Intraocular Lens Power Calculation Formulas—A Systematic Review

Stopyra, Wiktor; Langenbucher, Achim; Grzybowski, Andrzej

doi:10.1007/s40123-023-00799-6

Cited by 28 publications

(9 citation statements)

References 63 publications

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“…Refractive calculators currently in use for cataract surgery and phakic intraocular lens implantation typically employ regression or artificial intelligence to forecast the postoperative refractive state based on biometric parameters like the AL, K, ACD, LT, etc. [27]. The calculation might be more accurate if the parameters of the posterior segment of the eyes are taken into consideration.…”

Section: Discussionmentioning

confidence: 99%

Ocular Biometry Features and Their Relationship with Anterior and Posterior Segment Lengths among a Myopia Population in Northern China

Bian,

Li,

Qin

et al. 2024

JCM

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Objectives: The study aims to explore the ocular biometry of a myopic population in Northern China, focusing specifically on anterior and posterior segment lengths. Methods: This is a cross-sectional study. The medical records of 3458 myopic patients who underwent refractive surgery were evaluated. Axial length (AL), anterior chamber depth (ACD), lens thickness (LT) and other biometric parameters were measured using the IOL Master 700. The study determined the anterior segment length (ASL = ACD + LT), the posterior segment length (PSL = AL − ASL) and the ratio of ASL to PSL (ASL/PSL). Results: This study included 3458 eyes from 3458 myopic patients (1171 men and 2287 women). The mean age was 27.38 ± 6.88, ranging from 16 to 48 years old. The mean ASL was 7.35 ± 0.27 mm, and the mean PSL was 18.39 ± 1.18 mm. The ASL and PSL trends demonstrate an age-related increase for both genders, with notable gender-specific variations. Across most age groups, males typically exhibited higher ASLs and PSLs than females, with the exception of the 35–40 and 40–45 age groups. The ASL and PSL consistently increased with a rising AL. The AL strongly correlates with the PSL and negatively correlates with the ASL/PSL ratio. The ACD and LT moderately correlate with the ASL, but an increased LT does not imply a longer posterior segment. The CCT and SE show little correlation with axial eye parameters. Conclusions: Among Chinese myopic patients, a longer ASL and PSL were correlated with older age and the male gender. The AL strongly correlates positively with the PSL and negatively correlates with the ASL/PSL ratio. An elongation of the posterior segment may primarily account for an eyeball’s lengthening.

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Section: Discussionmentioning

confidence: 99%

Ocular Biometry Features and Their Relationship with Anterior and Posterior Segment Lengths among a Myopia Population in Northern China

Bian,

Li,

Qin

et al. 2024

JCM

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“…14 Fourth-generation formulas, such as Haigis, also consider the preoperative anterior chamber depth. 6 , 7 These modern formulas for predicting IOL power have much greater accuracy; however, the anterior chamber depth cannot be measured in cases of intrascleral fixation because of lens displacement in patients presenting for preoperative assessment.…”

Section: Discussionmentioning

confidence: 99%

“…In cataract surgery, refractive prediction errors in intrascleral fixation reduce visual acuity in the naked eye and are a major cause of patient dissatisfaction. 6 , 7 We consider that preoperative biometric measurements and the choice of IOL power calculation formula are important. According to a clinical survey conducted by the Japanese Society of Cataract and Refractive Surgery in 2018, the SRK/T formula is still the most commonly used formula for IOL power calculation in Japan.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Refractive Prediction Error by Axial Length in Flanged Intrascleral Intraocular Lens Fixation

Kabata,

Oki,

Nakano

2024

OPTH

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Purpose To evaluate the refractive prediction error in flanged intrascleral intraocular lens (IOL) fixation using the SRK/T formula and compare the axial length using a single IOL. Methods Seventy-six eyes from 70 patients (45 males and 25 females) were included in this study. The mean age at the time of surgery was 73.4 ±12.3 years. The patients underwent flanged IOL fixation using a PN6A (Kowa). All surgeries were performed by two surgeons (Y. K. and T. O.) between Jan 2020 and Dec 2022 at Jikei University Daisan Hospital. IOL power was calculated using the SRK/T formula with IOL Master 700 (Carl Zeiss) as the bag power. The recommended value of 119.0 was used for the A-constant. The actual refractive spherical equivalent was calculated and compared with preoperative predictions. Refractive prediction errors were defined as the deviation of the actual postoperative spherical equivalent refraction in diopters from the predicted preoperative spherical equivalent refraction. The patients were divided into three groups according to axial length: <22.0 mm (short eyes), 22.0–24.5 mm (medium eyes), and >24.5 mm (long eyes), and the refractive prediction errors and mean absolute errors were compared. Results The mean refractive prediction error was −0.20 ± 0.52D. The mean absolute error was 0.44 ± 0.33D. The mean refractive prediction errors were not significantly different between the 22.0–24.5 mm (medium eyes) and >24.5 mm (long eyes) groups. (P=0.06) The mean absolute errors were not significantly different between the two groups (P=0.10). Conclusion The SRK/T formula worked well regardless of whether the eyes were medium or long according to the axial length in the flanged intrascleral IOL fixation.

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“…Based on an analysis of the relevant literature, Professor Achim Langenbucher from Saarland University, Germany, appeared most frequently in the field. This individual’s main research directions are eye surgeries, cataracts, and evaluating the accuracy of the most commonly used IOL power calculation formulas [ 33 ] ; describing the impact of formula constants on predicted refraction and limitations of constant optimization for classical and modern IOL power calculation formulas [ 34 ] ; and investigation of the characteristics of surgically induced astigmatism after standardized microincision cataract surgery with a superior limbal incision [ 35 ] .…”

Section: Discussionmentioning

confidence: 99%

Intraocular lens power calculation formulas: a scientometric analysis

Alshammari,

Tarazi,

Aloqaili

et al. 2023

Med Hypothesis Discov Innov Ophthalmol

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Background: The most accurate method of intraocular lens (IOL) power calculation in cataract surgery has not been determined, and further studies are needed to reach a consensus. The aim of this study was to assess publications related to IOL power calculation formulas, mapping their yearly trends, most productive authors, top publishing countries and institutions, and areas of specialization for IOL power formulas. Methods: We conducted a comprehensive analysis of research articles published on the topic of IOL power calculation formulas. Using PubMed, we employed appropriate search terms and filtered the results for the period of January 1, 1946, to June 28, 2023. Data were analyzed using CiteSpace, VOSviewer, and Microsoft Excel programs. The visual representations of the collected data through the use of figures was provided to demonstrate the aspects of IOL power calculation research. Results: We retrieved 5475 documents in the initial search. Analysis of these documents revealed an increase in the number of publications, from one publication in 1946 to 201 publications in 2023. The top three countries contributing to these publications were the United States, China, and Japan, collectively accounting for over 27% of the total articles. However, the two institutions with the highest contributions were located in the United Kingdom and Hungary, neither of which was among the top 10 countries in overall contributions. Overall 15326 authors contributed to publications pertaining to IOL power calculation formulas. Among these authors, the most prolific contributors included Achim Langenbucher from Saarland University (Germany), Giacomo Savini from G.B. Bietti Foundation I.R.C.C.S. (Italy), and Kenneth J Hoffer from the University of California (United States). Saarland University emerged as the most productive institution, contributing equally to two distinct departments: the Dr. Rolf M. Schwiete Center for Limbal Stem Cell Research and Congenital Aniridia, as well as the Department of Experimental Ophthalmology. The School of Physical Science at the Open University in the United Kingdom engaged in partnership with various institutions including Eye & Laser Clinic Castrop Rauxel in Germany and Johannes Kepler University Linz in Austria. Among the top 10 keywords found in the publications were “cataract”, “cataract surgery”, and “intraocular lens”. Conclusions: This study represents the first scientometric analysis of publications related to IOL power calculation formulas. The study offers valuable insights into the geographic distribution, contributing authors, and emphasis of research on the IOL power calculation formulas. Further cooperation is essential to pinpoint the most suitable formula and to address gaps in our current understanding.

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Intraocular Lens Power Calculation Formulas—A Systematic Review

Cited by 28 publications

References 63 publications

Ocular Biometry Features and Their Relationship with Anterior and Posterior Segment Lengths among a Myopia Population in Northern China

Ocular Biometry Features and Their Relationship with Anterior and Posterior Segment Lengths among a Myopia Population in Northern China

Comparison of Refractive Prediction Error by Axial Length in Flanged Intrascleral Intraocular Lens Fixation

Intraocular lens power calculation formulas: a scientometric analysis

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