Morphologic features and surgically induced astigmatism of femtosecond laser versus manual clear corneal incisions

2017 ◽  
Vol 43 (11) ◽  
pp. 1430-1435 ◽  
Author(s):  
Sha Zhu ◽  
Naibin Qu ◽  
Wei Wang ◽  
Yanan Zhu ◽  
Xingchao Shentu ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Surgically Induced Astigmatism ◽  
Induced Astigmatism ◽  
Surgically Induced ◽  
Corneal Incisions

scholarly journals Prediction of surgically induced astigmatism in manual and femtosecond laser-assisted clear corneal incisions

2018 ◽  
Vol 28 (4) ◽  
pp. 398-405 ◽  
Author(s):  
Joaquín Fernández ◽  
Manuel Rodríguez-Vallejo ◽  
Javier Martínez ◽  
Ana Tauste ◽  
David P Piñero
Keyword(s):  
Femtosecond Laser ◽  
Corneal Astigmatism ◽  
Toric Intraocular Lens ◽  
Surgically Induced Astigmatism ◽  
Orthogonal Components ◽  
Induced Astigmatism ◽  
The Mean ◽  
Surgically Induced ◽  
Corneal Incisions ◽  
Intraocular Lens Calculation

Purpose: To assess the surgically induced astigmatism with femtosecond laser-assisted and manual temporal clear corneal incisions and to evaluate the performance of a model for prediction of the surgically induced astigmatism based on the preoperative corneal astigmatism. Methods: Clinical data of 104 right eyes and 104 left eyes undergoing cataract surgery, 52 with manual incisions and 52 with femtosecond laser-assisted incisions in each eye group, were extracted and revised retrospectively. In all cases, manual incisions were 2.2 mm width and femtosecond incisions were 2.5 mm width, both at temporal location. A predictive model of the surgically induced astigmatism was obtained by means of simple linear regression analyses. Results: Mean surgically induced astigmatisms for right eyes were 0.14D@65° (manual) and 0.24D@92° (femtosecond) (p > 0.05) and for left eyes, 0.15D@101° (manual) and 0.19D@104° (femtosecond) (p > 0.05). The orthogonal components of the surgically induced astigmatism (XSIA, YSIA) were significantly correlated (p < 0.05) with the preoperative orthogonal components of corneal astigmatism (Xpreop, Ypreop) (r = −0.29 for X and r = −0.1 for Y). The preoperative astigmatism explained 8% of the variability of the XSIA and 3% of the variability of YSIA. The postoperative corneal astigmatism prediction was not improved by the surgically induced astigmatism obtained from the model in comparison with the simple vector subtraction of the mean surgically induced astigmatism. Conclusion: Temporal incisions induce similar astigmatism either for manual or for femtosecond procedures. This can be clinically negligible for being considered for toric intraocular lens calculation due to the great standard deviation in comparison with the mean. The usefulness of the prediction model should be confirmed in patients with high preoperative corneal astigmatism.

scholarly journals Effect of femtosecond laser-assisted steepest-meridian clear corneal incisions on preexisting corneal regular astigmatism at the time of cataract surgery

2020 ◽  
Vol 13 (12) ◽  
pp. 1895-1900
Author(s):  
Wei Chen ◽  
Jian Wu ◽  
Yong Wang ◽  
Jing Zhou ◽  
Rong-Rong Zhu ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Corneal Incision ◽  
Surgically Induced Astigmatism ◽  
Clear Corneal Incision ◽  
Case Series Study ◽  
Induced Astigmatism ◽  
Surgically Induced ◽  
Corneal Incisions

AIM: To investigate the clinical efficacy and safety of femtosecond laser-assisted steepest-meridian clear corneal incisions for correcting preexisting corneal astigmatism performed at the time of cataract surgery. METHODS: This prospective case series study comprised consecutive age-related cataract patients with corneal regular astigmatism (range: +0.75 to +2.50 D) who had femtosecond laser-assisted steepest-meridian clear corneal incisions (single or paired). Corneal astigmatism was performed with the Pentacam preoperatively and 3mo postoperatively. Total corneal astigmatism and steepest-meridian measured in the 3-mm central zone were used to guide the location, size and number of clear corneal incision. The vector analysis of astigmatic change was performed using the Alpins method. RESULTS: Totally 138 eyes of 138 patients were included. The mean preoperative corneal astigmatism was 1.31±0.41 D, and was significantly reduced to 0.69±0.34 D (equivalent to difference vector) after surgery (P<0.01). The surgically-induced astigmatism was 1.02±0.54 D. The correction index (ratio of target induced astigmatism and surgically-induced astigmatism: 0.72±0.36) as well as the magnitude of error (difference between surgically-induced astigmatism and target induced astigmatism: -0.29±0.51) represented a slight under correction. For angle of error, the arithmetic mean was 1.11±13.70, indicating no significant systematic alignment errors. CONCLUSION: Femtosecond-assisted steepest-meridian clear corneal incision is a fast, customizable, adjustable, precise, and safe technique for the reduction of low to moderate corneal astigmatism during cataract surgery.

Comparison of surgically induced astigmatism between femtosecond laser and manual clear corneal incisions for cataract surgery

2015 ◽  
Vol 41 (10) ◽  
pp. 2075-2080 ◽  
Author(s):  
Vasilios F. Diakonis ◽  
Nilufer Yesilirmak ◽  
Florence Cabot ◽  
Vardhaman P. Kankariya ◽  
George A. Kounis ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Surgically Induced Astigmatism ◽  
Induced Astigmatism ◽  
Surgically Induced ◽  
Corneal Incisions

scholarly journals Astigmatism Correction during Femtosecond Laser-assisted Transepithelial Arcuate Keratotomy Using the Wound Open Method

2021 ◽  
Vol 62 (12) ◽  
pp. 1592-1599
Author(s):  
Joon Kyo Chung ◽  
Gyu Le Han ◽  
Hoon Noh ◽  
Dong Hui Lim ◽  
Tae-Young Chung
Keyword(s):  
Femtosecond Laser ◽  
Medical Center ◽  
Corneal Astigmatism ◽  
Retrospective Survey ◽  
Surgically Induced Astigmatism ◽  
Open Method ◽  
Astigmatism Correction ◽  
Before And After ◽  
Induced Astigmatism ◽  
Surgically Induced

Purpose: The purpose of this study was to compare corneal astigmatism correction between “wound open” and “wound intact” methods during femtosecond laser-assisted transepithelial arcuate keratotomy.Methods: From April 2016 to December 2018, a retrospective survey was conducted on patients undergoing femtosecond laser cataract surgery at the Ophthalmology Department of Samsung Medical Center. Size comparison and vector analysis of corneal astigmatism before and after surgery were performed in the wound open and wound intact groups.Results: In the wound open and wound intact groups, the target-induced astigmatism (TIA) was 1.28 ± 0.55; and 1.26 ± 0.29 diopters, the surgically induced astigmatism (SIA) was 0.80 ± 0.52; and 0.53 ± 0.32 diopters, and the correction index (CI) was 0.63 ± 0.28; and 0.43 ± 0.26, respectively. The astigmatism correction was superior in the wound open group (p = 0.048, p = 0.025). In a subgroup with TIA < 1.2 diopters, there were no significant differences in SIA or CI between the two groups; however, in the subgroup with a TIA > 1.2 diopters, the SIA was 1.09 ± 0.59; and 0.54 ± 0.37 diopters and the CI was 0.60 ± 0.28; and 0.36 ± 0.23 in the wound open and wound intact groups, respectively (p = 0.022, p = 0.047). Thus, astigmatism correction was superior in the wound open group.Conclusions: The wound open method during femtosecond laser-assisted transepithelial arcuate keratotomy was superior for astigmatism correction compared to the wound intact method.

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