Comparison of Five Intraocular Lens Power Formulas to Predict Postoperative Refraction Accuracy

2021 ◽  
Vol 11 (1) ◽  
pp. 129-134
Author(s):  
Tiecheng Wang ◽  
Shaochong Bu ◽  
Fang Tian ◽  
Hong Zhang
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Prediction Accuracy ◽  
Short Axis ◽  
Post Surgery ◽  
Age Related ◽  
Large Patient ◽  
Significant Difference ◽  
Hyperopic Shift ◽  
Intraocular Lens Calculation

The present study sought to investigate and compare the accuracy of two third-generation intraocular lens calculation formulas contrasted against three new-generation intraocular lens calculation formulas regarding their ability to predict postoperative refraction following cataract surgery. A retrospective case study following 172 patients (172 eyes) exhibiting age-related cataracts in their eyes who were subject to phacoemulsification between September 2017 and September 2018 at the Department of Cataracts, Tianjin Medical University Eye Hospital, was carried out. Based upon ocular axial length, the sampled patients were grouped into a short axis group (ocular axial length ≤ 22 mm; 17 cases; 17 eyes), a normal axis group (22 mm < ocular axial length ≥ 24.5 mm; 132 cases; 132 patients), and a long axis group (ocular axial length > 24.5 mm; 23 cases; 23 eyes); mean absolute prediction error (MAE) postoperative refraction in each group was determined using five formulas, and the percentage of eyes displaying postoperative myopic shift symptoms, postoperative hyperopic shift symptoms, alongside the percentage of eyes displaying postoperative refractive shift symptoms in the range of (−0.25 to 0.25 D, −0.50 to 0.50 D, −1.00 to 1.00 D), were all calculated following the procedures of the five selected formulas. The MAE of the 172 patient cases was compared within the five selected formulas, and SRK/T possessed the highest prediction accuracy, exhibiting a significant difference from the other four formulas (P < 0.05), with accuracy levels subsequently followed by the Holladay 1 and Barrett Universal II formulas-however, the two formulas lacked a significant difference between them (P > 0.05). In addition, the MAE of the normal axial group was compared and analyzed within the five formulas, with analysis revealing that the SRK/T, Holladay 1, and Barrett Universal II formulas exhibited strong prediction accuracy, with no significant difference present among these three formulas (P > 0.05), and also revealing a significantly difference between the aforementioned formulas and remaining two formulas (P < 0.05). For further analysis, the MAE of the short axis group was compared, and the SRK/T and Haigis (Holladay 1, and Barrett Universal II) demonstrated stronger prediction accuracy when compared to the Olsen formula (P < 0.05). Finally, the MAE of the long axis group was compared, and it was found that the SRK/T and Barrett Universal II formulas exhibits the best prediction accuracy, followed by the Haigis and Holladay 1 formulas, with no significant difference (P > 0.05) between the former two formulas or the latter two. The majority of patients exhibited hyperopic shift post-surgery. Of the five formulas studied, the SRK/T and Barrett Universal II formulas possessed strong accuracy capable of predicting postoperative refraction. However, more long-term observation, including large patient samples, is necessary in order to corroborate our result.

scholarly journals Effect of anterior chamber depth on the choice of intraocular lens calculation formula in patients with normal axial length

2014 ◽  
Vol 21 (4) ◽  
pp. 307 ◽  
Author(s):  
Hassan Hashemi ◽  
Mehdi Khabazkhoob ◽  
Farhad Rezvan ◽  
Akbar Fotouhi ◽  
Soheila Asgari ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Intraocular Lens ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Calculation Formula ◽  
Intraocular Lens Calculation

scholarly journals Predictive Refractive Error Post Congenital and Developmental Cataract Surgery

2021 ◽  
Vol 17 (2) ◽  
pp. 179
Author(s):  
Eva Imelda ◽  
Feti Karfiati ◽  
Maya Sari Wahyu ◽  
Irawati Irfani ◽  
Primawita Oktarima ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Refractive Error ◽  
Axial Length ◽  
Prediction Error ◽  
Visual Rehabilitation ◽  
Predictive Error ◽  
Age At Surgery ◽  
Significant Difference ◽  
Developmental Cataract

Abstract: Cataract is one of the leading treatable causes of visual impairment in children. Visual rehabilitation is crucial for the development of good visual function after cataract surgery in children. The research aimd to describe post-operative Predictive Refractive Error (PRE) in congenital and developmental cataracts in Cicendo National Eye Hospital from January 2017 to December 2018. This is a retrospective analytic observational study from medical records. We found 107 eyes of 62 children with congenital and developmental cataracts had had cataract surgery and primary implantation of Intraocular Lens (IOL) in Pediatric Ophthalmology and Strabismus Unit, Cicendo National Eye Hospital. The patients were divided into two groups, with axial length (AXL) of ≤ 24 mm and > 24 mm. The paired t-test was used to compare Predictive Error (PE) in SRK/T, SRK II, and Showa SRK formula. Mean age at surgery was 6.7 ± 4.0 years.  Ninety-five eyes had AXL ≤ 24 mm, and 12 eyes had AXL > 24 mm. Prediction Error from patients with AXL ≤ 24 mm was 0.29 D, and from patients with AXL > 24 mm was 2.40 D in SRK/T formula (P < 0.05). There was no significant difference between PE and Absolute Predictive Error (APE) in SRK/T, SRK II, and Showa SRK in patients with AXL > 24 mm (P > 0.05). SRK/T is the most predictable formula in patients with AXL ≤ 24 mm. There is no significant difference in patients with AXL > 24 mm in all formulas. Keywords: congenital and developmental cataract, axial length, Prediction Error, intraocular lens

scholarly journals Progress in Modern Cataract Surgery – New Steps and Algorithms for Precise Measuring and Intraocular-lens Calculations

2017 ◽  
Vol 11 (02) ◽  
pp. 95
Author(s):  
Fritz H Hengerer ◽  
Gerd U Auffarth ◽  
Ina Conrad-Hengerer ◽  
◽  
◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Intraocular Lens ◽  
Axial Length ◽  
Refractive Surgery ◽  
Anterior Chamber Depth ◽  
Corneal Surface ◽  
Intraocular Lens Calculations ◽  
Target Refraction ◽  
Intraocular Lens Calculation

In standard cataract surgery, one of the major goals is to reach target refraction. Based on keratometry measurements, axial length and anterior chamber depth, most of the intraocular lens calculation formulae are suitable to achieve this aim. Further evaluation of corneal refractive parameters like anterior and posterior corneal surface by Scheimpflug devices led to a significant enhancement of precision in astigmatic and post-refractive surgery cases.

scholarly journals Myopic Shift After Intraocular Lens Implantation in Children Less Than Two Years of Age

2018 ◽  
Vol 10 (1) ◽  
pp. 11-15
Author(s):  
Suma Ganesh ◽  
Reena Gupta ◽  
Sumita Sethi ◽  
Chandra Gurung ◽  
Raman Mehta
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
Early Years ◽  
P Value ◽  
Group I ◽  
Significant Difference ◽  
Myopic Shift ◽  
Second Year ◽  
Group Ii

Purpose: The purpose of this study was to evaluate the myopic shift over a period of 2 years following implantation of intraocular lens (IOL) in children less than 2 years of age with axial length less than 22 mm.Method: A retrospective analysis of records of children below 2 years of age with axial length less than 22 mm who had undergone cataract surgery with primary IOL implantation over a period of 7 years was undertaken. Mean myopic shift was analyzed at 6 months, in first year, second year and end of 2 years following surgery.Results: Total 40 eyes of 23 children were included (mean age 13.55±7.38 months); with mean myopic shift at end of 2 years -2.35±2.15. Myopic shift in eyes with undercorrection in range of 3-4 D (group-I) and 5-7 D (group-II) was compared using Mann-Whitney test. Mean myopic shift at end of 2 years was -2.93±2.55 in group-I and -1.88±1.77 in group-II (p value not significant). There was no significant difference in myopic shift between two groups at 6 months and 1 year; a borderline significant difference was found in second year (p= 0.04).Conclusion: In our study amount of myopic shift in first two years in children with axial length less than 22 mm is below the expected normal. There was not much significant difference in the myopic shift over a period of 2 years in eyes, which were undercorrected by 3-4 D against those with 5-7 D. Thus aiming for less residual hyperopia by less undercorrection did not increase myopic shift. Thus high-level hyperopic glasses in the early years could be avoided and help in prevention of amblyopia after paediatric cataract surgery.

scholarly journals Assessment of the Influence of Keratometry on Intraocular Lens Calculation Formulas in Long Axial Length Eyes

2021 ◽  
Author(s):  
Shengjie Yin ◽  
Chengyao Guo ◽  
Kunliang Qiu ◽  
Tsz Kin Ng ◽  
Yuancun Li ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Case Series ◽  
Absolute Error ◽  
Power Calculation ◽  
Prediction Errors ◽  
Retrospective Case ◽  
Iol Power Calculation ◽  
Iol Power ◽  
Intraocular Lens Calculation

Abstract Purpose: Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes.Methods: Retrospective case-series. 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average). Prediction errors (PE) were compared between different formulas. Multiple regression analysis was performed to investigate factors associated with the PE.Results: The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only. Conclusions: Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.

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.

True rotational stability of a single-piece hydrophobic intraocular lens

2018 ◽  
Vol 103 (2) ◽  
pp. 186-190 ◽  
Author(s):  
Daniel Schartmüller ◽  
Sabine Schriefl ◽  
Luca Schwarzenbacher ◽  
Christina Leydolt ◽  
Rupert Menapace
Keyword(s):  
Influencing Factors ◽  
Intraocular Lens ◽  
Axial Length ◽  
Rotational Stability ◽  
Confounding Factors ◽  
Time Points ◽  
Single Piece ◽  
Aspheric Iol ◽  
Significant Difference ◽  
Hydrophobic Acrylic

BackgroundTo evaluate rotation and its influencing factors of an aspheric one-piece hydrophobic acrylic intraocular lens (IOL) Vivinex XY1 during 6 months after operation.MethodsIn this institutional trial, 122 eyes of 66 patients were implanted with a non-toric aspheric IOL Vivinex XY1 (Hoya Corporation, Tokyo, Japan). IOL alignment was assessed at the end of surgery, 1 hour, 1 week, 1 month and 6 months after implantation. Confounding factors such as axial length, presence of anterior fibrosis and randomised implantation in four different intended axes (0°, 45°, 90°, 135°) were evaluated. Decentration and tilt were measured using a Purkinje metre.ResultsAssessment of rotational stability was possible for 103 of 122 implanted IOLs 6 months after eye surgery. The median absolute rotation was 1.1° (range: 0°–5°). Rotation was significantly increased within the first hour after operation compared with later time-points (p<0.001). No correlation was found with axial length and rotation (Spearman’s r=0.048, p=0.63). No significant difference was observed regarding different implantation axes (p=0.75). Rotation was not influenced by the presence of anterior fibrosis (p=0.98).ConclusionAssessing the true IOL position at the end of surgery is crucial for the evaluation of rotational stability of IOLs. No IOL rotation exceeding 5° could be detected 6 months after surgery.

scholarly journals Comparative Analysis of Visual Performance and Optical Quality with a Rotationally Asymmetric Multifocal Intraocular Lens and an Apodized Diffractive Multifocal Intraocular Lens

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xiao Wang ◽  
Haixia Tu ◽  
Yong Wang
Keyword(s):  
Visual Acuity ◽  
Cataract Surgery ◽  
Intraocular Lens ◽  
Visual Function ◽  
Optical Quality ◽  
Modulation Transfer ◽  
Multifocal Intraocular Lens ◽  
Distance Visual Acuity ◽  
Age Related ◽  
Significant Difference

Purpose. To compare the short-term visual outcomes and intraocular optical performance of a rotationally asymmetric multifocal intraocular lens (MIOL) (SBL-3, Lenstec, Inc., Christ Church, Barbados) and an apodized diffractive MIOL (the Acrysof IQ ResTOR SN6AD1, Alcon Laboratories, Inc., Fort Worth, Texas, United States). Methods. A prospective, comparative, nonrandomized, and single-center study. Sixty-eight age-related cataract patients (81 eyes) after phacoemulsification cataract surgery and in-the-bag MIOL implantation were enrolled. Thirty-eight eyes received SBL-3, and 43 eyes received SN6AD1. Ophthalmological evaluation included uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), modulation transfer function (MTF), Strehl ratio (SR), intraocular aberrations (4 mm optical zone), and defocus curve at 3 months postoperatively. The Chinese version of the visual function index-14 (VF-12-CN) and spectacle independence were assessed in all patients. Results. There was no statistically significant difference between groups in postoperative UDVA (p=0.186). Postoperative UIVA and UNVA were significantly better for the SBL-3 group than for the SN6AD1 group (p<0.01). Statistically significant differences were revealed in defocus levels from –3.50 D to −4.00 D with better visual acuities for the SBL-3 group (p<0.01). For intraocular optical quality outcomes, statistically significant differences between groups were observed in RMS of intraocular total aberrations, coma, and trefoil high-order aberrations, presenting significantly higher values of these parameters in the eyes of the SBL-3 group (p < 0.01). Statistically significant differences were revealed in the MTF values at spatial frequencies of 5 and 10 cycles/degree between groups. There were no significant differences in scores of VF-12-CN, and spectacle independence between the groups (p>0.05). Conclusions. Both MIOLs were able to successfully restore visual function after cataract surgery. SBL-3 provided better UIVA and UNVA with a wider range of intermediate vision.

scholarly journals Electrophysiological patterns of sciatic nerve in patients with arthrosis deformans of the hip

2021 ◽  
Vol 28 (2) ◽  
pp. 47-54
Author(s):  
Vladimir V. Ostrovskij ◽  
Galina A. Korshunova ◽  
Sergey P. Bazhanov ◽  
Andrey A. Chekhonatskij ◽  
Vladimir S. Tolkachev
Keyword(s):  
Sciatic Nerve ◽  
Hip Replacement ◽  
Tibial Nerve ◽  
Neurological Complications ◽  
Post Surgery ◽  
Age Related ◽  
Significant Difference ◽  
Electrophysiological Findings ◽  
Arthrosis Deformans ◽  
Fibular Nerve

BACKGROUND: Neurological complications in sciatic nerve (SN) after a total hip replacement (THR) are observed in 0.93.2% of cases in patients with arthrosis deformans and age-related morphologic changes in SN. These cause the need for SN evaluation before THR. This research was aimed at the evaluation of the initial SN capacity with electrophysiological findings in patients with arthrosis deformans of the hip. MATERIALS AND METHODS: Electroneuromyography (ENMG) was used to evaluate fibular and tibial nerves M-responses as well as F-waves in 66 patients with dysplastic coxarthrosis and 12 patients with posttraumatic coxarthrosis. The findings were compared to those of the controls. RESULTS: Changes in ENMG findings for fibular nerve in 49 patients with dysplastic coxarthrosis were bilateral and showed significant difference only from the norm. In 19 of 66 cases (27.9%) low M-responses (р 0.02) were found in the side subject to THR. In 87.3% of cases, the signs of a decrease in the conductivity of proximal segments of the tibial nerve were revealed. In patients with posttraumatic coxarthrosis, the significant decrease in ENMG findings from both fibular and tibial nerves was observed in the affected side, they made up just 42-50% of those in the opposite side. Asymptomatic progress of denervation damage in hip and tibia muscles sometimes required needle EMG to fund the signs of motor innervation disorder. A-waves revealed in 65% of patients suggested local damage to one or both portions of SN. CONCLUSION: ENMG findings in patients with dysplastic arthrosis of the hip enabled revealing of the signs of neuropathy before surgeries and decreasing the risk of neurologic post-surgery complications.

scholarly journals Clinical Characteristics of Intraocular Lens Dislocation in Chinese Han Populations

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Qi Fan ◽  
Xiaoyan Han ◽  
Xiangjia Zhu ◽  
Lei Cai ◽  
Xiaodi Qiu ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
Clinical Characteristics ◽  
Time Interval ◽  
Chinese Han ◽  
Open Globe ◽  
Significant Difference ◽  
Pars Plana ◽  
Iol Dislocation

Purpose. To investigate the clinical characteristics of patients with intraocular lens (IOL) dislocation after IOL implantation in Chinese Han populations. Methods. The medical records of patients with IOL dislocation were retrospectively reviewed from January 2007 to December 2017, and a total of 312 patients (male: 231, female: 97) (328 eyes) were included in this study. The axial length (AL), IOL power, and the time interval between cataract surgery and IOL dislocation as well as the ocular conditions associated with IOL dislocation were recorded. The IOL dislocation was classified and graded based on its relationship with the capsule and the position of the dislocated IOL. Results. The mean time between original cataract surgery and IOL dislocation was 5.63 ± 5.13 years; IOL dislocation occurred in up to 56.1% (184 eyes) of the eyes within 5 years. Trauma was found in 136 eyes (41.5%); pars plana vitrectomies were performed in 61 eyes (18.6%), and high myopia was detected in 108 eyes (32.9%). A total of 243 eyes (74.1%) had out-of-the-bag IOL dislocations, while 85 eyes (25.9%) had in-the-bag IOL dislocations. There was a statistically significant difference in the constituent ratio of trauma between in-the-bag dislocation and out-of-the-bag dislocation (Pearson’s chi2 = 33.3992, P<0.001); ocular blunt traumas were significantly higher in in-the-bag dislocations, while open-globe injuries were significantly higher in out-of-the-bag dislocations. A statistically significant difference was found for the ratio of patients with AL longer than 30 mm between in-the-bag dislocation and out-of-the-bag dislocation (Pearson’s chi2 = 9.7355, P<0.002). Conclusions. In Chinese Han populations, the most common IOL dislocation is out-of-the-bag dislocation; the most common risk factors were trauma, long axial length, and eyes undergoing pars plana vitrectomy; a minimum follow-up of 5 years is suggested for IOL dislocation-predisposed eyes undergoing cataract surgery.

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