Analysis of anterior corneal astigmatism before cataract surgery using power vector analysis in eyes of Korean patients

2015 ◽  
Vol 41 (6) ◽  
pp. 1256-1263 ◽  
Author(s):  
Eun-hye Oh ◽  
Hyojin Kim ◽  
Hyun Soo Lee ◽  
Kyu-yeon Hwang ◽  
Choun-Ki Joo
Keyword(s):  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Vector Analysis ◽  
Korean Patients ◽  
Anterior Corneal Astigmatism

scholarly journals Astigmatic correction of simultaneous femtosecond laser-assisted cataract surgery (FLACS) with intrastromal arcuate keratotomy (ISAK) versus Toric intraocular Lens Impantation with conventional phacoemulsification

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hye Ji Kwon ◽  
Hun Lee ◽  
Jin Ah. Lee ◽  
Jae Yong Kim ◽  
Hungwon Tchah
Keyword(s):  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Intraocular Lens ◽  
Retrospective Chart Review ◽  
Corneal Astigmatism ◽  
Vector Analysis ◽  
Toric Intraocular Lens ◽  
Toric Iol ◽  
Iol Implantation ◽  
Significant Difference

Abstract Background To compare the efficacies in astigmatic correction of simultaneous femtosecond laser-assisted cataract surgery (FLACS) with intrastromal arcuate keratotomy (ISAK) versus toric intraocular lens (IOL) implantation with conventional phacoemulsification in moderate astigmatism. Methods A retrospective chart review was conducted for patients who had undergone cataract surgery by one surgeon. We identified patients with preoperative corneal astigmatism from + 0.75 to + 2.00 diopters (D) who had undergone astigmatic correction with FLACS with ISAK or toric IOL implantation with conventional phacoemulsification. We measured the visual acuity, intraocular pressure, automated keratometer, manifest refraction, and topography preoperatively and 1-day, 1-month, 3-month, and 6-month postoperatively. The vector analysis of refractive astigmatism was performed. Results Of a total of 48 eyes of 48 patients, 27 eyes of 27 patients had FLACS with ISAK (AK group), and 21 eyes of 21 patients had conventional cataract surgery with toric IOL implantation (toric IOL group). Refractive astigmatism was significantly decreased in both groups. The mean preoperative and 6-month postoperative refractive astigmatism were 1.85 ± 1.07 and 0.99 ± 0.51 D, respectively, in the AK group (P = 0.028), and 1.84 ± 0.81 and 0.68 ± 0.21 D, respectively, in the toric IOL group (P < 0.001). There was no significant difference in refractive astigmatism between the two groups at 6-month postoperatively (0.99 ± 0.51 vs 0.68 ± 0.21 D, P = 0.057). At 6-month postoperatively, parameters for vector analysis of refractive astigmatism showed no statistical difference between the two groups. Corneal astigmatism was significantly decreased in the AK group. Corneal astigmatism from topography and the automated keratometer were significantly lower in the AK group 6-month postoperatively compared to toric IOL group (0.94 ± 0.40 vs. 1.53 ± 0.46 D, P = 0.018 for topography; and 0.98 ± 0.69 vs. 1.37 ± 0.41 D, P = 0.032 for the automated keratometer). Conclusions FLACS with ISAK could be an effective procedure for reducing astigmatism as well as toric IOL implantation in cataract surgery.

scholarly journals Toric Intraocular Lenses for the Management of Corneal Astigmatism at the Time of Cataract Surgery

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Colm McAlinden ◽  
David Janicek
Keyword(s):  
Cataract Surgery ◽  
Human Error ◽  
Data Entry ◽  
Corneal Astigmatism ◽  
Intraocular Lenses ◽  
Vector Analysis ◽  
Corneal Incision ◽  
Toric Iol ◽  
Iol Power ◽  
The Mean

Aims/Background. To assess astigmatic outcomes with the use of toric intraocular lenses (IOLs) for patients with significant amounts of corneal astigmatism undergoing cataract surgery. Methods. This audit was conducted in a UK ophthalmology department and included 48 eyes of 42 patients. Surgery was performed during 2019 in patients with 2.50 diopters (D) or more corneal astigmatism. Anterior keratometry readings were used to determine the toric IOL power. Vector analysis using the Alpins method was used to assess changes in astigmatism pre to postoperatively. Results. There were 18 right and 26 left eyes included. In terms of gender, 61% of patients were female and 39% were male. The mean (±standard deviation (SD)) age was 70 (±11) years. The mean (±SD) axial length, K1, K2, and delta K was 23.55 (±1.4) mm, 42.71 (±1.39) D, 45.78 (±1.60) D, and 3.01 (±0.89) D, respectively. Postoperatively, the median spherical, cylinder, and spherical equivalent refraction was 0.00 D, −1.00 D, and 0.00 D, respectively. Postoperatively, 41% of the eyes had ≤0.50 D of spectacle astigmatism and 80% had ≤1.00 D. No patient required a secondary procedure to reposition the IOL from rotation. In vector analysis with the use of polar diagrams, there was a tendency for overcorrection of with-the-rule astigmatism and undercorrection of against-the-rule astigmatism. Conclusions. Significant reductions in astigmatism can be achieved with the use of toric IOLs in patients undergoing cataract surgery. Further improvements may be possible with surgeon-specific determination of their surgically induced astigmatism and flattening effect from the main corneal incision. Furthermore, the use of an optical biometer that directly measures the posterior corneal curvature and permits automatic toric IOL power determination with modern formulas avoiding the need for manual data entry may reduce the risk of human error and improve visual and refractive outcomes.

scholarly journals The contribution of ocular residual astigmatism to anterior corneal astigmatism in refractive astigmatism eyes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian Lin
Keyword(s):  
Correlation Analysis ◽  
Interquartile Range ◽  
Corneal Astigmatism ◽  
Vector Analysis ◽  
Spearman Correlation ◽  
Inclusion Criteria ◽  
Ocular Residual Astigmatism ◽  
Anterior Corneal Astigmatism ◽  
Superimposed Effect

AbstractTo determine the distribution of ocular residual astigmatism (ORA) in astigmatic eyes and the influence on the anterior corneal (ACA) and refractive astigmatism (RA). A total of 165 children met the inclusion criteria. Right eyes’ data were analyzed. Using Thibos vector analysis to calculate ORA. Spearman correlation analysis was used to obtain the correlation between the magnitude of ORA, ACA and RA. The median magnitude of ORA in astigmatic eyes was 0.57 D, with interquartile range was 0.42 D. And they were main against-the-rule (57.6–75.8%) and oblique astigmatism (13.9–34.5%) ORA. The ORA in 140 eyes (84.8%) acted as an offset to ACA, meanwhile, 25 eyes (15.2%) superimposed it. About 98% (97.9–98.4%) against-the-rule and 75% (73.9–82.5%) oblique ORA counteracted ACA, nevertheless, all with-the-rule ORA had a superimposed effect on ACA. For with-the-rule ACA, about 86% (85.4–85.9%) ORA worked to offset it. There was statistically correlations between ORA and ACA (r = 0.17, P = 0.03), ORA and RA (r = − 0.27, P = 0.001). The magnitude of ocular residual astigmatism was relatively small in children’s astigmatic eyes. Both against-the-rule and oblique ORA can counteract with-the-rule ACA.

scholarly journals A Randomized Study of the Impact of a Corneal Pre-Cut During Cataract Surgery on Wound Architecture and Corneal Astigmatism

2021 ◽  
Author(s):  
Birgit Doeller ◽  
Nino Hirnschall ◽  
Maria Fichtenbaum ◽  
Phuong-Mai Nguyen ◽  
Ralph Varsits ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Randomized Study ◽  
Corneal Astigmatism ◽  
The Impact

Comparison of corneal astigmatism characteristics and prevalence of corneal astigmatism between Turkish individuals and Syrian refugees

2021 ◽  
pp. 112067212110307
Author(s):  
Soner Guven
Keyword(s):  
Quantitative Analysis ◽  
Cataract Surgery ◽  
Corneal Astigmatism ◽  
Syrian Refugees ◽  
Vector Method ◽  
Adjusted Analysis ◽  
Younger Age ◽  
The Mean ◽  
Age And Sex

Purpose: To compare the prevalence, magnitude and type of corneal astigmatism between Turkish individuals and Syrian refugees. Material and methods: Data of patients scheduled for cataract surgery between January 2019 and 2020 were reviewed. The patients were randomly stratified according to their ethnicity (Turkish individuals or Syrian refugees). Keratometry was performed with the keratometer of IOLMaster 500. Quantitative analysis was performed using the power vector method (J0 and J45). The association between age and astigmatism in the two groups was explored. Results: The study included 4085 eyes of 2049 patients (3962 eyes of Turkish individuals and 123 eyes of Syrian refugees). The mean magnitude of corneal astigmatism, J0, J45 and prevalence of against the rule (ATR) astigmatism and with the rule (WTR) astigmatism were 1.01 D, 0.06, 0.01 D, 37.6% and 43.7% in Turkish individuals and 1.13 D, −0.02, 0.07 D, 46.3% and 37.4% in Syrian refugees, respectively. There were no significant differences according to age, sex, right/left eyes, corneal astigmatism magnitude, keratometric values, J0 and J45 ( p > 0.05) between the two groups. Below 40 years of age, the mean corneal astigmatism magnitude in Syrian refugees was significantly higher than that in Turkish individuals ( p = 0.037). At all ages, ATR astigmatism prevalence was higher in Syrian refugees than in Turkish individuals. ATR astigmatic shift began at a younger age in Syrian refugees ( p = 0.037). Age- and sex-adjusted analysis showed that J0 was significantly lower in Syrian refugees than in Turkish individuals ( p = 0.013). Conclusion: The prevalence and magnitude of ATR astigmatism were higher and onset earlier in Syrian refugees than in Turkish individuals.

scholarly journals Does pterygium morphology affect corneal astigmatism?

2021 ◽  
Vol 13 ◽  
pp. 251584142110304
Author(s):  
Emine Doğan ◽  
Burçin Çakır ◽  
Nilgün Aksoy ◽  
Elif Köse ◽  
Gürsoy Alagöz
Keyword(s):  
Anterior Segment ◽  
Clinical Information ◽  
Corneal Astigmatism ◽  
Continuous Group ◽  
Optic Coherence Tomography ◽  
Morphological Pattern ◽  
Horizontal Length ◽  
The Mean ◽  
Anterior Corneal Astigmatism ◽  
Posterior Corneal Astigmatism

Purpose: The purpose of this study was to evaluate the correlation between corneal astigmatism and the morphology of pterygium with anterior segment optic coherence tomography (AS-OCT). Material and Methods: The size of pterygium (horizontal length, vertical width) was measured manually; pterygium area and percentage extension of the pterygium onto the cornea were calculated. Anterior and posterior corneal astigmatism, Sim K, K1, K2 were measured using a dual Scheimpflug analyzer. Morphological patterns of the pterygium analyzed with AS-OCT were determined according to the extension of the pterygium apex below the corneal epithelium. Two tomographic patterns were identified: continuous and nodular. Correlation between anterior corneal astigmatism and pterygium size, percentage extension of the pterygium, and morphological pattern of the pterygium was analyzed. Results: The mean ages of the 47 patients were 49.4 ± 16.6 (22–80) years. Mean horizontal pterygium length, vertical width, pterygium area, and percentage extension of the pterygium were 2.8 ± 1.2 mm, 4.8 ± 1.6 mm, 7.42 ± 5.6 mm2 and 24.5 ± 10.4%, respectively. Mean anterior corneal astigmatism was 2.3 ± 2.3 D and simulated keratometry was 43.4 ± 2.02 D. In terms of the morphological pattern of the pterygium, 24 eyes had continuous, 23 eyes had a nodular pattern and the median (interquartile range) anterior corneal astigmatism was 1.87 (1.01–3.80) and 1.22 D (0.58–2.35), respectively ( p = 0.102). Other topographic and pterygium size parameters were similar between groups. Analyzing the correlations in groups separately, a positive moderate statistically significant correlation was present between vertical width, percentage extension, pterygium area, and anterior corneal astigmatism in both continuous and nodular groups. Conclusions: Although not statistically significant, anterior corneal astigmatism was higher in continuous group. Using AS-OCT to standardize the morphology of pterygium could provide additional clinical information.

scholarly journals Analysis of corneal astigmatism and aberration in chinese congenital cataract and developmental cataract patients before cataract surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoyan Han ◽  
Qi Fan ◽  
Zhixiang Hua ◽  
Xiaodi Qiu ◽  
Dongjin Qian ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Congenital Cataract ◽  
Anterior Chamber Depth ◽  
Corneal Astigmatism ◽  
Imaging Device ◽  
Mean Values ◽  
Biometric Parameters ◽  
Developmental Cataract ◽  
Positive Linear Correlation ◽  
Cataract Patients

Abstract Background To investigate the distribution of corneal astigmatism, aberration, and biometric parameters in Chinese congenital cataract (CC) /developmental cataract patients before cataract surgery. Methods We evaluated eyes of CC /developmental cataract patients scheduled for cataract surgery from January 2016 to September 2019. Astigmatism, aberrations, and biometric parameters were measured with the Pentacam Scheimpflug imaging device (Pentacam HR, Oculus). Cataract was diagnosed and classified by slit-lamp examination after full mydriasis. Results We evaluated 538 eyes in 356 patients. The mean values of anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), and total corneal astigmatism (TCA) were determined as 1.98 ± 1.06 D (range 0.0‒4.8 D), 0.49 ± 0.26 D (range 0.0‒1.9 D), and 2.09 ± 1.19 D (range 0.2‒8.8 D), respectively. ACA and TCA ≥ 1.25 D was present in 379 eyes (70.3%) and 392 eyes (72.8%), respectively. PCA between 0.25 D and 0.75 D was found in 380 eyes (70.6%). There was a statistically significant positive linear correlation between lower-order aberrations root mean square values (LOA RMS) and corneal astigmatism (CA). Furthermore, in terms of distribution of central cornea thickness, anterior chamber depth, ACA, PCA, and TCA in different types of cataracts, ACA was highest in patients with zonular cataracts. Finally, we found anterior corneal measurements may overestimate WTR astigmatism, underestimate ATR astigmatism, and underestimate oblique astigmatism, respectively. Conclusions Most CC /developmental cataract patients had moderate to high astigmatism and ACA accounted for the largest proportion in the zonular group. This can provide a basis for planning of CC/developmental cataract surgery by ophthalmologists in clinical practice.

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