Publication
Title
Spherotoric bag-in-the-lens intraocular lens : power calculation and predictive misalignment nomogram
Author
Abstract
Purpose To propose a method of calculating the power of the 1-sided posterior chamber toric bag-in-the-lens (BIL) intraocular lens (IOL) and propose a misalignment nomogram to calculate the postoperative rotational misalignment or predict the effect of preoperative existing irregular corneal astigmatism. Setting Antwerp University Hospital, Department of Ophthalmology, Antwerp, Belgium. Design Cohort study. Methods The new IOL calculation formula uses the steepest corneal meridian and flattest corneal meridian separately (regular spherical IOL formula) followed by a customized A-constant approach based on the changes in the IOL principal plane depending on the spherical and cylindrical powers (thickness) of the IOL. The calculation of the remaining astigmatism (power and axis) in cases of postoperative rotational misalignment resulted in a nomogram that can also be used to predict the degree of tolerance for irregular corneal astigmatism correction at the lenticular plane. The calculation is performed using a worksheet. Results Because 10 degrees of misalignment would result in 35% refractive inaccuracy, it is the maximum acceptable corneal astigmatic irregularity for correction at the lenticular plane. Conclusions Calculation of spherocylindrical power is specific to each toric IOL. Because the surgeon must fully understand the optical properties of the toric IOL that is going to be implanted, a comprehensive outline of a new calculation method specific to the toric BIL IOL is proposed. Primary rotational misalignment of the toric BIL IOL can be fine tuned postoperatively. Financial disclosure Drs. Gobin and Mathysen have no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.
Language
English
Source (journal)
Journal of cataract and refractive surgery. - Fairfax, Va
Publication
Fairfax, Va : 2011
ISSN
0886-3350
Volume/pages
37:6(2011), p. 1020-1030
ISI
000291714900008
Full text (Publishers DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 28.07.2011
Last edited 13.04.2017
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