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109 EW RESIDENTS October 2016 underwent cataract surgery without adjusted IOL calculations, "Prospec- tive one-year evaluation of toric in- traocular lens in eyes with with-the- rule, against-the-rule and oblique astigmatism" by Ninomiya et al. in the October issue of the Journal of Cataract & Refractive Surgery summa- rizes the results of a 1-year follow-up of a prospective case series of 218 eyes (from 155 patients) implanted with single-piece hydrophobic acryl- ic toric IOLs. Follow-up outcomes of interest were: residual postoperative astigmatism magnitude and axis; postoperative visual acuity, contrast sensitivity, and higher-order aber- rations; and IOL rotational align- ment and stability. Patients ranged in age from 56 to 92 years, were roughly evenly split between male and female, and were required to have regular astigmatism resulting in toric IOL calculator recommen- dation of either a non-toric IOL or would be valuable for Goggin et al. to offer clearer justification for why they chose a geometric model to develop their nomogram. Finally, it would be helpful for the authors to offer more detail about the demo- graphic and biometric composition of their study cohort and historical controls—variables such as age, sex, race or ethnicity, and ocular param- eters may be important to consider in estimating the effects of posterior corneal astigmatism. 5, 12, 21–23 The above limitations notwith- standing, Goggin et al. offer an important step toward clinical validation of their previously de- rived nomogram, and their study highlights the importance and potential practical feasibility of refining existing toric IOL selection methodology to adjust for the role of posterior corneal astigmatism. On the related topic of IOL outcomes in astigmatic eyes that a toric IOL of no more than 3 D of cylinder power at the IOL plane. Eyes with history of previous ocular surgery or other ocular diseases that could affect surgical outcomes were excluded. All eyes underwent phacoemulsification using a 12 o'clock self-sealing sclerocorneal incision. The authors compared out- comes among different IOL models and also among different preopera- tive astigmatism categories. The authors' main conclusions are as follows: (1) both absolute postoperative astigmatism and error in predicted residual astigmatism were lower among eyes with preop- erative WTR than ATR or oblique astigmatism, but did not differ among eyes implanted with differ- ent toric IOL models; (2) toric IOL misalignment on postoperative day 1 was within 10 degrees in 84% of eyes, and rotation from day 1 to year 1 was within 10 degrees in 99% of eyes; and (3) neither contrast sensi- tivity nor ocular wavefront aberra- tions significantly varied with axis of preoperative astigmatism or type of implanted toric IOL. Consistent with previous reports, the authors also found a tendency for postop- erative residual astigmatism to be shifted toward the ATR direction. Particularly thought-provoking are Outcome of adjustment for posterior corneal curvature in toric intraocular lens calculation and selection Michael Goggin, FRCSI(Ophth), FRCOphth, Lourens van Zyl, FCOphth, MMed(Ophth), Silvestro Caputo MD, Adrian Esterman, PhD J Cataract Refract Surg. 2016;42(10). Article in press Purpose: Posterior corneal curvature affects total corneal refractive power related to the "rule" of the anterior corneal surface. Inclusion of the posterior corneal astigmatism in toric IOL calculation is required to improve outcome. The aim of this study is to present the accuracy of the IOL cylinder power choice and the astigmatic refractive outcome in eyes implanted with toric IOLs calculated using a nomogram that allows for the likely effect of posterior corneal astigmatism. Setting: Publicly funded hospital. Design: Observational case series compared with historic controls. Methods: Subjects: 31 consecutive eyes in 29 patients with preoperative anteriorly keratometric cylinder values of 1 D or more compared to a historical control group of 65 eyes. Intervention procedure: anteriorly measured keratometric cylinder values were altered by two coefficients of adjustment, one for WTR eyes and one for ATR eyes, before calculation of the IOL cylinder power to be implanted. For the controls, unadjusted keratometric cylinder values were used. Main outcome measure: absolute value of the prediction error of the toric IOL cylinder power effect, comparing adjusted eyes with controls. Results: The absolute error in prediction of the toric IOL cylinder power effect was reduced from a median (95% CI) of 0.45 D (0.33–0.58) in the controls to a median (95% CI) of 0.23 D (0.13–0.35) (p=0.004). Conclusions: Adjustment of toric IOL cylinder power by a coefficient of adjustment to anteriorly measured keratometric cylinder values based on the keratometric "rule" of the eye leads to a clinically and statistically significant improvement in refractive astigmatic outcome. continued on page 110 Prospective one-year evaluation of toric intraocular lens in eyes with with-the-rule, against-the-rule and oblique astigmatism Yoshihiko Ninomiya, MD, Keiichiro Minami, PhD, Kazunori Miyata, MD, Shuichiro Eguchi, MD, Rie Sato, MD, Fumiki Okamoto, MD, and Tetsuro Oshika, MD J Cataract Refract Surg. 2016;42(10). Article in press Purpose: To assess 1-year clinical results of toric intraocular lenses (IOLs) in eyes with corneal with-the-rule (WTR), against-the-rule (ATR), and oblique (OBL) astigmatism. Setting: Four ophthalmic surgical sites in Japan. Design: Prospective case series. Methods: Subjects were 218 eyes of 155 patients undergoing phacoemulsification and IOL implantation. Based on the suggestion of an online toric calculator with anterior corneal curvature data, 63 eyes received the SN6AT3 (AcrySof IQ toric), 55 eyes SN6AT4, 58 eyes SN6AT5, and 42 eyes SN60WF (AcrySof IQ non-toric). Results: One hundred ninety-four eyes (89.0%) completed 1-year follow-up. The centroid error in predicted residual astigmatism calculated using vector analysis was close to the origin in eyes with WTR astigmatism (0.17 D @174.9 degrees±0.54 D), while those with ATR (0.44 D @176.0 degrees±0.67 D), and OBL astigmatism (0.70 D @176.9 degrees±0.74 D) were significantly shifted toward the against-the-rule direction (p<0.001). The distance from the origin was significantly smaller in WTR than in ATR and OBL groups (p<0.05). The centroid errors in eyes with SN6AT3~5 were all shifted toward against-the-rule (p<0.001), but the distance from the origin was not different among groups (p=0.52). The mean absolute misalignment of IOL was 5.92±5.59 degrees at 1 day and 6.24±5.87 degrees at 1 year postoperatively. The mean absolute rotation from 1 day to 1 year after surgery was 2.26±2.13 degrees. The results of other clinical parameters, such as uncorrected and corrected visual acuity, higher-order aberration, and contrast sensitivity, were excellent, with no significant differences among astigmatism categories and IOL models. Conclusions: Based on anterior corneal curvature alone, toric IOLs undercorrect ATR and OBL astigmatism, but 1-year clinical results of toric IOLs were highly stable and satisfactory.

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