scholarly journals Tomographic Analysis of Incision Sequence on Anterior and Posterior Surgically Induced Astigmatism in Cataract Surgery

Author(s):  
Mehmet Adam ◽  
Osman Sayın ◽  
Okan Ağca ◽  
Hasan Altınkaynak

Abstract Purpose: To evaluate of effect incision sequence on anterior and posterior astigmatism and SIA at cataract surgery using Scheimpflug tomography measurements.Methods: We evaluated 86 patients who had gone cataract surgery between October 2018 to March 2019. All eyes were measured with a Scheimpflug tomography system preoperatively and at 1 month after surgery which included anterior and posterior corneal surfaces. The surgery was begin with side incision in group 1 differently the main incision was done first in group 2. Student t test and Pearson’s correlation were performed. P values < 0.05 were considered statistically significant.Result: Surgically induced anterior astigmatism (SIA-A) 0.76±0.43, 0.67±0.38 and surgically induced posterior astigmatism(SIA-P) 0.27±0.19 0.23±0.19 respectively in group 1 and group 2. 1D or greater SIA-A was found 24.4 % and 15.6% and 0.5 D or greater SIA-P was found 14.6% and 12.2% respectively in group 1 and group 2. There was a significant increase in anterior astigmatism (p=0.002, 0.005 respectively in group 1 and 2), but not in the posterior astigmatism (p=0.471 and 0.247 respectively in group 1 and 2). In the subgroup analysis, group 2 has lower SIA-A then group 1 except oblique subgroup and group 2 has lower SIA-P for all subgroups but it wasn't statistically significant.Conclusion: Making the main incision first caused less SIA on both anterior and posterior surfaces however this difference was not significant.

2019 ◽  
Vol 16 (3) ◽  
pp. 168-178
Author(s):  
Anu Malik ◽  
Smruti Ranjan Dethi ◽  
Yogesh Kumar Gupta ◽  
Alka Gupta

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.


2021 ◽  
Vol 62 (8) ◽  
pp. 1029-1035
Author(s):  
Zee Yoon Byun ◽  
Jung Hyun Lee ◽  
Sang-Mok Lee ◽  
Daniel Duck-Jin Hwang

Purpose: To compare the long-term changes in surgically induced astigmatism (SIA) in patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together with patients who underwent cataract surgery only.Methods: We retrospectively reviewed SIA changes for 1 year after surgery in patients who received only cataract surgery using phacoemulsification (group 1) and patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together (group 2). Flat keratometry (K1), steep keratometry (K2), and astigmatism axis were measured with automatic keratometry before and after the surgery. Vector analysis was used to calculate SIA at 1, 3, 6, and 12 months postoperatively. We then examined whether the SIA values at each time point were different between the two groups.Results: A total of 86 eyes were included in this study (group 1, n = 45; group 2, n = 41). The mean SIA values calculated at 1, 3, 6, and 12 months after surgery in group 1 were 0.83 ± 0.37, 0.69 ± 0.39, 0.60 ± 0.33, and 0.59 ± 0.33, respectively. In group 2, the values were 0.82 ± 0.47, 0.69 ± 0.38, 0.62 ± 0.28, and 0.61 ± 0.30, respectively. Over time, SIA decreased in both groups (all p < 0.001). There was no significant difference in the mean SIA between the two groups at each follow-up time point after surgery (p = 0.296, p = 0.728, p = 0.361, and p = 0.356, respectively).Conclusions: When 23-gauge sutureless vitrectomy and cataract surgery were performed together, the astigmatism change caused by surgery did not show a significant difference compared with that of the group who received cataract surgery only. Thus, 23-gauge sutureless vitrectomy may not significantly affect corneal astigmatism.


Author(s):  
Reinhard Angermann ◽  
Christoph Palme ◽  
Philipp Segnitz ◽  
Andreas Dimmer ◽  
Eduard Schmid ◽  
...  

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.


Author(s):  
Gannaram Laxmiprasad ◽  
Chhaya Shori ◽  
Rakesh Shori ◽  
Ashalatha Alli

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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Young-chae Yoon ◽  
Minji Ha ◽  
Woong-Joo Whang

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.


2019 ◽  
Vol 30 (6) ◽  
pp. 1320-1327
Author(s):  
Yi-Ju Ho ◽  
Chi-Chin Sun ◽  
Jiahn-Shing Lee ◽  
Ken-Kuo Lin ◽  
Chiun-Ho Hou

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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