RESEARCH ARTICLE


Efficacy and Safety of Cataract Extraction with Negative Power Intraocular Lens Implantation§



Michael A Kapamajian1, Kevin M Miller*, 2, #
1 From the Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago Eye and Ear Infirmary, USA
2 From the Department of Ophthalmology, David Geffen School of Medicine at UCLA and the Jules Stein Eye Institute, Los Angeles, California, USA


2008 Bentham Science Publishers Ltd

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.

* Address correspondence to this author at the Department of Ophthalmology, David Geffen School of Medicine at UCLA and the Jules Stein Eye Institute, Los Angeles, California 90095-7002, USA; E-mail: miller@jsei.ucla.edu
§ Presented in part at the annual meeting of the American Society of Cataract and Refractive Surgery, San Francisco, California, April 2003.
# Dr. Miller is the Kolokotrones Professor of Clinical Ophthalmology at UCLA.


Abstract

Purpose:

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.

Design:

Interventional case series.

Methods:

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.

Results:

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.

Conclusions:

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.