scholarly journals Posterior Corneal Asphericity Effect on Postoperative Astigmatism after EDOF Intraocular Lens Implantation in Cataract Patients

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Mark Rabinovich ◽  
Ivo Guber ◽  
Laëtitia Jessy Niegowski ◽  
Ana Maria Aramburu del Boz ◽  
Danial Al Khatib ◽  
...  
Keyword(s):  
Anterior Chamber Depth ◽  
Q Value ◽  
Corneal Surface ◽  
Surgically Induced Astigmatism ◽  
Postoperative Astigmatism ◽  
Corneal Asphericity ◽  
Induced Astigmatism ◽  
The Impact ◽  
Surgically Induced ◽  
Cataract Patients

Aim. To assess the impact of posterior corneal asphericity on postoperative astigmatism. Methods. We included retrospectively 70 eyes of 70 patients that underwent cataract surgery. We included data of the Q value, Kmax, K1, K2, astigmatism AL, and ACD. We performed a vectorial analysis to calculate the astigmatic vectors. Results. Seventy eyes were evaluated. 40 eyes were of females (58%) and 30 of males (42%). The average cohort age was 73 ± 8.9 years. Axial length (AL) was 23.5 ± 0.9, anterior chamber depth (ACD) was 3.13 ± 0.3, and the average posterior Q value was −0.35 ± 0.2. The only significant predictive variable for the correction index (CI) was the posterior Q value (r = 0.24, p  < 0.05) and for the surgically induced astigmatism (SIA) (β = 0.34, r = 0.58, p  < 0.05). Conclusion. Posterior corneal surface asphericity significantly influences the surgically induced astigmatism and the overcorrection for cataract patients after Lucidis EDOF IOL implantation.

scholarly journals Comparison of surgically induced astigmatism between anterior and total cornea in 2.2 mm steep meridian incision cataract surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Young-chae Yoon ◽  
Minji Ha ◽  
Woong-Joo Whang
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Corneal Surface ◽  
Polar Plot ◽  
Mean Values ◽  
Surgically Induced Astigmatism ◽  
Induced Astigmatism ◽  
The Mean ◽  
Surgically Induced ◽  
Corneal Refractive Power

Abstract Background This study aimed to compare surgically induced astigmatism (SIA) on the anterior and total cornea during cataract surgery through a 2.2 mm steep meridian incision. Methods The study included 69 left eyes of 69 patients who had undergone cataract surgery. The 69 eyes were classified into three subgroups according to the preoperative steep meridian. Following phacoemulsification, an intraocular lens was inserted into the bag. The keratometric measurements were taken 12 months postoperatively, on the anterior cornea (automated keratometer and anterior keratometry [K] from a rotating Scheimpflug camera) and total cornea (equivalent K reading [EKR] 3.0 mm, EKR 4.5 mm, total corneal refractive power (TCRP) 2.0 mm ring, TCRP 3.0 mm zone, TCRP 4.0 mm zone). The SIA was analyzed for each parameter. Results On the double-angle polar plot, the summated vector mean values of SIA determined by the automated keratometer and Scheimpflug anterior K were 0.28 diopter (axis: 177°) and 0.37 diopter (axis: 175°) in with-the-rule (WTR) astigmatism; 0.03 diopter (axis: 156°) and 0.18 diopter (axis: 177°) in oblique astigmatism; 0.15 diopter (axis: 96°) and 0.17 diopter (axis: 73°) in against-the-rule (ATR) astigmatism. The mean SIAs on the total cornea ranged from 0.31 to 0.42 diopter in WTR astigmatism; from 0.16 to 0.27 diopter in oblique astigmatism; from 0.04 to 0.11 diopter in ATR astigmatism. Mean magnitude SIA ranged from 0.41 to 0.46 diopter on anterior corneal surface and 0.50 to 0.62 diopter on total cornea. J0 and J45 of the posterior cornea showed no significant changes after cataract surgery, and the changes in J0 and J45 did not show any statistical differences between the anterior and total cornea (all p > 0.05). Conclusions There were no differences in the summed vector mean values of SIA between the anterior cornea and the total cornea.

scholarly journals Preliminary experiences with limbal relaxing incision for treatment of astigmatism during phacoemulsification

1970 ◽  
Vol 1 (2) ◽  
pp. 90-94 ◽  
Author(s):  
BR Sharma ◽  
A Kumar
Keyword(s):  
Visual Acuity ◽  
Analysis Method ◽  
Surgically Induced Astigmatism ◽  
Early Experiences ◽  
Postoperative Astigmatism ◽  
Uncorrected Visual Acuity ◽  
Induced Astigmatism ◽  
The Mean ◽  
Surgically Induced ◽  
Relaxing Incisions

Introduction: This small study relates our early experiences with the Limbal Relaxing Incision (LRI) for management of astigmatism in patients undergoing cataract surgery. Aims: To evaluate the efficacy of LRI in the management of primary astigmatism when combined with phacoemulsification. Subjects and methods: Limbal relaxing incisions were performed to correct primary astigmatism in 12 eyes of 12 cataract patients who underwent phacoemulsification as the primary procedure. The length and number of incisions were determined using the AMO LRI calculator software programme using Donnenfield and NAPA nomograms. Keratometric astigmatism was measured preoperatively and postoperatively on day 1 and after 3 weeks or more. Surgically-induced astigmatism (SIA) and the intended angle of error were evaluated by the vector analysis method. Preoperative and postoperative uncorrected visual acuity (UCVA) and best spectacle corrected visual acuity (BSCVA) were evaluated in each visit. Results: The mean age of patients was 52.92 ±10.91 years. There were 75 % male and 25 % female patients. The mean keratometric preoperative astigmatism was 2.08 ±1.05 diopter. The mean 1st postoperative day keratometric astigmatism was 1.74 ±1.32 diopter and the mean final keratometric astigmatism at 3 weeks postoperatively was 1.05± 0.68 diopter. The mean SIA on the 1st postoperative day was 2.97 ±1.72 diopter at 103.25±56.57 degree with intended angle of error 6.53±9.61 degree. The mean SIA on the 3rd postoperative week was 2.26±0.87 Diopter at 107.08±49.96 degrees with intended angle of error 2.90±7.87 degrees. Conclusion: Limbal relaxing incisions are effective method to reduce postoperative astigmatism with good predictability of intended angle. Keywords: limbal relaxing incision (LRI); uncorrected visual acuity (UCVA); surgically induced astigmatism (SIA); angle of error; target astigmatic treatment (TAT) DOI: 10.3126/nepjoph.v1i2.3681 Nep J Oph 2009;1(2):90-94

scholarly journals Polar Value Analysis of Low to Moderate Astigmatism with Wavefront-Guided Sub-Bowman Keratomileusis

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Pisong Yan ◽  
Zhiyu Du ◽  
Yu Zhang
Keyword(s):  
Corneal Astigmatism ◽  
Corneal Surface ◽  
Value Analysis ◽  
Surgically Induced Astigmatism ◽  
Induced Astigmatism ◽  
A Minor ◽  
Surgically Induced ◽  
Myopic Astigmatism ◽  
Anterior Corneal Astigmatism ◽  
Posterior Corneal Astigmatism

Purpose. To evaluate the astigmatic outcomes of wavefront-guided sub-Bowman keratomileusis (WFG-SBK) for low to moderate myopic astigmatism.Methods. This study enrolled 100 right eyes from 100 patients who underwent WFG-SBK for the correction of myopia and astigmatism. The polar value method was performed with anterior and posterior corneal astigmatism measured with Scheimpflug camera combined with Placido corneal topography (Sirius, CSO) and refractive astigmatism preoperatively and 1 month, 3 months, and 6 months postoperatively.Results. Similar results for surgically induced astigmatism (SIA) and error of the procedure in both anterior corneal astigmatism (ACA) and total ocular astigmatism (TOA). There was a minor undercorrection of the cylinder in both ACA and TOA. Posterior corneal astigmatism (PCA) showed no significant change.Conclusions. Wavefront-guided SBK could provide good astigmatic outcomes for the correction of low to moderate myopic astigmatism. The surgical effects were largely attributed to the astigmatic correction of the anterior corneal surface. Posterior corneal astigmatism remained unchanged even after WFG-SBK for myopic astigmatism. Polar value analysis can be used to guide adjustments to the treatment cylinder alongside a nomogram designed to optimize postoperative astigmatic outcomes in myopic WFG-SBK.

scholarly journals Corneal Surface Irregularity and Surgically Induced Astigmatism Changes in the Small Incision Versus Microincision After SMILE

2020 ◽  
Author(s):  
Junjie Piao ◽  
Ying Li ◽  
Meng Wang
Keyword(s):  
Biomechanical Properties ◽  
Surface Irregularity ◽  
Corneal Surface ◽  
Surgically Induced Astigmatism ◽  
Small Incision ◽  
Incision Size ◽  
Surface Irregularities ◽  
Induced Astigmatism ◽  
Surgically Induced

Abstract Background: To evaluate the corneal surface irregularity and surgically induced astigmatism changes in the small incision versus microincision after small incision lenticule extraction (SMILE) surgery.Methods: A total of 70 eyes of 35 patients with myopia who underwent SMILE surgery were enrolled in this retrospective study. Patients were divided into two groups according to the incision size (small incision, 4.0 mm or microincision, <2.5 mm) and subjected to a standard ophthalmologic examination preoperatively. The changes in corneal topographic and surface irregularities were evaluated using a TMS-4N topographer during a 6-month follow-up period.Results: According to Friedman’s ANOVA test, there were statistically significant changed in SRI, SAI, and IOP between two groups during a 6-month follow-up (all p < 0.001). At last follow-up, SRI values less than 0.50 D were shown 27 eyes (75%) in the small incision group and 28 eyes (82%) in the microincision group; SAI values less than 0.50 D were shown 22 eyes (61%) in the small incision group and 18 eyes (53%) in the microincision group (all p<0.001).Conclusions: SMILE procedures, using both small incisions and microincisions, are safe and effective surgical options for patients with low to high myopia and provide stable postoperative biomechanical properties and superior postoperative visual outcomes.

scholarly journals A COMPARATIVE STUDY OF SURGICALLY INDUCED ASTIGMATISM IN SUPERIOR AND TEMPORAL SCLERAL INCISION IN MANUAL SMALL INCISION CATARACT SURGERY AT SKMCH, MUZAFFARPUR, BIHAR

2020 ◽  
pp. 1-3
Author(s):  
Md. Imamul Hoda ◽  
Shiv Kumar ◽  
R. K. Singh ◽  
Debarshi Jana
Keyword(s):  
Comparative Study ◽  
Cataract Surgery ◽  
Visual Outcome ◽  
Small Incision Cataract Surgery ◽  
Surgically Induced Astigmatism ◽  
Small Incision ◽  
Incision Size ◽  
Postoperative Astigmatism ◽  
Induced Astigmatism ◽  
Surgically Induced

Aim: To evaluate the amount and type of surgically induced astigmatism in superior and temporal scleral incision inManual Small Incision Cataract Surgery (MSICS). Material and Methods: A prospective randomized comparative study was carried out in 100 cases of senile or pre-senile cataract. All the patients underwent MSICS under peribulbaranaesthesia. The patients with very hard cataract were excluded so as to keep the incision size uniformity (6-6.5mm). 50 cases received superior scleral incision and 50 cases received temporal scleral incision. Post operative astigmatism was studied in both groups using Bausch & Lomb Keratometer on 1stday, 7thday, 6thweek and 3rdmonth. Results: After 3 months of surgery, out of 50 patients in superior scleral incision group 74% patients had ATRastigmatism and 16% patients had WTR astigmatism whereas in temporal scleral incision group 56 % of the patients had WTR astigmatism and 36 % had ATR astigmatism. The mean surgically induced astigmatism (SIA) in temporal incision group was significantly less than the superior incision group after 3 months postoperatively (t=2.33, p<0.05). Conclusion: This study reveals that temporal approach MSICS produces less postoperative astigmatism and hasmanifold advantages over superior incision MSICS with excellent visual outcome.

scholarly journals The Analysis of Corneal Asphericity and its Related Factors in Cataract Patients

2021 ◽  
Author(s):  
Chen Li ◽  
Peirong Lu
Keyword(s):  
Individual Differences ◽  
Age Groups ◽  
Posterior Surface ◽  
Q Value ◽  
Corneal Surface ◽  
Related Factors ◽  
Corneal Asphericity ◽  
Q Values ◽  
Cataract Patients ◽  
Selection Of

Abstract Purpose: To determine the corneal asphericity and its related factors in cataract patients.Methods: This study enrolled 121 eligible eyes of 121 cataract patients. The corneal Q values of anterior and posterior surface were measured in the central 3.0, 4.0, 5.0, and 6.0 mm zone using the Sirius System. Age, gender, and corneal higher-order aberrations (HOAs) were recorded. Comparison of preoperative and postoperative Q value was conducted in 103 eyes of 103 patients three months after surgery.Results: The Q value of the anterior corneal surface at 6.0 mm zone and the posterior surface in 3.0, 4.0, 5.0, and 6.0 mm zone were statistically significant across the different age groups. The Q value of the posterior surfaces in 3.0, 4.0, 5.0, and 6.0 mm zone was statistically significant between the male and the female groups. The Q values of the anterior corneal surface in the 6.0 mm zone were positively correlated with Z40 cornea, Z40 CF, Z33,-3 CF, and total corneal HOAs; While the Q value of the posterior surface in the 6.0 mm zone were negatively correlated with Z31,-1 cornea, Z33,-3 cornea, Z33,-3 CF, Z31,-1CB, Z40 CB, and total corneal HOAs. Besides, no significant change was found in corneal Q value 3 months after surgery.Conclusion: There were great individual differences between the corneal asphericity of the cataract patients. Age, sex, and HOAs seemed to be correlated with the corneal asphericity. The preoperative Q value can be used as one of the parameters for personalized selection of intraocular lens.

scholarly journals Surgically induced astigmatism and coupling effect-mediated keratometric changes after conventional phacoemulsification cataract surgery

2021 ◽  
Author(s):  
Reinhard Angermann ◽  
Christoph Palme ◽  
Philipp Segnitz ◽  
Andreas Dimmer ◽  
Eduard Schmid ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Coupling Effect ◽  
Case Series ◽  
Corneal Incision ◽  
Surgically Induced Astigmatism ◽  
Incision Size ◽  
Case Series Study ◽  
Induced Astigmatism ◽  
Surgically Induced ◽  
Phacoemulsification Cataract Surgery

Summary Background The aim of the present study was to describe surgically induced astigmatism (SIA) and the coupling effect after conventional phacoemulsification cataract surgery (CPS) in relation to the incisional axis. Material and methods A total of 42 patients were included in the retrospective case series study. Corneal topography was obtained for patients with significant cataract before and 6 weeks after CPS with a main clear corneal incision size of 2.4 mm. Patients were grouped according to the relationship of the incisional axis to the position of the steep axis into a steep incisional group and a flat incisional group. Results In total, 46 eyes were included in the study. While the steep incisional group showed an SIA of −0.15 D (± 0.35), the flat incisional group had a significantly higher SIA of 0.20 D (± 0.51) (p = 0.03). The coupling ratio (CR) in the steep incisional group was −0.38 (± 1.41) and in the flat incisional group it was 0.16 (± 0.97). Correspondingly, a coupling constant (CC) of −0.25 was found for group 1 and a CC of 0.0 for group 2. Conclusion Our results suggest that the location of the main incision should be decided with consideration of the corneal astigmatism in order to minimize the SIA. The CR helps to understand the effect of induced astigmatism and the change in spherical equivalent.

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