scholarly journals Biometric parameters and intra ocular lens power used for cataract eyes in Karnali, Nepal

2014 ◽  
Vol 6 (2) ◽  
pp. 192-196
Author(s):  
Pawan Baral ◽  
Nabin Baral ◽  
Indra Man Maharjan ◽  
Bhoj Raj Gautam ◽  
Madhavendra Bhandari
Keyword(s):  
Cataract Surgery ◽  
Axial Length ◽  
Total Sample ◽  
Ocular Lens ◽  
Biometric Parameters ◽  
Number Of Patients ◽  
Case Files ◽  
Iol Power ◽  
The Mean ◽  
Lens Power

Introduction: The biometric parameters of the eye are measured for the calculation of the intra ocular lens power to be used in cataract surgery. Objective: To report the keratometry reading, axial length and intra ocular lens power used for eyes operated for cataract in Karnali Zone, Nepal, and to compare these findings with those reported in other similar studies. Subjects and methods: The data for the study were retrospectively collected from the case files of patients who had undergone cataract surgery between January 2011 and July 2012 in Karnali Zone, Nepal. These surgeries were performed in an outreach surgical camp organized by the Himalaya Eye Hospital, Nepal, as a part of its annual program. The SPSS 16.0 and Microsoft Excel 2007 software were used for the data analysis.Results: The total number of patients taken for the study was 1055 and the total number of eyes was 1055. There were 530 (50.23%) males and 525 (49.77%) females, with the mean age of 64.34±11.25, ranging from 8 to 98 years.The mean keratometry reading for the total sample was 44.11±1.6 (range, 34.00D to 49.00D). The mean axial length for the total sample was 22.68±0.88 (range, 17.75 to 26.17). The mean IOL power for the total sample was 21.60±1.74 (range, +15.00 to +30.00).Conclusion: The biometric eye parameters of keratometry, axial length and IOL power of this study required for cataract surgery in a Karnali population are similar to those presented in other similar studies from Nepal and abroad.DOI: http://dx.doi.org/10.3126/nepjoph.v6i2.11690Nepal J Ophthalmol 2014; 6(12): 192-196

scholarly journals Comparison of Biometric Values and Intraocular Lens Power Calculations Obtained by Ultrasound and Optical Biometry

2016 ◽  
Vol 17 (4) ◽  
pp. 321-326
Author(s):  
Aleksandra Cvetkovic ◽  
Suncica Sreckovic ◽  
Marko Petrovic
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Mean Values ◽  
Optical Biometry ◽  
Refractive Power ◽  
Number Of Patients ◽  
Significant Difference ◽  
Iol Power ◽  
The Mean ◽  
Lens Power

Abstract This study sought to compare the biometric values and intraocular lens (IOL) power obtained by standard ultrasound and optical biometry. We examined 29 eyes in preparation for cataract surgery. None of the patients had refractive surgery or corneal anomaly. In all patients, the horizontal and vertical refractive power of the cornea was determined using a keratometer (Bausch&Lomb). The axial length of the eye was determined via A-scan ultrasound (BVI-compact-V-plus) using Hollady’s formula. The IOL power and complete biometric measurements were obtained via an IOL Master-500-Zeiss using the Hollady-2 formula. All obtained values were compared and analysed using the statistical program SPSS 20. The average age of treated patients was 71.21±1.68 years. In 16 patients with dense cataracts (55.17%), it was not possible to determine the IOL power by optical biometry. Optical biometry obtained significantly increased axial length values of 24.04±0.29 mm compared with those obtained with ultrasound biometry (23.89±0.28 mm, p=0.003). The mean refractive cornea power values of the horizontal meridian measured using a keratometer (42.50±0.47 D) and an IOL Master (42.69±0.49 D) were not statistically different (p=0.187). The mean values of the refractive cornea power of the vertical meridian obtained using a keratometer (42.62±0.48D) and an IOL Master (43.36±0.51 D) exhibited a statistically significant difference (p=0.000). The keratometer obtained statistically significant lower mean values of corneal refractive power (42.73±0.32 D) compared with those obtained with optical biometry (43.22±0.35 D, p=0.000). Ultrasound biometry obtained significantly increased the mean values of IOL power (20.19±0.48D) compared with those obtained with optical biometry (19.71±0.48 D, p=0.018). The large number of patients who receive an operation for dense cataracts indicate the need for representation of both biometric methods in our clinical practice.

scholarly journals Congenital and developmental cataract surgery with undercorrected Intraocular lens (IOL) power implantation targeting emmetropia at 8 years of age and post-operative refractive status

2021 ◽  
Vol 12 (9) ◽  
pp. 126-129
Author(s):  
Kabindra Bajracharya ◽  
Anjita Hirachan ◽  
Kriti Joshi ◽  
Bimala Bajracharya
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Axial Length ◽  
Iol Implantation ◽  
Refractive Status ◽  
Developmental Cataract ◽  
Iol Power ◽  
The Mean ◽  
One Year

Background: In congenital and developmental cataract primary undercorrection of intraocular lens (IOL) power is a common practice. However, long-term refractive status of these children is largely unknown. Aims and Objective: To analyse refractive status after cataract surgery with undercorrected IOL power implantation in congenital and developmental cataract. Materials and Methods: This study was descriptive, retrospective conducted for three years from 1st January 2013 to 31st December 2015. The children (> 6 months to <=7 years of age) who underwent cataract surgery for congenital and developmental cataract with a primary IOL implantation and had reached the age of 8 years were studied. The data were collected in terms of demography, axial length, biometry, IOL implanted, hyperopic correction and postoperative refractive status at 8 years. Results: Total numbers of children operated were 181 with total eyes 288. Unilateral cases were 74 (40.88%) and bilateral 107 (59.12%). Male were 121 (66.85%) and female were 60 (33.15%) with male is to female ratio of 2:1. Right eye was involved in 152 (52.8%) and left eye 136 (47.2%). The mean axial length at the age of one year was 20.75 mm, and gradually increased as age increased which was 22.47 mm at 6 years. The mean biometry was 27.9 diopter (D) at the age of one year which gradually decreased as age increased. Of the total 288 congenital cataract operated, complete follow-up documents were available for 77 (26.74%) eyes up to 8 years which showed emmetropia achieved in 25.97%, myopia in 28.57% and hypermetropia in 45.45%. Conclusion: Primary IOL implantation with hyperopic correction is accepted practice in congenital and developmental cataract. Emmetropia can be achieved however some hyperopic or myopic refractive status at the age of 8 years is not a surprise. Myopic shift continues as the age increases. Parent awareness for early detection and surgery, optical correction and regular follow-up are essential for good outcome.

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 Gender differences in refraction prediction error of five formulas for cataract surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yibing Zhang ◽  
Tingyang Li ◽  
Aparna Reddy ◽  
Nambi Nallasamy
Keyword(s):  
Gender Differences ◽  
Cataract Surgery ◽  
Prediction Error ◽  
Statistical Difference ◽  
Independent Predictor ◽  
Study Data ◽  
Prediction Errors ◽  
Optical Biometry ◽  
Iol Power ◽  
Lens Power

Abstract Objectives To evaluate gender differences in optical biometry measurements and lens power calculations. Methods Eight thousand four hundred thirty-one eyes of five thousand five hundred nineteen patients who underwent cataract surgery at University of Michigan’s Kellogg Eye Center were included in this retrospective study. Data including age, gender, optical biometry, postoperative refraction, implanted intraocular lens (IOL) power, and IOL formula refraction predictions were gathered and/or calculated utilizing the Sight Outcomes Research Collaborative (SOURCE) database and analyzed. Results There was a statistical difference between every optical biometry measure between genders. Despite lens constant optimization, mean signed prediction errors (SPEs) of modern IOL formulas differed significantly between genders, with predictions skewed more hyperopic for males and myopic for females for all 5 of the modern IOL formulas tested. Optimization of lens constants by gender significantly decreased prediction error for 2 of the 5 modern IOL formulas tested. Conclusions Gender was found to be an independent predictor of refraction prediction error for all 5 formulas studied. Optimization of lens constants by gender can decrease refraction prediction error for certain modern IOL formulas.

scholarly journals Evaluation of Anterior Chamber Depth in 28,709 Adult Cataract Patients in China using Swept-Source Optical Biometry

2021 ◽  
Author(s):  
Qiong Lei ◽  
Haixia Tu ◽  
Xi Feng ◽  
Yong Wang
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Axial Length ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Multivariate Regression Analysis ◽  
Swept Source ◽  
Mean Values ◽  
The Mean ◽  
Cataract Patients

Abstract Background: To create an anterior chamber depth (ACD) regression model for adult cataract surgery candidates from China, and to evaluate the distribution of their ocular biometric parameters.Methods: The ocular biometric records of 28,709 right eyes of cataract surgery candidates who were treated at Aier Eye Hospitals in nine cities from 2018 to 2019 were retrospectively analyzed. All measurements were taken with IOLMaster 700. We included patients who were at least 40 years old and were diagnosed with cataract.Results: The mean age of the patients was 68.6 ± 11.0 years. The mean values recorded were as follows: axial length (AL), 24.17 ± 2.47 mm; mean keratometry (Km) value, 44.09 ± 3.25 D; corneal astigmatism (CA), 1.06 ± 0.98 D; ACD, 3.02 ± 0.45 mm; lens thickness (LT), 4.52 ± 0.45 mm; central corneal thickness (CCT), 0.534 ± 0.04 mm; and white to white (WTW) corneal diameter, 11.64 ± 0.46 mm. The proportion of patients with long axial length (AL >25 mm) decreased with age. ACD, LT, AL, Km, WTW, and age were correlated. In the multivariate regression analysis of ACD, which included LT, AL, WTW, sex, Km, CCT, and age, there was a reasonable prediction with adjusted R2 = 0.629.Conclusions: The results show that high myopes are inclined to schedule cataract surgery at a younger age. LT and AL were found to be important factors that affect ACD. This study provides reference data for cataract patients from China.

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.

Accuracy of common IOL power formulas in 611 eyes based on axial length and corneal power ranges

2020 ◽  
pp. bjophthalmol-2020-315882
Author(s):  
Veronika Röggla ◽  
Achim Langenbucher ◽  
Christina Leydolt ◽  
Daniel Schartmüller ◽  
Luca Schwarzenbacher ◽  
...  
Keyword(s):  
Axial Length ◽  
Prediction Error ◽  
Absolute Error ◽  
Power Calculation ◽  
Corneal Power ◽  
Biometric Parameters ◽  
Iol Power Calculation ◽  
Iol Power ◽  
Median Absolute Error ◽  
Axial Eye Length

AimsTo provide clinical guidance on the use of intraocular lens (IOL) power calculation formulas according to the biometric parameters.Methods611 eyes that underwent cataract surgery were retrospectively analysed in subgroups according to the axial length (AL) and corneal power (K). The predicted residual refractive error was calculated and compared to evaluate the accuracy of the following formulas: Haigis, Hoffer Q, Holladay 1 and SRK/T. Furthermore, the percentages of eyes with ≤±0.25, ≤±0.5 and 1 dioptres (D) of the prediction error were recorded.ResultsThe Haigis formula showed the highest percentage of cases with ≤0.5 D in eyes with a short AL and steep K (90%), average AL and steep cornea (73.2%) but also in long eyes with a flat and average K (65% and 72.7%, respectively). The Hoffer Q formula delivered the lowest median absolute error (MedAE) in short eyes with an average K (0.30 D) and Holladay 1 in short eyes with a steep K (Holladay 1 0.24 D). SRK/T presented the highest percentage of cases with ≤0.5 D in average long eyes with a flat and average K (80.5% and 68.1%, respectively) and the lowest MedAE in long eyes with an average K (0.29 D).ConclusionOverall, the Haigis formula shows accurate results in most subgroups. However, attention must be paid to the axial eye length as well as the corneal power when choosing the appropriate formula to calculate an IOL power, especially in eyes with an unusual biometry.

scholarly journals Ocular biometry and power of intra ocular lens among cataract patients in rural Eastern Ethiopia

2020 ◽  
Author(s):  
MANDEFRO SINTAYEHU KASSA ◽  
GIRUM W GESSESSE
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Multiple Linear Regression Model ◽  
P Value ◽  
Corneal Curvature ◽  
Ocular Lens ◽  
Eastern Ethiopia ◽  
Ocular Biometry ◽  
The Mean

Abstract Background : The main objective of the study was to report on the main parameters of ocular biometry and Intra ocular lens power of patients attending a cataract surgical program in Eastern Ethiopia. Methods : The study was a cross sectional study on 765 eyes which were legible for cataract surgery during a mass eye camp conducted from April 04 to April 10, 2018 at Bisidimo Hospital,Eastern Ethiopia.Ocular biometric parameters such as axial length (AL), anterior chamber depth (ACD), mean corneal curvature (MCC) were measured using automated keratorefractometer(Retinomax) and Sonomed A - Scan. Analysis of variance and multivariate analysis were done to determine association of ocular biometry components with socio demography of the study subjects. Results : A total of 765 eyes were enrolled in this study. The mean corneal curvature and the mean anterior chamber depth were found to be 7.61 mm and 2.88mm respectively. The mean axial length was estimated to be 22.98 mm. The mean refractive power of Intra ocular lenses was calculated to be 19.34D. The mean axial length in females was shorter than that of males by 0.24 and this was statistically significant ( P - value = 0.01). Under multiple linear regression model gender had a statistically significant impact on the axial length. The mean Anterior chamber depth in males was also larger than that of females by nearly 0.1 and this was statistically significant (P - value = 0.001). Under multiple linear regression model both age and gender had a statistically significant impact on the anterior chamber depth. There was no a statistically significant difference on the mean Intra ocular lens power required for male and female patients.Conclusion : This study is the first of its kind to provide a larger population based normative data on the most important parameters of ocular biometry in Ethiopia.The female sex was a strong predictor of small axial length and shallow anterior chamber. Increasing age had no effect on the axial length but was found to be a stronger predictor of shallow anterior chamber. Key words : Axial length, Anterior chamber depth, Corneal curvature, Intra ocular lens.

Comparison of Axial Length and Anterior Chamber Depth Measurement among Optical, Applanation and Immersion Biometry

2019 ◽  
Vol 11 (1) ◽  
pp. 59-64
Author(s):  
Harun Ur Rashid ◽  
AQM Omar Sharif ◽  
Zinat Rehana Shipu ◽  
Debashish Ghosh ◽  
Sofia Akhter ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Anterior Chamber ◽  
Axial Length ◽  
Anterior Chamber Depth ◽  
Power Calculation ◽  
Strong Positive Correlation ◽  
Care Hospital ◽  
Optical Biometry ◽  
Depth Measurement ◽  
The Mean

Background: Precise biometry is one of the major key factors for obtaining desired refractive outcome after cataract surgery. Visual outcome strongly depends on accuracy of ocular parameters especially axial length (AL) and anterior chamber depth (ACD). It is very important to evaluate different biometry methods to have accurate measurements for IOL power calculation. Objective: The aim of the study is to compare and analyze the difference between the measurement of axial length (AL) and anterior chamber depth (ACD) using ultrasound applanation, immersion and optical biometry. Methodology: A prospective study conducted on 168 patients enrolled for cataract surgery from January 2018 to December 2018 in Dhaka Eye Care Hospital, Dhaka. 280 eyes have been tested by a single observer. Axial length (AL) and anterior chamber depth (ACD) was measured consecutively by optical, applanation and immersion biometry. The results have been statistically evaluated to establish efficacy and correlation among the three methods of biometry. Results: Statistical analysis showed the mean of axial length (AL) obtained from optical biometry is 23.36 ± 1.99 mm, which is 0.10mm (p=0.00) less by applanation biometry and 0.04 mm (p=0.00) less by immersion biometry. For anterior chamber depth (ACD), the mean value from optical biometry is 3.13 ± 0.47mm. This value is highest in compare to both applanation (0.002 mm less with p = 0.824) and immersion (0.04 mm less with p = 0.00) biometry. Further analysis reveals strong correlation of optical biometry with applanation biometry (r = 0.994 for AL and 0.945 for ACD) and immersion biometry (r = 0.995 for AL and 0.947 for ACD). Conclusion: The study reveals that among optical, applanation and immersion method the optical biometry method appeared to be the most precise way of measuring axial length (AL) and anterior chamber depth (ACD) of eye. The study also shows an excellent agreement and strong positive correlation of optical biometry with applanation and immersion biometry. J Shaheed Suhrawardy Med Coll, June 2019, Vol.11(1); 59-64

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