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.

scholarly journals Inter-ocular and inter-visit differences in ocular biometry and refractive outcomes after cataract surgery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hyun Sup Choi ◽  
Hyo Soon Yoo ◽  
Yerim An ◽  
Sam Young Yoon ◽  
Sung Pyo Park ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
The Other ◽  
Corneal Power ◽  
Refractive Outcomes ◽  
Ocular Biometry ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Group D

Abstract This study aimed to determine whether inter-ocular differences in axial length (AL), corneal power (K), and adjusted emmetropic intraocular lens power (EIOLP) and inter-visit differences in these ocular biometric values, measured on different days, are related to refractive outcomes after cataract surgery. We retrospectively reviewed 279 patients who underwent phacoemulsification. Patients underwent ocular biometry twice (1–4 weeks before and on the day of surgery). Patients were divided into three groups: group S (similar inter-ocular biometry in different measurements; n = 201), group P (inter-ocular differences persisted in the second measurement; n = 37), and group D (inter-ocular difference diminished in the second measurement; n = 41). Postoperative refractive outcomes (mean absolute errors [MAEs]) were compared among the groups. Postoperative MAE2, based on second measurement with reduced inter-ocular biometry difference, was smaller than that calculated using the first measurement (MAE1) with borderline significance in group D (MAE1, 0.49 ± 0.45 diopters vs. MAE2, 0.41 ± 0.33 diopters, p = 0.062). Postoperative MAE2 was greater in group P compared to the other two groups (p = 0.034). Large inter-ocular biometry differences were associated with poor refractive outcomes after cataract surgery. These results indicate that measurements with smaller inter-ocular differences were associated with better refractive outcomes in cases with inter-visit biometry differences.

scholarly journals Accuracy of intraocular lens power calculation using Scheimpflug tomography and OKULIX ray tracing software in corneal scarring

2019 ◽  
Author(s):  
Karim Mahmoud Nabil
Keyword(s):  
Visual Acuity ◽  
Ray Tracing ◽  
Intraocular Lens ◽  
Absolute Error ◽  
Power Calculation ◽  
Corneal Scarring ◽  
Iol Power Calculation ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Lens Power

Abstract Background: To evaluate the accuracy of intraocular lens power (IOL) calculation using Scheimpflug tomography and OKULIX ray tracing software in corneal scarring. Methods: This study was conducted on 40 consecutive eyes, 20 cases with corneal scarring and coexisting cataract, and 20 controls with clear cornea, which underwent uneventful phacoemulsification and IOL implantation following Scheimpflug tomography and OKULIX ray tracing software and third generation IOL power calculation formulas for IOL power calculation. Accuracy of IOL power calculation was evaluated by subtracting expected and achieved spherical refraction 3 months postoperatively and was recorded as mean absolute error (MAE). Distance uncorrected visual acuity (UCVA) for each eye was measured using Snellen chart preoperatively and 3 months postoperatively; visual acuity was scored and converted to the logarithm of the minimum angle of resolution (LogMar). Results: In cases of corneal scarring, 20 eyes (100 %) yielded a postoperative spherical refraction which differed less than 1 diopter (D) from predicted, in 16 eyes (80 %) the postoperative spherical refraction was within 0.50 D from expected. The MAE was 0.2 D in cases, which did not differ significantly compared to controls (MAE 0.1 D). In corneal scarring cases, distance UCVA showed significant improvement from 1.3 Log Mar (Snellen equivalent 20/400) preoperatively to 0.5 Log Mar (Snellen equivalent 20/60) 3 months postoperatively. Conclusion: Scheimpflug tomography combined with OKULIX ray tracing software for calculation of IOL power provides accurate results in cases of corneal scarring.

scholarly journals Comparison of four formulas for the intraocular lens power prediction

2019 ◽  
Author(s):  
Yanjun Hua ◽  
Wei Qiu ◽  
Qiang Wu
Keyword(s):  
Prospective Study ◽  
Intraocular Lens ◽  
Axial Length ◽  
Power Prediction ◽  
Ocular Biometry ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Lens Power ◽  
Better Than

Abstract Purpose To assess the accuracy of four formulas for intraocular lens (IOL) power prediction in cataractous eyes. METHODS In this prospective study, 51 eyes of 38 cataractous patients with an axial length (AL) between 24.0 and 26.0 mm were included. Preoperatively, Topolyzer, IOLMaster and A-scan were performed. At least 3 months after the surgery, subjective refraction was conducted. Haigis, SRK/T, Hoffer Q and Holladay 1 formulas based on ocular biometry from A-scan combining Topolyzer, IOLMaster combining Topolyzer and IOLMaster only were applied for IOL power prediction. RESULTS The four formulas based on biometry from IOLMaster combining Topolyzer and IOLMaster only performed better than those based on biometry from A-scan combining Topolyzer. Based on biometry from IOLMaster combining Topolyzer, Haigis formula had a mean NEs of -0.03 ± 0.71 D and a mean AEs of 0.53 ± 0.47 D, SRK/T formula had a mean NEs of 0.37 ± 0.72 D and a mean AEs of 0.63 ± 0.50 D, Hoffer Q formula had a mean NEs of 0.05 ± 0.62 D and a mean AEs of 0.43 ± 0.44 D, Holladay 1 formula had a mean NEs of 0.32 ± 0.63 D and a mean AEs of 0.54 ± 0.45 D. Based on biometry from IOLMaster only, Haigis formula had a mean NEs of 0.02 ± 0.54 D and a mean AEs of 0.41 ± 0.36 D, SRK/T formula had a mean NEs of 0.41 ± 0.54 D and a mean AEs of 0.52 ± 0.43 D, Hoffer Q formula had a mean NEs of 0.05 ± 0.58 D and a mean AEs of 0.36 ± 0.46 D, Holladay 1 formula had a mean NEs of 0.32 ± 0.45 D and a mean AEs of 0.43 ± 0.35 D. CONCLUSIONS Haigis and Hoffer Q formulas performed slightly better than SRK/T and Holladay 1 formulas. Therefore, for cataractous patients with moderate AL, all four formulas based the biometry from IOLMaster combining Topolyzer and IOLMaster only can be used for the prediction of IOL power, and the Haigis and Hoffer Q formulas are particularly recommended.

scholarly journals Axial length elongation in adults with long-standing unilateral traumatic cataract

2016 ◽  
Vol 75 (1) ◽  
Author(s):  
Jonel Steffen ◽  
Nagib Du Toit ◽  
James C. Rice ◽  
Shaheer Aboobaker
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
Visual Deprivation ◽  
Length Difference ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
Axial Myopia ◽  
Fellow Eyes ◽  
Rule Out

Background: Unilateral eye elongation with resultant axial myopia has been reported to occur secondary to visual deprivation from birth or early childhood. Acquired axial length elongation secondary to visual deprivation in adults has rarely been reported.Aim: To report acquired axial myopia in adults with visual deprivation due to long-standing unilateral traumatic cataract.Methods: Eleven consecutive adult patients who presented for cataract surgery with unilateral, long-standing, mature, traumatic cataracts and an interocular axial length difference of more than 1 mm were studied. Patients with a post-operative best corrected visual acuity (BCVA) of < 6/12 were excluded to rule out possible pre-existing anisometropic amblyopia.Results: Of the 11 patients with significant interocular axial length difference, 5 patients were excluded on the basis of possible pre-existing amblyopia. The remaining 6 patients had final BCVA of 6/12 or better. The median length of the cataractous eyes was 2.83 mm longer than the fellow eyes (range 1.12 mm – 3.52 mm). The intraocular lens power required for emmetropia was 6.8 dioptres (range 3.5 dioptres – 11.5 dioptres) less in the cataractous eyes. A refractive outcome within 1 dioptre of the target refraction was achieved in all patients. The median delay between ocular trauma and cataract surgery was 20 years (range 8–24 years).Conclusion: Significant unilateral axial length elongation may occur in adults with longstanding traumatic cataracts and visual deprivation. A potential correlation may exist between delay to surgery and degree of axial length difference. This rare phenomenon must be considered when determining intraocular lens power to avoid post-operative refractive surprises.

The Accuracy of Different Generation Intraocular Lens Power Formulas in Eyes with Axial Length Lower than 22 millimeter

2019 ◽  
Author(s):  
Aydın Yildiz ◽  
Sedat Arikan
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Statistical Significance ◽  
Absolute Error ◽  
Accurate Estimation ◽  
Intraocular Lens Power ◽  
Significant Difference ◽  
Iol Calculation ◽  
Iol Power ◽  
Lens Power

Abstract Background:To investigate the accurate formulas for eyes with axial length (AL) lower than 22 millimeters among usually used six intraocular lens (IOL) calculation formulas. MethodsA total of 122 eyes with short ALs that is lower than 22 mm of 122 patients who underwent phacoemulsification surgery with the same type of IOL implantation were included in this retrospective study. The biometric values of the patients were obtained by using optical low coherence reflectometry (OLCR) for six formulas involving Hoffer Q, SRK-T, Haigis, Barett Universal II, Holladay 2 and Hill-RBF. All patients had a postoperative best corrected visual acuity level that is equal or higher than 20/40. While comparing the accuracy of these six IOL calculation formulas, the mean absolute error (MAE), and the median absolute error (MedAE) values were taken into account.ResultsThe MAE values for Hoffer Q, SRK-T, Haigis, Holladay 2, Hill-RBF and Barrett Universal II formulas were 0.390, 0.390, 0.324, 0.327, 0.331 and 0.208 respectively. Also the rank of MedAE values for the mentioned formulas was 0.245, 0.310, 0.310, 0.250, 0.255 and 0.190. The lowest MAE and MedAE value was found in Barrett Universal II formula, whereas the highest one was in the SRK/T formula with a statistical significance (p<0.001). After Bonferroni correction, there were no statistically significant difference between Barret Universal II formula and the other formulas except SRK/T (p>0.01). Three patients (2.5%) were in the ±0.75 D range, 15 patients (12.3%) were in the ±0.50 D, and the remaining 104 (85.2%) patients were in the ±0.25 D at the first month follow-up. ConclusionsAlthough Barrett Universal II appears to be the most accurate IOL calculation formula, third, fourth and other newer generation formulas have also a good predictive value for accurate estimation of IOL power in short eyes.

Intraocular lens power calculation formula accuracy: Comparison of 12 formulas for a trifocal hydrophilic intraocular lens

2020 ◽  
pp. 112067212098069
Author(s):  
Carlos Rocha-de-Lossada ◽  
Elvira Colmenero-Reina ◽  
David Flikier ◽  
Francisco-Javier Castro-Alonso ◽  
Alvaro Rodriguez-Raton ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Absolute Error ◽  
Power Calculation ◽  
Intraocular Lens Power Calculation ◽  
Accuracy Comparison ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Lens Power ◽  
Lens Power Calculation

Purpose: To evaluate the accuracy of 12 intraocular lens (IOL) power formulas; Barrett Universal II, Emmetropia Verifying Optical (EVO), Haigis, Hill-Radial Basis Function (RBF), Hoffer Q, Holladay I, Kane, Ladas Super Formula, Olsen Lenstar, Panacea, Pearl-DGS, Sanders-Retzlaff-Kraff/theoretical (SRK/T). In addition, an analysis of the efficacy as a function of the axial length was performed. Methods: About 171 from 93 patients: 68 male eyes and 103 female eyes. Twelve IOL power formula calculations were studied with one IOL platform (trifocal hydrophilic IOL, FineVision Micro F), one biometer (Lenstar LS 900), one topographer (CSO Sirius Topographer), one surgeon, and one optometrist. Optimization were determined to be zeroed mean refractive prediction error. Mean error (ME), mean absolute error (MAE), median absolute error (MedAE) and refractive accuracy within ±1.00 D was calculated. Axial length was split in short and medium eyes. Results: One hundred and seventy eyes were included. Formulas were ranked by percentage within ±0.50 diopters and MAE (D). Among all eyes, Olsen 86.55% (0.273 D) and Barrett Universal II 86.55% (0.285D). For short eyes (<22.5 mm), Olsen 90.70% (0.273 D) and Kane 90.70% (0.225 D). For medium eyes, Barrett 89.34% (0.237 D) and Pearl 86.89% (0.263 D). Conclusion: Olsen and Barrett formula obtained excellent accuracy for overall eyes. Kane and Olsen formula obtained the best results in short eyes. For medium axial length Barrett formula achieved the best accuracy results.

scholarly journals Accuracy of intraocular lens power calculation using Scheimpflug tomography and OKULIX ray tracing software in corneal scarring

2020 ◽  
Author(s):  
karim Mahmoud nabil
Keyword(s):  
Visual Acuity ◽  
Ray Tracing ◽  
Intraocular Lens ◽  
Pearson Correlation ◽  
Power Calculation ◽  
Corneal Scarring ◽  
Iol Power Calculation ◽  
Intraocular Lens Power ◽  
Iol Power ◽  
Lens Power

Abstract Background: To evaluate the accuracy of intraocular lens power (IOL) calculation using Scheimpflug tomography and OKULIX ray tracing software in corneal scarring. Methods: This study was conducted on 40 consecutive eyes, 20 cases with corneal scarring and coexisting cataract, and 20 controls with clear cornea, which underwent uneventful phacoemulsification and IOL implantation following Scheimpflug tomography and OKULIX ray tracing software and third generation IOL power calculation formulas for IOL power calculation. Accuracy of IOL power calculation was evaluated by subtracting expected and achieved spherical refraction 3 months postoperatively and was recorded as mean absolute error (MAE). Distance uncorrected visual acuity (UCVA) for each eye was measured using Snellen chart preoperatively and 3 months postoperatively; visual acuity was scored and converted to the logarithm of the minimum angle of resolution (LogMar).Values were recorded as mean ±SD (standard deviation). Student t-test (t) and Mann Whitney test (U) were used for parametric comparison of the means. Intra class Correlation (ICC) coefficient and Pearson correlation Coefficient (r) were used to assess agreement. A P value less than 0.05 was considered statistically significant. Results: In cases of corneal scarring, 20 eyes (100 %) yielded a postoperative spherical refraction which differed less than 1 diopter (D) from predicted, in 16 eyes (80 %) the postoperative spherical refraction was within 0.50 D from expected. The MAE was 0.2 D in cases, which did not differ significantly compared to controls (MAE 0.1 D). In corneal scarring cases, distance UCVA showed significant improvement from 1.3 Log Mar (Snellen equivalent 20/400) preoperatively to 0.5 Log Mar (Snellen equivalent 20/60) 3 months postoperatively. Conclusion: Scheimpflug tomography combined with OKULIX ray tracing software for calculation of IOL power provides accurate results in cases of corneal scarring.

scholarly journals The Relationship between Anterior Chamber Depth, Axial Length and Intraocular Lens Power among Candidates for Cataract Surgery

10.19082/3127 ◽  
2016 ◽  
Vol 8 (10) ◽  
pp. 3127-3131 ◽  
Author(s):  
Mohammad Reza Sedaghat ◽  
Ali Azimi ◽  
Peyman Arasteh ◽  
Naghmeh Tehranian ◽  
Shahram Bamdad
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Intraocular Lens ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Intraocular Lens Power ◽  
Lens Power ◽  
The Relationship
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