COMPARISON OF ASTIGMATIC OUTCOMES AFTER PHACOEMULSIFICATION WITH SUPERIOR, TEMPORAL OR OBLIQUE CLEAR CORNEAL INCISIONS: A RANDOMIZED PROSPECTIVE TRIAL

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Kapil Chopra ◽  
Neelima Mehrotra ◽  
Akhil Agarwal ◽  
Arvind Ram ◽  
B. D. Sharma ◽  
...  

<bold>Introduction :</bold> A variety of modalities are available presently to deal with astigmatism in relation to phacoemulsification surgery. Of these, toric intraocular lenses are expensive, limbal Paper Submission Daterelaxing incisions are unpredictable and both of these cater to a limited dioptric range and type of astigmatism. Simply planning the incision according to pre-existing corneal astigmatism is an economical and rationale way of addressing this issue. To compare residual post operative astigmatism after phacoemulsification with foldable IOL’simplantation with different sites of clear corneal incision in patients with pre-existing astigmatism. <bold>Material and Methods:</bold> Study was done to evaluate residual corneal astigmatism after July 2016 phacoemulsification with foldable intraocular lens implantation from Jan 13 to May 14. A total of 90 eyes of 85 patients were selected having visually significant cataract. Incision was planned on steeper axis on basis of preoperative keratometric values and divided into 3 groups namely, WTR who received superior clear corneal incision (CCI),ATR who received temporal and OBQ received superotemporal or superonasal CCI respectively. Surgically induced astigmatism (SIA) was also calculated by SIA calculator using vector method. Statistical analysis used is Kruskal Wallis test, Chi-square test, F-test. <bold>Results:</bold> Residual corneal astigmatism among the three groups was found to be nonsignificant. Comparison of mean preoperative and postoperative corneal astigmatism between 3 groups came out be statistically significant. <bold>Conclusion:</bold> Study concludes that preoperative astigmatism should always be assessed and addressed peroperatively by suitable incision sites to provide best results.

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Paul Ernest ◽  
Warren Hill ◽  
Richard Potvin

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.


2021 ◽  
Author(s):  
Dan Liu ◽  
Cong Fan ◽  
Chunyan Li ◽  
Jian Jiang

Abstract Background: Multifocal intraocular lenses (IOLs) is very intolerant to residual corneal astigmatism and patients with more than 1.0 D of residual corneal astigmatism are not suitable candidates for implantation of multifocal IOLs. The purpose of this study was to evaluate the efficacy of a single clear corneal incision (CCI) or an opposite clear corneal incision (OCCI) made on a steep meridian for correction of low to moderate corneal astigmatism during implantation of multifocal IOLs.Methods: This is a retrospective cohort study. A total of 50 patients with pre-operative total corneal astigmatism, ranging between 0.5 and 2.0 diopters (D), who underwent cataract surgery and received multifocal IOLs were included. Correction of corneal astigmatism was done via single CCIs on steep meridians in patients with 0.5–1.2 D total corneal astigmatisms, and OCCIs in patients with 1.3–2.0 D total corneal astigmatisms. Visual acuity, corneal astigmatism, ocular aberrations, corneal aberrations, and subjective vision quality were evaluated after surgery.Results: At 12-weeks post-surgery, the mean uncorrected distance vision (UCDV) was 0.06±0.09 logarithm of the minimum angle of resolution (logMAR) and 0.03±0.09 logMAR, and the mean uncorrected near vision (UCNV) was 0.08±0.11 logMAR and 0.09±0.09 logMAR in the CCI and OCCI groups, respectively. The change in corneal astigmatism was 0.52 ± 0.22D and 1.06 ± 0.23D in the CCI and OCCI groups, respectively (P<0.001). Total corneal higher-order aberrations (HOAs) and trefoil increased in both groups (P<0.05); however, there was no difference in the change in total corneal HOAs between the two groups (P>0.05). Conclusions: CCI and OCCI made on a steep axis could be an option for correction of mild-to-moderate astigmatism during cataract surgery with multifocal IOL implantation.


2018 ◽  
Vol 30 (1) ◽  
pp. 104-111
Author(s):  
Serap Sonmez ◽  
Cagatay Karaca

Purpose: The purpose of this study is to evaluate the effects of variation in tunnel length of same-sized clear corneal phacoemulsification incisions on the generation of surgically induced astigmatism and corneal astigmatism. Methods: A total of 126 cataract patients treated in four study groups based on location and tunnel length of the clear corneal incisions (superior long, superior short, temporal long, temporal short) were reviewed. In the short tunnel groups, a 2.8 mm keratome was used with a motion parallel to the iris surface, while in the long tunnel groups, the same keratome was advanced in the corneal stroma until the mark on the keratome was reached. The surgically induced astigmatism and the corneal astigmatism were measured with corneal topography. The tunnel lengths were determined by anterior segment optical coherence tomography. Results: The tunnel lengths of the long tunnel groups were significantly longer than the short tunnel groups. The total and anterior corneal surgically induced astigmatism of the superior long group was significantly higher than the other groups. Posterior corneal surgically induced astigmatism was similar. The postoperative total and anterior corneal astigmatism values of the superior long group was significantly higher than the other groups. No difference was observed for mean change in corneal astigmatism between the groups. Conclusion: The tunnel length of a clear corneal incision is a significant determinant of surgically induced astigmatism for superior placed corneal incisions. Therefore, for superiorly positioned clear corneal incision, the incision should be rectangular with a shorter tunnel to keep the surgically induced astigmatism to a minimum. For squarer-shaped clear corneal incision, limbal-temporal incisions may be performed for astigmatic neutrality.


2020 ◽  
Vol 13 (12) ◽  
pp. 1895-1900
Author(s):  
Wei Chen ◽  
Jian Wu ◽  
Yong Wang ◽  
Jing Zhou ◽  
Rong-Rong Zhu ◽  
...  

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.


F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 825
Author(s):  
Najah K. Mohammad ◽  
Tamer F. Elewa ◽  
Enas B. Aldehaimy ◽  
Tareq A. Almamoun

Background: Phacoemulsification is regarded as a type of refractive surgery by which it is possible to ‎reduce pre-existing corneal stigmatism.‎ This study aimed to evaluate the efficacy and safety of on-axis corneal incision with or without opposite clear corneal incisions (OCCI) to correct preoperative corneal astigmatism during uncomplicated phacoemulsification ‎surgeries.‎ Methods: A randomized, prospective, parallel two-arm interventional study, which included a ‎total 40 eyes from 40 patients, was conducted.‎ Patients were divided into two groups: 20 patients as controls underwent phacoemulsification with on-axis incision (CCI group), and 20 patients underwent phacoemulsification with OCCI (OCCI group). Results: Mean astigmatic correction was significantly higher in the OCCI group (0.665 vs 0.265 diopters, p-value <0.001), compared to the CCI group. Most of the parameters (surgical induced astigmatism, magnitude of error, and correction index) were significantly higher in the OCCI group compared to the CCI group (p-value <0.01). There were no ‎incision-related complications. Conclusions: Both incisional methods are useful methods for correction of preoperative corneal ‎astigmatism but OCCIs correct a higher amount of astigmatism than the on-axis clear ‎corneal incision.‎ Registration: ClinicalTrials.gov NCT04418986 (05/06/2020).


2021 ◽  
Vol 8 ◽  
Author(s):  
Kazutaka Kamiya ◽  
Kei Iijima ◽  
Wakako Ando ◽  
Nobuyuki Shoji

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.


2021 ◽  
Author(s):  
Dan Liu ◽  
Cong Fan ◽  
Chunyan Li ◽  
Jian Jiang

Abstract Background: Multifocal intraocular lenses (IOLs) is very intolerant to residual corneal astigmatism and patients with more than 1.0 D of residual corneal astigmatism are not suitable candidates for implantation of multifocal IOLs. The purpose of this study was to evaluate the efficacy of a single clear corneal incision (CCI) or an opposite clear corneal incision (OCCI) made on a steep meridian for correction of low to moderate corneal astigmatism during implantation of multifocal IOLs.Methods: This is a retrospective cohort study. A total of 80 patients with pre-operative total corneal astigmatism, ranging between 0.5 and 2.0 diopters (D), who underwent cataract surgery and received multifocal IOLs were included. Correction of corneal astigmatism was done via single CCIs on steep meridians in patients with 0.5–1.2 D total corneal astigmatisms, and OCCIs in patients with 1.3–2.0 D total corneal astigmatisms. Visual acuity, corneal astigmatism, ocular aberrations, corneal aberrations, and subjective vision quality were evaluated after surgery.Results: At 12-weeks post-surgery, the mean uncorrected distance vision acuity (UDVA) was 0.06±0.09 logarithm of the minimum angle of resolution (logMAR) and 0.03±0.09 logMAR, and the mean uncorrected near vision acuity(UNVA) was 0.08±0.11 logMAR and 0.09±0.09 logMAR in the CCI and OCCI groups, respectively. The change in corneal astigmatism was 0.52 ± 0.22D and 1.06 ± 0.23D in the CCI and OCCI groups, respectively (P<0.001). Total corneal higher-order aberrations (HOAs) and trefoil increased in both groups (P<0.05); however, there was no difference in the change in total corneal HOAs between the two groups (P>0.05). Conclusions: CCI and OCCI made on a steep axis could be an option for correction of mild-to-moderate astigmatism during cataract surgery with multifocal IOL implantation.


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