Efficacy and Safety of Cataract Extraction with Negative Power Intraocular Lens Implantation§
Michael A Kapamajian1, Kevin M Miller*, 2, #
Identifiers and Pagination:Year: 2008
First Page: 15
Last Page: 19
Publisher Id: TOOPHTJ-2-15
Article History:Received Date: 1/1/2008
Revision Received Date: 18/1/2008
Acceptance Date: 20/1/2008
Electronic publication date: 15/2/2008
Collection year: 2008
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
To evaluate the visual and refractive outcomes, lens power calculation accuracy, and safety of negative power intraocular lenses (IOLs) implanted in highly myopic eyes at the time of cataract surgery.
Interventional case series.
Sixteen consecutive highly myopic eyes implanted with IOLs from –1 D to –6 D were identified. IOL power; preoperative and postoperative best-corrected visual acuity (BCVA); postoperative uncorrected visual acuity (UCVA); preoperative, intended, and achieved spherical equivalent (SE) refractive errors; and operative complications were recorded.
Median UCVA improved from finger counting to 20/50-2. Median BCVA improved from 20/125-1 to 20/30+1. Mean axial length was 32.65 mm. The mean SE refractive error was –22.19 ± 5.4 D before surgery and -0.28 ± 1.4 D after surgery. The difference between the mean intended and mean achieved SE refractive errors was +1.16 D for the SRK/T, +1.2 D for the Holladay 1, and +1.60 D for the Hoffer Q formulas. Only 5 (33.3%) of 15 eyes in which postoperative measurements were possible were within 1 D of the intended SE postoperative refraction. Postoperative complications included a mildly hyperopic postoperative refractive error (+1.75 D) in one eye necessitating an IOL exchange and posterior capsule opacification in most eyes. There were no retinal detachments.
The SRK/T formula had the greatest accuracy and predictability when immersion A-scan ultrasonography was used to measure axial length. The mean achieved postoperative refractive error was +1.16 D more hyperopic than predicted by this formula. We recommend targeting highly myopic eyes for –1.5 D using the SRK/T formula if a negative power IOL is calculated and emmetropia or mild residual myopia is the desired postoperative result.