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@#AIM: To investigate the difference and consistency between iTrace and Pentacam in measuring corneal spherical aberration(SphA)and curvature.<p>METHODS: The corneal spherical aberration and curvature were measured by iTrace and Pentacam in 63 cases(125 eyes)separately, and the SphA, the minimum corneal curvature(K1), maximum corneal curvature(K2)and corneal astigmatism(CA)were recorded respectively. Paired <i>t</i>-test was used for statistical analysis of econometric data, Bland-Altman analysis was used to evaluate the consistency of measurement results(SphA and curvature)measured by iTrace and Pentacam.<p>RESULTS: The measurement result of SphA, K1, K2 and CA were(0.230±0.086)μm,(43.01±2.38)D,(44.08±2.48)D and(1.03±0.57)D measured by iTrace, and(0.247±0.114)μm,(42.88±1.44)D,(43.86±1.51)D and(1.07±0.62)D measured by Pentacam, there was no significant difference of the measurement result of SphA, K1, K2 and CA between iTrace and Pentacam(<i>P</i>>0.05). The difference of SphA, K1, K2 and CA between iTrace and Pentacam was close to 0, the consistency was good because of the narrow 95% confidence interval.<p>CONCLUSION:There is no significant difference of the measurement result between iTrace and Pentacam, the consistency is good, and both can be used as a mutual reference in clinical.
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@#AIM:To investigate the distribution of corneal spherical aberration in age-related cataract.<p>METHODS: Retrospective study. Totally 217 cases of age related cataract(217 eyes)were collected in the Central Hospital of Kaifeng from August 2017 to August 2018. Patients were divided into 3 groups according to age: 50-60 years(63 eyes)in group Ⅰ, 61-70 years(107 eyes)in group Ⅱ, 71-80 years(47 eyes)in group Ⅲ. Pentacam anterior segment analysis was used to measure the anterior and posterior corneal K-readings. The corneal spherical aberration of anterior, posterior and total were calculated on an area of 6mm diameter by Zernike analysis and a descriptive study was used.<p>RESULTS:The Mean±SD of total corneal spherical aberration was 0.311±0.098μm for all the patients. Statically significant were found for the anterior and total corneal spherical aberration(<i>F</i>=34.434, 32.896; <i>P</i><0.05). The anterior, posterior corneal K-readings and posterior corneal spherical aberration had no correlation with age(<i>r</i>=0.040, 0.066, 0.097, <i>P</i>>0.05). The anterior and total corneal spherical aberration were positively correlated with age(<i>r</i>=0.506, 0.509, <i>P</i><0.05).<p>CONCLUSION:The total corneal spherical aberration in age-related cataract was slightly higher than that before. The anterior and total corneal spherical aberration increased with age, and then the posterior corneal spherical aberration was not.
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AIM:To find out the mean corneal spherical aberration and its changes with age in Kaifeng population. METHODS: A total of 466 eyes of 427 Kaifeng subjects with cataract, whose age ranged from 52 to 75 years old, were divided into three groups according to the age. All the subjects were included in measuring K-readings of cornea, the corneal anterior and posterior surfaces of the spherical aberration and the total corneal spherical aberration using Pentacam(Oculus, Germany) at the 6-mm optical zone. RESULTS:The mean corneal spherical aberration( CSA) of the whole groups was 0. 339±0. 153μm. Patients from 50 to 60 years old had CSA of 0. 322±0. 137μm, 0. 326±0.157μm was the CSA of the patients from 60 to 70 years old, while those from 70 to 80 years old have a CSA of 0.401 ± 0. 182μm. The corneal K - readings had no correlation with the total corneal spherical aberration ( r=0. 034, P>0. 05), anterior surfaces CSA, posterior surfaces and total CSA were positively correlated with age ( r =0.253, 0. 327, 0. 233, all P CONCLUSION:CSA is varied among the population and CSA of elderly in Kaifeng area are slightly higher than white people, and positively correlated with age.
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·AlM: To investigate the distribution and related factors of corneal spherical aberration in the age-related cataract patients, and to provide a scientific basis for the application of aspheric intraocular lens ( lOL ) in cataract surgery patients. · METHODS: Retrospective study of 509 age -related cataract patients of 610 eyes in our hospital. Corneal spherical aberration, corneal curvature, corneal astigmatism and corneal Q -value were examined by iTrace visual function analysis. Statistical software SPSS16.0 was used to analyze statistically. · RESULTS: The range of corneal spherical aberration was 0 ~1.800μm. The mean coefficient of corneal spherical aberration was 0.266 ±0.010μm. Corneal spherical aberration was no significantly correlation with age, corneal curvature, corneal astigmatism ( r =0.71, 0.56, 0.93, P>0.05 ). There was positive correlation between corneal spherical aberration and Q-value ( r=0.086, P=0.03). · CONCLUSlON: Corneal spherical aberration varied greatly among age-related cataract patients.The choice of asphericity intraocular lens should be a matter of personal choice.
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PURPOSE: To formulate an equation to estimate corneal spherical aberration using Orbscan (Bausch & Lomb Surgical, Rochester, NY, USA) parameters. METHODS: The study was carried out retrospectively. The participants were 76 eyes of 76 senile cataract patients with the mean age of 57.37 +/- 17.63 years. Both Orbscan and KR-1W (Topcon Corp, Tokyo, Japan) were taken as preoperative examinations. Correlation analysis between various parameters from Orbscan and corneal spherical aberrations for a 6 mm pupil by KR-1W was performed. And multivariable linear regression was performed with the significantly correlated Orbscan parameters from the correlation analysis. RESULTS: The mean corneal spherical aberration from KR-1W system was 0.25 +/- 0.08 microm. As a result of the multivariable linear regression, we could generate following equations. If the Q-value was available, estimated corneal spherical aberration = 0.389 x Q-value + (0.022 x Axial power 3 mm) - 0.633 (R2 = 0.436). If the Q-value was not available, estimated corneal spherical aberration = 0.184 x (Mean power 5 mm - Mean power 3 mm) + (0.02 x Axial power 3 mm) - 0.563 (R2 = 0.429). By using the equations, 93.4-94.7% of subjects were in the error range of 0.10 microm. CONCLUSIONS: Even when equipped with Orbscan only, an appropriate aspheric intraocular lens can be selected using the estimated corneal apherical aberration by the equations.