scholarly journals Eyes of Aniso-Axial Length Individuals Share Generally Similar Corneal Biometrics with Normal Eyes in Cataract Population

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Min Zhang ◽  
Tianhui Chen ◽  
Michael Deng ◽  
Jiahui Chen ◽  
Qinghe Jing ◽  
...  
Keyword(s):  
Axial Length ◽  
Case Series ◽  
High Order ◽  
Corneal Astigmatism ◽  
Retrospective Case ◽  
Corneal Aberrations ◽  
Length Group ◽  
Cataract Patients ◽  
High Order Aberrations ◽  
Anterior Corneal Astigmatism

Aims. To determine the characteristics of corneal biometrics in eyes from aniso-axial length cataract patients compared with eyes from non-aniso-axial length individuals. Methods. This is a retrospective case series. Cataract patients with preoperative binocular measurements were recruited. A binocular axial difference of ≥1 mm was considered to indicate aniso-axial length. The anterior segmental biometrics were measured using Pentacam HR (Oculus, Wetzlar, Germany) and IOLMaster 500 (Carl Zeiss Meditec, Jena, Germany). Comparisons of biometrics were made among 4 eye conditions: the longer eyes from aniso-axial length patients, the shorter eyes from aniso-axial length patients, the longer eyes from non-aniso-axial length patients, and the shorter eyes from non-aniso-axial length patients. The aniso-axial length eyes were also stratified into 8 subgroups with axial length (AL) increments of 1 mm, and the biometrics of the subgroups were compared. Results. There was smaller anterior corneal astigmatism in the shorter aniso-axial length group than those in the longer aniso-axial length group (1.01 ± 0.70 D vs 1.12 ± 0.76 D, P = 0.031 ). The longer aniso-axial length eyes had greater anterior corneal steep curvature (44.13 ± 1.69 D vs 43.87 ± 1.69 D, P = 0.009 ) and anterior corneal astigmatism (1.12 ± 0.76 D vs 1.02 ± 0.69 D, P = 0.023 ) compared with longer non-aniso-axial length subjects. Other corneal biometrics were similar between the aniso-axial length eyes and the non-aniso-axial length eyes. In the longer aniso-axial length group, the posterior corneal aberrations of eyes in the ≥5 mm subgroups were greater than those in the <5 mm subgroups (0.879 ± 0.183 μm vs 0.768 ± 0.178 μm for total aberrations, P < 0.001 ; 0.228 ± 0.086 μm vs 0.196 ± 0.043 μm for high-order aberrations, P = 0.036 ; 0.847 ± 0.173 μm vs 0.741 ± 0.179 μm for low-order aberrations, P = 0.001 ). Conclusion. Eyes of aniso-axial length individuals share generally similar corneal biometrics with normal eyes in cataract population. Anterior corneal astigmatism of the longer eyes from the aniso-axial length cataract patients was higher than that of the longer eyes from the non-aniso-axial length individuals. Total posterior corneal aberrations of the longer aniso-axial length eyes increased when the binocular axial difference was over 5 mm.

scholarly journals Correlations of Corneal Spherical Aberration with Astigmatism and Axial Length in Cataract Patients

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Min Zhang ◽  
Dongjin Qian ◽  
Qinghe Jing ◽  
Jiahui Chen ◽  
Michael Deng ◽  
...  
Keyword(s):  
Axial Length ◽  
Spherical Aberration ◽  
Case Series ◽  
Corneal Astigmatism ◽  
Control Group ◽  
Negative Effects ◽  
Retrospective Case ◽  
Department Of Ophthalmology ◽  
Cataract Patients ◽  
Anterior Corneal Astigmatism

Purpose. To clarify the distribution of corneal spherical aberrations (SAs) in cataract patients with different corneal astigmatism and axial length. Setting. Department of Ophthalmology and Vision Science of the Eye and ENT Hospital of Fudan University, Shanghai, China. Design. Retrospective case series. Methods. The axial length, corneal SAs, and other corneal biometrics were collected in cataract patients with Pentacam HR and IOLMaster 500. The statistical analysis of the corneal SAs was based on the stratification of axial length and anterior corneal astigmatism. Results. In total, 6747 eyes of 6747 patients were recruited, with 2416 eyes (58.17 ± 16.81 years old) in the astigmatism group (anterior corneal astigmatism ≥1 D) and others (61.82 ± 12.64 years old) in the control group. In patients with astigmatism <2 D, the total and anterior SAs decreased as the axial length increased (P<0.001). The total corneal SAs of patients with astigmatism of 2-3 D stabilized at around 0.29 μm, whereas those of patients with anterior corneal astigmatism ≥3 D tended to be variable. Age and anterior corneal astigmatism had positive and negative effects, respectively, on SA in the regression model. Conclusions. Axial length has a negative effect on the anterior and total corneal SAs, which stabled around 0.33 μm and 0.30 μm in patients with axial length of ≥26 mm, respectively. Individualized SA adjustments are essential for patients undergoing aspheric toric IOL implantation with preoperative anterior corneal astigmatism of 1-2 D or ≥3 D. Toric IOLs with a negative SA of −0.20 μm are recommended for patients with anterior corneal astigmatism of 2-3 D if no customized therapy is warranted.

scholarly journals Characteristics of corneal high-order aberrations in adolescents with mild to moderate myopia

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xu Zhang ◽  
Jin-Hui Ma ◽  
Xin Xi ◽  
Lin Guan
Keyword(s):  
Spherical Aberration ◽  
Anterior Segment ◽  
Corneal Astigmatism ◽  
Surface Shape ◽  
Corneal Surface ◽  
Corneal Aberrations ◽  
Anterior Posterior ◽  
High Order Aberrations ◽  
Posterior Corneal Curvature ◽  
Anterior Corneal Astigmatism

Abstract Background This study investigated the characteristics of corneal higher-order aberrations (HOAs) of the anterior surface, posterior surface, and total cornea in adolescents with mild to moderate myopia. Methods A total of 183 patients with myopia (183 eyes) aged 8 to 18 years were enrolled in this study. The axial length (AL) of the eyes was measured by an IOL-Master, and corneal curvatures (K-values) and HOAs were measured by a Pentacam anterior segment diagnostic analyzer. Results Results of this study showed that the anterior, posterior and total corneal horizontal coma Z31 were − 0.1249 ± 0.105 μm, 0.0009 ± 0.001 μm, and − 0.1331 ± 0.116 μm, respectively; the anterior, posterior and total corneal vertical coma Z3− 1 were − 0.0212 ± 0.164 μm, 0.0003 ± 0.043 μm, and − 0.0216 ± 0.168 μm, respectively; and spherical aberration (SA) Z40 values were 0.2244 ± 0.091 μm, 0.1437 ± 0.029 um, and 0.1889 ± 0.090 μm, respectively. Total corneal Z31 was statistically correlated with posterior corneal astigmatism (K2b − K1b) (p = 0.038). Total corneal Z3− 1 was correlated with anterior corneal astigmatism (K2f − K1f) (p = 0.027). Anterior, posterior, and total corneal Z40 were correlated with anterior and posterior corneal curvature (K1f, K2f, K1b, K2b) (p = 0.001). Posterior corneal Z40b was also significantly correlated with AL. Conclusions In adolescents with mild to moderate myopia, the posterior corneal surface shape may play a compensatory role in the balance of corneal aberrations, and the posterior corneal SA tended to become less negative as the AL increased. The corneal coma may also play a compensatory role in posterior corneal surface astigmatism, which was valuable for the treatment for improving visual quality. This conclusion still needs to be verified.

Power Vector Analysis of Corneal Astigmatism among Chinese over Fifty Years Old: a retrospective cross-sectional study

2020 ◽  
Author(s):  
Yilin Pang ◽  
Xiaoguang Cao ◽  
Xianru Hou ◽  
Li Yuan ◽  
Yongzhen Bao
Keyword(s):  
Axial Length ◽  
Linear Trend ◽  
Linear Regression Analysis ◽  
Corneal Astigmatism ◽  
Vector Analysis ◽  
Cross Sectional ◽  
Age Related ◽  
Relationship Of ◽  
The Relationship ◽  
Cataract Patients

Abstract Background: To investigate the relationship between corneal astigmatism and age, axial length (AL) among Chinese over fifty years old. Methods: This study enrolled 1,082 right eyes of age-related cataract patients over 50 years old in the clinic of Peking University People’s Hospital, Beijing, China. Axial length, magnitude and meridian of anterior corneal astigmatism were measured by IOLMaster. Restricted cubic splines and Spearman rank correlation coefficients were used to investigate the relationship of the magnitude of cornea astigmatism to age and AL. Power vector analysis method and linear regression analysis were used to assess the relationship of the meridian of astigmatism to age and AL. Results: For this study , mean age, AL, and corneal astigmatism value were 72.45 ±9.28 years, 23.90±1.93mm, and 1.12±0.74D, respectively. The magnitude of corneal astigmatism was 0.75D or higher in 63.8% eyes. The magnitude of corneal astigmatism increased with age after 65 years old. This correlation was statistically significant when AL was between 22.00mm and 26.00mm. The vector value in J 0 was inversely correlated with age. The mean vector value change from with-the-rule (WTR) to against-the-rule (ATR) corneal astigmatism was 0.22D/10 years during 50-65 years old and 0.15D/10 years during 65-85 years old, and was 0.22D/10 years in male and 0.12D/10 years in female, respectively. Conclusions: A large proportion of elderly Chinese cataract patients over 50 years old have corneal astigmatism more than 0.75D . There was a non-linear trend from WTR astigmatism towards ATR astigmatism with age, which was more obvious in elder age and in male. When AL is between 22.00mm and 26.00mm, the magnitude of corneal astigmatism increases with age after 65 years old.

scholarly journals Comparison of Outcomes after Phacoemulsification with Two Different Corneal Incision Distances Anterior to the Limbus

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Lijun Wang ◽  
Lin Zhao ◽  
Xiting Yang ◽  
Yi Zhang ◽  
Dingying Liao ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Anterior Segment ◽  
Case Series ◽  
Senile Cataract ◽  
Retrospective Case ◽  
Corneal Incision ◽  
Clear Corneal Incision ◽  
Corneal Aberrations ◽  
Anterior Segment Parameters ◽  
Group B

Purpose. To compare visual performance and visual quality outcomes after phacoemulsification with two different clear corneal incision (CCI) distances anterior to the limbus in senile cataract patients. Methods. Retrospective case series. Patients who had undergone phacoemulsification were divided into two groups according to the CCI distances anterior to the limbus. The CCI distances in group A range from 1 mm to 1.5 mm, while those in group B range from 0.5 mm to 1 mm. The visual acuity, refraction, surgically induced astigmatism (SIA), corneal aberrations, anterior segment parameters, and subjective vision quality were evaluated. Results. This study enrolled 54 eyes, with 27 eyes per group. Both groups had significant improvement in postoperative uncorrected visual acuity (UCVA) and corrected distance visual acuity (CDVA) (P<0.05). There were no statistically significant between-group differences in postoperative UDVA, CDVA, SIA, corneal aberrations, anterior segment parameters, or VF-QOL questionnaire performance (P>0.05). Conclusions. The phacoemulsification with CCI distances ranging from 0.5 mm to 1.5 mm is an effective and safe therapy to senile cataract. The CCI distance anterior to the limbus that ranges from 0.5 mm to 1.5 mm is recommended for routine phacoemulsification.

scholarly journals Distribution and internal correlations of corneal astigmatism in cataract patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuanfeng Jiang ◽  
Ying Qin ◽  
Shaochong Bu ◽  
Hong Zhang ◽  
Xiaomin Zhang ◽  
...  
Keyword(s):  
Distribution Patterns ◽  
Corneal Astigmatism ◽  
Morphological Parameters ◽  
Summation Effect ◽  
Age Related ◽  
Cataract Patients ◽  
Age Related Changes ◽  
Anterior Corneal Astigmatism ◽  
Posterior Corneal Astigmatism ◽  
Total Corneal Astigmatism

AbstractThe aim of the study is to explore the distribution patterns and internal correlations of the morphological parameters of the cornea in patients with age-related cataract. The Pentacam HR was used to measure anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), total corneal astigmatism (TCA) and keratometric corneal astigmatism (KCA). With age, the proportion of with-the-rule (WTR) ACA decreased from 65.31% to 23.63%, while the against-the-rule (ATR) ACA increased from 26.53% to 56.20%. PCA exceeded 0.50 D in 9.14% of eyes, while 76.35% of them were ATR. The magnitude of ACA was positively correlated with PCA in the whole sample, with a more significant correlation in WTR eyes (sr = 0.349, P < 0.001). The vector summation effect of PCA to ACA changed from compensation to augmentation with aging. In 57.53% of WTR eyes, KCA was overestimated by an average of 0.21 ± 0.17 D, while it was underestimated by 0.38 ± 0.27 D in 87.62% of ATR eyes. In conclusion, among age-related cataract patients, ACA and TCA gradually shifted from WTR to ATR with aging, while most PCA remained as ATR. Ignoring the age-related changes and real PCA might cause overestimation of WTR astigmatism and underestimation of ATR astigmatism.

scholarly journals Assessment of the Influence of Keratometry on Intraocular Lens Calculation Formulas in Long Axial Length Eyes

2021 ◽  
Author(s):  
Shengjie Yin ◽  
Chengyao Guo ◽  
Kunliang Qiu ◽  
Tsz Kin Ng ◽  
Yuancun Li ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Axial Length ◽  
Case Series ◽  
Absolute Error ◽  
Power Calculation ◽  
Prediction Errors ◽  
Retrospective Case ◽  
Iol Power Calculation ◽  
Iol Power ◽  
Intraocular Lens Calculation

Abstract Purpose: Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes.Methods: Retrospective case-series. 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average). Prediction errors (PE) were compared between different formulas. Multiple regression analysis was performed to investigate factors associated with the PE.Results: The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only. Conclusions: Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.

scholarly journals Age Differences in Axial Length, Corneal Curvature, and Corneal Astigmatism in Marfan Syndrome with Ectopia Lentis

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Jiahui Chen ◽  
Qinghe Jing ◽  
Yating Tang ◽  
Dongjin Qian ◽  
Yi Lu ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Axial Length ◽  
Young Patients ◽  
Case Series ◽  
Corneal Astigmatism ◽  
Corneal Curvature ◽  
Biometric Data ◽  
Ectopia Lentis ◽  
Case Series Study ◽  
Significant Difference

Purpose. To investigate the differences in axial length, corneal curvature, and corneal astigmatism with age in patients with Marfan syndrome (MFS) and ectopia lentis. Methods. A retrospective case series study was conducted. MFS patients with ectopia lentis were divided into groups according to age. Axial length, corneal curvature, and corneal astigmatism were measured. Results. This study included 114 MFS patients (215 eyes) with a mean age of 19.0 ± 13.9 years. Axial length differed significantly across age groups in MFS patients (P<0.001), whereas corneal curvature did not (P=0.767). Corneal astigmatism was statistically significant throughout the MFS cohort (P=0.009), but no significant difference was found in young MFS patients (P=0.838). With increasing age, the orientation of the corneal astigmatism changed from with-the-rule astigmatism to against-the-rule or oblique astigmatism (P<0.001). A linear correlation analysis showed weak correlations between age and axial length for both eyes and with corneal astigmatism for the left eye, but there was no correlation between age and corneal curvature. Conclusions. In MFS, axial length varies with age, corneal curvature remains stable, and corneal astigmatism is higher in young patients and tends to shift toward against-the-rule or oblique astigmatism. Therefore, it is important to consider age when diagnosing MFS with ocular biometric data.

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