&lt;p&gt;Contribution of Posterior Corneal Astigmatism to Total Corneal Astigmatism in a Sample of Egyptian Population&lt;/p&gt;

Hosny, Mohamed; Badawy, Alaa; Khazbak, Lobna; Anis, Mohamed; Azzam, Sarah

doi:10.2147/opth.s265647

Cited by 9 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…reported that the PCA was 0.11 ± 0.24 D in the ATR eyes contributing to 8% to the TCA, which is less compared to our result. 12 This discrepancy may be due to the fact that the patients enrolled in their study were younger population aged from 18 to 45 years old. As various studies had established that the ACA gradually shifted from WTR to ATR while the change of the posterior surface of the cornea is much less.…”

Section: Discussionmentioning

confidence: 93%

The impact of posterior corneal astigmatism on the surgical planning of toric multifocal intraocular lens implantation

Jiang²,

Gao³

et al. 2023

Advances in Ophthalmology Practice and Research

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 93%

The impact of posterior corneal astigmatism on the surgical planning of toric multifocal intraocular lens implantation

Jiang²,

Gao³

et al. 2023

Advances in Ophthalmology Practice and Research

View full text Add to dashboard Cite

“…Previous studies have shown that ignoring the posterior corneal surface may lead to inaccurate estimation of total corneal power and astigmatism in some eyes. [1][2][3][4] Even though the K value considers the effect of PCA in calculations using mathematical extrapolation, these methods do not consider outliers and irregularities into account. [5][6][7] The latest modalities, such as Pentacam, Galilei, and IOLMaster 700, allow obtaining TCRP via direct measurement instead of estimating the posterior corneal curvature, which is a promising tool for determining toric IOL cylinder power.…”

Section: Discussionmentioning

confidence: 99%

“…However, over the past few years, the effect of posterior corneal astigmatism (PCA) during toric intraocular lens (IOL) implantation has received considerable attention. [1][2][3][4] One of the strategies to minimize the effects of PCA is to optimize K astigmatism using nomograms, 5 regression equations, 6 or mathematical models. 7 However, these methods are based solely on mathematical extrapolation and do not consider individual differences.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intraocular lens constant optimization in toric intraocular lens calculation using keratometry and total corneal power

Liang

Liu

Zhou

et al. 2022

European Journal of Ophthalmology

View full text Add to dashboard Cite

Purpose To evaluate intraocular lens (IOL) constant optimization in toric IOL calculation with keratometry (K) and total corneal refractive power (TCRP). Methods Predicted spherical equivalent (SE) and residual astigmatism (RA) with K and TCRP were retrospectively calculated using the Haigis, Holladay 1, and SRK/T formulae and optimized IOL constants. The results of the Barrett calculator and the Abulafia–Koch formula with K were also calculated. The median absolute error in SE (MedAE-SE), mean absolute error in RA (MAE-RA), and centroid error (CE) were analyzed. Results Seventy-nine eyes of 71 patients implanted with toric IOLs were included. With K, there were no significant differences between the results before and after constant optimization using all the formulae. With TCRP, constant optimization significantly reduced MedAE-SE; however, significantly increased MAE-RA and CE using the Holladay 1 and SRK/T formulae. MedAE-SE, MAE-RA, and CE using the Haigis formula did not show significant differences. The difference in the predicted RA before and after constant optimization increased with IOL toricity. The MedAE-SE predicted by TCRP was significantly higher than that predicted by K despite constant optimization. The MAE-RA and CE predicted by TCRP were significantly lower than those predicted by K without posterior corneal astigmatism optimization; however, were not significantly different from those predicted by the Barrett and Abulafia-Koch formulae. Conclusions Constant optimization is recommended when using the TCRP in toric IOL calculations, particularly for patients with large astigmatism. However, TCRP did not yield more accurate results than optimized K in toric IOL calculations despite constant optimization.

show abstract

“…With the application of toric and presbyopia-correcting intraocular lens (IOL, toric IOL and PC-IOL), precise assessment of preoperative corneal astigmatism (CA) has played an increasingly important role in the past twenty years [1][2][3][4]. The larger the CA, the poorer the postoperative visual acuity at all distances after implantation of either monofocal or multifocal IOLs [5,6].…”

Section: Introductionmentioning

confidence: 99%

Comparison of Total Corneal Astigmatism between IOLMaster and Pentacam

Cao

Bao

2022

BioMed Research International

View full text Add to dashboard Cite

Purpose. To compare the total corneal astigmatism (TCA) measured by IOLMaster 700 and Pentacam and to investigate the consistency of corneal keratometry (CK) measured by IOLMaster and Pentacam. Methods. Cataract patients were retrospectively enrolled in March and April, 2021. Retrospective analysis was performed on those patients with binocular and monocular CK measured by IOLMaster and Pentacam. Results. A total of 102 patients (204 eyes) were included, 64 of whom were female (62.75%). The flat (K1) and steep (K2) CK of anterior corneal surface (ACS) and flat (TK1) and steep (TK2) of total cornea measured with IOLMaster 700 were 44.16 ± 1.60 D , 45.09 ± 1.68 D , 44.12 ± 1.62 D , and 45.14 ± 1.69 D , respectively. Those measured with Pentacam were 44.31 ± 1.57 D , 45.22 ± 1.65 D , 44.15 ± 1.67 D , and 45.19 ± 1.82 D , respectively. The astigmatism of ACS and TCA were − 0.94 ± 0.63 D and − 1.02 ± 0.69 D ( p < 0.01 ) in the IOLMaster group and − 0.90 ± 0.59 D and − 1.05 ± 0.81 D in the Pentacam group, respectively ( p < 0.01 ). TCA measurement results of IOLMaster and Pentacam were consistent ( Pearson = 0.710 , p < 0.01 ), and there was no significant difference ( p = 0.591 ). Conclusions. Total corneal astigmatism measured by IOLMaster was consistent with that measured by Pentacam. The difference between the astigmatism of anterior corneal surface and total cornea was detected in the measurement of IOLMaster and Pentacam, respectively.

show abstract

<p>Contribution of Posterior Corneal Astigmatism to Total Corneal Astigmatism in a Sample of Egyptian Population</p>

Cited by 9 publications

References 12 publications

The impact of posterior corneal astigmatism on the surgical planning of toric multifocal intraocular lens implantation

The impact of posterior corneal astigmatism on the surgical planning of toric multifocal intraocular lens implantation

Intraocular lens constant optimization in toric intraocular lens calculation using keratometry and total corneal power

Comparison of Total Corneal Astigmatism between IOLMaster and Pentacam

Contact Info

Product

Resources

About