scholarly journals Corneal astigmatism change and wavefront aberration evaluation after cataract surgery: "Single" versus "paired opposite" clear corneal incisions

2014 ◽  
Vol 3 (1) ◽  
pp. 163 ◽  
Author(s):  
Alireza Peyman ◽  
Behrooz Rahimi ◽  
Hasan Razmjoo ◽  
MohammadHadi Vaezi ◽  
Nima Koosha
Keyword(s):  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Wavefront Aberration ◽  
Single Versus ◽  
Corneal Incisions

Corneal astigmatism after cataract surgery with 4.1 mm BENT scleral and 4.1 mm plus meridian corneal incisions

1999 ◽  
Vol 25 (3) ◽  
pp. 427-431 ◽  
Author(s):  
Yasuo Kurimoto ◽  
Yusuke Komurasaki ◽  
Nagahisa Yoshimura ◽  
Takehisa Kondo
Keyword(s):  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Corneal Incisions

scholarly journals Minimizing Surgically Induced Astigmatism at the Time of Cataract Surgery Using a Square Posterior Limbal Incision

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Paul Ernest ◽  
Warren Hill ◽  
Richard Potvin
Keyword(s):  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Intraocular Lenses ◽  
Corneal Incision ◽  
Surgically Induced Astigmatism ◽  
Clear Corneal Incision ◽  
Refractive Outcomes ◽  
Induced Astigmatism ◽  
Surgically Induced ◽  
Corneal Incisions

Purpose. To compare the surgically induced astigmatism from clear corneal and square posterior limbal incisions at the time of cataract surgery.Methods. Surgically induced astigmatism was calculated for a set of eyes after cataract surgery using a temporal 2.2 mm square posterior limbal incision. Results were compared to similar available data from surgeons using clear corneal incisions of similar size.Results. Preoperative corneal astigmatism averaged 1.0 D and was not significantly different between the incision types. Surgically induced astigmatism with the 2.2 mm posterior limbal incision averaged0.25±0.14 D, significantly lower in magnitude than the aggregate surgically induced astigmatism produced by the 2.2 mm clear corneal incision (0.68±0.49 D).Conclusion. The 2.2 mm square posterior limbal incision induced significantly less, and significantly less variable, surgically induced astigmatism relative to a similar-sized clear corneal incision. This is likely to improve refractive outcomes, particularly important with regard to premium intraocular lenses.

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.

scholarly journals Correcting Corneal Astigmatism with Corneal Arcuate Incisions during Femtosecond Laser Assisted Cataract Surgery

2019 ◽  
Vol 7 (24) ◽  
pp. 4260-4265 ◽  
Author(s):  
Nguyen Xuan Hiep ◽  
Pham Thi Minh Khanh ◽  
Do Quyet ◽  
Than Van Thai ◽  
Vu Thi Nga ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Modern Method ◽  
Corneal Astigmatism ◽  
Spherical Equivalent ◽  
Efficacy And Safety ◽  
Interventional Study ◽  
Corrected Distance Visual Acuity ◽  
Induced Astigmatism ◽  
Corneal Incisions

BACKGROUND: Astigmatic management is an important step to achieve the best visual quality after refractive cataract surgery. Nowadays, along with progress in cataract surgery, the femtosecond laser can produce the arcuate incisions high precisely that help the astigmatic correction. In Vietnam, it has not yet any study about this issue, so we perform this study. AIM: To assess the efficacy and safety of arcuate corneal incisions in treatment corneal astigmatism during femtosecond laser-assisted cataract surgery. METHODS: In this clinical interventional study, forty-five cases with cataract and corneal astigmatism (> 0.50D) were treated with corneal arcuate incisions and femtosecond-laser assisted cataract surgery in Vietnam National Institute of Ophthalmology, from January 2017 to May 2018. The uncorrected and corrected distance visual acuity, refraction spherical equivalent, corneal astigmatism were measured (using an OPD-Scan III topographer) before, 1 week and 3 months after surgery. Some features of arcuate corneal incisions (quantity, depth, length and morphology), spectacle independence at a distance and complications were recorded. RESULTS: The rate of postoperative spherical refraction equivalent was within ± 0.50D and ± 1.0D at 3 months (in 95.6% and 100% of the eyes respectively). Mean length of arcuate corneal incisions was 53.78o ± 17.683o (range: 20o to 85o). The average of preoperative corneal astigmatism was 1.65 ± 0.83D, decreased to 0.59 ± 0.549D in the third month after surgery. Surgical induced astigmatism was 1.05 ± 0.449D and lower than preoperative corneal astigmatism (1.65 ± 0.83D), thereby this indicated undercorrection. However, the rate of spectacle independence was 82.3%, and no complications were recorded. CONCLUSION: Correcting of corneal astigmatism in femtosecond laser-assisted cataract surgery combined with the formation of the arcuate incisions is a new and modern method for high safety and efficacy.

scholarly journals A Randomized Study of the Impact of a Corneal Pre-Cut During Cataract Surgery on Wound Architecture and Corneal Astigmatism

2021 ◽  
Author(s):  
Birgit Doeller ◽  
Nino Hirnschall ◽  
Maria Fichtenbaum ◽  
Phuong-Mai Nguyen ◽  
Ralph Varsits ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Randomized Study ◽  
Corneal Astigmatism ◽  
The Impact

Comparison of corneal astigmatism characteristics and prevalence of corneal astigmatism between Turkish individuals and Syrian refugees

2021 ◽  
pp. 112067212110307
Author(s):  
Soner Guven
Keyword(s):  
Quantitative Analysis ◽  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Syrian Refugees ◽  
Vector Method ◽  
Adjusted Analysis ◽  
Younger Age ◽  
The Mean ◽  
Age And Sex

Purpose: To compare the prevalence, magnitude and type of corneal astigmatism between Turkish individuals and Syrian refugees. Material and methods: Data of patients scheduled for cataract surgery between January 2019 and 2020 were reviewed. The patients were randomly stratified according to their ethnicity (Turkish individuals or Syrian refugees). Keratometry was performed with the keratometer of IOLMaster 500. Quantitative analysis was performed using the power vector method (J0 and J45). The association between age and astigmatism in the two groups was explored. Results: The study included 4085 eyes of 2049 patients (3962 eyes of Turkish individuals and 123 eyes of Syrian refugees). The mean magnitude of corneal astigmatism, J0, J45 and prevalence of against the rule (ATR) astigmatism and with the rule (WTR) astigmatism were 1.01 D, 0.06, 0.01 D, 37.6% and 43.7% in Turkish individuals and 1.13 D, −0.02, 0.07 D, 46.3% and 37.4% in Syrian refugees, respectively. There were no significant differences according to age, sex, right/left eyes, corneal astigmatism magnitude, keratometric values, J0 and J45 ( p > 0.05) between the two groups. Below 40 years of age, the mean corneal astigmatism magnitude in Syrian refugees was significantly higher than that in Turkish individuals ( p = 0.037). At all ages, ATR astigmatism prevalence was higher in Syrian refugees than in Turkish individuals. ATR astigmatic shift began at a younger age in Syrian refugees ( p = 0.037). Age- and sex-adjusted analysis showed that J0 was significantly lower in Syrian refugees than in Turkish individuals ( p = 0.013). Conclusion: The prevalence and magnitude of ATR astigmatism were higher and onset earlier in Syrian refugees than in Turkish individuals.

scholarly journals The number of intracorneal ring segments in asymmetric and central cones

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Canan Asli Utine ◽  
Denizcan Özizmirliler ◽  
Mustafa Kayabaşı ◽  
Üzeyir Günenç
Keyword(s):  
Corneal Astigmatism ◽  
Laser Device ◽  
Double Ring ◽  
Ring Segment ◽  
Corneal Asphericity ◽  
Intracorneal Ring Segment ◽  
Group 2 ◽  
Postoperative Improvement ◽  
Single Versus ◽  
Group 1

Abstract Background To compare the results of single versus double intracorneal ring segment (ICRS) (KeraRing) implantation in keratoconus with respect to different cone locations. Methods Twenty-two eyes of 18 patients with totally asymmetric cones (20–80% or 0–100% distribution along steep axis) were implanted with single ICRS (Group 1), 38 eyes of 32 patients with central or partially asymmetric cones (50–50% or 40–60% distribution along steep axis) were implanted with double ICRS (Group 2), at a depth of 80% of the site of implantation, in channels created with femtosecond laser device. All patients had uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively) of ≤ 0.3 Snellen lines. Results In both groups, patients had median UDVA and CDVA gain of 3 Snellen lines (P > 0.05). Postoperative improvement in indices of vertical asymmetry and height decentration in Group 1; simulated keratometry, corneal astigmatism and anterior corneal asphericity values in Group 2 were greater (P < 0.05). A total of 10 eyes (45.5%) in Group 1 were recommended double ring implantation by the manufacturer’s nomogram, but underwent single ICRS implantation and achieved visual, refractive, tomographic outcomes comparable to that in Group 2, although corneal cylindrical correction was less and final topographic astigmatism was greater. Conclusion Double ICRS implantation seems to be superior in terms of keratometry, corneal astigmatism and anterior corneal asphericity improvement. Single ICRS implantation in totally asymmetric cones seems to provide satisfactory visual, refractive and tomographic results, similar to double ICRS implantation in central and partially asymmetric cones, by inducing central shift of the cone.

scholarly journals Analysis of corneal astigmatism and aberration in chinese congenital cataract and developmental cataract patients before cataract surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoyan Han ◽  
Qi Fan ◽  
Zhixiang Hua ◽  
Xiaodi Qiu ◽  
Dongjin Qian ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Congenital Cataract ◽  
Anterior Chamber Depth ◽  
Corneal Astigmatism ◽  
Imaging Device ◽  
Mean Values ◽  
Biometric Parameters ◽  
Developmental Cataract ◽  
Positive Linear Correlation ◽  
Cataract Patients

Abstract Background To investigate the distribution of corneal astigmatism, aberration, and biometric parameters in Chinese congenital cataract (CC) /developmental cataract patients before cataract surgery. Methods We evaluated eyes of CC /developmental cataract patients scheduled for cataract surgery from January 2016 to September 2019. Astigmatism, aberrations, and biometric parameters were measured with the Pentacam Scheimpflug imaging device (Pentacam HR, Oculus). Cataract was diagnosed and classified by slit-lamp examination after full mydriasis. Results We evaluated 538 eyes in 356 patients. The mean values of anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), and total corneal astigmatism (TCA) were determined as 1.98 ± 1.06 D (range 0.0‒4.8 D), 0.49 ± 0.26 D (range 0.0‒1.9 D), and 2.09 ± 1.19 D (range 0.2‒8.8 D), respectively. ACA and TCA ≥ 1.25 D was present in 379 eyes (70.3%) and 392 eyes (72.8%), respectively. PCA between 0.25 D and 0.75 D was found in 380 eyes (70.6%). There was a statistically significant positive linear correlation between lower-order aberrations root mean square values (LOA RMS) and corneal astigmatism (CA). Furthermore, in terms of distribution of central cornea thickness, anterior chamber depth, ACA, PCA, and TCA in different types of cataracts, ACA was highest in patients with zonular cataracts. Finally, we found anterior corneal measurements may overestimate WTR astigmatism, underestimate ATR astigmatism, and underestimate oblique astigmatism, respectively. Conclusions Most CC /developmental cataract patients had moderate to high astigmatism and ACA accounted for the largest proportion in the zonular group. This can provide a basis for planning of CC/developmental cataract surgery by ophthalmologists in clinical practice.

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