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Introducción: Globalmente, existe un aumento de la prevalencia del queratocono y su diagnóstico en edades tempranas. Se notifican un gran número de casos subclínicos y otros con una rápida progresión, condicionada por el inicio precoz de la enfermedad y la asociación a factores de riesgo. Objetivo: Describir los aspectos epidemiológicos, clínicos y el resultado de los medios de diagnóstico implicados en la detección precoz del queratocono infantil. Desarrollo: En niños con ametropía hay elementos que alertan la presencia de un queratocono como causa del defecto refractivo. Desde el punto de vista epidemiológico se encuentran: distribución geográfica, rol de la herencia y factores ambientales. Clínicamente se señalan los antecedentes de enfermedades, tales como las alergias, la presencia de miopía o astigmatismo miópico con inestabilidad refractiva y los signos clínicos relacionados con la progresión del cono. En los pacientes de riesgo es preciso realizar exámenes mediante diferentes medios de diagnóstico según su disponibilidad, siendo primordial el análisis refractivo, queratométrico y topográfico. Conclusiones: En la evaluación de los niños con ametropía se deben tener en cuenta elementos epidemiológicos y clínicos que permiten sospechar y diagnosticar precozmente el queratocono. En la interpretación de los resultados de los medios de diagnóstico involucrados en su detección, se deben considerar los hallazgos más frecuentes en la población infantil según el grado de progresión de la ectasia.
Introduction: Globally, there is an increase of the keratoconus prevalence and its diagnosis in early ages. A great number of subclinical cases and others with a quick progression are notified, conditioned by the early onset of the disease and the association with risk factors. Objective: To describe the epidemiological, clinical aspects and the result of diagnostic means involved in the early detection of infant keratoconus. Development: There are elements that alert the presence of a keratoconus as a cause of the refractive defect in children with ametropia. From the epidemiologic point of view they are: geographical distribution, heredity role and environmental factors. History of previous diseases are clinically pointed out, such as allergies, myopia or myopic astigmatism with refractive instability and the clinical signs related to cone progression. In risk patients it is necessary to carry out exams by means of different diagnostic means according to their availability, being essential the refractive, keratometric and topographic analysis. Conclusions: In the evaluation of children with ametropia, epidemiological and clinical elements should be taken into account that allow to suspect and early diagnose the keratoconus. In the interpretation of results of the diagnostic means involved in their detection the most frequent findings in the infant population, should be considered according to the ectasia degree of progression.
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AIM: To compare the binocular and monocular accommodation among normal group, premyopia group and mild myopia group, and to study the characteristics of accommodation in the premyopia group, thus providing clinical evidence for the delay/prevention of myopia and the effective decrease of the incidence of myopia.METHODS: Cross-sectional descriptive study. A total of 179 children who had abnormal/high-risk visual acuity indicated by the vision screening in school from October 2021 to February 2023 were selected, including 92 males and 87 females, aged from 6 to 12(mean 8.55±1.66)years old, then they were referred to the Juvenile Myopia Prevention and Control Center in Cuizu Community Health Service Center. They were divided into normal group(+0.75 D<SE≤+2.00 D), the premyopia group(-0.50 D<SE≤+0.75 D)and the mild myopia group(-3.00 D≤SE≤-0.50 D)according to the diopters after cycloplegia, and binocular myopia grouping is defined by the eye with lower diopter. Binocular positive relative accommodation(PRA), negative relative accommodation(NRA), accommodative facility(AF), and monocular AF and amplitude of accommodation(AA)were examined. The age, binocular and monocular accommodation of different groups were compared.RESULTS: There were no difference in the sex ratio of different groups(χ2=0.167, P=0.920). There was no difference in age between the normal group and the premyopia group(P=0.310), but there were differences between the mild myopia group and the normal group and premyopia group(P=0.018, <0.01); Binocular NRA, PRA, and AF had significance between the normal group and the premyopia group(P<0.01), while there was no significance between the premyopia group and the mild myopia(P>0.05). Monocular AF had significance between the normal group and the premyopia group(P<0.01), while there was no significance between the premyopia group and the mild myopia group(P>0.05); The monocular AA had significance among the three groups(P<0.05).CONCLUSION: Although the diopters was normal, binocular NRA, PRA, monocular and binocular AF had significantly decreased in the premyopia group, and there was no significant difference compared with mild myopia group; monocular AA had decreased in the premyopia group and it was also significantly different from the mild myopia group. The accommodation function should be examined in premyopic children. Recovering the abnormal visual function through visual training may be a way to prevent and control premyopia from progressing to myopia.
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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>SE>+0.50 D). There was a statistically significant difference in SE, AL and AL/CR values among different refractive states(P<0.01), but there was no difference in CR(P>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<0.01; r=-0.758, P<0.01), but no significant correlation between SE and CR(r=0.067, P>0.05), there was a positive correlation between AL and CR(r=0.483, P<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 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<0.001).The negative growth rate of AL after 6 mo of treatment was significantly higher than that of the control group(P<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<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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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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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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The foveal avascular zone(FAZ)is the most sensitive region of the retina, which is interconnected by the macular capillary plexus. Its morphology can indirectly reflect the alterations of macular microcirculation. With strong repeatability and reliability, optical coherence tomography angiography(OCTA)can non-invasively visualize and quantify the FAZ. The great value of OCTA makes it an important supplemental examination tool in ophthalmology and other professions. The area and perimeter of FAZ have been demonstrated to be an effective clinical diagnostic indicator in high myopia, diabetic retinopathy, glaucoma and other ocular diseases. In recent years, the geometry of FAZ has also proven to have clinical value. The parameters describing the geometry of FAZ, such as circularity index, acircularity index and axial ratio, provide a new perspective for ocular disease research. The comprehensive investigation of the morphological characteristics of the FAZ is helpful to explore the pathological mechanism of the occurrence and development of ocular diseases, predict preclinical changes, make pathological stages of the disease precise, and provide a theoretical basis for monitoring the disease's progression and assessing patients' visual prognosis.
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AIM: To evaluate the pathogenic variants of the SCO2(OMIM 604272)gene in patients with high myopia from Enshi Tujia and Miao Autonomous Prefecture of China.METHODS: A total of 384 patients with high myopia whose spherical refractive error was ≤ -6.00 D and whose axial length was ≥26.00 mm in at least one eye were recruited. DNA was extracted by the phenol-chloroform method from 5 mL of peripheral venous blood. Sanger sequencing was performed to identify pathogenic variants in exon 2 of SCO2. The detected variants were evaluated via in silico prediction software. A total of 288 people from the same district were included as the normal control cohort.RESULTS: Seven variants were detected, namely, four synonymous variants(c.201C>T/p.=, c.576C>T/p.=, c.633A>C/p.=, c.780T>C/p.=.), two missense variants(c.187A>G/p.Ile63Val, c.59G>C/p.Arg20Pro)and one nonsense variant(c.544C>T/p.Gln182*). The two missense variants were not damaging, as predicted by PolyPhen2, SIFT and Provean. The novel nonsense variant(c.544C>T/p.Gln182*)cannot be found in the 1000 Genomes Project and was not identified in 288 normal controls. Variant Taster suggested that the nonsense variant site was conserved.CONCLUSION: The newly identified nonsense mutation may be responsible for high myopia of the patients in our cohort. SCO2 is associated with high myopia, while the incidence of SCO2 variants in high myopia in this cohort was as low as 1/384; the nonsense mutation may be a scarce variant of high myopia in the Enshi Tujia and Miao Autonomous Prefecture of China.
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AIM: To compare the outcome of C3F8 versus silicone oil tamponade after pars plana vitrectomy(PPV)and inverted internal limiting membrane(ILM)for the treatment of highly myopic macular hole retinal detachment(MHRD).METHODS: Retrospective clinical study. Totally 45 patients(45 eyes)with highly myopic MHRD who visited our hospital between January 2019 and August 2022 were selected as the research subjects. The patients were divided into two groups according to different intraocular tamponade agents: C3F8(22 eyes)and silicone oil(23 eyes)groups. All patients underwent conventional three-incision PPV, ILM was tamped, a venous blood clot was placed on the tamped ILM, and 15% C3F8 and silicone oil were used as tamponade, respectively. The best corrected visual acuity(BCVA), multifocal electroretinogram(mfERG), the closure of the macular hole, retinal reattachment and the complications were observed.RESULTS: The macular hole closure rate was 77% in the C3F8 group and 83% in the silicone oil group, respectively(P>0.05), and retinal reattachment rates were 95% and 96%, respectively(P>0.05). The visual acuity of the two groups significantly improved, which was 0.99±0.34 and 1.22±0.37, respectively, and the C3F8 group was better than that of the silicone oil group(t=-2.156, P=0.037). After operation, the response density of the first ring of P1 wave in the first order kernel in mfERG was 114.27±26.37 nV/deg2 for the C3F8 group and 98.08±24.36 nV/deg2 for the silicone oil group, and the response density of the second ring of P1 wave was 80.45±14.94 nV/deg2 for the C3F8 group and 67.73±15.33 nV/deg2 for the silicone oil group, all of which were significantly higher compared to pre-operation [the response density of the first ring of P1 wave: 58.13±13.96 nV/deg2 for the C3F8 group and 55.30±10.48 nV/deg2 for the silicone oil group, the response density of the second ring of P1 wave: 51.18±8.19 nV/deg2 for the C3F8 group and 47.43±11.97 nV/deg2 for the silicone oil group](all P<0.05). It was found that the response density of the first ring of P1 wave was lower in the silicone oil group than in the C3F8 group(P<0.05). There was no statistically significant difference in the incidence of complications between the two groups(P>0.05).CONCLUSION: Silicone oil tamponade or C3F8 tamponade after PPV combined with ILM can both promote retinal reattachment and macular hole closure in patients with MHRD, and the C3F8 tamponade was superior to silicone oil in visual function recovery.
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AIM: To understand the current status and differences in visual acuity of children of the same age from different regions of Xi'an, and to take an effective basis for the prevention of children's myopia.METHODS: Random stratified sampling was used to select the uncorrected distance visual acuity and computed dioptric data of 41 285 children aged 6-12 from 6 towns, 10 urban and rural areas and 112 country schools screened by Xi'an Central Hospital in December 2022.RESULTS: The myopia detection rate in different regions of Xi'an is 47.16% in towns, 38.59% in urban and rural areas, and 32.29% in the country, and the total myopia rate is 37.50%. The myopia rate of 6-12 years old in towns is higher than that in urban and rural areas, and that of urban and rural areas is higher than that of country; the myopia rate of girls is higher than that of boys; myopia rate increases with age; mild myopia: the myopia rate in towns is significantly higher than that of the urban and rural areas and the country; high myopia: the myopia rate in the country is significantly higher than that of the towns and the urban and rural areas. The total rate of deficient hyperopia reserves in different regions of Xi'an is 92.08% in towns, 93.67% in urban and rural areas, and 90.92% in the country, and the total rate of deficient hyperopia reserves is 92.09%. The rate of deficient hyperopia reserves at the age of 6-12 is higher in the urban and rural areas than in the towns, and higher in the towns than in the country; the total rate of deficient hyperopia reserve is higher in girls than in boys; it is the peak period of the development of hyperopia reserve rate before the age of 8.CONCLUSION: The total myopia rate and the total vision reserve deficiency rate of 6-12 years old in different regions of Xi'an are different, and 8-9 years old is the accelerated period of myopia development, and the peak of deficient hyperopia reserve is before the age of 8 years old. With the growth of age, the myopia rate shows a certain growth trend, and the rate of deficient hyperopia reserve shows a decreasing trend after reaching the peak. The total myopia rate and insufficient acuity reserve rate of girls are higher than those of boys.
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The incidence of myopia among Chinese adolescents is progressively rising, indicating a distinct trend toward younger age onset.This paper aims to comprehensively review the impact of various visual performance on myopia and its progression, with a specific emphasis on accommodative function, convergence function, and ocular position. A meticulous exploration of accommodation function, encompassing accommodative amplitude, accommodative facility, accommodative response, positive relative accommodation, and negative relative accommodation, has been undertaken to elucidate its contributory role in myopia progression. Concurrently, an exhaustive analysis of convergence function has been conducted including esotropia and exotropia, convergence insufficiency and convergence excess, fusional function vergence, divergence insufficiency, and excess, providing a nuanced understanding of convergence's implications for myopia advancement. Furthermore, the influence of ocular position on myopia progression, along with other factors affecting perceptual ocular position and intermittent exotropia, is discussed. The primary objective of this article is to unveil the multifaceted visual performance influencing myopia and its progression, elucidating the paramount significance of accommodative function, convergence function, and ocular position in this context.
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In medical research,predictive models have been widely used to predict disease progression and identify high-risk populations in advance, especially in the prevention and diagnosis of chronic diseases. In ophthalmology, the predictive and diagnostic models for fundus diseases such as age-related macular degeneration and diabetic retinopathy have demonstrated expert-level accuracy. However, the application of predictive models is still in the exploratory stage as for myopia prevention and control. The establishment of a predictive model is helpful to identify the high-risk myopic children in advance, so that preventive measures such as adequate outdoor activities and reducing near work can be taken in time, which is of great significance to prevent or slow down the occurrence and development of myopia. Because the mechanism of myopia has not been fully elucidated, there are still challenges and limitations in the selection of application objects, predictors and predictive outcomes. This paper reviews the research progress of different types of myopia predictive models in order to provide reference for further development and improvement.
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AIM: To investigate the effects of 0.01% atropine eye drops on macular blood flow density and retinal thickness in children with different degrees of myopia. METHODS: This was a prospective case-control study. Sixty-four patients (112 eyes) diagnosed with myopia for the first time with 0.01% atropine eye drops before and 6 months after medication were investigated with the uncorrected distance visual acuity (UCVA), axial length (AL), spherical equivalent (SE), macular ganglion cell-inner plexiform layer thicknes (mGCIPL) using slit lamp examination and optical coherence tomography (OCT), vascular density in the macular area and the area of the avascular in the fovea using optical coherence tomography angiography (OCTA) . Changes in various indicators before and after medication were compared. RESULTS: Compared with before medication, the AL of the three groups of myopia patients increased significantly (P0.05). The difference was statistically significant between the moderate myopia group and the high myopia group (P0.05). After 6 months of medication, the central circle macular vessel density (cCVD) increased in the low myopia group and moderate myopia group (P0.05). Before and after medication, there was no significant difference in outer circle macular vessel density (oCVD), inner circle macular vessel density (iCVD), and whole circle macular vessel density (wCVD) among the three myopia groups (P>0.05). The increase in mGCIPL was statistically significant in the low myopia group (P0.05). There was no significant difference in foveal avascular zone (FAZ) among the three myopia groups before and after medication (P>0.05). There was no correlation between CVD, AL, and SE in the three myopia groups (P>0.01). There was a low correlation between CVD and mGCIPL in the low myopia group (r=0.442, P0.01). CONCLUSION: 0.01% atropine can significantly reduce the rate of axial and refractive growth in children with low to moderate myopia, increase the density of central macular vessels, and increase the thickness of mGCIPL in children with low to moderate myopia.
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AIM: To explore the clinical effect of small incision lenticule extraction(SMILE)on the treatment of myopic anisometropia.METHODS: Clinical data of 76 patients(146 eyes)with myopic anisometropia who received SMILE or femtosecond assisted laser in situ keratomileusis(FS-LASIK)in our hospital from January 2021 to December 2022 were retrospectively analyzed. The patients were divided into SMILE group(39 cases, 77 eyes)and FS-LASIK group(37 cases, 69 eyes)according to surgical methods. Uncorrected visual acuity(UCVA), diopter, anisometropia, corneal aberration and occurrence of postoperative complications were compared between the two groups at 1 wk, 1 and 3 mo after surgery.RESULTS: The UCVA of the two groups was improved after surgery compared with that before surgery, and the coma, trefoil, spherical aberration and total higher-order aberration were significantly increased compared to those before surgery(P<0.05), and the coma, trefoil, spherical aberration and total higher-order aberration in the FS-LASIK group were significantly higher than those in the SMILE group(P<0.05). After follow-up to 3 mo after surgery, the incidence of postoperative complications was significantly lower in the SMILE group than that in the FS-LASIK group(5.2% vs 15.9%, P<0.05).CONCLUSION: Both SMILE and FS-LASIK can effectively enhance the UCVA and improve the visual quality in patients with myopic anisometropia, but SMILE has lower corneal higher order aberrations, lower incidence of postoperative complications and better overall effect.
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AIM: To evaluate the accuracy of the formulas, including Haigis, SRK/T, Holladay 1, and Holladay 2, in predicting the diopter of the intraocular lens implanted in high myopia cataract patients.METHODS: Prospective study. A total of 168 cases(168 eyes)of age-related cataract with an axial length(AL)≥26 mm who were treated in our hospital from August 2017 to November 2021 were selected. According to the preoperative AL measured by IOL Master 700, the patients were divided into five groups, including 37 cases(37 eyes)in group A with 26 mm≤AL<27 mm, 34 cases(34 eyes)in group B with 27 mm≤AL<28 mm, 42 cases(42 eyes)in group C with 28 mm≤AL<29 mm, 28 cases(28 eyes)in group D with 29 mm≤AL<30 mm, and 27 patients(27 eyes)in group E with AL ≥ 30 mm. Subjective refraction was performed at 3 mo postoperatively, and the mean numerical error(MNE)and mean absolute error(MAE)of each formula for predicting diopters were calculated.RESULTS: The MNE and MAE of the Haigis and Holladay 2 formulas were relatively less in each group, and MNE and MAE did not significantly increase with the growth of the axial length. However, the MAE and MNE of the SRK/T and Holladay 1 formulas significantly increased with the growth of the axial length, with the MNE and MAE of the Holladay 1 formula increasing more significantly in groups C, D, and E.CONCLUSION: For patients with age-related cataract, with an axial length of ≥26 mm, the accuracy of predicting the diopter of the intraocular lens using the Haigis and Holladay 2 formulas were higher.
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AIM: To evaluate the binocular visual function in high myopia patients after the implantation of implantable collamer lens(ICL)V4c.METHODS: A total of 35 cases(70 eyes)that received binocular ICL implantation at our hospital from May 2019 to May 2021 were enrolled in this prospective study. Binocular full-range visual acuity, contrast sensitivity, stereopsis, mesopic vision and glare sensitivity, and monocular wavefront and the quality of vision questionnaire were assessed before the surgery and at 1 mo postoperatively.RESULTS: At 1 mo postoperatively, 35 cases(100%)had binocular uncorrected distance visual acuity(UDVA)≤0.00(LogMAR), 16 cases(46%)had binocular UDVA≥preoperative corrected distance visual acuity(CDVA). Binocular UDVA and uncorrected intermediate visual acuity(UIVA,80 cm)were improved compared to preoperative CDVA and distance-corrected intermediate visual acuity(DCIVA,80 cm)(all P<0.05).While there were no differences in the binocular postoperative UIVA(60 cm)and preoperative DCIVA(60 cm),and uncorrected near visual acuity(UNVA,40 cm)and preoperative distance-corrected near visual acuity(DCNVA,40 cm)(all P>0.05). The binocular contrast sensitivity was significantly improved postoperatively(P=0.001), and the postoperative binocular mesopic vision, glare sensitivity(no glare/glare)and binocular stereopsis(5 m/40 cm)had no differences(all P>0.05). The postoperative total higher-order aberration, trefoil aberration, coma and spherical aberration were increased, besides the median of total coma in the right eye with a pupil diameter of 3.0 mm was decreased after surgery. The mean total score of quality of vision questionnaire was significantly increased from 54.87 preoperatively to 80.92 after implantation(P<0.05), with high satisfaction and no obvious visual disturbance in patients.CONCLUSION: Although the monocular high-order aberrations increased in the early stage after ICL V4c binocular implantation in patients with high myopia, the binocular visual function was improved.
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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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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 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.
ABSTRACT
Abstract@#The choroid is a multifunctional dynamic structure located between the sclera and the Bruch membrane, which may be involved in the regulation of eye growth and the development of myopia. Choroidal thickness may serve as an important biomarker for predicting the development of myopia and the effectiveness of myopia control treatments in children and adolescents. The study reviews and summarizes the physiological structure and measuring methods of the choroid, and discusses its influencing factors including age, physiological changes, refractive status, axial length, drug effects, optical environment and so on. The review points out the potential applications of choroidal thickness in myopia research among children and adolescents.