Determining the imaging quality of intraocular lenses

Autor: Christine F. Dr. Kreiner, Edward P. Geraghty, Laurence W. Grossman, Anil S. Patel, Donn M. Silberman, N.E. Sverker Norrby, Masatoshi Mihori, Valdemar Portney
Rok vydání: 1998
Předmět:
Zdroj: Journal of cataract and refractive surgery. 24(5)
ISSN: 0886-3350
Popis: Purpose: To validate the proposed optical requirements of a draft international standard for intraocular lenses (IOLs). Setting: Eight optical testing laboratories in the United States, Germany; Japan, and The Netherlands. Methods: The testing laboratories performed modulation transfer function (MTF) tests on various IOLs using a model eye and visual resolution tests in air. Each laboratory performed duplicate measurements on a set of 43 lenses that was circulated among the testing laboratories. Results: The interlaboratory tests showed that the MTF measurements using a model eye had better repeatability and reproducibility than the more common industry practice of resolution testing in air with parallel light and the United States Air Force three-bar target. However, the two methods correlated well. The commonly applied criterion that an IOL resolve in air at least 60% of the Rayleigh cutoff spatial frequency corresponded to a minimum requirement of 0.43 MTF units at 100 mm−1 in a model eye. Conclusions: Either criterion may be applied in accordance with a proposed international standard for IOLs. The model eye method can be applied over a broader range of dioptric powers and is relevant for materials that interact with aqueous. Both tests appear to have a greater ability to detect unwanted surface aberrations than resolution testing of IOLs in a water cell using parallel light, a method described in the current American National Standards Institute standard.
Databáze: OpenAIRE