the stature and the respective prints/ length.  Footprint is valuable physical evidence that can be found at scene of crime and its identification can facilitate elimination of the suspects and establishing the identity of the criminal. Also handprints to some extent can help in estimation of stature. The study aimed to estimate the stature in a sample of 1000 bilateral footprints and handprints collected from 500 adult Indian male Maharashtrians and 500 adult Indian female Maharashtrians from Mumbai who consented to volunteer in the study and ranged in the age-group of 18 to 25 years. Samples were collected and data was entered in Microsoft Excel 2007 and statistically analyzed using linear regression analysis. In case of both males and females all footprint lengths exhibit a statistically positive significant correlation with stature. Similarly, handprint lengths exhibit a statistically positive significant correlation with stature. The values of correlation co-efficient shows that the footprint length is more significantly correlated with stature compare to handprint lengths.

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