Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Chemical Formulas02:52

Chemical Formulas

61.0K
A chemical formula presents information about the proportions of atoms constituting a particular chemical compound or molecule, mainly using symbols of elements and numbers. At times other symbols, such as dashes, parentheses, brackets, commas, plus, and minus signs, are also used. A chemical formula can be one of three types – molecular, empirical, and structural.
61.0K
Uncertainty in Measurement: Accuracy and Precision03:37

Uncertainty in Measurement: Accuracy and Precision

100.5K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value. 
100.5K
Ionic Compounds: Formulas and Nomenclature03:34

Ionic Compounds: Formulas and Nomenclature

86.3K
An element composed of atoms that readily lose electrons (a metal) can react with an element composed of atoms that readily gain electrons (a nonmetal) to produce ions through complete electron transfer. The compound formed by this transfer is stabilized by the electrostatic attractions (ionic bonds) between the oppositely charged ions.
86.3K
Formula Mass and Mole Concepts of Compounds02:56

Formula Mass and Mole Concepts of Compounds

80.8K
Formula Mass of Covalent Compounds
80.8K
Molecular Compounds: Formulas and Nomenclature03:10

Molecular Compounds: Formulas and Nomenclature

55.4K
Molecular compounds or covalent compounds result when atoms share electrons to form covalent bonds. Since there is no electron transfer, molecular compounds do not contain ions; instead, they consist of discrete, neutral molecules. 
55.4K
Experimental Determination of Chemical Formula02:37

Experimental Determination of Chemical Formula

46.5K
The elemental makeup of a compound defines its chemical identity, and chemical formulas are the most concise way of representing this elemental makeup. When a compound’s formula is unknown, measuring the mass of its constituent elements is often the first step in determining the formula experimentally.
46.5K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Reply : Randomized comparative multicenter study assessing two dispersive viscosurgical devices for cataract surgery.

Journal of cataract and refractive surgery·2026
Same author

Randomized comparative multicenter study assessing two dispersive viscosurgical devices for cataract surgery.

Journal of cataract and refractive surgery·2025
Same author

Quality Assurance in Cataract and Lens Surgery with Special Consideration of Subjective Patient Reported Outcome Measures and Clinical Reported Outcome Measures.

Klinische Monatsblatter fur Augenheilkunde·2021
Same author

Considerations on the Castrop formula for calculation of intraocular lens power.

PloS one·2021
Same author

[Back-calculation of the keratometer index-Which value would have been correct in cataract surgery?]

Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft·2020
Same author

Prevention of lens capsule opacification with ARC neodymium:YAG laser photolysis after phacoemulsification.

Journal of cataract and refractive surgery·2010

Related Experiment Video

Updated: Jan 23, 2026

Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation
04:59

Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation

Published on: July 7, 2023

3.0K

Prediction Accuracy of Total Keratometry Compared to Standard Keratometry Using Different Intraocular Lens Power

Ekkehard Fabian, Wolfram Wehner

    Journal of Refractive Surgery (Thorofare, N.J. : 1995)
    |June 12, 2019
    PubMed
    Summary

    Total Keratometry (TK) improves intraocular lens (IOL) power calculation accuracy compared to standard keratometry (K). Using TK with new formulas resulted in lower prediction errors for both spherical equivalent and cylinder, enhancing refractive outcomes.

    More Related Videos

    Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application
    11:49

    Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application

    Published on: March 8, 2019

    13.1K
    Measuring the Behavioral Effects of Intraocular Scatter
    05:10

    Measuring the Behavioral Effects of Intraocular Scatter

    Published on: February 18, 2021

    3.9K

    Related Experiment Videos

    Last Updated: Jan 23, 2026

    Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation
    04:59

    Author Spotlight: Enhancing Visual Outcomes in Cataract Surgery: A Novel Technique to Prevent Posterior Capsular Opacification Through IOL Rotation

    Published on: July 7, 2023

    3.0K
    Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application
    11:49

    Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application

    Published on: March 8, 2019

    13.1K
    Measuring the Behavioral Effects of Intraocular Scatter
    05:10

    Measuring the Behavioral Effects of Intraocular Scatter

    Published on: February 18, 2021

    3.9K

    Area of Science:

    • Ophthalmology
    • Refractive Surgery
    • Biomedical Optics

    Background:

    • Accurate intraocular lens (IOL) power calculation is crucial for achieving desired refractive outcomes after cataract surgery.
    • Standard keratometry (K) measurements may not fully capture the cornea's refractive power, potentially leading to prediction errors.
    • Total Keratometry (TK), which includes posterior corneal surface data, offers a more comprehensive assessment of corneal power.

    Purpose of the Study:

    • To compare the accuracy of IOL power calculations using standard keratometry (K) versus the novel Total Keratometry (TK).
    • To evaluate the performance of established and new IOL calculation formulas with both K and TK data.

    Main Methods:

    • A post-hoc analysis of 145 pseudophakic astigmatic eyes was performed.
    • Absolute prediction error (APE) for spherical equivalent (SE) and cylinder (CYL) was calculated using K and TK data.
    • Comparisons were made between standard formulas (Haigis-T, Barrett Universal II, Barrett Toric) using K, and new TK-based formulas (Barrett TK Universal II, Barrett TK Toric).

    Main Results:

    • Mean APE for both SE and CYL was significantly lower when using TK compared to K.
    • TK-based formulas demonstrated improved accuracy, with a higher percentage of eyes achieving APE within ±0.50 D for both SE and CYL.
    • Specifically, APE in CYL was reduced from 44% (K) to 58% (TK) within ±0.50 D using the Haigis formula.

    Conclusions:

    • Total Keratometry (TK) provides higher prediction accuracy for IOL power calculations compared to standard keratometry (K).
    • Newly developed TK-based formulas, such as Barrett TK Universal II and Barrett TK Toric, enhance refractive predictability.
    • TK data is compatible with existing IOL calculation formulas and optimized IOL constants, facilitating clinical integration.