Comparison of the refractive prediction errors of artificial intelligence formula with 3 conventional formulas and 11 combination methods in cataract surgery on eyes with short axial length

ABSTRACT Purpose: To compare the refractive prediction error of Hill-radial basis function 3.0 with those of 3 conventional formulas and 11 combination methods in eyes with short axial lengths. Methods: The refractive prediction error was calculated using 4 formulas (Hoffer Q, SRK-T, Haigis, and Hill-RBF) and 11 combination methods (average of two or more methods). The absolute error was determined, and the proportion of eyes within 0.25-diopter (D) increments of absolute error was analyzed. Furthermore, the intraclass correlation coefficients of each method were computed to evaluate the agreement between target refractive error and postoperative spherical equivalent. Results: This study included 87 eyes. Based on the refractive prediction error findings, Hoffer Q formula exhibited the highest myopic errors, followed by SRK-T, Hill-RBF, and Haigis. Among all the methods, the Haigis and Hill-RBF combination yielded a mean refractive prediction error closest to zero. The SRK-T and Hill-RBF combination showed the lowest mean absolute error, whereas the Hoffer Q, SRK-T, and Haigis combination had the lowest median absolute error. Hill-radial basis function exhibited the highest intraclass correlation coefficient, whereas SRK-T showed the lowest. Haigis and Hill-RBF, as well as the combination of both, demonstrated the lowest proportion of refractive surprises (absolute error >1.00 D). Among the individual formulas, Hill-RBF had the highest success rate (absolute error ≤0.50 D). Moreover, among all the methods, the SRK-T and Hill-RBF combination exhibited the highest success rate. Conclusions: Hill-radial basis function showed accuracy comparable to or surpassing that of conventional formulas in eyes with short axial lengths. The use and integration of various formulas in cataract surgery for eyes with short axial lengths may help reduce the incidence of refractive surprises.

Correlation of axial length and corneal power with refractive status of patients with refractive error in Kano, North-Western Nigeria

Background: Uncorrected refractive errors are a major cause of blindness and low vision. Determination of the etiology is essential in planning appropriate treatment modalities. Aim of this study was to determine the correlation between axial length and corneal power with refractive status of patients with refractive error in Kano, Nigeria. Methods: Observational cross-sectional study in which 385 eligible patients were recruited. Relevant history was obtained from the patients and ocular examination was done. Objective and Subjective refraction were performed. Spherical equivalent was calculated for patients with astigmatism. Keratometric readings (k1 and k2) and measurement of axial length were taken. Data was analyzed using the statistical package for the social sciences (SPSS) version 22. Results: Statistically significant inverse association (r=-1.7, r2=56.8%, p<0.0001) was found between Spherical equivalent objective refraction and axial length of right eye. Statistically significant inverse association (r=-1.2, r2=53.3%, p<0.0001) was found between Spherical equivalent subjective refraction and axial length of right eye. Statistically significant inverse association (r=-0.5, r2=8.5%, p<0.0001) was found between spherical equivalent objective refraction and corneal power of the right eye. Statistically significant inverse association (r=-0.3, r2=6.4%, p<0.0001) was found between spherical equivalent subjective refraction and Corneal power of right eye. Negative correlation existed between axial length and corneal power but was not statistically significant (r=-0.0, p<0.4). Conclusions: The study established that axial length and corneal power are the determinants of refractive status and that axial length is a stronger determinant.

Síndrome de Wilkie como reto diagnóstico en obstrucción intestinal: reporte de caso / Wilkie syndrome as a diagnostic challenge in intestinal obstruction: case report

RESUMEN El síndrome de Wilkie es una patología poco frecuente que genera un cuadro de obstrucción intestinal, debido a la disminución del ángulo aortomesentérico comprometiendo la tercera porción del duodeno. Describimos el caso de una paciente de 18 años de edad, diagnosticada con síndrome de Wilkie, con cuadro clínico de obstrucción intestinal y pérdida de peso. El diagnóstico se realizó con tomografía abdominal. El síndrome de Wilkie es una patología rara, que se vuelve un reto diagnóstico, por presentar un cuadro similar a otras patologías más comunes. Recomendamos que se sospeche ante un cuadro de obstrucción duodenal.

ABSTRACT Wilkie syndrome is a rare pathology that generates intestinal obstruction due to a decrease of the aortomesenteric angle compromising the third portion of the duodenum. We describe a case of an 18-year-old female patient, diagnosed with Wilkie syndrome, with clinical symptoms of intestinal obstruction and weight loss. The diagnosis was made with abdominal CT. Wilkie syndrome is a rare pathology, which becomes a diagnostic challenge because it presents a similar picture to other more common pathologies. We recommend that it should be suspected in the presence of duodenal obstruction.

Role of spherical aberration and coma in orthokeratology for myopia control / 国际眼科杂志(Guoji Yanke Zazhi)

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.

Research progress on the stress-strain index of Corvis ST / 国际眼科杂志(Guoji Yanke Zazhi)

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.

Control effect of high aspherical lenticule in children and adolescents with low myopia / 国际眼科杂志(Guoji Yanke Zazhi)

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&#x0026;#x003C;0.001).The negative growth rate of AL after 6 mo of treatment was significantly higher than that of the control group(P&#x0026;#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&#x0026;#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.

Accuracy of the ratio of axial length to corneal radius in the assessment of myopia in children and adolescents / 国际眼科杂志(Guoji Yanke Zazhi)

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&#x0026;#x003E;SE&#x0026;#x003E;+0.50 D). There was a statistically significant difference in SE, AL and AL/CR values among different refractive states(P&#x0026;#x003C;0.01), but there was no difference in CR(P&#x0026;#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&#x0026;#x003C;0.01; r=-0.758, P&#x0026;#x003C;0.01), but no significant correlation between SE and CR(r=0.067, P&#x0026;#x003E;0.05), there was a positive correlation between AL and CR(r=0.483, P&#x0026;#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.

Research advances on optical characteristics in central serous chorioretinopathy / 基础医学与临床

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.

Three-dimensional finite element analysis of a new horizontal screw-screw crosslink in posterior atlantoaxial internal fixation / 中国组织工程研究

BACKGROUND:The addition of traditional rod-rod fixation for atlantoaxial joint disease to C1-C2 pedicle screw-rod fixation(C1-C2 PSR)can provide stronger anti-rotation stability for screw/rod fixation,but there is a risk of installation difficulties,impact on bone graft bed,and spinal cord injury.The new horizontal screw-screw crosslink(hS-S CL)designed by the authors can effectively overcome the above shortcomings,but its biomechanical properties are unclear. OBJECTIVE:To analyze biomechanical properties of new horizontal screw-screw crosslink in C1-C2 PSR by three-dimensional finite element analysis. METHODS:CT thin layer scanning data were collected from the occipital base to the axis(C0-2)of one adult healthy male volunteer.The atlantoaxial finite element models were established respectively:the normal group,the unstable group,the non-crosslink group(unstable+C1-C2 PSR),and the crosslink group(C1-C2 PSR+hS-S CL).Range of motion and Von Miss Stresses in flexion and extension,lateral flexion and rotation of the four groups were calculated by applying 1.5 Nm torque to each finite element model,and the stress cloud was extracted. RESULTS AND CONCLUSION:(1)Range of motion of the unstable group was increased by 43.8%-78.7%compared with the normal group,and the range of motion of the internal fixation groups was 90.2%-98.7%lower than that of the unstable group under six conditions.The range of motion of the crosslink group and the non-crosslink group was basically the same in flexion and extension states,but in lateral flexion and rotation states,the range of motion of the crosslink group decreased 34.3%-43.8%and 78.6%-79.1%,respectively,compared with the non-crosslink group,and range of motion decreased most obviously in rotation state.(2)The stress peak of the internal plant model:The maximum stress of the crosslink group was generally smaller than that of the non-crosslink group,and the stress peak value of all the internal fixation groups was the lowest when the extension was carried out.(3)The stress cloud of internal plants showed that there was no obvious stress concentration phenomenon in the internal fixation,and the main stress distribution areas were the screw root and bone joint,and the crosslink ends were the screw tail groove or the joint rod joint.(4)The new horizontal screw-screw crosslink can obviously improve the anti-rotation stability of internal fixation and it can share part of the pressure in the three-dimensional motion direction of the internal fixation system and reduce the maximum stress of the internal plants.However,the stress distribution is obvious at both ends of the crosslink,and this part may be prone to fracture of the crosslink.

Prediction of critical energy release rate for cortical bone structure under different failure modes / 中国组织工程研究

BACKGROUND:Critical energy release rate is a global fracture parameter that could be measured during the failing process,and its value may change under different failure modes even in the same structure. OBJECTIVE:To propose an approach to predict the critical energy release rate in the femoral cortical bone structure under different failure modes. METHODS:Three-point bending and axial compression experiments and the corresponding fracture simulations were performed on the rat femoral cortical bone structures.Different critical energy release rates were repeatedly assigned to the models to perform fracture simulation,and the predicted load-displacement curves in each simulation were compared with the experimental data to back-calculate the critical energy release rate.The successful fit was that the differences in the fracture parameters between the predicted and experimental results were less than 5%. RESULTS AND CONCLUSION:(1)The results showed that the cortical bone structure occurred tensile open failure under three-point bending load,and the predicted critical energy release rate was 0.16 N/mm.(2)The same cortical bone structure occurred shear open failure under axial compression load,and the predicted critical energy release rate was 0.12 N/mm,which indicates that the critical energy release rate of the same cortical bone structure under different failure modes was different.(3)A comprehensive analysis from the perspectives of material mechanical properties and damage mechanism was conducted to reveal the reasons for the differences in the critical energy release rate in the cortical bone structure under different failure modes,which provided a theoretical basis for the measurement of the energy release rate and the accurate fracture simulation.

Analysis of risk factors for postoperative retinal re-detachment in patients with rhegmatogenous retinal detachment / 眼科新进展

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.

Influencing factors and prediction model construction of diffuse chorioretinal atrophy in patients with high myopia / 眼科新进展

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.

Study on the control effect of orthokeratology lenses on children with differ-ent types of myopic anisometropia / 眼科新进展

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.

Long-term efficacy of self-designed posterior atlas polyaxial screw-plate in the treatment of unstable atlas fracture / 中华创伤杂志

Objective:To investigate the long-term efficacy of self-designed posterior atlas polyaxial screw-plate in the treatment of unstable atlas fracture.Methods:A retrospective case series study was conducted to analyze the clinical data of 20 patients with unstable atlas fracture who were admitted to Affiliated Honghui Hospital of Xi′an Jiaotong University from January 2011 to April 2013, including 14 males and 6 females, aged 23-60 years [(42.7±8.6)years]. All the patients were treated with internal fixation using self-designed posterior atlas polyaxial screw-plate. The operation time and intraoperative bleeding volume were recorded. The fracture reduction was evaluated by CT scan at 3 days after surgery. The bone healing was observed by X-ray (anterior-posterior and lateral views of the cervical spine) and CT scan at 9 months after surgery. The delayed spinal cord injuries were evaluated by Frankel grade at 1 and 2 years after surgery and at the last follow-up. The Visual Analogue Scale (VAS) before surgery, at 3 months, 1 year, 2 years after surgery and at the last follow-up were compared. The axial rotation, flexion and extension range of the cervical spine at 3 months, 1 year, 2 years after surgery and at the last follow-up were compared. Intraoperative and postoperative complications were observed.Results:All the patients were followed up for 121-148 months [(135.0±6.8)months]. The operation duration was 68-122 minutes [(86.0±14.1)minutes], with the intraoperative blood loss of 90-400 ml [(120.0±67.9)ml]. The CT scan of the cervical spine at 3 days after surgery showed all satisfactory fracture reduction. Satisfactory bone reunion was observed at 9 months after surgery. All patients were scaled as Frankel grade E at 1 year, 2 years and at the last follow-up after surgery, with no delayed spinal cord injuries observed. The VAS scores of the cervical spine at 3 months, 1 year, 2 years after surgery and at the last follow-up were 2.0(1.3, 3.0)points, 1.0(1.0, 1.8)points, 1.0(0.3, 1.0)points and 1.0(0.3, 1.0)points, which were significantly lower than that before surgery [7.0(6.0, 7.8)points] ( P<0.05), with significantly lower scores at 1-, 2-year after surgeny and at the last follow-up than at 3 months after surgery ( P<0.05). There were no significant differences among the other time points ( P>0.05). The axial rotation ranges of the cervical spine were (103.0±8.3)°, (128.3± 11.4)° and (129.8±13.6)° at 1 year, 2 years after surgery and at the last follow-up respectively, which were significantly higher than that at 3 months after surgery [(85.3±7.0)°] ( P<0.05); It was further improved at 2 years after surgery and at the last follow-up compared with that at 1 year after surgery ( P<0.05), with no significant difference at the last follow-up compared with that at 2 years after surgery ( P>0.05). The flexion and extension range of the cervical spine at 1 year, 2 years after surgery and at the last follow-up were (65.5±4.8)°, (78.3±6.5)° and (79.3±6.9)° respectively, which were significantly higher than that at 3 months after surgery [(54.3±4.4)°] ( P<0.05); It was further improved at 2 years after surgery and at the last follow-up compared with that at 1 year after surgery ( P<0.05), with no significant difference between the last follow-up and 2 years after surgery ( P>0.05). No intraoperative injuries such as arteriovenous injury were observed. No incision infection or dehiscence occurred after surgery, with no complications caused by long-term bed rest such as lung or urinary tract infection, pressure sore formation or deep vein thrombosis occurred. No loosening or breakage of the screw and atlas plate was observed at the long-term follow-up. One patient had mild cervical pain, snap during rotation, and limited range of motion at the last follow-up. Conclusion:Self-designed posterior atlas polyaxial screw-plate has merits including small surgical wounds, satisfactory reduction, solid fixation, obvious pain relief, effective preservation of the previous cervical motion, few complications, and satisfactory long-term efficacy in the treatment of unstable atlas fracture.

Grey-scale Reversed T1-weighted MRI for Detecting Structural Lesions of the Sacroiliac Joint in Patients with Axial Spondyloarthritis / 中山大学学报(医学科学版)

ObjectiveTo analyze the value of grey-scale reversed T1-weighted （rT1） MRI in the detection of structural lesions of the sacroiliac joint （SIJ） in patients with axial spondyloarthritis （ax-SpA）. MethodsFifty-two ax-SpA patients who underwent both MRI and CT in our hospital within a week from February 2020 to December 2022 were retrospectively included. Both sacral and iliac side of each SIJ on oblique coronal images were divided into anterior， middle and posterior portion. Two radiologists reviewed independently three groups of MRI including T1-weighted imaging （T1WI）， rT1 and T1WI + rT1 images to evaluate the structural lesions like erosions， sclerosis and joint space changes in each of the 6 regions of the SIJ. One of the radiologist did the evaluation again one month later. CT images were scored for lesions by a third radiologist and served as the reference standard. Intra-class correlation coefficients （ICC） were calculated to test the inter- and intra-reader agreement for the assessment of SIJ lesions. A Friedman test was performed to compare the lesion results of MRI and CT image findings. We examined the diagnostic performance ［accuracy， sensitivity （SE） and specificity］ of different groups of MRI in the detection of lesions by using diagnostic test. A McNemar test was used to compare the differences of three groups of MRI findings. ResultsCT showed erosions in 71 joints， sclerosis in 65 and joint space changes in 53. Good inter-and intra-reader agreements were found in three groups of MRI images for the assessment of lesions， with the best agreement in T1WI + rT1. There were no difference between T1WI + rT1 and CT for the assessment of all lesions， nor between rT1 and CT for the assessment of erosions and joint space changes （P>0.05）. T1WI + rT1 yielded better accuracy and SE than T1WI in detection of all lesions （Accuracy erosions： 90.3% vs 76. 9%； SE erosions： 91.6% vs 76.1%； Accuracy sclerosis： 89.4% vs 80.8%； SE sclerosis： 84.6% vs 73.9%； Accuracy joint space changes： 86.5% vs 73.1%； SE joint space changes： 84.9% vs 60.4%； P<0.05）. rT1 yielded better accuracy and SE than T1WI in detection of erosions and joint space changes （Accuracy erosions： 87.5% vs 76.9%； SE erosions： 88.7% vs 76.1%； Accuracy joint space changes： 85.6% vs 73.1%； SE joint space changes： 83.0% vs 60.4%； P<0.05）. ConclusionsIn the detection of SIJ structural lesions in ax-SpA， rT1 improves the diagnostic performance and T1WI + rT1 is more superior to others.

Repeatability and Reproducibility of a New Ocular Biometer Based on Partial Coherence Interferometry and Its Agreement with IOL Master 500 / 中山大学学报(医学科学版)

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.

Efficacy of orthokeratology lenses with increased compression factor in the control of axial length for myopic patients of different ages / 国际眼科杂志(Guoji Yanke Zazhi)

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&#x003C;0.001); however, there was no statistical significance between the two groups after 6 mo, 1 and 2 a(all P&#x003E;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&#x003C;0.05); there was no statistical significance at 6 mo, 1 and 2 a(all P&#x003E;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&#x003E;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.

Advances in the effect of ocular hypertension on ocular refraction / 国际眼科杂志(Guoji Yanke Zazhi)

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.

Advances in peripheral defocus and myopia prevention and control / 国际眼科杂志(Guoji Yanke Zazhi)

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.

Comparison of IOL Master 700 versus Lenstar LS900 for preoperative biometric measurement and intraocular lens calculation in cataract patients with high myopia / 国际眼科杂志(Guoji Yanke Zazhi)

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&#x003C; AL ≤30 mm)and 52 eyes in group C(AL &#x003E;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&#x003C;0.05), with a difference of AL measured by the two devices: group C&#x003E;group B&#x003E;group A. However, there was no statistical significance in LT, Km, and WTW measured by the two instruments(all P&#x003E;0.05). All biometric parameters measured by the two devices were positively correlated(all r&#x003E;0.9, P&#x003C;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&#x003E;0.05), but the IOL Master 700 calculated a smaller PE than Lenstar LS900(P&#x003C;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.