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Biometry accuracy using zero- and negative-powered intraocular lenses.

Robert E MacLaren·Mandeep S Sagoo·Marie Restori·Bruce D S Allan
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Abstract

PURPOSE: To audit the accuracy of biometry using the SRK/T formula when negative- or zero-powered intraocular lenses (IOLs) are predicted and to compare the results between A-scan, B-scan, and optical methods of biometry. SETTING: Moorfields Eye Hospital, London, United Kingdom. METHODS: This retrospective analysis comprised 78 eyes of 54 patients having cataract surgery with zero- or negative-powered IOLs. Axial lengths were measured with A-scan, B-scan, applanation, or optical methods. Differences between SRK/T-predicted and actual postoperative refraction were analyzed for 75 eyes having cataract surgery. Ocular comorbidity, visual acuity, and biometry readings were also compared. RESULTS: Forty-one percent of 75 patients analyzed were within +/-1.00 diopter (D) of the predicted refraction, although there was a significant tendency toward a hyperopic overcorrection by 1.14 D (95% confidence interval, 0.89-1.39 D). This overcorrection error was consistent across all 3 biometry methods used to estimate axial length and increased with the use of stronger (more negative) IOLs. CONCLUSION: Surgeons should be aware of the tendency for negative-powered lenses to overcorrect and lead to a hyperopic outcome when using the SRK/T biometry formula in highly myopic eyes. A weaker-powered negative IOL is recommended to aim for a more myopic postoperative outcome by about 1.00 to 2.00 D.

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Accommodation, OcularBiometryHumansLens Implantation, IntraocularLenses, IntraocularMyopiaPhacoemulsificationRefraction, OcularReproducibility of ResultsRetrospective StudiesComparative StudyJournal Article

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BibTeXRIS

Robert E MacLaren, Mandeep S Sagoo, Marie Restori, Bruce D S Allan. 2005. Biometry accuracy using zero- and negative-powered intraocular lenses.. https://doi.org/10.1016/j.jcrs.2004.04.054

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