The Effect of Lens Sphere and Cylinder Power on Residual Astigmatism and Its Resolution After Toric Intraocular Lens Implantation.

PURPOSE To analyze correlations between residual refractive cylinder (and its correction through lens reorientation) with the sphere and cylinder power of the toric intraocular lens (IOL) implanted. METHODS An online toric back-calculator (www.astigmatismfix.com) allows users to input toric IOL planning data, along with postoperative IOL orientation and refractive results; these data are used to determine the optimal orientation of the IOL to reduce refractive astigmatism. This was a retrospective data analysis; aggregate historical data were extracted from this calculator to investigate the relationship between residual refractive astigmatism and IOL cylinder and sphere power. RESULTS A total of 12,812 records, 4,619 of which included IOL sphere power, were available for analysis. There was no significant effect of sphere power on residual refractive astigmatism (P = .25), but lower IOL cylinder powers were associated with significantly lower residual refractive astigmatism (P < .05). The difference between the intended and ideal orientation was higher in the lower IOL cylinder power groups (P < .01). Overcorrection of astigmatism was significantly more likely with higher IOL cylinder power (P < .01), but not with sphere power (P = .33). Reorientation to correct residual refractive cylinder to less than 0.50 diopters (D) was more successful with IOL cylinder powers of 1.50 D or less (P < .01); IOL sphere power had no apparent effect. CONCLUSIONS There were significant effects of IOL cylinder power on residual refractive astigmatism, the difference between intended and ideal orientation, the likelihood of overcorrection, and the likelihood of astigmatism reduction with lens reorientation. IOL sphere power appeared to have no such effects. [J Refract Surg. 2017;33(3):157-162.].

[1]  R. Potvin,et al.  Residual astigmatism after toric intraocular lens implantation: Analysis of data from an online toric intraocular lens back‐calculator , 2016, Journal of cataract and refractive surgery.

[2]  R. Potvin,et al.  Toric intraocular lens orientation and residual refractive astigmatism: an analysis , 2016, Clinical ophthalmology.

[3]  J. Hjortdal,et al.  Toric Intraocular Lenses in the Correction of Astigmatism During Cataract Surgery: A Systematic Review and Meta-analysis. , 2016, Ophthalmology.

[4]  G. Grabner,et al.  Randomized controlled clinical trial to evaluate different intraocular lenses for the surgical compensation of low to moderate‐to‐high regular corneal astigmatism during cataract surgery , 2015, Journal of cataract and refractive surgery.

[5]  H. Helaly,et al.  Comparison Between Digital and Manual Marking for Toric Intraocular Lenses , 2015, Medicine.

[6]  Yong Yeon Kim,et al.  Comparison of SRK/T and Haigis formulas for predicting corneal astigmatism correction with toric intraocular lenses , 2015, Journal of cataract and refractive surgery.

[7]  Xiangjia Zhu,et al.  Factors influencing 1-year rotational stability of AcrySof Toric intraocular lenses , 2015, British Journal of Ophthalmology.

[8]  Young Jae Woo,et al.  Comparison of the Astigmatic Power of Toric Intraocular Lenses Using Three Toric Calculators , 2015, Yonsei medical journal.

[9]  D. Koch,et al.  Prediction of refractive outcomes with toric intraocular lens implantation , 2015, Journal of cataract and refractive surgery.

[10]  A. Esterman,et al.  Adjustment of anterior corneal astigmatism values to incorporate the likely effect of posterior corneal curvature for toric intraocular lens calculation. , 2015, Journal of refractive surgery.

[11]  G. Savini,et al.  An analysis of the factors influencing the residual refractive astigmatism after cataract surgery with toric intraocular lenses. , 2015, Investigative ophthalmology & visual science.

[12]  Linda M Tsai,et al.  Clinical outcomes of TECNIS toric intraocular lens implantation after cataract removal in patients with corneal astigmatism. , 2015, Ophthalmology.

[13]  K. Shimizu,et al.  Long‐term clinical outcomes of toric intraocular lens implantation in cataract cases with preexisting astigmatism , 2014, Journal of cataract and refractive surgery.

[14]  Oliver Findl,et al.  Evaluation of factors influencing the remaining astigmatism after toric intraocular lens implantation. , 2014, Journal of refractive surgery.

[15]  S. Masket,et al.  Prospective multicenter study of toric IOL outcomes when dual zone automated keratometry is used for astigmatism planning. , 2013, Journal of refractive surgery.

[16]  R. Nuijts,et al.  Toric intraocular lenses: Historical overview, patient selection, IOL calculation, surgical techniques, clinical outcomes, and complications , 2013, Journal of cataract and refractive surgery.

[17]  A. Vasavada,et al.  Rotational stability of a toric intraocular lens: Influence of axial length and alignment in the capsular bag , 2012, Journal of cataract and refractive surgery.

[18]  W. Hütz,et al.  Analysis of biometry and prevalence data for corneal astigmatism in 23 239 eyes , 2010, Journal of cataract and refractive surgery.

[19]  S. Tseng,et al.  Calculating the optimal rotation of a misaligned toric intraocular lens , 2008, Journal of cataract and refractive surgery.

[20]  Warren Hill,et al.  Expected effects of surgically induced astigmatism on AcrySof toric intraocular lens results , 2008, Journal of cataract and refractive surgery.