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Anjali Tannan, Randy Epstein, Vanee Virasch, Parag Majmudar, Charles Faron, Jonathan Rubenstein; Utility of intraoperative wavefront aberrometry in post-refractive cataract patients. Invest. Ophthalmol. Vis. Sci. 2013;54(15):3004. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
To compare the accuracy of current intraocular lens (IOL) power formulas with intraoperative wavefront aberrometry in post-refractive cataract patients.
A retrospective chart review was performed on 30 eyes in 24 patients who underwent cataract extraction between April 2011 and October 2012 using the Optiwave Refractive Analysis (ORA) wavefront aberrometer system (WaveTec Vision System, Inc). All patients had a history of prior radial keratotomy (RK), Laser in situ keratomileusis (LASIK) or photorefractive keratoplasty (PRK). Biometry measurements were obtained preoperatively. The IOL power was calculated using the SRK/T or Holladay 1 formula and the ASCRS Post Keratorefractive IOL calculator (http://iolcalc.org/). The intraoperative ORA-recommended IOL power, the actual implanted IOL power, and the postoperative UCVA and manifest refraction were recorded. IOL back-calculation for emmetropia was done using previously published formulas (JCRS 2003;29:2063-2068). The two-tailed unpaired t-test was used to compare the refractive outcomes of the chosen IOL with the ORA, ASCRS calculator, and conventional formulas IOL predictions.
The study included 30 eyes of 24 patients. Twelve had a history of RK and 18 had previous myopic/hyperopic LASIK/PRK. Mean postoperative UCVA was 20/40. Mean postoperative spherical equivalent (SE) was 0.07D (R: -1.75 to +4.50D). There was a significant difference between the mean postoperative SE in the LASIK/PRK and RK groups (-0.31 and 0.63 respectively, p=0.039). The actual IOL implanted, ORA prediction, ASCRS calculator, and conventional formulas were within 0.5D of emmetropia in 66%, 53%, 43%, 23% of eyes and within 1D in 77%, 70%, 63%, and 47% respectively. In the LASIK/PRK cohort, the implanted IOL, ORA, ASCRS calculator and conventional formulas were within 0.5D of emmetropia in 94%, 72%, 33%, 17% and within 1D in 94%, 89%, 61%, and 50% of eyes. RK patients were within 0.5D of emmetropia in 25%, 25%, 58%, and 33% and within 1D in 50%, 42% 67%, and 41%. The ORA’s ability to predict IOL power was significantly better in LASIK/PRK patients than in RK patients (p=0.0064).
Combined use of the ORA, ASCRS calculator and conventional formulas to predict IOL power allows cataract surgeons to achieve better refractive outcomes than the use of any one method alone. The ORA’s ability to predict IOL power in LASIK/PRK patients is better than in RK patients.
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