Impact of measured total keratometry versus anterior keratometry on the refractive outcomes of the AT TORBI 709-MP toric intraocular lens

Levron, Antoine; Chehab, Hussam El; Agard, Émilie; Chudzinski, Roman; Billant, Jérémy; Dot, Corinne

doi:10.1007/s00417-020-05046-3

Cited by 14 publications

(6 citation statements)

References 25 publications

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“…29 In our study, the Goniotrans application was used to allow reference the angular position of the IOL axis on an image of the eye. Likewise, the ZCALC calculator was used that have been shown to provide reliable and accurate refractive outcomes in toric IOL calculation, 30,31 introducing some adjustments to consider the potential contribution of posterior corneal astigmatism to total corneal astigmatism. Furthermore, IOL reposition was always performed in those cases showing a clinically significant level of IOL rotation in the early postoperative period.…”

Section: Discussionmentioning

confidence: 99%

Short-term clinical results with a trifocal diffractive toric intraocular lens using an optimized preoperative and intraoperative protocol

Paredes

Mora

Martín

et al. 2023

European Journal of Ophthalmology

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Purpose To evaluate the short-term clinical outcomes of a specific toric diffractive trifocal intraocular lens (IOL) implanted following an optimized clinical protocol in a large population. Methods Retrospective analysis of 337 eyes of 231 patients (mean age, 62.2 years) undergoing cataract surgery with implantation of the trifocal diffractive IOL AT.LISA tri toric 939M/MP (Carl Zeiss Meditec). A strict and careful clinical protocol was followed, including an accurate measurement of corneal astigmatism, use of a latest generation IOL power calculator, photography-based method intraoperative control of IOL alignment and IOL reposition at 1 week postoperatively if needed. Clinical outcomes in terms of visual acuity, refraction, efficacy of astigmatic correction analysed by vector analysis and patient satisfaction were evaluated during a 3-month follow-up. Results A total of 82% and 98% of eyes achieved a postoperative uncorrected distance visual acuity of 0.00 and 0.10 logMAR or better, respectively. Furthermore, 99.7%, and 100.0% of eyes showed a postoperative spherical equivalent within ± 0.50 D and ± 1.00 D, with 97.9% of eyes having a postoperative cylinder ≤ 0.50 D. Uncorrected near and intermediate visual acuities were 0.2 logMAR or better in 89.0% and 99.1% of eyes, respectively. Mean difference vector, magnitude of error and angle of error were 0.02 ± 0.14 D, 0.02 ± 0.13 D and 0.11 ± 1.18°. Patient satisfaction was referred as high or very high by 97.6% of patients. Conclusions The implantation of the trifocal toric IOL evaluated following a careful clinical protocol provides an efficacious visual rehabilitation and astigmatic correction, leading to high levels of patient satisfaction.

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Section: Discussionmentioning

confidence: 99%

Short-term clinical results with a trifocal diffractive toric intraocular lens using an optimized preoperative and intraoperative protocol

Paredes

Mora

Martín

et al. 2023

European Journal of Ophthalmology

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“…The newer IOLMaster 700 obtains a reading of total corneal power, taking both corneal thickness and actual values for the radius of the posterior cornea into account, using telecentric 3-zone K and swept-source OCT technology. By replacing hypotheses and modeling with actual measurements, the IOLMaster 700 may provide reliable data on corneal power in some challenging cases, such as surgically modified [ 7 , 28 , 29 , 34 ] and high astigmatic corneas [ 17 , 35 , 36 ]. Here, we found no significant difference between TK and standard K in highly myopic eyes within this certain range of corneal thickness.…”

Section: Discussionmentioning

confidence: 99%

Application of total keratometry in ten intraocular lens power calculation formulas in highly myopic eyes

Wei

Cheng

et al. 2022

Eye and Vis

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Background The accuracy of using total keratometry (TK) value in recent IOL power calculation formulas in highly myopic eyes remained unknown. Methods Highly myopic patients who underwent uneventful cataract surgery were prospectively enrolled in this prospective comparative study. At one month postoperatively, standard deviation (SD) of the prediction errors (PEs), mean and median absolute error (MedAE) of 103 highly myopic eyes were back-calculated and compared among ten formulas, including XGboost, RBF 3.0, Kane, Barrett Universal II, Emmetropia Verifying Optical 2.0, Cooke K6, Haigis, SRK/T, and Wang-Koch modifications of Haigis and SRK/T formulas, using either TK or standard keratometry (K) value. Results In highly myopic eyes, despite good agreement between TK and K (P > 0.05), larger differences between the two were associated with smaller central corneal thickness (P < 0.05). As to the refractive errors, TK method showed no differences compared to K method. The XGBoost, RBF 3.0 and Kane ranked top three when considering SDs of PEs. Using TK value, the XGboost calculator was comparable with the RBF 3.0 formula (P > 0.05), which both presented smaller MedAEs than others (all P < 0.05). As for the percentage of eyes within ± 0.50 D or ± 0.75 D of PE, the XGBoost TK showed comparable percentages with the RBF 3.0 TK formula (74.76% vs. 66.99%, or 90.29% vs. 87.38%, P > 0.05), and statistically larger percentages than the other eight formulas (P < 0.05). Conclusions Highly myopic eyes with thinner corneas tend to have larger differences between TK and K. The XGboost enhancement calculator and RBF 3.0 formula using TK showed the most promising outcomes in highly myopic eyes.

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“…This total keratometry value is most likely composed from the corneal front and back surface data in addition to the central corneal thickness using some upgraded version of the Gullstrand formula for spherocylindrical surfaces. The first studies on the total keratometry value provided by the IOLMaster 700 show that these data seem to be a good indicator for calculation of toric intraocular lenses (Levron et al 2021), but further studies with a larger study population have to proof the potential of total keratometry especially for toric lens power calculations.…”

Section: Discussionmentioning

confidence: 99%

“…The first studies on the total keratometry value provided by the IOLMaster 700 show that these data seem to be a good indicator for calculation of toric intraocular lenses (Levron et al. 2021), but further studies with a larger study population have to proof the potential of total keratometry especially for toric lens power calculations.…”

Section: Discussionmentioning

confidence: 99%

Prediction of total corneal power from measured anterior corneal power on the IOLMaster 700 using a feedforward shallow neural network

Langenbucher

Cayless

Szentmáry

et al. 2021

Acta Ophthalmologica

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Background: The corneal back surface is known to add some astigmatism against-the-rule, which has to be considered in cataract surgery with toric lens implantation. The purpose of this study was to set up a deep learning algorithm which predicts the total corneal power from keratometry and biometric measures. Methods: Based on a large data set of measurements with the IOLMaster 700 from two clinical centres, data from N = 21 108 eyes were included, each record containing valid data for keratometry K, total keratometry TK, axial length AL, central corneal thickness CCT, anterior chamber depth ACD, lens thickness LT and horizontal corneal diameter W2W from an individual eye. After a vector decomposition of K and TK into equivalent power (.EQ) and projections of astigmatism to the 0°/90°(.AST 0°) and 45°/135°(.AST 45°) axis, a multi-output feedforward shallow neural network was derived to predict TK from K, AL, CCT, ACD, LT, W2W and patient age. Results: After some trial and error, the neural network having a Levenberg-Marquardt training function and three hidden layers (10/8/5 neurons) performed best and showed a fast convergence. The data set was split into training data (70%), validation data (15%) and test data (15%). The prediction error (predicted corneal power CP pred minus TK) of the network trained with the training and cross-validated with test data showed systematically narrower distributions for CPEQ-TKEQ, CPAST 0°-TKAST 0°a nd CPAST 45°-TKAST 45°c ompared with KEQ-TKEQ, KAST 0°-TKAST 0°a nd KAST 45°-TKAST 45°. There was no systematic offset in the components between CP pred and TK. Conclusion: Unlike any fixed correction term, which can compensate only for a static intercept of the astigmatic components TKEQ, TKAST 0°a nd TKAST 45°c ompared with KEQ, KAST 0°a nd KAST 45°, our trained neural network was able to reduce the variance in the prediction error significantly. This neural network could be used to account for the corneal back surface astigmatism for biometers where the corneal back surface measurement or total keratometry is not available.

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Impact of measured total keratometry versus anterior keratometry on the refractive outcomes of the AT TORBI 709-MP toric intraocular lens

Cited by 14 publications

References 25 publications

Short-term clinical results with a trifocal diffractive toric intraocular lens using an optimized preoperative and intraoperative protocol

Short-term clinical results with a trifocal diffractive toric intraocular lens using an optimized preoperative and intraoperative protocol

Application of total keratometry in ten intraocular lens power calculation formulas in highly myopic eyes

Prediction of total corneal power from measured anterior corneal power on the IOLMaster 700 using a feedforward shallow neural network

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