scholarly journals Effects of posterior corneal astigmatism on the accuracy of AcrySof toric intraocular lens astigmatism correction

2016 ◽  
Keyword(s):  
Intraocular Lens ◽  
Corneal Astigmatism ◽  
Toric Intraocular Lens ◽  
Astigmatism Correction ◽  
Posterior Corneal Astigmatism

scholarly journals Toric Intraocular Lens Results Considering Posterior Corneal Astigmatism with Online Calculators: Phacoemulsification vs. Femtosecond

Optics ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 184-192
Author(s):  
Joaquín Fernández ◽  
Manuel Rodríguez-Vallejo ◽  
Noemí Burguera ◽  
Patrizia Salvestrini ◽  
Nuria Garzón
Keyword(s):  
Intraocular Lens ◽  
Univariate Analysis ◽  
Clinical Results ◽  
Corneal Astigmatism ◽  
Power Calculation ◽  
Toric Intraocular Lens ◽  
Iol Power Calculation ◽  
Astigmatism Correction ◽  
Iol Power ◽  
Posterior Corneal Astigmatism

To evaluate the prediction error (PE) obtained in Phacoemulsification (Phaco) or Femtosecond (Femto) surgeries without considering posterior corneal astigmatism correction (non-PCA) versus the correction based on Abulafia-Koch + Medicontur (AK) and Barrett calculators in toric intraocular lens (IOL) power calculation. 58 right eyes were retrospectively retrieved from our database. Two groups formed by 28 and 30 eyes depending on the surgery type, Phaco or Femto respectively, were defined. Astigmatism PE were evaluated considering the approach used for calculation of the implanted IOL power (AK) versus the estimation of PEs in non-PCA and Barrett formula. A doubly-multivariate analysis was conducted to assess the differences between-surgery types, within-methods of calculation, and interaction. Mean centroid PE was significantly different between non-PCA, AK and Barrett approaches (p < 0.0005), and neither differences (p < 0.239) nor interaction (p = 0.672) between Phaco or Femto were found. Post-hoc univariate analysis showed a higher PE for the x-component of the non-PCA method versus AK (0.15 D, p < 0.0005) and non-PCA versus Barrett (0.18 D, p < 0.0005), though no differences were found between AK and Barrett (0.03 D, p = 0.93). Against-the-rule under-correction and with-the-rule overcorrection were found in both arms when PCA was not considered. Both calculators provide comparable clinical results.

scholarly journals Long-term changes in the refractive effect of a toric intraocular lens on astigmatism correction

2021 ◽  
Author(s):  
Ken Hayashi ◽  
Motoaki Yoshida ◽  
Shunsuke Hayashi ◽  
Akira Hirata
Keyword(s):  
Intraocular Lens ◽  
Marked Change ◽  
Corneal Astigmatism ◽  
Toric Intraocular Lens ◽  
Toric Iol ◽  
Time Points ◽  
Astigmatism Correction ◽  
Ocular Residual Astigmatism ◽  
Long Term Changes

Abstract Purpose To examine the long-term changes in the astigmatism-correcting effect of a toric intraocular lens (IOL) after stabilization of surgically induced astigmatic changes due to cataract surgery. Methods Unilateral eyes of 120 patients that received a toric IOL for against-the-rule (ATR) or with-the-rule (WTR) astigmatism were enrolled. Manifest refractive and anterior corneal astigmatism, and ocular residual astigmatism which is mainly derived from internal optics were examined preoperatively, at approximately 2 months postoperatively (baseline) and at 5 ~ 10 years postbaseline. The astigmatism was decomposed to vertical/horizontal (Rx) and oblique components (Ry), which was compared between baseline and 5 ~ 10 years postbaseline. Results In the eyes having ATR astigmatism, the mean Rx and Ry of the manifest refractive and corneal astigmatism significantly changed toward ATR astigmatism between the baseline and 5 ~ 10 years postbaseline (p ≤ 0.0304), but those of ocular residual astigmatism did not change significantly between the 2 time points. In the eyes having WTR astigmatism, the Rx and Ry of refractive, corneal, and ocular residual astigmatism did not change significantly between the 2 time points. Double-angle plots revealed an ATR shift in refractive and corneal astigmatism and no marked change in the ocular residual astigmatism in the eyes with ATR astigmatism, and there is no change in this astigmatism in the eyes with WTR astigmatism. Conclusion The long-term changes with age in the effect of a toric IOL significantly deteriorated due to an ATR shift of corneal astigmatism in the eyes having ATR astigmatism, while it was maintained in eyes having WTR astigmatism, suggesting that ATR astigmatism should be overcorrected.

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