Astigmatism, coupled with cataracts, seems to be as frequent as the common cold; a dataset of 15,000-plus cataract patients showed that 46.8% of eyes had astigmatism with the rule; 34.4% had astigmatism against the rule; and those with the oblique type, 18.9%.¹ A toric IOL would seem in order for these patients, but which one? Some tend to move after placement, and a lot of movement could make the IOL placement nearly a moot exercise. For every degree that the toric lens is off its intended mark, an approximate 3.3% decrease in efficacy ensues.²

“Stability is critical when you have presbyopia and astigmatism. You want rotational stability,” said Sergio Duplan, region president for Alcon’s North American operations, in an interview earlier this year. Alcon’s AcrySof IQ ReStor +2.5 D multifocal IOL, he said, is a stable toric IOL.

Positioned in the eye’s posterior chamber, the +2.5 D, built on a haptic platform, is indicated for placement during cataract surgery; it is designed to correct presbyopia and astigmatism.

Research seems to confirm its stability. In an August 2016 article published in Dove Press, researchers looked at various toric IOLs on the market. What they found: the ReStor +2.5 moved (n=1953) 0.75% unintentionally off target.³

Toric IOLs also have other patient-favoring characteristics. In a February 2016 study published in Ophthalmology, researchers looked at 13 randomized controlled trials, splitting 1,413 eyes between toric and nontoric IOLs.

They found “high-quality” evidence of better uncorrected distance visual acuity (logMAR mean difference, -0.07); greater spectacle independence; and “moderate quality evidence that IOL implantation was not associated” with a greater risk of complications.⁴ OM

REFERENCES

1. Hoffmann PC, Hütz WW. Analysis of biometry and prevalence data for corneal astigmatism in 23,239 eyes. J Cataract Refract Surg. 2010;36:1479-1485.
2. Felipe A, Artigas JM, Díez-Ajenjo A, García-Domene C, Alcocer P. Residual astigmatism produced by toric intraocular lens rotation. J Cataract Refract Surg. 2011;37:1895-1901.
3. Potvin R, Kramer BA, Hardten DR, Berdahl JP. Toric intraocular lens orientation and residual refractive astigmatism: an analysis. Clin Ophthalmol. 2016;10:1829-1836.
4. Kessel L, Andresen J, Tendal B, et al. Toric intraocular lenses in the correction of astigmatism during cataract surgery: a systematic review and meta-analysis. Ophthalmology. 2016;123:275-286.