scholarly journals Pre-existing Corneal Astigmatism in patients undergoing Cataract Surgery in Western Nepal; A hospital-based Unicentered, Comprehensive, Prospective Observational Study

2020 ◽  
Vol 5 (2) ◽  
pp. 21-25
Author(s):  
Shristi Shrestha ◽  
Khemraj Kaini
Keyword(s):  
Visual Acuity ◽  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Cross Sectional ◽  
Postoperative Visual Acuity ◽  
Department Of Ophthalmology ◽  
Induced Astigmatism ◽  
Different Populations ◽  
The Mean ◽  
Surgically Induced

Introduction: Cataract surgery is one of the most commonly performed surgical procedures worldwide. The final postoperative visual acuity is dependent on the pre-existing corneal astigmatism, accurate biometry and surgically induced astigmatism. Because of the increase in the patient’s demand for better postoperative visual acuity, it becomes important to evaluate the distribution of pre-existing corneal astigmatism in different populations. The objective of the study was to analyze the magnitude and pattern of pre-existing corneal astigmatism in cataract surgery patients in Western Nepal.Methods: A hospital-based cross-sectional descriptive study was carried out in the Department of Ophthalmology, Manipal Teaching Hospital, Pokhara. Three hundred and two patients undergoing routine cataract surgery between February 2016 and January 2018 were recruited in the study. Keratometric data from these patients were collected and were analyzed using the statistical software SPSS version 21.Results: The mean age of the subjects was 70.25 ± 10.97 years (range 35 to 94 years). There was a preponderance of females (62%) over males (38%). The mean corneal astigmatism was 0.78 ± 0.59 D (range 0.00 to 5.00 D). The pre-existing corneal cylinder ≥ 1.00 D was seen in 40.06% of patients. The corneal astigmatism was mainly against the rule (65.56%). The amount of corneal astigmatism and corneal steepness increased with age.Conclusion: Corneal astigmatism of 1.00 D or more was seen in 40.06% of the patients undergoing cataract surgery which should be corrected to meet the patient’s expectation for good, unaided visual acuity after cataract surgery.

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 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

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 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 Mean difference of visual acuity with auto refraction and subjective refraction.

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Shakeel Ahmad ◽  
Rashida RIaz ◽  
Muhammad Haseeb ◽  
Hafiza Ammara Rasheed ◽  
Samia Iqbal
Keyword(s):  
Visual Acuity ◽  
Demographic Data ◽  
Anterior Segment ◽  
Cross Sectional Study ◽  
Mean Difference ◽  
P Value ◽  
Cross Sectional ◽  
Department Of Ophthalmology ◽  
The Mean ◽  
Cylindrical Axis

Purpose: To compare the mean difference of visual acuity as measured by auto refraction and subjective refraction. Study Design:  Descriptive cross-sectional study. Place and Duration of Study:  Department of ophthalmology, Services hospital Lahore from November 2013 to April 2014. Material and Methods:  Using non-probability consecutive sampling 300 eyes of 300 patients fulfilling inclusion criteria were recruited through OPD registration slip. Demographic data including age and gender was recorded. Complete ophthalmic examination was performed. This included measurement of refractive error by auto-refraction as well as subjective refraction. Detailed anterior segment examination with slit lamp and dilated fundus examination with indirect ophthalmoscopy was performed. The collected data was analyzed by using software SPSS version 17. Results:  The mean age of patients was 34.71 ± 7.45 years. There were 156 (52%) males and 144 (48%) females. There were 263 (87.69%) patients who had visual acuity of 6/6 and 37 (12.33%) had 6/9. Mean spherical auto-refraction and subjective refraction was 0.0290 ± 2.58 and -0.2842 ± 2.37 D with mean difference of -0.3133 ± 1.27 D. The mean cylindrical auto and subjective refraction in this study was -.9742 ± 0.78 D and -0.7500 ± 0.81 D and mean difference was 0.2242 ± 0.74 D. The mean cylindrical axis of auto and subjective refraction was 114.88 ± 49.75 and 115.60 ± 49.70 with mean difference as 0.72 ± 3.02 D (p-value < 0.05). Conclusion:  Difference of spherical, cylindrical and cylindrical axis in auto and subjective refraction was significantly different.

A COMPARATIVE STUDY OF SURGICALLY INDUCED ASTIGMATISM IN SUPERIOR AND TEMPORAL SCLERAL INCISION IN MANUAL SMALL INCISION CATARACT SURGERY

2021 ◽  
pp. 1-3
Author(s):  
Nitu Kumari ◽  
Kumari Preeti ◽  
Alka Jha ◽  
Debarshi Jana
Keyword(s):  
Comparative Study ◽  
Cataract Surgery ◽  
Visual Outcome ◽  
Small Incision Cataract Surgery ◽  
Surgically Induced Astigmatism ◽  
Small Incision ◽  
Incision Size ◽  
Department Of Ophthalmology ◽  
Induced Astigmatism ◽  
Surgically Induced

Aim: To evaluate the amount and type of surgically induced astigmatism in superior and temporal scleral incision in Manual Small Incision Cataract Surgery (MSICS). Material and Methods: A prospective randomized comparative study was carried out in Upgraded Department of Ophthalmology, DMCH, Laheriasarai, Bihar. Total 100 cases of senile or pre-senile cataract included in this study from July 2019 to December 2019. All the patients underwent MSICS under peribulbar anaesthesia. 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 1st day, 7th day, 6th week and 3rd month. Results: After 3 months of surgery, out of 50 patients in superior scleral incision group 74% patients had ATR astigmatism 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 signicantly 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 has manifold advantages over superior incision MSICS with excellent visual outcome.

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.

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