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 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.

scholarly journals Outcomes of coaxial microincision cataract surgery versus conventional phacoemulsification surgery

2019 ◽  
Vol 16 (3) ◽  
pp. 168-178
Author(s):  
Anu Malik ◽  
Smruti Ranjan Dethi ◽  
Yogesh Kumar Gupta ◽  
Alka Gupta
Keyword(s):  
Cataract Surgery ◽  
Randomized Study ◽  
Corrected Visual Acuity ◽  
Age Related ◽  
Significant Difference ◽  
Induced Astigmatism ◽  
The Mean ◽  
Group 2 ◽  
Surgically Induced ◽  
Group 1

Aim: To compare surgical parameters and visual outcomes of coaxial microincision cataract surgery (MICS) with standard phacoemulsification. Methods: A prospective randomized study was conducted on 60 eyes of 60 patients with age-related uncomplicated cataract who underwent: standard phacoemulsification surgery (30 eyes) i.e., Group 1, or coaxial MICS (30 eyes) i.e., Group 2. Intraoperative parameters were mean effective phacoemulsification power (EPP), effective phacoemulsification time (EPT), and total volume of balanced salt solution (BSS) used. Best-corrected visual acuity (BCVA) and surgically induced astigmatism (SIA) were evaluated pre- and postoperatively. Results: Mean BCVA at 6 weeks was 0.04 ± 0.07 in Group 1 and 0.05 ± 0.08 in Group 2. No significant difference was observed in SIA between the two groups. Mean EPT was 29.80 ± 3.67 seconds in Group 1 and 31.93 ± 4.08 seconds in Group 2. The mean total EPP in Group 1 was 35.77 ± 5.17%, whereas it was 33.70 ± 3.05% in Group 2. There was a significant statistical difference between mean EPP and EPT in the two groups. Mean total BSS volume used in Group 1 was 128.83 ± 19.81 ml, whereas it was 139.33 ± 13.57 ml in Group 2. Conclusion: Although EPT and BSS volume used were significantly higher in coaxial MICS, the postoperative results of the two techniques were comparable.

scholarly journals Comparative study between conventional extra capsular cataract extraction versus manual small incision cataract surgery

2017 ◽  
Vol 5 (3) ◽  
pp. 996 ◽  
Author(s):  
Gannaram Laxmiprasad ◽  
Chhaya Shori ◽  
Rakesh Shori ◽  
Ashalatha Alli
Keyword(s):  
Cataract Surgery ◽  
Tertiary Care ◽  
Posterior Chamber ◽  
Small Incision Cataract Surgery ◽  
Visual Rehabilitation ◽  
Surgically Induced Astigmatism ◽  
Small Incision ◽  
Significant Difference ◽  
Induced Astigmatism ◽  
Surgically Induced

Background: Recent reports indicate that both manual small incision cataract surgery and extra capsular cataract excision surgery with posterior chamber intraocular lens implantation are safe and effective for treatment of cataract surgery, however, manual small incision cataract surgery gives better uncorrected vision. Objectives of the study were to compare intraoperative and postoperative complications, to compare induced astigmatism and to compare the visual rehabilitation.Methods: This is a prospective study of 100 consecutive patients assigned to undergo conventional extra capsular cataract excision surgery (50 cases) and manual small incision cataract surgery (50 cases). Study was done for a period of two years at a tertiary care referral hospital. Institutional Ethics Committee permission was taken. Also the informed consent was obtained from each patient.Results: In conventional ECCE, the most common surgically induced astigmatism was WTR in 73.4% of cases with mean of 2.79 D±1.3 on first day. 70% of cases with mean 2.1 D±1.28 and 64% of cases with mean of 1.86 D±1.14 at six weeks. ATR was common in MSICS group, 83.67% of cases with mean of 1.5 D±0.72 on first day, 86% of cases with mean of 1.03 D±0.6 at one week and 88% of cases with mean of 1.27 D±0.81 at six weeks. The induced astigmatism was less in MSICS group compared to ECCE group at first day but after six weeks there was no much significant difference found. Early visual recovery was better in MSICS groupConclusions: MSICS has definitive advantages over conventional ECCE in terms of early visual rehabilitation, minimal surgically induced astigmatism; no suture related complications and reduced surgical time.

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

Comparison of using Galilei Dual Scheimpflug Analyzer G4 and Barrett formula in predicting low cylinder preoperatively for cataract surgeries

2019 ◽  
Vol 30 (6) ◽  
pp. 1320-1327
Author(s):  
Yi-Ju Ho ◽  
Chi-Chin Sun ◽  
Jiahn-Shing Lee ◽  
Ken-Kuo Lin ◽  
Chiun-Ho Hou
Keyword(s):  
Cataract Surgery ◽  
Absolute Error ◽  
Corneal Astigmatism ◽  
Intraocular Lens Implantation ◽  
Surgically Induced Astigmatism ◽  
Lens Implantation ◽  
Induced Astigmatism ◽  
Median Absolute Error ◽  
The Difference ◽  
Surgically Induced

Purpose: To compare corneal astigmatism estimation from Barrett toric calculator, with measurement from Galilei Dual Scheimpflug Analyzer G4 in low corneal cylinder patients. Methods: Preoperative corneal astigmatism was measured using Auto Kerato-Refractometer (AutoKM), IOL Master, and Galilei G4 (combined Placido-dual Scheimpflug analyzer) and was processed by Barrett toric calculator with measurements obtained from Auto Kerato-Refractometer and from IOL Master. A total of 42 eyes undergoing cataract surgery with nontoric intraocular lens implantation were included. Corneal astigmatism was calculated based on manifest refractive astigmatism with implications of surgically induced astigmatism. Errors in predicted residual astigmatism were calculated by the difference between postoperative manifest cylindrical refractive error and preoperative corneal cylinder using vector analysis. Results: Centroid error in predicted residual astigmatism was with-the-rule 0.36 D for AutoKM and 0.48 D for IOL Master, was lower at 0.24 D for the Barrett–IOL Master, and was lowest at 0.21 D for the Barrett–AutoKM ( p < .001). The Galilei G4 demonstrated the highest centroid error for SimK (0.53 D) and lower for total corneal power (0.49 D). The Barrett toric calculator obtained the lowest median absolute error in predicted residual astigmatism for AutoKM (0.43 D) and IOL Master (0.54 D). The Barrett–IOL Master demonstrated that 61% and 76% of eyes were within 0.50 and 0.75 D of the predicted residual astigmatism, respectively. Conclusion: The Barrett–IOL Master had more accurate prediction of residual astigmatism for low astigmatism eyes before cataract surgery compared to Galilei Dual Scheimpflug Analyzer G4 in this study.

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