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IOL calculation concepts
Author(s) -
Langenbucher Achim
Publication year - 2019
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2019.5022
Subject(s) - vergence (optics) , intraocular lens , intraocular lens power calculation , offset (computer science) , optometry , lens (geology) , mathematics , optics , computer science , medicine , physics , cornea , keratometer , programming language
The first intraocular lenses implanted resampled the shape of the natural lens and resulted in high postoperative myopia. First attempts to preoperatively calculate the intraocular lens (IOL) power by vergence formulas were presented by Fjodorov in 1967. Other authors soon followed presenting numerous attempts to estimate the required IOL power. While most of the calculation schemes nowadays are based on the vergence formula, there were also empirical approaches such as the SRK and SRK‐II formulas. Beside different interpretation of corneal power from the measured radii of curvature and several offset values, the main difference between formulas is in the estimation of the effective lens position (reference plane of the thin lens in the pseudophakic eye) (ELP): We will present various approaches for calculating IOL power and discuss differences between formulas as well as the pros and cons of these different concepts.