scholarly journals Correlation of Binocular Refractive Errors and Calculation of Intraocular Lens Power for the Second Eye

2020 ◽  
Author(s):  
Pengcheng Zhang ◽  
Yuhuan Yang ◽  
Hong Yan ◽  
Jie Zhang ◽  
Weijia Yan
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Control Group ◽  
Refractive Errors ◽  
Age Related ◽  
Department Of Ophthalmology ◽  
Group A ◽  
Iol Power ◽  
Lens Power

Abstract Background How to reduce the refractive error has always been a tricky problem. The aim of this study was to verify the correlation between binocular refractive errors (RE) after sequential cataract surgery and explore the individualized calculation method of intraocular lens (IOL) for the second eye. Methods This is a prospective study. One hundred eighty-eight affected eyes of 94 age-related cataract patients with sequential cataract surgery from the Department of Ophthalmology, Tangdu Hospital, china, were recruited. Complete case data of 94 patients were included for correlation analysis of binocular RE. Thereafter, data of patients with RE values greater than 0.50 diopter (D) in the first eyes were extracted and divided randomly into two groups- Group A and B. As the adjustment group, in group A we modified the IOL power for the second eyes according to 50% of the RE of the first eye, and group B was the control group without modify. The mean absolute refractive error (MARE) values of the second eyes were evaluated one month after surgery. Results The correlation coefficient of binocular RE after sequential cataract surgery was 0.760 ( P < 0.001). After the IOL power of the second eyes were adjusted, the MARE of the second eyes was 0.57±0.41 D while MARE of the first eyes was 1.18±0.85 D, and the difference was statistically significant ( P <0.001). Conclusions Binocular REs were correlated positively after sequential cataract surgery. The RE of the second eye can be reduced by adjusting the IOL power based on 50% of the postoperative RE of the first eye.

scholarly journals Correlation of Binocular Refractive Errors and Calculation of Intraocular Lens Power for the Second Eye

2020 ◽  
Author(s):  
Pengcheng Zhang ◽  
Yuhuan Yang ◽  
Hong Yan ◽  
Jie Zhang ◽  
Weijia Yan
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Control Group ◽  
Refractive Errors ◽  
Age Related ◽  
Department Of Ophthalmology ◽  
Group A ◽  
Iol Power ◽  
Lens Power

Abstract Background: How to reduce the refractive error has always been a tricky problem. The aim of this study was to verify the correlation between binocular refractive errors (RE) after sequential cataract surgery and explore the individualized calculation method of intraocular lens (IOL) for the second eye.Methods: This is a prospective study. One hundred eighty-eight affected eyes of 94 age-related cataract patients with sequential cataract surgery from the Department of Ophthalmology, Tangdu Hospital, china, were recruited. Complete case data of 94 patients were included for correlation analysis of binocular RE. Thereafter, data of patients with RE values greater than 0.50 diopter (D) in the first eyes were extracted and divided randomly into two groups- Group A and B. As the adjustment group, in group A we modified the IOL power for the second eyes according to 50% of the RE of the first eye, and group B was the control group without modify. The mean absolute refractive error (MARE) values of the second eyes were evaluated one month after surgery.Results: The correlation coefficient of binocular RE after sequential cataract surgery was 0.760 (P < 0.001). After the IOL power of the second eyes were adjusted, the MARE of the second eyes was 0.57±0.41 D while MARE of the first eyes was 1.18±0.85 D, and the difference was statistically significant (P<0.001).Conclusions: Binocular REs were correlated positively after sequential cataract surgery. The RE of the second eye can be reduced by adjusting the IOL power based on 50% of the postoperative RE of the first eye.

scholarly journals Post Cataract Surgery Refractive Error in Myopic Patients Using SRK/T Versus Holladay 1 Formula for IOL Power Calculation

2019 ◽  
Vol 34 (2) ◽  
Author(s):  
Sidra Anwar, Atif Mansoor Ahmad, Irum Abbas, Zyeima Arif
Keyword(s):  
Intraocular Lens ◽  
Refractive Error ◽  
Axial Length ◽  
Power Calculation ◽  
Mean Error ◽  
Iol Power Calculation ◽  
Group A ◽  
Iol Power ◽  
The Mean ◽  
Group B

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.

scholarly journals Improving Intraocular Lens Calculation in Fuchs Endothelial Dystrophy According To Preoperative Degree of Corneal Edema

2021 ◽  
Author(s):  
Beatriz Gargallo-Martinez ◽  
Amanda Ortiz-Gomariz ◽  
Ana Maria Gomez-Ramirez ◽  
Angel Ramon Gutiérrez-Ortega ◽  
Jose Javier Garcia-Medina
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Target Selection ◽  
Corneal Transplantation ◽  
Corneal Edema ◽  
Power Calculation ◽  
Iol Power Calculation ◽  
Iol Power ◽  
Fuchs Endothelial Dystrophy

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.

scholarly journals A comparison of axial length measurement by using applanation A- Scan and IOL master for accuracy of predicting postoperative refraction

2021 ◽  
Vol 7 (3) ◽  
pp. 477-481
Author(s):  
Harish R Trivedi ◽  
Bhavik C Zala ◽  
Nitesh S Pancholi
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
Length Measurement ◽  
Power Calculation ◽  
Spherical Equivalent ◽  
Significant Difference ◽  
Group A ◽  
Iol Power ◽  
Group B

The higher cost of IOL master is an issue in developing countries and hence it cannot be widely used for calculation of IOL power in such countries. Thus, the aim of the current study is to evaluate a cheaper alternative for the calculation of IOL power by comparing the axial length measurement obtained using applanation A-scan with that of IOL Master for accuracy of predicting postoperative refraction.A prospective, randomized, comparative study was done with 100 patients who were posted for cataract surgery. The patients were randomly divided into two groups of 50 patients each using computerized random number method. In Group A (n=50) axial length was measured with applanation A-scan and in Group B (n=50) axial length was measured with IOL Master. Before cataract surgery keratometry reading was taken with auto keratometer and intraocular lens (IOL) power calculation was done using SRK 2 formula in all patients. All patients were operated for cataract surgery by phacoemulsification and foldable intraocular lens were implanted in the bag. Postoperatively, best accepted refraction at 8th week was taken and mean spherical equivalent was calculated. 100 patients of cataract were subjected for cataract surgery by phacoemulsification.Corrected spherical equivalent on 8th postoperative week showed: 88% patients in Group A and 96% patients of Group B were within ± 1.00 D.56% patients of Group A and 76% patients of Group B were within ± 0.50 D.There was no statistically significant difference (p &#62; 0.05) in axial length and corrected spherical equivalent between the two groups. There is no extra advantage of IOL Master over applanation A-scan for measuring Axial Length between 21 and 24.50 and predicting post-operative refractive outcome.

scholarly journals Intraocular lens power calculations in eyes with pseudoexfoliation syndrome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandra Wlaź ◽  
Agnieszka Kustra ◽  
Agnieszka Rozegnał-Madej ◽  
Tomasz Żarnowski
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Prediction Error ◽  
Absolute Error ◽  
Pseudoexfoliation Syndrome ◽  
Control Group ◽  
Refractive Outcomes ◽  
Iol Calculation ◽  
Lens Power ◽  
And Control

AbstractTo compare refractive outcomes after cataract surgery in pseudoexfoliation syndrome (PEX) and control eyes and to investigate the accuracy of 3 intraocular lens (IOL) calculation formulas in these eyes. In this prospective comparative study 42 eyes (PEX group) and 38 eyes (control group) of 80 patients were included. The follow-up was 3 months. The refractive prediction error (RPE), mean absolute error (MAE), median absolute error (MedAE) and the percentages of eyes within ± 0.25 D, ± 0.5 D, ± 1.0 D and ± 2.0 D of prediction error were calculated. Three IOL calculation formulas (SRK/T, Barrett Universal II and Hill-RBF) were evaluated. PEX produced statistically significantly higher mean absolute errors and lower percentages of eyes within ± 0.5 D than control eyes in all investigated IOL calculation formulas. There were no statistically significant differences in the median absolute errors between the 3 formulas in either PEX or control eyes. Refractive outcomes after cataract surgery are statistically significantly worse in PEX than in control eyes. All three IOL calculation formulas produced similar results in both PEX and control eyes.Trial registration: ClinicalTrials.gov registration number NCT04783909.

scholarly journals Comparison of accuracy of Partial Coherence Interferometry based Zeiss IOL Master 500 and Immersion Ultrasound [Ocuscan RXP] for intraocular lens power calculation

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Vijaya Pai ◽  
Divya Shastri ◽  
Asha Kamath
Keyword(s):  
Intraocular Lens ◽  
Refractive Error ◽  
Partial Coherence ◽  
Power Calculation ◽  
Partial Coherence Interferometry ◽  
Iol Power Calculation ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Group B ◽  
Lens Power

Aim: To compare accuracy of intraocular lens power (IOL) calculation using Partial coherence Interferometry based Carl Zeiss IOL master 500 and Immersion ultrasound (Alcon Ocuscan RXP). Methods: A prospective randomized study of patients who underwent clear corneal phacoemulsification with foldable (IOL) by a single surgeon, during the period September 2010 to 2012. Group A included those patients in whom IOL power calculation using Immersion ultrasound (Ocuscan RXP) was used. Group B included those patients in whom IOL power calculation using Partial coherence Interferometry based Zeiss IOL master was used. SRK T formula was used to calculate the IOL power in both the groups. Postoperative final refraction was done at 6 weeks. Unaided visual acuity and best corrected visual acuity was assessed. Postoperative refractive error was compared with predicted refractive error with each biometry method. Statistical analysis was done using SPSS 16.5. Continuous variables expressed as mean (standard deviation). P < 0.05 was considered significant.Results: There were 50 patients in Group A, 44 patients in Group B. Axial length of the patients varied from 22-26mm in both the groups. The postoperative refraction using Ocuscan, 88% had refractive error ≤± 0.5 D, 94% had ≤±1.00D, and 100% had ≤±2.0D of emmetropia. Using Zeiss IOL Master 72.7% had ≤± 0.5 D, 100% had ≤±1.00D of refractive error. Difference in absolute postoperative refractive error using Ocuscan vs. IOL Master was not statistically significant. Conclusion: In our study both ultrasound Ocuscan and IOL master were accurate in calculating intraocular lens power and achieving postoperative refraction closer to emmetropia. 

scholarly journals Evaluating newer generation intraocular lens calculation formulas in manual versus femtosecond laser-assisted cataract surgery

2021 ◽  
Vol 14 (8) ◽  
pp. 1174-1178
Author(s):  
Harrish Nithianandan ◽  
◽  
Eric S. Tam ◽  
Hannah Chiu ◽  
Rajiv Maini ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Radial Basis Function ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Basis Function ◽  
Case Series ◽  
Absolute Error ◽  
Iol Power ◽  
Intraocular Lens Calculation

AIM: To determine the refractive accuracy of the Haigis, Barrett Universal II (Barrett), and Hill-radial basis function 2.0 (Hill-RBF) intraocular lens (IOL) power calculations formulas in eyes undergoing manual cataract surgery (MCS) and refractive femtosecond laser-assisted cataract surgery (ReLACS). METHODS: This was a REB-approved, retrospective interventional comparative case series of 158 eyes of 158 patients who had preoperative biometry completed using the IOL Master 700 and underwent implantation of a Tecnis IOL following uncomplicated cataract surgery using either MCS or ReLACS. Target spherical equivalence (SE) was predicted using the Haigis, Barrett, and Hill-RBF formulas. An older generation formula (Hoffer Q) was included in the analysis. Mean refractive error (ME) was calculated one month postoperatively. The lens factors of all formulas were retrospectively optimized to set the ME to 0 for each formula across all eyes. The median absolute errors (MedAE) and the proportion of eyes achieving an absolute error (AE) within 0.5 diopters (D) were compared between the two formulas among MCS and ReLACS eyes, respectively. RESULTS: Of the 158 eyes studied, 64 eyes underwent MCS and 94 eyes underwent ReLACS. Among MCS eyes, the MedAE did not differ between the formulas (P=0.59), however among ReLACS eyes, Barrett and Hill-RBF were more accurate (P=0.001). Barrett and Hill-RBF were both more likely to yield AE<0.5 D among both groups (P<0.001). CONCLUSION: The Barrett and Hill-RBF formula lead to greater refractive accuracy and likelihood of refractive success when compare to Haigis in eyes undergoing ReLACS.

scholarly journals Effects of Residual Anterior Lens Epithelial Cell Removal on Axial Position of Intraocular Lens after Cataract Surgery

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Seung Pil Bang ◽  
Young-Sik Yoo ◽  
Jong Hwa Jun ◽  
Choun-Ki Joo
Keyword(s):  
Epithelial Cell ◽  
Cataract Surgery ◽  
Intraocular Lens ◽  
Anterior Chamber Depth ◽  
Lens Epithelial Cell ◽  
Axial Position ◽  
Control Group ◽  
Anterior Capsule ◽  
Age Related ◽  
The Mean

Purpose. The aim of this study was to assess the effects of residual anterior lens epithelial cell (LEC) removal by anterior capsule polishing on the effective lens position (ELP) and axial position stability of the intraocular lens (IOL) after cataract surgery via postoperative measurement of the anterior chamber depth. Methods. We enrolled 30 patients (60 eyes) requiring bilateral cataract surgery for age-related cataracts. Meticulous anterior capsule polishing and removal of residual LECs under the capsule were performed using a bimanual irrigation/aspiration system for one randomly selected eye in each patient. The eye without polishing served as a control. ELP was measured at five different time points after surgery, and axial shifting of IOL was determined at each visit by comparison with the position at the previous visit. Results. The polishing and control groups showed significant differences with regard to the mean ELP at 1 (3.40 ± 0.29 versus 3.53 ± 0.32 mm, resp.; p=0.026) and 2 months (3.42 ± 0.32 versus 3.61 ± 0.35 mm, resp.; p=0.001) after surgery, the mean standard deviation for the five ELP values (0.087 ± 0.093 versus 0.159 ± 0.138 mm, p=0.001), and the root mean square of the change in ELP at each follow-up visit (0.124 ± 0.034 versus 0.246 ± 0.038 mm, p=0.047). The eyes in the control group exhibited a tendency for backward IOL movement with a concurrent hyperopic shift in refraction of approximately 0.2 diopter at 2 months after surgery. Conclusion. Our findings suggest that residual anterior LEC polishing enhances the axial position stability of IOLs, without any complications, after cataract surgery.

scholarly journals OPTIMAL SINGLE INTRAOCULAR LENS POWER (IOL) CALCULATION FOR ADULT POPULATION

1969 ◽  
Vol 4 (2) ◽  
pp. 497-502
Author(s):  
ASIF IQBAL ◽  
FAKHAR UL ISLAM ◽  
BILAL BASHIR ◽  
MOHAMMAD IDRIS ◽  
OMER KHAN ORAKZAI
Keyword(s):  
Visual Acuity ◽  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
Adult Population ◽  
Small Incision Cataract Surgery ◽  
Minimum Power ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Lens Power

OBJECTIVES: To determine the single optimal intraocular lens power based on average biometricassessment for adult cataract surgery in free eye camps.MATERIALS AND METHODS: Prospective observational study of 4 years duration from 1stFebruary 2010 to 31st January 2014.SETTING: Community based Trust eye hospital in Tarakai village of District Swabi.METHODS: All adult patients, undergoing cataract surgery with intraocular lens (IOL) implantationwere included in the study after informed consent and fulfilling the inclusion and exclusion criteria. Allpatients were operated by manual small incision cataract surgery by the same surgeon (AI). Preoperative and Post- operative best spectacle corrected visual acuity (BSCVA) at two months follow upwas noted. Keratometric readings (K1 & K2), axial length and IOL power were calculated and dataanalyzed by using SPSS version 20 software database.RESULTS: Out of 1500 patients with cataract 668 (44.5%) were males and 832 (55.5%) were females.Right eye was involved in 826 (55.1%) patients whereas; left eye was involved in 674 (44.9%) patients.Mean K1 reading was 44.82± 1.80 D. Mean K2 reading was 44.94± 1.80 D. Mean axial length readingwas 23.11± 1.28 mm. 36.6 ifc(n=403) patients had axial length between 23-23.99 mm. Mean IOL powerin dioptres for males was 20.06± 2.53 D with minimum power of 2.00 D, maximum was 27 D and modewas 20.00 D. Mean IOL power in dioptres for females was 20.12 ± 3.43 D with minimum power of -2.00 D, maximum was 36.50 D and mode was 20.00 D. Mean IOL power was 20.10 ± 3.06 D. In 798patients (53.2 %) IOL used was in the range of 20.00 D to 22.00 D. Pre-operative best spectaclecorrected visual acuity was <6/60 in 58.4% (n=877) patients. Post operative best corrected visual acuity6/18 or better was present in 90.5% (n= 1357) patients at two months follow up.CONCLUSION: In community eye care centers located in far-flung areas with no facilities for properbiometric assessment of cataract patients, using an IOL power in the range of 20.00 D to 22.00 D wouldgive optimal visual results.KEY WORDS: Biometry, Keratometric readings, Axial Length, Intraocular lens.

Effect of capsular tension ring on refractive results in cases with pseudoexfoliation syndrome

2020 ◽  
pp. 112067212096546
Author(s):  
Nilay Kandemir Besek ◽  
Gulsah Gumus ◽  
Gamze Ozturk Karabulut ◽  
Senay Asik Nacaroglu ◽  
Ahmet Kirgiz ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Capsular Tension Ring ◽  
Significant Difference ◽  
Hyperopic Shift ◽  
The Mean ◽  
Group 2 ◽  
Lens Power ◽  
Group 1

Purpose: To investigate the effect of capsular tension rings (CTRs) on postoperative refractive results in patients with pseudoexfoliation (PSX) syndrome. Materials and Methods: Sixty-nine patients with PSX syndrome who had uncomplicated cataract surgery between March 2016 and February 2019 were reviewed retrospectively. The patients were divided into two groups. The 35 patients in Group 1 received CTRs prior to intraocular lens implantation during cataract surgery, and the 34 patients in Group 2 had cataract surgery without CTRs. Significant zonular weakness, uncontrolled glaucoma, and ocular pathologies causing low visual acuity were excluded. The preoperative and postoperative keratometry and autorefraction measurements, preoperative expected refractive values, and absolute refractive error were recorded. Results: The mean ages of patients were 73.54 ± 9.78 years in Group 1 and 72.23 ± 6.72 years in Group 2 ( p = 0.521). There was no statistically significant difference between Group 1 and Group 2 in terms of expected preoperative refraction values (–0.52 ± 0.12,–0.56 ± 0.08, respectively, p = 0.118). There was a statistically significant difference in postoperative spherical equivalent values between Group 1 and Group 2 (–0.05 ± 0.97 and −0.92 ± 0.57, respectively, p < 0.01). A statistically significant difference was found between the two groups in terms of absolute refractive error (0.46 ± 0.74 in Group 1 and −0.34 ± 0.59 in Group 2 p < 0.01). Conclusion: CTR implantation causes hyperopic shift, which should be taken into consideration when calculating the lens power of intraocular lens in patients with PSX syndrome.

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