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Central serous chorioretinopathy(CSC)is a chorioretinal disease that causes idiopathic serous retinal detachment(SRD),which is associated with one or more areas of pigment epithelial detachment(PED)or defect in the retinal pigment epithelium,also with characteristic ocular structural changes.CSC was classified as pachy-choroid spectrum diseases(PSD);recent studies have found it mainly in Haller layer.Recent studies focused on the thick sclera in CSC patients,illustrated the close relation between which and choroidal circulation and put for-ward the probable pathogenesis similar to uveal effusion syndrome(UES).In addition,short axial length,hypero-pia and shallow anterior chamber are also the characteristics in CSC patients,indicating that CSC is the disease not limiting to posterior oculus,but involving the whole oculus.This review summarizes the latest research advances on optical characteristics in CSC,providing the new ideas for further research on pathogenesis of CSC.
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Objective To explore the risk factors that may cause recurrent retinal detachment in rhegmatogenous retinal detachment(RRD)patients after surgery.Methods A total of 403 patients(403 eyes)with RRD diagnosed in the Department of Ophthalmology of the First Affiliated Hospital of Soochow University from October 2020 to April 2022 were included in this study.Among them,35 patients underwent the scleral buckling,79 patients underwent the pars plana vit-rectomy(PPV)+intravitreal gas tamponade,222 patients underwent the PPV+intravitreal silicone oil tamponade,and 67 patients underwent the PPV+vitreous silicone oil tamponade+silicone oil removal.The postoperative follow-up lasted for at least 3 months.Risk factors affecting one-time retinal reattachment after RRD surgery were analyzed by univariate and multivariate Logistic analyses,and Logistic regression was applied to construct a risk prediction model.Results Among the 403 eyes with RRD,369 eyes had retinal reattachment on the first try,and 34 eyes did not,with a one-time reat-tachment rate of 91.6%.The univariate analysis showed that the differences in axial length(AL),surgical approach,loca-tion of the tear,and size of the tear between patients with one-time retinal reattachment and those without reattachment were statistically significant(all P<0.05).From the regression equation,it was found that the risk of non-reattachment af-ter RRD surgery of patients with an AL ≥ 26 mm was 4.248 times higher than those with an AL<26 mm(P<0.05).The multivariate Logistic regression analysis showed that AL,location of the tear,size of the tear,and surgical approach were risk factors for non-reattachment after RRD surgery(all P<0.05).The Hosmer-Lemeshow test yielded P=0.165.The re-sults of the receiver operating characteristic curve analysis showed that the area under the curve to predict whether retinal re-detachment occurs after RRD surgery was 0.892(95%CI:0.832-0.953),and the sensitivity and specificity were 79.4%and 87.3%,respectively(P<0.05).Conclusion AL is an independent risk factor for retinal re-detachment after RRD surgery.The prediction model constructed based on AL,location of the tear,size of the tear,and the surgical method can accurately predict whether retinal detachment will occur after RRD surgery.
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Objective To investigate the factors that lead to diffuse chorioretinal atrophy(DCA)in patients with high myopia(HM)and to establish a prediction model.Methods In this retrospective case-control study,a total of 169 HM patients(338 eyes)admitted to the Department of Ophthalmology,Harbin 242 Hospital from October 2018 to October 2022 were selected.All patients underwent comprehensive ophthalmic examination at the time of inclusion.The incidence of DCA was evaluated according to the International Photographic Classification and Grading System for myopic maculopa-thy,and the risk factors of DCA in HM patients were analyzed by multivariate Logistic regression.The predictive model of DCA in HM patients was established by the receiver operating characteristic curve(ROC)based on risk factors,and the calibration degree of the predictive model was tested by Hosmer-Lemeshow(H-L).Results Among the 169 patients,34 patients were divided into the DCA group,and 135 patients were divided into the non-DCA group;there were statistically significant differences in age and gender distribution between the two groups(both P<0.05).The axial length(AL),pat-tern standard deviation(PSD),positive rate of carbonic anhydrase 2(CAII)antibody in the DCA group were higher than those in the non-DCA group,while the best corrected visual acuity(BCVA),mean defect(MD)of the visual field,spheri-cal equivalent(SE),deep retinal microvessel density(MVD)and serum 25-hydroxyvitamin D[25(OH)D]were lower than those in the non-DCA group(all P<0.05).Older age,longer AL and positive CAII antibody were the risk factors for DCA in HM patients(all P<0.05),while greater deep retinal MVD and higher 25(OH)D were the protective factors(both P<0.05).ROC analysis showed that the area under the curve of the prediction model for DCA in HM patients was 0.864(95%CI:0.802-0.911,P<0.001),and the sensitivity and specificity were 85.29%and 88.15%,respectively.According to the H-L test,the prediction model for DCA in HM patients was relatively consistent with the actual results(P>0.05).Con-clusion The occurrence of DCA in HM patients is affected by age,AL,CAII antibody,deep retinal MVD and 25(OH)D level,and a prediction model established based on the above factors can predict the risk of DCA well.
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Objective To explore the effect of the orthokeratology lenses on the control of different types of aniso-metropia in myopic children.Methods A total of 99 myopic children aged 8 to 16 years who got the orthokeratology len-ses at the Department of Ophthalmology,Heping Hospital Affiliated to Changzhi Medical College from September 2020 to November 2022 with complete data were included.These children were divided into the simple myopic anisometropia group(monocular myopia,binocular diopter difference ≥ 1.00 D,n=39)and the compound myopic anisometropia group(binoc-ular myopia,binocular diopter difference ≥ 1.00 D,n=60).The children with higher anisometropia(binocular diopter difference ≥ 2.50 D)in the two groups were set as the high anisometropia subgroup(n=18 and 29,respectively),and chil-dren with lower anisometropia(1.00 D≤ binocular diopter difference<2.50 D)were set as the low anisometropia subgroup(n=21 and 31,respectively).In each group,eyes with a higher diopter were set as the high diopter eyes,and the contra-lateral eyes with a lower diopter were set as the low diopter eyes.Diopter,corneal topography,intraocular pressure,cor-neal endothelium and axial length of children in the two groups were examined and recorded.The changes in axial length before and after wearing orthokeratology lenses for 1 year were compared between the two groups,analyzing the correla-tion between the degree of anisometropia and changes in the binocular axial length.Results After wearing orthokeratolo-gy lenses for 1 year,children in both groups had an increase in the axial length with a lower increase in the axial length of the high diopter eyes compared to the low diopter eyes;before and 1 year after wearing orthokeratology lenses,the axial length of high diopter eyes was greater than that of the low diopter eyes in both groups,and the differences were statistical-ly significant(all P<0.05).Both groups of children showed a decrease in the binocular axial length difference after wear-ing the orthokeratology lenses for 1 year;before and 1 year after wearing orthokeratology lenses,the binocular axial length difference of children in the simple myopic anisometropia group was greater than that in the compound myopic anisometro-pia group,and the differences were statistically significant(t=4.903 and 2.670;both P<0.05).The changes in binocular axial length difference before and after wearing the orthokeratology lenses of children in the high anisometropia subgroup and low anisometropia subgroup of the simple myopic anisometropia group were greater than those in the high anisometro-pia subgroup and low anisometropia subgroup of the compound myopic anisometropia group,respectively,and the differ-ences were statistically significant(both P<0.05).In the simple myopic anisometropia and compound myopic anisometro-pia groups,the degree of anisometropia was positively correlated with the binocular axial length changes before and 1 year after wearing the orthokeratology lenses(r=0.423 and 0.510,both P<0.05).Conclusion Orthokeratology lenses can effectively reduce the difference in binocular axial length of children with myopic anisometropia,and their control effect on simple myopic anisometropia is better than that of compound myopic anisometropia.
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Objective:To compare the effect of delaying progression of myopia in children between defocus incorporated multiple segments (DIMS) spectacle lens and orthokeratology.Methods:A nonrandomized controlled clinical study was conducted.A total of 390 children (390 eyes) with myopia who were treated in the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2020 were included, with the spherical equivalent (SER) of -0.75 to -6.00 D. According to the willingness of patients and patients' guardians, the subjects were divided into DIMS group, orthokeratology group and single-vision spectacle lens group, with 130 cases (130 eyes) in each group, wearing DIMS spectacle lenses, standard or astigmatic design orthokeratology and conventional single-vision full-correction aspheric spectacle lenses, respectively.The SER of the eyes was measured using an automatic computerized refractometer in combination with subjective refraction before and one year after lens wear, and the axial length (AL) of the eyes was measured using IOLMaster.A total of 327 patients in the three groups met the inclusion and exclusion criteria, including 107 in the DIMS group, 112 in the orthokeratology group, and 104 in the single-vision spectacle lens group.All the right eyes were included in this study.The changes in SER and AL before and after wearing lenses for 1 year were compared among the three groups.The relationship between AL and SER changes and baseline data in the DIMS group was evaluated by Pearson linear correlation analysis.The study followed the Declaration of Helsinki, and the study protocol was reviewed and approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (No.2023-KY-0174-002). The subjects and their guardians were fully aware of the purpose and methodology of the study, and voluntarily signed an informed consent form.Results:There were statistically significant overall differences in SER and AL at different time points among the three groups (SER: Fgroup=7.065, P=0.009; Ftime=183.730, P<0.001.AL: Fgroup=6.151, P=0.014; Ftime=175.290, P<0.001). One year later, the differences in SER and AL changes among the three groups were statistically significant ( F=7.065, P=0.009; F=6.151, P=0.014). The SER and AL of each group after 1 year was greater than the baseline, with the SER and AL and their changes significantly smaller in orthokeratology group and DIMS group than in single-vision spectacle lens group and greater in DIMS group than in orthokeratology group, showing statistically significant differences (all at P<0.05). Compared with single-vision spectacle lenses, wearing orthokeratology for 1 year can inhibit SER and AL progression by 58.3% and 59.0%, and wearing DIMS frame glasses for 1 year can inhibit SER and AL progression by 46.9% and 43.6%.The percentage of eyes with no change in SER was 5.77%(6/104), 24.11%(27/112) and 17.76%(19/107) in the single-vision spectacle lens group, orthokeratology group and DIMS group, respectively, and the percentage of AL was 0.00%(0/104), 8.93%(10/112) and 7.48%(8/107), respectively, showing statistically significant differences among the three groups ( χ2=9.316, 8.676; both at P<0.001). The AL change in the DIMS group was weakly negatively correlated with age ( r=-0.252, P=0.006). Conclusions:Wearing DIMS spectacle lenses is not as effective as orthokeratology in delaying myopia in children, but it is significantly better than wearing conventional single-vision spectacle lenses.
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ObjectiveTo assess the repeatability (intra-operator variability) and reproducibility (inter-operator variability) of a new partial coherence interferometry (PCI)-based ocular biometer, Myopia Master, and its agreement with IOL Master 500 for measuring axial length (AL) and corneal curvature (K) in children aged 8-12 years. MethodsThe same operator measured school children with the Myopia Master and the IOL Master 500 in random order to assess agreement. Additionally, some of these children received measurements from another operator using the Myopia Master to assess repeatability and reproducibility. AL, flat keratometry (Kf), steep keratometry (Ks), mean keratometry (Km), J0 and J45 were analyzed. The repeatability and reproducibility were assessed by the within-subject standard deviation (Sw), test-retest repeatability (TRT), coefficient of variation (CoV) and intra-class correlation coefficient (ICC). The agreement between the Myopia Master and the IOL Master 500 was assessed by Bland-Altman plots and 95% limits of agreement (LoA). ResultsBoth repeatability and reproducibility of the Myopia Master were high for AL measurements (Sw=0.02 mm, ICC=0.999; Sw=0.04 mm, ICC=0.998), but moderate for K measurements (Sw range, 0.04 to 0.12 D, ICC range, 0.861 to 0.991; Sw range, 0.06 to 0.20 D, ICC range, 0.835 to 0.992). There were significant mean differences between the Myopia Master and the IOL Master 500 in measurements of AL (-0.01±0.04) mm, Kf (-0.09 ± 0.15) D, Ks (-0.47±0.40) D, and Km (-0.28±0.23) D, J0 (0.18±0.20) D and J45 (-0.01±0.12) D. ConclusionsThe Myopia Master provided high repeatability and reproducibility for AL measurements in schoolchildren with myopia, but the Myopia Master and the IOL Master 500 cannot be used interchangeably in measuring AL and K.
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As a highly prevalent global condition, myopia significantly impacts the ocular health of young individuals in China. Orthokeratology lens, as a rigid corneal contact lens, has demonstrated effective control over the progression of myopia; however, its mechanism of action remains incompletely elucidated. As one of the factors influencing visual acuity, higher-order aberrations will undergo marked changes after orthokeratology, with particular emphasis on the alterations in spherical aberrations and coma. The changes in corneal morphology induced by orthokeratology lead to significant positive increase in both spherical aberration and coma. Furthermore, the elevation of spherical aberration and coma demonstrates a negative correlation with the rate of axial length growth following orthokeratology. The interplay among spherical aberration, coma, defocus, accommodation, astigmatism, and pseudo-accommodation may constitute the underlying mechanism governing the control of myopia through orthokeratology.
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Corneal visualization Scheimpflug technology(Corvis ST)is currently the most commonly used clinical device for assessing in vivo corneal biomechanics. The new parameter stress-strain index(SSI)has been a hot topic of clinical research in recent years, which not only directly reflect corneal biomaterial stiffness, but also closely correlates with the progression of certain diseases. SSI was generated based on the predictions of corneal behavior using finite element(FE)numerical modeling to simulate the effects of intraocular pressure and Corvis ST jets. The SSI algorithm does not change with central corneal thickness(CCT), intraocular pressure, or biomechanically corrected intraocular pressure(BIOP), but it is clearly associated with altered collagen fibres in the corneosclera. The principles of SSI, the relationship between age and SSI, the relationship between axial length and SSI, the relationship between myopia and SSI, and the application of SSI are summarized and concluded.
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AIM:To explore the effect of high aspherical lenticule on controlling low myopia.METHODS: Prospective study. A total of 100 patients aged 7 to 12 years old with low myopia who visited our hospital from May 1 to 31, 2022 were collected. They were divided into two groups with 50 cases in each group according to the wishes of patients. The control group was given single vision glasses after optometry, while the study group was given high aspherical lenticule. The myopia progression(absolute value), axial length(AL)growth, transition rate to moderate myopia, and AL negative growth rate over 6 mo and 1 a were compared between the two groups.RESULTS: The myopia progression and the AL growth of study group was lower than that of the control group after 6 mo and 1 a(all P&#x003C;0.001).The negative growth rate of AL after 6 mo of treatment was significantly higher than that of the control group(P&#x003C;0.001). The transition rate to moderate myopia between the two groups was not statistically significant(P=0.62); while the transition rate to moderate myopia in the study group was significantly lower than that in the control group after wearing lens for 1 a(P&#x003C;0.001), and there was no statistically significant difference in AL negative growth rate between the two groups(P=0.12). Compare with single vision glasses, high aspherical lenticule achieved an 88.2% control rate for low myopia progression over 6mo and a 90.0% control rate of AL growth. The control rate for low myopia to moderate myopia was 66.7%; while the control rate of myopia progression growth was 75.6% after wearing lens for 1a, the control rate of AL growth was 69.2%, and the control rate of the transition rate to moderate myopia was 88.9%.CONCLUSION: For children and adolescents aged 7 to 12 with low myopia, high aspherical lenticule was more effective than single vision glasses in controlling myopia, making it one of the optimal choices for myopia control.
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AIM: To explore the accuracy of the ratio of axial length(AL)to the average corneal radius(CR)(AL/CR value, i.e., axial ratio)in assessing myopia in children and adolescents.METHOD:Cross-sectional study. A total of 340 cases(680 eyes)of children and adolescents aged 4-16 years old were collected from the ophthalmology clinic of Shangyu People's Hospital of Shaoxing between January 2022 and October 2022. All patients were subjected to optometry after cycloplegia to obtain spherical equivalent(SE), check and record the patient's AL, average CR, and calculate the AL/CR value.RESULTS:All subjects in this study underwent optometry after cycloplegia, and a total of 609 eyes(89.6%)were found to have myopia(SE≤-0.50 D), 58 eyes(8.5%)with hyperopia(SE≥+0.50 D)and 13 eyes(1.9%)with emmetropia(-0.50 D&#x003E;SE&#x003E;+0.50 D). There was a statistically significant difference in SE, AL and AL/CR values among different refractive states(P&#x003C;0.01), but there was no difference in CR(P&#x003E;0.05). All subjects have refractive parameters: SE +8.75--8.75(average -2.25±2.38)D; AL 19.91-27.54(average 24.41±1.22)mm; CR 7.17-8.71(average 7.83±0.27); AL/CR values range from 2.50-3.50(average 3.12±0.14), correlation analysis showed a relative strong negative correlation between SE and AL/CR and AL(r=-0.891, P&#x003C;0.01; r=-0.758, P&#x003C;0.01), but no significant correlation between SE and CR(r=0.067, P&#x003E;0.05), there was a positive correlation between AL and CR(r=0.483, P&#x003C;0.01). The linear relationships between SE and AL/CR, AL were SE=45.026-15.162×AL/CR, R2=0.794, SE=33.741-1.474×AL, R2=0.574, respectively. The gold standard was based on the optometric results of cycloplegia, the sensitivity, specificity, misdiagnosis rate and missed diagnosis rate of AL/CR value for myopia were 0.962, 0.839, 0.169, 0.038, respectively, and the accuracy was 94.85%, the Kappa coefficient was 0.742, and the area under the ROC curve was 0.972.CONCLUSION:With high qualitative diagnostic value for myopia and a certain clinical significance for myopia monitoring, AL/CR value can be used to guide myopia prevention and control and other related ophthalmic clinical work.
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AIM: To compare the changes in axial length of myopic patients of different ages after wearing orthokeratology lenses with increased compression factor(ICF)or conventional compression factor(CCF)for 2 a.METHODS: Retrospective study. A total of 141 myopia patients(141 right eyes)aged 8 to 15 years who fitted with orthokeratology lenses in the General Hospital of Foshan Aier Eye Hospital from July 2020 to July 2021 were continuously included. They were divided into the CCF group(70 cases, 70 eyes)and the ICF group(71 cases, 71 eyes). The patients in the CCF group were fitted with orthokeratology lens of 0.75 DS CCF, while patients in the ICF group were fitted with orthokeratology lens of 1.25 D ICF. Taking 12 years old as a boundary, these two groups were divided into 8-11 years old and 12-15 years old group. The uncorrected visual acuity(UCVA), horizontal corneal curvature(K1)and corneal staining were recorded for all subjects after wearing lenses for 1 d, 1 wk, 1, 6 mo, 1 and 2 a. The axial length(AL)was recorded after wearing lenses for 6 mo, 1 and 2 a, and the complication and corneal epithelial staining were observed during lens wearing.RESULTS:The improvement of UCVA in the ICF group was faster than that in the CCF group, which were statistical significant after wearing lenses for 1 d, 1 wk and 1 mo, respectively(all P<0.001); however, there was no statistical significance between the two groups after 6 mo, 1 and 2 a(all P>0.05); K1 of the ICF group decreased faster than that of the CCF group, and there were statistical significance at 1 d, 1 wk, and 1 mo after wearing lenses(all P<0.05); there was no statistical significance at 6 mo, 1 and 2 a(all P>0.05). The axial length growth of patients aged 8-11 years old in the ICF group and CCF group was 0.35±0.17 and 0.48±0.26 mm, respectively(P=0.010), after wearing lenses for 2 a, and the axial length growth of patients aged 12-15 years old in the ICF group and CCF group was 0.16±0.15 and 0.31±0.29 mm, respectively(P=0.011). During the follow-up period, corneal spotting occurred in 6 eyes(8.5%)in the ICF group, and 7 eyes(10%)in the CCF group(P>0.05), all of which were grade 1 spotting.CONCLUSION:Wearing ICF orthokeratology lens is more effective than wearing CCF lenses in controlling the growth of axial length, with faster shaping and more obvious improvement in UCVA, especially for the prevention of high myopia in children under 12 years. Therefore, young children can give priority to wearing lenses that increase the compression factor, and for children over 12 years old, the compression factor of the lens can be selectively increased according to the wearer's eye habits, health status of ocular surface and visual function.
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Ocular hypertension(OH)can cause a variety of ocular structural and functional damage, among which the effect on ocular refraction has long been recognized in the clinic. The effect of OH on ocular refraction is related to the transparency and shape of refractive media, as well as the changes of the axial length. Due to the different speed and degree of intraocular pressure(IOP)elevation, the changes of refraction are reversible or irreversible. Irreversible changes in refraction are often accompanied by visual transmission impairment, and have a certain reference value for the evaluation of the latter condition. IOP changes lead to changes in the axial length, which are related to scleral remodeling and choroidal perfusion changes, and have a certain impact on the development of myopia and refractive error after cataract surgery. In this paper, the research progress of the changes of refractive media and axial length caused by OH, as well as the characteristics of the effects on ocular refraction are summarized, hoping to deepen the understanding of the effect of OH on ocular refraction, and provide reference for preventing irreversible ocular refractive changes, guiding the assessment of visual transmission damage and preventing or controlling the development of axial myopia.
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The global prevalence of myopia is increasing year by year, leading to many ocular health issues and social problems. In recent years, it has been confirmed that peripheral defocus is closely related to the occurrence and development of myopia. Alteration of the state of peripheral defocus can significantly influence the progression of myopia and emmetropization, but the exact mechanisms are still unclear. At present, there is no method that can completely control myopia. Nowadays, the main controlling methods, including orthokeratology lens, peripheral defocus lens and multi-focal soft lens, have been confirmed to be closely related to peripheral defocus. In this paper, we will review and summarize the development and effect of these peripheral defocus relating control methods. In addition, the researches on the related mechanisms of peripheral retinal defocus and myopia prevention and control at home and abroad are reviewed, as well as the potential mechanisms of peripheral defocus, with a view to further improving the controlling effects of existing methods, developing new prevention and control methods and reducing the incidence and progression of myopia.
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AIM:To compare the differences, correlations and consistency of IOL Master 700 or Lenstar LS900 in preoperative ocular biometry and the accuracy of intraocular lens(IOL)degree calculation of cataract patients with high myopia.METHODS: Retrospective study. A total of 136 cases(136 eyes)of high myopia and cataract patients who underwent phacoemulsification at the ophthalmology department of Army Medical Center of PLA from March 2021 to March 2023 were collected, with a mean age of 57.38±8.08 years. Patients were divided into 3 groups based on axial length(AL): 41 eyes in group A(26 mm≤ AL ≤28 mm), 43 eyes in group B(28 mm< AL ≤30 mm)and 52 eyes in group C(AL >30 mm). AL, mean keratometry(Km), anterior chamber depth(ACD), lens thickness(LT)and white-to-white(WTW)were preoperatively measured by two instruments, respectively. Barrett Universal II formula was used to calculate the IOL degrees of all patients, the appropriate reserved diopter was decided individually, and the prediction error(PE)and absolute error(AE)of the two instruments were compared.RESULTS:The AL and ACD of patients in the three groups measured by Lenstar LS900 were higher than the AL measurd by IOL Master 700(all P<0.05), with a difference of AL measured by the two devices: group C>group B>group A. However, there was no statistical significance in LT, Km, and WTW measured by the two instruments(all P>0.05). All biometric parameters measured by the two devices were positively correlated(all r>0.9, P<0.05), and consistent(95% LoA of all groups were narrow). There was no statistically significant difference in AE calculated by the two devices(P>0.05), but the IOL Master 700 calculated a smaller PE than Lenstar LS900(P<0.05), with lower percentage of hyperopic shift in IOL Master 700.CONCLUSION:In cataract patients with high myopia, AL measured by Lenstar LS900 is longer than that by IOL Master 700, and the differences of AL increase along with the growth of AL. Both devices have a good prediction for IOL calculation, but IOL Master 700 has less refractive error, lower percentage of hyperopic shift, and greater clinical advantages IOL Master 700.
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AIM:To compare the differences of ocular biometric parameters of age-related cataract between Tibetan and Han ethnic groups, and to analyze the distribution characteristics of ocular biometric parameters in Tibetan cataract patients.METHODS:Retrospective cohort study. A total of 661 patients(1 030 eyes)with age-related cataract confirmed in the hospital between January 2019 and December 2020 were enrolled. The parameters of axial length, anterior chamber depth, keratometry, corneal astigmatism and astigmatic axis were measured by IOL Master 500 in 483 cases(739 eyes)of Tibetan age-related cataract patients and 178 cases(291 eyes)of Han patients.RESULTS:The axial length, anterior chamber depth and corneal astigmatism of the Tibetan patients with age-related cataract were 23.33(22.81, 23.86)mm, 3.04(2.79, 3.30)mm and 0.73(0.47, 1.07)D. The mean keratometry was 43.89±1.35 D. The results indicated that Tibetan cataract patients had shorter axial lengths and smaller keratometry compared to Han patients(all P<0.05). Age in Tibetan patients was negatively correlated with axial length and anterior chamber depth, and positively correlated with keratometry(all P<0.05). Tibetan male patients had longer axial lengths, deeper anterior chambers, and flatter corneas compared to female patients(all P<0.05).CONCLUSION:There were differences in ocular biometric parameters between age-related cataract patients of Tibetan and Han ethnicities. The distribution of ocular biometric parameters in Tibetan cataract patients varied across different age groups and gender groups.
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Objective@#To explore the pattern of change of axial length/curvatrue radius ratio (AL/CR) and associated factors in primary and secondary school students in Yunnan, so as to provide scientific basis and prospective guidance for early myopia intervention and control.@*Methods@#A total of 685 students from grades 2 to 3 and grade 7 in 2 cities/counties in Yunnan Province were selected by multi stage stratified random cluster sampling method in 2020. All the participants were followed up twice with questionnaire of myopia related factors, uncorrected distance visual acuity, and refractive parameter measurement from October,2021 and March,2023,respectivelty. The distribution and change of AL/CR in different classes and groups were analyzed, and the influencing factos of AL/CR cumulative progression were explored using generalized linear model.@*Results@#AL/CR ratio in primary school students was (2.95±0.09) at baseline, increased to (2.99±0.11) at the first follow up and (3.04±0.12) at the second follow up. AL/CR ratio in middle school students(3.08±0.13) at baseline, increased to (3.12±0.15) at the first follow up and (3.15±0.14) at the second follow up. The generalized linear model showed that after controlling for environmental factors, ethnicity ( β =-0.017) , cumulative progression of the SE ( β =-0.027) influenced the changes of AL/CR ratio among the primary school students, whereas the changes of AL/CR ratio were associated with baseline AL ( β =-0.005), baseline corneal curvatrue radius ( β =0.032) and cumulative progression of SE( β =-0.035) among middle school students ( P <0.05).@*Conclusions@#The AL/CR ratio of primary and secondary school students in Yunnan can be used to judge different refractive status types, but its variation is not only related to SE progression, but also affected by different ethnic groups and baseline ocular biological parameters. so the value of AL/CR application in assessing the progression of myopia needs to be further confirmed.
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@#Objective To investigate the clinical effect of highly aspherical lenslets(HAL)in myopia control in adolescents.Methods Totally 101 cases(202 eyes)of adolescent myopia patients treated in ophthalmology outpatient department of our hospital from January 2021 to February 2022 were selected as the study objects.Of these,43 cases(86 eyes)wore HAL lenses as an observation group and 58 cases(116 eyes)wore single-vision spectacle lenses(SVL)as a control group.After 12 months of follow-up,the equivalent spherical lens degree and axial length were recorded in 6 months and 12 months respectively.Results The change of equivalent spherical lens in the HAL group was(-0.18±0.22)D and that in the SVL group was(-0.47±0.21)D,and the change in the HAL group was less than that in the SVL group,the difference was significant(P<0.001).The equivalent spherical lens degree in the HAL group was(-0.33±0.32)D and the HAL group was(-0.82±0.20)D at the 12th month,and the change in the HAL group was less than that in the SVL group,the difference was significant(P<0.001).The axial length of the eye in the HAL group was(0.09±0.09)mm and the SVL group was(0.20±0.07)mm in June,and the change in the HAL group was less than that in the SVL group,and the difference was significant(P<0.001).The axial length of the eye in the HAL group was(0.14±0.13)mm and that in the SVL group was(0.37±0.08)mm,and the change in the HAL group was less than that in the SVL group,and the difference was significant(P<0.001).Conclusion Wearing HAL lens for 12 months can effectively slow down the growth of myopia degree and axial length in adolescent myopia patients.
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AIM: To analyze ocular biometric parameters among candidates for cataract surgery.METHODS: This cross-sectional study was conducted on 4 607 cataract patients(4 607 eyes)in Farabi Eye Hospital, Tehran, Iran from January 2017 to September 2021. Axial length(AL), keratometry(Kf, Ks and Km), and anterior chamber depth(ACD)were assessed using IOLMaster 700. All eyes were categorized into three groups based on AL: short eyes(22 mm<AL), normal eyes(22 mm≤AL≤25 mm), and long eyes(AL>25 mm)and ACD as follows: low(3.00 mm<ACD), normal(3.00 mm≤ACD ≤3.60 mm)high(ACD>3.60 mm).RESULTS: The mean age of patients was 60.3±14.1(range 8-95)years [2 243(48.69%)female and 2 364(51.31%)male]. The AL, ACD and mean keratometry ranges were 23.1 to 23.4 mm, 3.1 to 3.2 mm and 44.50 to 45.00 diopter(D), respectively. The mean amount of ACD in the long eyes group was significantly higher than the normal and short eyes group(P<0.001). The mean AL in the high ACD group was significantly higher than low and normal ACD patients(P<0.001). But the mean of Kf, Ks and Km in the low ACD and long eyes group was significantly higher than in high ACD and short AL groups(P<0.001).CONCLUSION: Those candidates with long eyes had deeper ACD with flatter cornea; while short eyes had shallower ACD with steeper cornea. Also, patients with high ACD had longer AL with flatter cornea, and patients with low ACD had lower AL with steeper cornea.
ABSTRACT
Myopia is becoming more and more common all over the world, and the incidence of myopia is gradually increasing. Many treatments have been used to prevent and control myopia, including optics, drugs, environment or behavior, but the results are different and lack standardization. At present, many experiments have proved that peripheral defocus technology has a certain effect on myopia control. Based on this technology, three kinds of framed eyeglass lenses with peripheral defocus design, namely defocus incorporated multiple segments(DIMS), highly aspherical lenslets(HAL)and cylindrical annular reactive elements(CARE), are commonly used in medical and optometry institutions in China. These lenses provide not only clear vision in the central area, but also a certain amount of myopic defocus in the periphery to control the progression of myopia. This paper aims to focus on the design principle and myopia prevention and control effect of the above three peripheral defocus lenses, and evaluate their effectiveness in clinical practice.
ABSTRACT
AIM: To evaluate the value of the ratio of axial length to corneal radius of curvature(AL/CR)in the diagnosis of myopia in children and adolescents.METHODS: The refraction and ocular biometric parameters of 2 182 cases of children and adolescents(4 364 eyes)who initially visited the optometry clinic of the Second People's Hospital of Beihai from January 2022 to December 2023 were collected and analyzed.RESULTS: The receiver operating characteristic curve(ROC curve)showed that AL/CR had a higher area under the curve(AUC=0.925, 95%CI: 0.917-0.933)in diagnosing myopia. When AL/CR was 3.053, the Youden index was the largest. As the threshold of AL/CR decreased, the sensitivity of myopia diagnosis increased, while the specificity decreased. Compared with screening myopia, the sensitivity of AL/CR=3.053 in diagnosing myopia was low, but the specificity was high, especially in the cases of hyperopia and pre-myopia.CONCLUSION: The accuracy of AL/CR in diagnosing myopia is superior to that of axial length and average corneal curvature, with higher specificity. As the threshold of AL/CR decreases, the sensitivity of diagnosing myopia increases, but the specificity decreases. In cases of hyperopia and pre-myopia, the specificity of AL/CR in diagnosing myopia is higher than that of screening myopia.