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.

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.

A STUDY ON COMPARISON OF KERATOMETRIC CHANGES BETWEEN PREINCISION AND SINGLE-STEPPED CLEAR CORNEAL INCISION IN PHACOEMULSIFICATION SURGERY

2021 ◽  
pp. 4-5
Author(s):  
Sourav Kumar Das ◽  
Aritro Nandi ◽  
Rupam Datta ◽  
Debarshi Jana
Keyword(s):  
Cataract Surgery ◽  
West Bengal ◽  
Corneal Incision ◽  
Surgically Induced Astigmatism ◽  
Medical College ◽  
Clear Corneal Incision ◽  
Lens Implantation ◽  
Induced Astigmatism ◽  
Surgically Induced ◽  
Corneal Incisions

Phacoemulsication surgery is the most widely used technique for cataract surgery nowadays. It can be done by either pre-incision or by clear corneal incisions. Clear corneal incisions are becoming more popular option for cataract surgery and IOL (intraocular lens) implantation. The availability of foldable IOL that can be inserted through small incisions has created a trend for clear corneal incisions. To compare post-operative kera to metric changes after phacoemulsication surgery between pre-incision or tunnel-based incision and single stepped clear corneal incisions. Fifty patients undergoing phacoemulsication surgery in the Dept. Of Ophthalmology, Nilratan Sircar Medical College & Hospital, Kolkata, West Bengal. Both pre-incision and clear-corneal incision in phacoemulsication surgery results in surgically induced astigmatism post-operatively, but there was no signicant difference in post-operative induced astigmatism in between both techniques.

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 Induced astigmatism after cataract surgery - a retrospective analysis of cases from the University of Port Harcourt Teaching Hospital, Nigeria

2011 ◽  
Vol 70 (2) ◽  
Author(s):  
A. O. Adio ◽  
N. Aruoto
Keyword(s):  
Cataract Surgery ◽  
Teaching Hospital ◽  
Cataract Extraction ◽  
Corneal Astigmatism ◽  
Iol Implantation ◽  
Surgically Induced Astigmatism ◽  
Port Harcourt ◽  
Induced Astigmatism ◽  
The University ◽  
Surgically Induced

Visual rehabilitation after cataract surgery may often be disappointing due to induction of corneal astigmatism following issues in realigning, point to point, the corneal wound margin in the process of surgery despite biometry and use of the appropriateintraocular lens. The purpose of this study is to determine the amount of surgically induced astigmatism after sutured cataract extraction-extracapsular cataract extraction (ECCE) and intracapsular cataract extraction (ICCE) and intraocular lens (IOL)implantation in the University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria. Folders of all cataract patients operated on in the eye theatre of the aforenamed tertiary facility between2002 and 2006 were considered.  Relevant patient details and intraoperative and postoperative management were examined and reported upon. One hundred and fourteen eyes (114) of one hundred patients who had cataract surgeries done within the five-year period of this study were examined. ECCE + IOL implantation were examined in the period under review. The post-operative refraction objectively and subjectively was retrieved from the records of each patient. The post-operative cylinderpower (total astigmatism) was recorded.Of 114 eyes, only 83 eyes (72.8%) had refraction results postoperatively due to loss of fol-low-up. The total number with astigmatism was 57(68.7%). Forty-two had against-the-rule (73.7%), twelve (21.1%) with-the-rule, while five (0.09%) were oblique. The mean post-operative astigmatism was 1.85 D. The surgically induced corneal astigmatism was highest with ECCE with PCIOL. Astigmatism less than 2 D was highest in this group (ECCE with IOL) while ICCE with ACIOL had the highest number with astigmatism in the range between 2 D and 4 D. The total astigmatism which was mainly with-the-rule (vertical plus cylinder) did not seem to impair severely the post-operative visual acuity of the patients.In conclusion, surgically induced astigmatism affected almost 75% of the patients operated and refracted within the period under review. This can be reduced with better operating skills using small incision suture-less techniques. Existing postoperative astigmatism can be reduced by suture cutting at specific periods particularly if there is follow-up at the critical periods. (S Afr Optom 2011 70(2)75-80)

scholarly journals Comparison of Mean and Centroid of Surgically Induced Astigmatism After Standard Cataract Surgery

2021 ◽  
Vol 8 ◽  
Author(s):  
Kazutaka Kamiya ◽  
Kei Iijima ◽  
Wakako Ando ◽  
Nobuyuki Shoji
Keyword(s):  
Cataract Surgery ◽  
Arithmetic Mean ◽  
Corneal Astigmatism ◽  
Corneal Incision ◽  
Surgically Induced Astigmatism ◽  
Clear Corneal Incision ◽  
Induced Astigmatism ◽  
The Individual ◽  
The Right ◽  
Surgically Induced

Purpose: To compare the arithmetic mean of surgically induced astigmatism (M-SIA) and the centroid of surgically induced astigmatism (C-SIA) after standard cataract surgery.Methods: We retrospectively examined 200 eyes of 100 consecutive patients undergoing bilateral cataract surgery through a 2.8 mm temporal clear corneal incision. We quantitatively measured the magnitude and axis of corneal astigmatism preoperatively and 3 months postoperatively using an automated keratometer (TONOREFF-II, Nidek). We assessed the M-SIA, the C-SIA, and the double angle plots for the display of the individual SIA distributions.Results: For bilateral data analysis, the magnitude of corneal astigmatism significantly increased from 0.66 ± 0.39 D preoperatively to 0.74 ± 0.46 D postoperatively (paired t-test, p = 0.012). The M-SIA was 0.50 ± 0.36 D. On the other hand, the C-SIA was 0.18 ± 0.60 D at an axis of 97°. For unilateral analysis, we obtained similar outcomes between the right and left eye groups.Conclusions: According to our experience, standard cataract surgery induces the M-SIA by approximately 0.5 D. The magnitude of the C-SIA largely decreased to approximately 40% of the M-SIA, and the direction of the C-SIA showed a tendency toward with-the-rule astigmatism. It should be noted that the M-SIA was considerably different from the C-SIA, especially when selecting the appropriate toric IOL model and power.

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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