Intraoperative Biometry for Intraocular Lens (IOL) Power Calculation at Silicone Oil Removal

2003 ◽  
Vol 13 (7) ◽  
pp. 622-626 ◽  
Author(s):  
S.M. El-Baha ◽  
A. Ei-Samadoni ◽  
H.F. Idris ◽  
K.M. Rashad
2019 ◽  
Vol 34 (2) ◽  
Author(s):  
Sidra Anwar, Atif Mansoor Ahmad, Irum Abbas, Zyeima Arif

Purpose: To compare post-operative mean refractive error with SandersRetzlaff-Kraff/theoretical (SRK-T) and Holladay 1 formulae for intraocular lens (IOL) power calculation in cataract patients with longer axial lengths. Study Design: Randomized controlled trial. Place and Duration of Study: Department of Ophthalmology, Shaikh Zayed Hospital Lahore from 01 January 2017 01 January, 2018. Material and Methods: A total of 80 patients were selected from Ophthalmology Outdoor of Shaikh Zayed Hospital Lahore. The patients were randomly divided into two groups of 40 each by lottery method. IOL power calculation was done in group A using SRK-T formula and in group B using Holladay1 formula after keratomery and A-scan. All patients underwent phacoemulsification with foldable lens implantation. Post-operative refractive error was measured after one month and mean error was calculated and compared between the two groups. Results: Eighty cases were included in the study with a mean age of 55.8 ± 6.2 years. The mean axial length was 25.63 ± 0.78mm, and the mean keratometric power was 43.68 ± 1.1 D. The mean post-operative refractive error in group A (SRK/T) was +0.36D ± 0.33D and in group B (Holladay 1) it was +0.68 ± 0.43. The Mean Error in group A was +0.37D ± 0.31D as compared to +0.69D ± 0.44D in group B. Conclusion: SRK/T formula is superior to Holladay 1 formula for cases having longer axial lengths. Key words: Phacoemulsification, intraocular lens power, longer axial length, biometry.


2020 ◽  
pp. 112067212096203
Author(s):  
David Carmona-González ◽  
Alfredo Castillo-Gómez ◽  
Carlos Palomino-Bautista ◽  
Marta Romero-Domínguez ◽  
María Ángeles Gutiérrez-Moreno

Purpose To compare the accuracy of 11 intraocular lens (IOL) power calculation formulas (SRK-T, Hoffer Q, Holladay I, Haigis, Holladay II, Olsen, Barrett Universal II, Hill-RBF, Ladas Super formula, EVO and Kane). Setting Private university hospital (QuironSalud, Madrid, Spain). Design Retrospective case series Methods Data were compiled from 481 eyes of 481 patients who had undergone uneventful cataract surgery with IOL insertion. Preoperative biometric measurements were made using an IOL Master® 700. Respective ULIB IOL constants ( http://ocusoft.de/ulib/c1.htm ) for each of 4 IOL models implanted were used to calculate the predictive refractive outcome for each formula. This was compared with the actual refractive outcome determined 3 months postoperatively. The primary outcome was mean absolute prediction error (MAE). The study sample was divided according to axial length (AL) into three groups of eyes: short (⩽22.00 mm), normal (22.00–25.00 mm) and long (⩾25.00 mm). Results The Barrett Universal II and Haigis formulas yielded the lowest MAEs over the entire AL range ( p < .01, except EVO) as well as in the long ( p < .01, all formulas) and normal ( p < .01, except Haigis, Holladay II, Olsen and LSF) eyes. In the short eyes, the lower MAEs were provided by Haigis and EVO ( p < .01 except Hoffer Q, SRK/T and Holladay I). Conclusions Barrett Universal II was the most accurate for IOL power calculation in the normal and long eyes. For short eyes, the formulas Haigis and EVO seem best at predicting refractive outcomes.


2018 ◽  
Vol 9 (2) ◽  
pp. 264-268
Author(s):  
Tao Ming Thomas Chia ◽  
Hoon C. Jung

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.


2021 ◽  
Author(s):  
Beatriz Gargallo-Martinez ◽  
Amanda Ortiz-Gomariz ◽  
Ana Maria Gomez-Ramirez ◽  
Angel Ramon Gutiérrez-Ortega ◽  
Jose Javier Garcia-Medina

Abstract Fuchs endothelial dystrophy (FED) is a bilateral, asymmetric, progressive corneal endothelium disorder that causes corneal edema. Resolution of corneal edema is only possible by corneal transplantation. Cataract surgery is a common surgery that replaces the natural lens of the eye by an artificial intraocular lens (IOL). The IOL-power calculation depends mainly on the anterior corneal keratometry and the axial length. In patients with FED, anterior keratometry may be affected by corneal edema and calculations may be less accurate. Therefore, the aim of this study is to establish the theorical postoperative refractive error due to corneal edema resolution after Descemet stripping endothelial keratoplasty combined with cataract surgery and IOL implantation. For this, anterior keratometry was measure preoperatively with edematous cornea and postoperatively after corneal edema resolution. Both keratometries were compared and used to calculate the respective theorical IOL-powers. The difference between target IOLs was used to establish the theorical refractive error due to corneal edema resolution. The results showed that corneal edema resolution induces a change in anterior keratometry, which affects IOL-power calculations and causes a hyperopic shift. The patients with moderate-to-severe preoperative corneal edema had higher theorical refractive error so their target selection should be adjusted for additional − 0.50D.


2020 ◽  
Vol 17 (2) ◽  
pp. 233-242
Author(s):  
Juanita Noeline Chui ◽  
Keith Ong

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.


2019 ◽  
Author(s):  
Han Zhao ◽  
Wanpeng Wang ◽  
Zhengping Hu ◽  
Baihua Chen

Abstract Background To investigate the long-term outcomes and complications of scleral-fixated intraocular lens (SFIOL) implantation without conjunctival peritomies and sclerotomy in patients with a history of ocular trauma with inadequate capsular support during primary pars plana vitrectomy or silicone oil removal. Methods Records of ocular trauma patients who underwent implantation of SFIOL without conjunctival peritomies and sclerotomy during primary pars plana vitrectomy or silicone oil removal. Results Sixty-nine eyes of 69 patients were included in this study. The median follow-up period was 34 months (range, 6-99 months). The average patient age at the time of surgery was 44 years old (range, 4-80 years). At the end of follow-up, the preoperative mean of best corrected visual acuity (BCVA) was 0.79 ± 0.86 log of the minimum angle of resolution (logMAR), which improved 0.20 ± 0.26 logMAR postoperatively (P = 0.01). BCVA improved or remained unchanged in 64 eyes (92.8%), VA decreased two lines in five eyes (7.2%). Early postoperative complications included transient corneal edema in seven eyes (10.1%), minor vitreous hemorrhage in four eyes (5.8%), transient elevated intraocular pressure (IOP) in one eye (1.4%), and hypotony in three eyes (4.3%). Late postoperative complications included persistent elevated IOP in five eyes (7.2%), epiretinal membrane formation in three eyes (4.3%), and cystoid macular edema noted in one eye (1.4%). Conclusion Use of a scleral-fixated intraocular lens implantation without conjunctival peritomies and sclerotomy in ocular trauma patients during either primary pars plana vitrectomy or second silicone oil removal is a valuable approach for the management of traumatic aphakia in the absence of capsular support.


2020 ◽  
Vol 13 (4) ◽  
pp. 15-20
Author(s):  
Dmitrii Fedorovich Belov ◽  
Vadim Petrovich Nikolaenko

Aim to compare intraocular lens (IOL) power calculation before and after different types glaucoma procedures. Material and methods.Into the study, 115 patients were included, divided into 3 groups: group 1 patients, in whom sinustrabeculectomy was performed (n= 86); group 2 patients with implanted Ex-PRESS shunt (n= 19), group 3 patients after Ahmed glaucoma valve implantation (n= 10). For each patient before surgery optical biometry (IOL-Master 500) was performed and IOL power calculation using Barrett Universal II Formula (target refraction emmetropia). Baseline data were compared with corresponding examinations results obtained in 6 months after glaucoma procedure, to evaluate its effect on main biometric parameters of the eye and the IOL calculation accuracy. Results.Despite significant changes of optical and anatomic indices, mean values of target refraction before and after glaucoma surgery did not differ significantly: 0.00 0.03 versus 0.03 0.52 D (p= 0.628), 0.00 0.1 versus 0.19 0.61 D (p= 0.173), 0.04 0.08 versus 0.11 0.42 D (p= 0.269) for groups, respectively. However, there was a pronounced trend to the increase of target refraction data scattering. Conclusion.Glaucoma procedures cause changes of biometrical parameters of the eye, which leads to decrease in accuracy of IOL calculation. Consequently, when choosing intraocular lens, it is recommended to use measurement results obtained after glaucoma surgery. Keywords:intraocular lens; IOL power calculation; glaucoma; sinustrabeculectomy; Ex-PRESS shunt; Ahmed glaucoma valve; biometry; phacoemulsification; axial length; anterior chamber depth; keratometry.


2020 ◽  
Author(s):  
jing dong ◽  
yaqin zhang ◽  
xiaogang wang

Abstract PURPOSE: To investigate interdevice agreement among toric power calculation difference based on corneal topography/ray-tracing aberrometry (iTrace), partial coherence interferometry (IOLMaster 500), and Scheimpflug imaging (Pentacam) for the measurement of anterior corneal astigmatism. METHODS: The analysis included 101 eyes with regular astigmatism of 101 subjects. The main outcome measures were corneal cylinder power, axis of astigmatism, keratometry values. The toric power and intraocular lens (IOL) power was calculated using online Barrett toric calculator. Interdevice measurement and calculation agreement was assessed using paired sample t-test, and nonparametric test. RESULTS: Significant interdevice difference existed for astigmatism magnitude, flat keratometry, steep keratometry and mean keratometry between iTrace and IOLMaster (all P < 0.01). Significant interdevice difference existed for flat keratometry, steep keratometry and mean keratometry (all P < 0.001) but not astigmatism magnitude (P = 0.325) between iTrace and Pentacam. Significant interdevice difference existed for astigmatism magnitude, steep keratometry and mean keratometry (all P < 0.01) but not flat keratometry (P = 0.310) between IOLMaster and Pentacam. For toric IOL power calculation, iTrace calculation was statistically higher than IOLMaster (0.49±0.36, P <0.001) and Pentacam (0.39±0.42, P <0.001). Moreover, Pentacam IOL power calculation was statistically lower than IOLMaster (-0.10±0.39, P =0.009). Toricity calculation difference was also existed among the three groups (P = 0.004).CONCLUSIONS: The toric IOL power and toricity calculation difference based on iTrace, IOLMaster 500, and Pentacam anterior keratometry data should be noticed in clinic practice.


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