Klin Monbl Augenheilkd 2022; 239(08): 960-970
DOI: 10.1055/a-1896-0738
Übersicht

Update on Biometry and Lens Calculation – A Review of the Basic Principles and New Developments

Article in several languages: deutsch | English
1   IROC, Institut für Refraktive und Ophthalmo-Chirurgie, Zürich, Schweiz
2   Abteilung für Augenheilkunde und Optometrie, Johannes Kepler Universität Linz, Österreich
3   Institut für Experimentelle Ophthalmologie, Universität des Saarlandes, Homburg/Saar, Deutschland
,
Thomas Kohnen
4   Klinik für Augenheilkunde, Goethe-Universität, Frankfurt, Deutschland
,
Marina Casazza
2   Abteilung für Augenheilkunde und Optometrie, Johannes Kepler Universität Linz, Österreich
,
Michael Heath
5   College of Medicine, University of Oklahoma, Norman, Oklahoma, United States
,
6   University of Oklahoma, Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States
,
David L. Cooke
7   Great Lakes Eye Care, Saint Joseph, United States
8   Department of Neurology and Ophthalmology, Michigan State University, East Lansing, Michigan, United States
,
Peter Hoffmann
9   Augen- und Laserklinik Castrop-Rauxel, Deutschland
,
Achim Langenbucher
3   Institut für Experimentelle Ophthalmologie, Universität des Saarlandes, Homburg/Saar, Deutschland
› Author Affiliations

Abstract

These days, accurate calculation of artificial lenses is an important aspect of patient management. In addition to the classic theoretical optical formulae there are a number of new approaches, most of which are available as online calculators. This review aims to explain the background of artificial lens calculation and provide an update on study results based on the latest calculation approaches. Today, optical biometry provides the computational basis for theoretical optical formulae, ray tracing, and also empirical approaches using artificial intelligence. Manufacturer information on IOL design and IOL power recorded as part of quality control could improve calculations, especially for higher IOL powers. With modern measurement data, there is further potential for improvement in the determination of the axial length to the retinal pigment epithelium and by adopting a sum-of-segment approach. With the available data, the cornea can be assumed to be a thick lens. The Kane formula, the EVO 2.0 formula, the Castrop formula, the PEARL-DGS, formula and the OKULIX calculation software provide consistently good results for artificial lens calculations. Excellent refractive results can be achieved using these tools, with approximately 80% having an absolute prediction error within 0.50 dpt, at least in highly selected study populations. The Barrett Universal II formula also produces excellent results in the normal and long axial length range. For eyes with short axial lengths, the use of Barrett Universal II should be reconsidered; in this case, one of the methods mentioned above is preferable. Second Eye Refinement can also be considered in this patient population, in conjunction with established classic third generation formulae.



Publication History

Received: 27 June 2022

Accepted: 30 June 2022

Article published online:
16 August 2022

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