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@#AIM:To evaluate the effect of keratometry on the calculation accuracy of intraocular lens(IOL)diopter in patients with normal axial cataract.METHODS:Totally 157 cases(157 eyes)with age related cataract were collected in Kaifeng Central Hospital from June 2020 to June 2021. Patients were divided into 3 groups according to keratometry: group A(53 eyes)(K<42D), group B(55 eyes)(42D≤K≤46D), group C(49 eyes)(K>46D). The IOL diopter was calculated by SRK/T, Hoffer Q, Holladay 2, Haigis, Kane and Barrett Ⅱ formulas respectively. Subjective optometry was performed after 1mo operation. The average refractive prediction error(RPE)and mean absolute error(MAE)were calculated, and their differences were compared and analyzed.RESULTS:There were significant difference between RPE of each formula and 0D in groups A and C(<i>P</i><0.05), and Barrett Ⅱ formula was significantly different with SRK/T, Hoffer Q, Holladay 2 and Haigis formula(<i>P</i><0.01), but was no significantly different with Kane formula in RPE(<i>P</i>>0.01). There was no significant difference in RPE between group B and 0D(<i>P</i>>0.05). The ratio of Barrett Ⅱ formula in MAE≤0.5D in group A was significantly higher than SRK/T, Hoffer Q, Holladay 2 and Haigis formula(all <i>P</i><0.01), but there was no significant difference compared with Kane formula(<i>P</i>>0.01). In group B, there was no significant difference among Barrett Ⅱ formula and the other formulas in the ratio of MAE≤0.5D and ≤1.0D(all <i>P</i> >0.01). In group C, the ratio of SRK/T and Hoff Q formula in MAE≤0.5D was lower than Barrett Ⅱ formula(all <i>P</i><0.01), and there were no significant difference among Barrett Ⅱ formula and the other formulas in the ratio of MAE≤1.0D(<i>P</i> >0.01).CONCLUSION:If K<42D or K>46D before operation, the commonly used formulas will produce refractive error, but the accuracy of Kane and Barrett Ⅱ formulas are still higher than other formulas.
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@#AIM: To observe the effectiveness and safety of the active-fluidics configuration with Centurion phacoemulsifier in cataract surgery.<p>METHODS: One hundred and thirty-three eyes with Ⅱ-Ⅳ grades cataracts were enrolled in this randomized prospective study from October to December 2018. They were divided into two groups, the experimental group used active-fluidics configuration for cataract surgery, while the control group used gravity-fluidics configuration. Cumulative dissipated energy(CDE), aspiration time(AT)and estimated fluid used(EFU)of each patient were recorded during the operation, endothelial cell density(ECD)and central corneal thickness(CCT)were measured before and one day after operation.<p>RESULTS: The CDE, AT and EFU were significantly lower with the active-fluidics configuration than with the gravity-fluidics configuration(<i>P</i><0.05); ECD was slightly decreased and CCT was slightly increased in both groups 1d after operation, but there was no difference between the two groups(2056.06±308.10cells/mm2 <i>vs</i> 1997.26±297.55cells/mm2, 532.75±12.02μm <i>vs</i> 531.02±13.00μm; <i>P</i>>0.05). No serious ocular adverse events related to the study devices or device deficiencies were observed.<p>CONCLUSION:Centurion active-fluidics configuration can maintain constant intraocular pressure during the operation, improve the stability of anterior chamber effectively. So it is safer and more efficient than traditional gravity-fluidics configuration.
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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 evaluate the accuracy of the Barrett True K intraocular lens(IOL)calculation formulas in eyes with previous radial keratotomy(RK).<p>METHODS: From February 2017 to February 2019, 42 eyes of 22 cataract patients with previous RK were selected in our hospital. Two methods were used to calculate IOL refraction before surgery: 1)Selected the smallest anterior surface K value in the area of 3mm central corneal diameter, used SRK/T formula, the target refraction was set at -1.0D; 2)Used Barrett True K on-line calculation formula, the mode of RK was selected and the target refraction was set at -1.0D. Three months after operation, the refractive state of the eyes was examined and the refractive errors calculated by the two methods were compared.<p>RESULTS: The average refractive error of Barrett formula method was 0.61(-0.37, 0.88)3mo after operation, which was significantly lower than that of traditional formula method 0.35(-0.25, 0.63)D(<i>P</i><0.05). There was no significant difference in absolute refractive error between the two methods(<i>P</i>>0.05). The refractive errors of traditional formula method in the range of ±0.5D, ±1.0D, ±2.0D accounted for 21%, 45%, 90% respectively. The refractive errors of Barrett formula method in the range of ±0.5D, ±1.0D, ±2.0D accounted for 31%, 74%, 100% respectively(<i>P</i><0.05).<p>CONCLUSION: Barrett True K online formula applied to cataract patients after RK can achieve satisfactory refractive status.
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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.