Different Degrees Of Myopia Research Articles

AI-based fully automatic analysis of retinal vascular morphology in pediatric high myopia

PurposeTo investigate the changes in retinal vascular structures associated with various stages of myopia by designing automated software based on an artificial intelligence model.MethodsThe study involved 1324 pediatric participants from the National Children’s Medical Center in China, and 2366 high-quality retinal images and corresponding refractive parameters were obtained and analyzed. Spherical equivalent refraction (SER) degree was calculated. We proposed a data analysis model based on a combination of the Convolutional Neural Networks (CNN) model and the attention module to classify images, segment vascular structures, and measure vascular parameters, such as main angle (MA), branching angle (BA), bifurcation edge angle (BEA) and bifurcation edge coefficient (BEC). One-way ANOVA compared parameter measurements between the normal fundus, low myopia, moderate myopia, and high myopia groups.ResultsThe mean age was 9.85 ± 2.60 years, with an average SER of -1.49 ± 3.16D in the right eye and − 1.48 ± 3.13D in the left eye. There were 279 (12.38%) images in the normal group and 384 (16.23%) images in the high myopia group. Compared with normal fundus, the MA of fundus vessels in different myopic refractive groups was significantly reduced (P = 0.006, P = 0.004, P = 0.019, respectively), and the performance of the venous system was particularly obvious (P < 0.001). At the same time, the BEC decreased disproportionately (P < 0.001). Further analysis of fundus vascular parameters at different degrees of myopia showed that there were also significant differences in BA and branching coefficient (BC). The arterial BA value of the fundus vessel in the high myopia group was lower than that of other groups (P = 0.032, 95% confidence interval [CI], 0.22–4.86), while the venous BA values increased (P = 0.026). The BEC values of high myopia were higher than those of low and moderate myopia groups. When the loss function of our data classification model converged to 0.09, the model accuracy reached 94.19%.ConclusionThe progression of myopia is associated with a series of quantitative retinal vascular parameters, particularly the vascular angles. As the degree of myopia increases, the diversity of vascular characteristics represented by these parameters also increases.

Retinal nerve fiber layer thickness and radial peripapillary capillaries density in myopic adults with optical coherence tomography angiography

PurposeTo evaluate retinal nerve fiber layer thickness (RNFLT) and radial peripapillary capillaries (RPC) density in adults with different degrees of myopia using optical coherence tomography angiography (OCTA) and explore their relationship with ocular factors, such as axial length (AL) and disc area.MethodsA total of 188 subjects were included in this cross-sectional study. The eyes were divided into four groups according to AL. OCTA was used for the assessment of RNFLT, RPC density, and other optic disc measurements, such as disc area. One-way analysis of variance was performed to compare differences between four groups, and P value < 0.01 was considered significant.ResultsThe RNFLT was significantly thinner in high myopia (HM) group at inferior nasal (IN) quadrant (P = 0.004) than low myopia (LM) group, but thicker at temporal inferior (TI) quadrant (P = 0.006). The RPC density of nasal superior (NS) quadrant, nasal inferior (NI) quadrant, and inferior nasal (IN) quadrant significantly decreased as AL increasing. By simple linear regression analysis, the inside disc RPC (iRPC) density tended to be correlated significantly with AL (0.3997%/mm, P < 0.0001). Peripapillary RPC (pRPC) density was in significant correlation with AL (-0.2791%/mm, P = 0.0045), and peripapillary RNFLT (pRNFLT) was in significant correlation with disc area (0.2774%/mm2, P = 0.0001).ConclusionRNFLT and RPC density were closely associated with AL and disc area. They might be new indexes in assessing and detecting myopia development via OCTA.

Analysis of factors affecting the progression of visual field defects in patients with myopia and primary open-angle glaucoma

Objective: To investigate the factors affecting the progression of visual field defects in patients with myopia and primary open-angle glaucoma (POAG), and to clarify whether the factors vary in patients with different degrees of myopia. Method: An ambispective cohort study was conducted among patients diagnosed with myopia and POAG from the glaucoma outpatient department at the Zhongshan Ophthalmic Center of Sun Yat-sen University between January 2006 and January 2024. Based on the criteria of functional visual field progression, patients were divided into the progression group and non-progression group, and further divided into the low to moderate myopia subgroup and high myopia subgroup according to the degree of myopia. The patient age, gender, type of glaucoma (high tension glaucoma and normal tension glaucoma), spherical equivalent refraction, best corrected visual acuity (BCVA, recorded as the logarithm of the minimum angle of resolution), intraocular pressure (IOP), central corneal thickness, baseline visual field, history of ophthalmic surgery (corneal refractive surgery and glaucoma surgery), and number of anti-glaucoma medications were summarized. The generalized estimation equation was used for comparison between groups, and the Cox proportional hazards model was used to analyze the factors affecting the progression of visual field defects. Results: A total of 182 eyes from 106 patients were included in this study. There were 57 eyes in the progression group and 125 eyes in the non-progression group. Compared with the non-progression group, the progression group had the older age [43 (29, 53) years old], worse BCVA [0.05 (0.00, 0.17)], greater IOP fluctuation [1.8 (1.3, 2.9)mmHg(1 mmHg=0.133 kPa)], more common baseline central defects [52.6%(30/57)], higher visual field pattern standard deviations [8.92 (5.32, 12.00)dB], lower visual field index [77% (67%, 88%)], and more anti-glaucoma medications [35.1% (20/57) patients used three medications] (all P<0.05). The Cox proportional hazards models showed that the baseline moderate visual field defects [hazard ratio (HR)=2.33, 95% confidence interval (CI): 1.25 to 4.36, P=0.008], baseline central defects (HR=2.09, 95%CI: 1.11 to 3.93, P=0.022), older age (Model A, HR=1.03, 95%CI: 1.00 to 1.05, P=0.017; Model B, HR=1.02, 95%CI: 1.00 to 1.05, P=0.019), and greater IOP fluctuation (Model A, HR=1.54, 95%CI: 1.32 to 1.81, P<0.001; Model B, HR=1.49, 95%CI: 1.26 to 1.75, P<0.001) were risk factors for visual field progression. In the low to moderate myopia subgroup, the increased risk of progression was associated with baseline central defects (HR=5.74, 95%CI: 1.72 to 19.20, P=0.005), worse BCVA (Model A, HR=15.80, 95%CI: 2.07 to 121.00, P=0.008; Model B, HR=12.50, 95%CI: 2.65 to 58.70, P=0.001), and older age (Model A, HR=1.05, 95%CI: 1.02 to 1.08, P=0.002; Model B, HR=1.07, 95%CI: 1.03 to 1.11, P<0.001). In the high myopia subgroup, the increased risk of progression was associated with baseline moderate visual field defects (HR=2.35, 95%CI: 1.12 to 4.92, P=0.024) and greater IOP fluctuation (Model A, HR=1.50, 95%CI: 1.24 to 1.82, P<0.001; Model B, HR=1.52, 95%CI: 1.26 to 1.83, P<0.001). Conclusions: Age, IOP fluctuation, baseline moderate visual field defects, and baseline central defects were the factors affecting the progression of visual field defects in patients with myopia and POAG. There were differences in the influencing factors of visual field progression in patients with different degrees of myopia.

Clinical Efficacy of MiSight 1 day Soft Contact Lenses in Korean Myopic Children.

This study aimed to investigate the clinical efficacy of MiSight 1 day soft contact lenses (MiSight CL) in Korean children with mild-to-moderate myopia. In addition, the study compared the effects of MiSight CL in children who had or had not previously used orthokeratology contact lenses (Ortho-K). A total of 66 children aged 5 to 16 years, who were prescribed MiSight CL, were included in the study. Based on a myopia degree of -4 diopters (D), children were divided into mild and severe myopia groups to compare the effectiveness of myopia suppression. In addition, 55 eyes previously using Ortho-K were compared with 76 eyes using MiSight CL for the first time. The average follow-up period was 6.58±3.74 months. The average refractive value before using MiSight CL was 3.64±1.56 D, and there was no significant change in the final visit. Comparing myopia suppression between different degrees of myopia and previous use of Ortho-K lenses, there was no significant change in refractive error before and after using MiSight CL (unpaired t test, P >0.05). The main reason for Ortho-K failure was low visual acuity after correction. Regardless of Ortho-K history, children showed good visual acuity after wearing MiSight CL, and no other side effects were observed. MiSight CL effectively inhibited the progression of myopia in Korean children with mild-to-moderate myopia. MiSight CL offer the advantage of easy application, making them a viable alternative when Ortho-K are not suitable.

Ocular surface in patients with different degrees of myopia.

To investigate the clinical features of the ocular surface in patients with different degrees of myopia. A cross-sectional study was conducted involving 122 participants with myopia in Beijing Tongren Hospital from February to June, 2023. After completing the Ocular Surface Disease Index (OSDI) score scale, measurements were taken for refraction, biometric parameters and ocular surface parameters. The prevalence, severity and related parameters of the dry eye among different groups based on axial length (AL) were compared. Correlation analysis was performed between ocular surface parameters and refraction/biometric measurement parameters. Statistically significant differences were observed in refractive error, corneal thickness, anterior chamber depth, and subfoveal choroidal thickness among the groups (all P<0.05). With the increase in AL, the incidence and severity of dry eye increased significantly (P<0.05). Moreover, the tear film break-up time (BUT) shortened (P<0.05), and the corneal fluorescein staining (CFS) points increased significantly (P<0.05). OSDI scores were positively correlated with AL and spherical equivalent (SE; both P<0.05); BUT was negatively correlated with AL, SE, and corneal astigmatism (AST; all P<0.05); Schirmer I test (SIT) results were negatively correlated with AL and SE (both P<0.05). AL elongation is a risk factor for dry eye onset in myopic participants. The longer the AL, the more severe the dry eye is, with the increased CFS spots and tear film instability. Additionally, SE and AST exhibit negative correlations with dry eye symptom scores and ocular surface parameters.

Changes in posterior corneal elevation after small incision lenticule extraction for different myopic diopters.

To study the changes and effect factors of posterior corneal surface after small incision lenticule extraction (SMILE) with different myopic diopters. Ninety eyes of 90 patients who underwent SMILE were included in this retrospective study. Patients were allocated into three groups based on the preoperative spherical equivalent (SE): low myopia (SE≥-3.00 D), moderate myopia (-3.00 D>SE>-6.00 D) and high myopia (SE≤-6.00 D). Posterior corneal surfaces were measured by a Scheimpflug camera preoperatively and different postoperative times (1wk, 1, 3, 6mo, and 1y). Posterior mean elevation (PME) at 25 predetermined points of 3 concentric circles (2-, 4-, and 6-mm diameter) above the best fit sphere was analyzed. All surgeries were completed uneventfully and no ectasia was found through the observation. The difference of myopia group was significant at the 2-mm ring at 1 and 3mo postoperatively (1mo: P=0.017; 3mo: P=0.018). The effect of time on ΔPME was statistically significant (2-mm ring: P=0.001; 4-mm ring: P<0.001; 6-mm ring: P<0.001). The effect of different corneal locations on ΔPME was significant except 1wk postoperatively (1mo: P=0.000; 3mo: P=0.000; 6mo: P=0.001; 1y: P=0.001). Posterior corneal stability was linearly correlated with SE, central corneal thickness, ablation depth, residual bed thickness, percent ablation depth and percent stromal bed thickness. The posterior corneal surface changes dynamically after SMILE. No protrusion is observed on the posterior corneal surface in patients with different degrees of myopia within one year after surgery. SMILE has good stability, accuracy, safety and predictability.

Quantitative Evaluation of the Topographical Maps of Three-Dimensional Choroidal Vascularity Index in Children With Different Degrees of Myopia.

To investigate topographical maps of the three-dimensional choroidal vascularity index (3D-CVI) in children with different levels of myopia. We enrolled 274 eyes from 143 children with various severity of myopia, including emmetropia (EM), low myopia (LM), and moderate-high myopia (MHM). The choroidal vessel volume (CVV), choroidal stroma volume (CSV), and 3D-CVI in different eccentricities (fovea, parafovea, and perifovea) and quadrants (nasal, temporal, superior, and inferior) were obtained from swept-source optical coherence tomography angiography (SS-OCTA) volume scans. All choroidal parameters were compared among groups, and the associated factors contributing to different 3D-CVIs were analyzed. Compared to the less myopic group, the more myopic group showed a significant decrease in CVV and CSV (MHM < LM < EM) and a significant increase in the 3D-CVI (MHM > LM > EM) in most areas (all P < 0.05). The nasal quadrant had the greatest 3D-CVI and lowest CSV and CVV, and vice versa in the temporal quadrant. The 3D-CVIs of the EM and LM groups gradually increased from the fovea to the perifovea, whereas the 3D-CVI of the MHM group first decreased and then increased. Regression analysis showed that axial length was an independent risk factor affecting foveal and parafoveal 3D-CVIs. Restricted cubic spline analysis revealed that the 3D-CVI increased with spherical equivalent (SE) when the SE was less than threshold and decreased when the SE was greater than threshold (SE thresholds for foveal, parafoveal, and perifoveal 3D-CVIs were -5.25 D, -5.125 D, and -2.00 D, respectively; all P < 0.05). Children with myopia exhibited decreased CSV and CVV, increased 3D-CVIs, and altered 3D-CVI eccentricity characteristics (from the fovea to the perifovea). The quadratic relationship between the 3D-CVI and SE should be explored in longitudinal investigations.

Topographic and surgical risk factors for high postoperative residual astigmatism after small incision lenticule extraction in patients with different degrees of myopia: a retrospective cohort study

BackgroundTo evaluate the possible topographic and surgical risk factors for high postoperative residual astigmatism in patients who undergo small-incision lenticule extraction (SMILE) surgery and have different myopia degrees.MethodsA retrospective cohort study was conducted, and patients who underwent SMILE surgery were enrolled. A total of 80 and 150 eyes from 40 to 75 individuals, respectively, were selected as the low myopia and high myopia groups. The demographic data, visual acuity, refraction, topographic parameters and surgical settings were recorded. Multiple linear regression with interaction tests were performed to survey the risk factors for high postoperative residual astigmatism in each group.ResultsFive (6.25%) and 9 (6.00%) eyes presented with high postoperative residual astigmatism in the low myopia and high myopia groups, respectively, but these differences were not significant (P = 0.569). A steep corneal curvature was correlated with a greater risk of high postoperative residual astigmatism in the low myopia group (P = 0.015), while a higher degree of cycloplegic cylinder power, steeper corneal curvature, greater topographic cylinder power, smaller optic zone and longer incision length were associated with a high rate of postoperative residual astigmatism in the high myopia group (all P < 0.05). In addition, the interaction effects of cycloplegic and topographic cylinder power and longer incision length on the incidence of high postoperative residual astigmatism development were more evident in the high myopia group than in the low myopia group (all P < 0.05).ConclusionsA steep corneal curvature correlates with a high risk of high postoperative residual astigmatism after SMILE surgery, and a higher degree of cycloplegic and topographic cylinder and longer incision are associated with high postoperative residual astigmatism in individuals with high myopia.

A comparative analysis of the effectiveness of laser correction with a mechanical and laser microkeratome for myopia.

Myopia, or nearsightedness, is one of the most common eye conditions worldwide. However, a comparison of the effectiveness of different laser-assisted interventions is lacking. Thus, we aimed to compare the efficacy and safety of LASIK and IntraLASIK in addressing myopia. The study was conducted in two ophthalmology clinics in Beijing, China, in 2022. A total of 84 patients (152 eyes) with different degrees of myopia were examined and underwent LASIK (n=46, 80 eyes) or IntraLASIK (n=38, 72 eyes). Keratometry, corneal topography, pachymetry, visual acuity evaluation, and corneal biomechanical analysis were performed before and after the intervention. IntraLASIK produced more precise flaps than LASIK, with deviations of <8 mm and 0.1 mm from the intended thickness and diameter, respectively. LASIK resulted in nonuniform flaps, with thickness deviations of 5-86 mm. IntraLASIK demonstrated a superior efficacy for patients with severe myopia and thin corneas, with a mean spherical equivalent of 0.9 D at 6 months compared to the 1.4 D for LASIK. Approximately 91% and 83% of the patients with mild to moderate and severe myopia, respectively, achieved results within ± 0.49 D from the refractive target with IntraLASIK. Corneal hysteresis and corneal resistance factor decreased with an increase in laser intensity, and they decreased faster with thinner corneas. Thus, IntraLASIK is more useful than LASIK in patients with thin corneas and severe myopia.

Comparison of errors in ablation depth calculation after myopic femtosecond laser in situ keratomileusis in patients with different degrees of myopia: a prospective study

BackgroundTo investigate the difference between the predicted preoperative corneal ablation depth and the measured ablation depth for femtosecond laser in situ keratomileusis (FS-LASIK) in patients with different degrees of myopia, and to analyze the source of the difference.MethodsA total of 55 patients (109 eyes) were included in this study. Multiple logistics regression was applied to analyze the sources affecting postoperative refractive outcomes. The difference between the preoperative predicted corneal ablation depth and the 1-day postoperative ablation depth in patients with different degrees of myopia was explored using linear regression. Corneal biomechanical parameters influencing error in ablation depth calculation were examined using multiple linear regression.ResultsOne hundred and nine eyes were divided into low to moderate myopia (55 eyes, myopia of 6 D or less), high myopia (45 eyes, myopia ranging from 6 D to a maximum of 9 D), and very high myopia group (9 eyes, myopia greater than 9 D) based on preoperative refractive error (spherical equivalent). Postoperative visual outcomes were comparable among the three groups of patients, with no significant difference in uncorrected visual acuity (UCVA). We did find notable disparities in spherical equivalent (SE) and central corneal thickness (CCT) in patients with different degrees of myopia at 1 day postoperatively (all p < 0.001). Logistic regression analysis showed that error in ablation depth calculation was an independent risk factor for refractive outcomes one day after surgery (OR = 1.689, 95% CI: 1.366 – 2.089). There was a substantial discrepancy in error in ablation depth calculation at 1 day postoperatively between the three groups. The measured ablation depth of the laser platform was lower than the predicted ablation depth in the low to moderate myopia and very high myopia groups, but the opposite was true in the high myopia group. Pre-operative SE (p < 0.001) and corneal front minimum radius of curvature (Front Rmin) (p = 0.007) obviously influenced the error in ablation depth calculation.ConclusionsError in ablation depth calculation values vary significantly between patients with different degrees of myopia and correlate highly with preoperative SE and Front Rmin. At the same time, the available evidence suggests that error in ablation depth calculation is an influential factor in postoperative refractive status, so it is imperative to control error in ablation depth calculation.

Dynamics of Accommodative Asthenopia in Patients with Visually Intense Work after LASIK with Different Degrees of Myopia

Purpose — to study the dynamics of accommodative asthenopia (AA) in patients with visually stressful labor (VLT) after laser keratomileusis in situ (LASIK) with different degrees of myopia. Patients and methods. There were 300 patients with VLT under supervision, divided into three groups of equal age and gender, corresponding to weak (up to 3.0 diopters, 100 patients, 200 eyes), medium (3.25–6.0 diopters, 100 patients, 200 eyes) and high (6.25–8.0 diopters, 100 patients, 200 eyes) degrees of myopia. All patients underwent objective accommodation using the Righton Speedy-I device (Japan) with further calculation of the coefficient of microfluctuations of the ciliary muscle of the eye (CMF). Diagnosis of the type of AA was carried out according to the following indicators: with CMF less than 53.0 rel. un. — asthenic form of accommodative asthenopia (AFAA); at CMF from 53.0 to 58.0 rel. un. — NORM; at CMF more than 58.0 rel. un. — habitual excess tension of accommodation (PINA). The survey was carried out before and three months after the operation. Statistical analysis of the results of the study was performed on the basis of the rate of occurrence (in % of the total number of eyes) of different dynamics (before-after surgery) AA (NORM-NORM; PINA-PINA; AFAA-AFAA; NORM-AFAA; NORM; PINA-AFAA; AFAA-NORM; AFAA-PINA). Results. The change in the form of AA varied from 2 % (APAA-PINA) to 18 % (PINANORM), averaged 15 % and was not statistically significant. The results obtained naturally reflect the state of AA as an adequate physiological response of the accommodative system of the eye to long-term, intense visual work with a fairly high level of responsibility for the result. Based on the above situation and the patient’s desire to maintain (in some cases even increase) the volume of daily visual load after the operation, it is unlikely to expect a significant improvement in the state of accommodation. Conclusion. LASIK with different degrees of myopia in patients with VLT has practically no effect on the dynamics of AA and requires a complex of therapeutic and restorative measures based on the development of methodological principles from the standpoint of a differentiated approach to the form of AA and the basic provisions of medical rehabilitaton.

Динамика результатов транс-ФРК при коррекции миопии различной степени на аппарате Микроскан Визум

Difficulties in choosing the method of excimer laser correction for high-grade myopia pose to ophthalmologists the task of finding a technique for excimer laser correction of this type of ametropia, combining safety and a good refractive result. The dynamics of the results of correction of myopia of various degrees by the method of transepithelial PRK on the installation of Microscan Visum for up to 6 months was evaluated. Depending on the degree of myopia, 3 groups of patients were formed. Transepithelial PRK has proven to be a safe technique that provides a good refractive result. The results of this study help predict the dynamics of visual functions in the postoperative period in patients with different degrees of myopia. Key words: transepithelial photorefractive keratectomy, myopia, Microscan Visum.

Excimer Laser Correction of Myopia in Patients with Visually Intense Work — Is It Necessary to Determine the Form of Accommodative Asthenopia?

Рurpose — to study the frequency of occurrence of various forms of accommodative asthenopia (AA) in patients with visually stressful work (VSW) with different degrees of myopia planning LASIK.Methods. As part of the preoperative examination, 300 patients with VSW were under observation. There were three groups of equal age and gender, corresponding to weak (up to 3.0 diopters, 100 patients), moderate (3.25–6.0 diopters, 100 patients ) and high (6.25–8.0 diopters, 100 patients) degrees of myopia. All patients underwent objective accommodation using the Righton Speedy-I device (Japan) with further calculation of the coefficient of microfluctuations of the ciliary muscle of the eye (KMF). Diagnosis of the type of AA was carried out according to the following indicators: with KMF less than 53.0 rel. un. — asthenic form of accommodative asthenopia (AFAA), pathology; at KMF from 53.0 to 58.0 rel. — norm; at KMF more than 58.0 rel.un. — Habitual Excessive Tension of Accommodation (HETA), pathology.Results. The incidence of AA (any form) was 51–57 % and weakly depended on the degree of myopia. A significant increase (compared with the literature data) in patients with AA according to the results of this work is due to the following factors: the examination of patients exclusively with VSW, who daily perform professional visual activity at the time of the examination, as well as a wide (24–34 years) the age range of the subjects. The probability of occurrence of HETA and AFAA is quite comparable and amounted to 29–36 % and 21–23 %, respectively. The obtained results are illustrated by typical accomodograms. Conclusion: the high incidence of both forms of AA actualizes further research aimed at assessing the dynamics of the state of the accommodative system of the eye after excimer laser surgery for myopia, as well as the development of a method for correcting AA, taking into account a personalized approach that allows performing the correct diagnosis of various forms of AA (HETA, AFAA), which, ultimately, will provide adequate treatment from the position of choosing both the actual method (physical factor) and the required optical, amplitude and time parameters of exposure.

Effect of Vitamin D Supplement on Axial Length of Myopes

Myopia is triggered on by excessive axial elongation. Vitamin D deficiency somehow relevant to myopia genic visual cues. Objectives: To compare the level of vitamin D 25(OH)D in myopes and emmetropes and to access the effect of vitamin D 25(OH)D supplements in different degrees of myopia and compare the axial length. Methods: A Randomize Controlled Trail Study was conducted in Madina Teaching Hospital, Faisalabad on 60 subjects from September 2022 to April 2023 with age ranges 15-25 years. All were subjected to following examinations; BCVA, slit-lamp examination, A-scan and vitamin D level. The sample was randomly divided into two groups through Non-probability Purposive Sampling Technique. Group 1 was emmetropic, whereas group 2 exhibits various degrees of myopia. Group 2 takes up supplemental vitamin D followed by 1 month. Results: Mean age was 20.82 years ± 2.32. Out of the total 60 subjects, 24 (40%) were male while 36 (60%) were female.47 subjects (78.3%) reported having less than 4 hours of outdoor exposure while 13 subjects (21%) reported having more than 4 hours. Mean axial length 21.97 ± .80 and 22.66 ± 1.29 of emmetropes (p=0.008) while myopes 24.30 ± .91 and 24.13 ± 1.04 at baseline and after one month respectively (p=0.023). Mean vitamin D level was 18.36 ± 1.37and 17.13 ± 1.35 of emmetropes (p=0.00) while 15.63 ± 1.54and 16.90 ± 2.75 at baseline and after one month respectively (p=0.00). Conclusions: There was a significant association between low levels of vitamin D and the development of myopia in emmetropes and vitamin D supplementation can help to prevent the axial length elongation of myopes

Variation of choroidal thickness during the waking period over three consecutive days in different degrees of myopia and emmetropia using optical coherence tomography.

To investigate the diurnal variation in subfoveal choroidal thickness (SFCT) during the waking period over three consecutive days in different degrees of myopia and emmetropia. A total of 60 adult volunteers were grouped into low, moderate, high myopia, and emmetropia subgroups. SFCT, axial length (AL), anterior chamber depth (ACD), and intraocular pressure (IOP) were measured every 2 h from 8 AM to 8 PM for three successive days. The mean values of daily change amplitude were 3.18 mmHg (IOP), 0.05 mm (AL), 0.17 mm (ACD), and 13.51 μm (SFCT). The values of AL and ACD increased simultaneously with spherical equivalent refraction (SER), but SFCT was the opposite. IOP had a diurnal variation, and there was no difference among the four groups. AL of the high myopia group, ACD of the emmetropia group, and SFCT of each myopia group had diurnal variation over three consecutive days. AL had a high mean value at noon every day, and SFCT had a low mean value at noon every day. The choroid thickness of subjects with different degrees of myopia had a significant diurnal variation. The change of diurnal variation between emmetropic and myopic subjects may be one of the causes of myopia.

The Influence of Myopia on the Foveal Avascular Zone and Density of Blood Vessels of the Macula-An OCTA Study.

Background and Objectives: Myopia is the most common refractive eye anomaly with a prevalence that is constantly increasing. High myopia is associated with numerous complications that can lead to permanent vision loss. It is believed that the basis of these complications lies in changes in the microvasculature of the retina caused by an increase in the longitudinal axis of the eye. Materials and Methods: Optical coherence tomography angiography (OCTA) was used to analyze differences in macular zone vascular and perfusion density and foveal avascular zone (FAZ) parameters in myopic subjects. The following OCTA parameters were analyzed: the vessel and perfusion density of retinal blood vessels in the superficial plexus; the area, perimeter, and index of circularity of the foveal avascular zone (FAZ); and foveal and ganglion cell complex (GCC) thickness. Results: Subjects with low myopia did not show statistically significant differences compared to the control for any of the analyzed parameters. Groups with moderate and high myopia showed a significant decrease in vessel and perfusion density in the parafoveal and the entire 3 × 3 mm analyzed field. Foveal vessel and perfusion densities in the myopic groups were similar to those of the control regardless of the degree of myopia. The area and perimeter of the FAZ, as well as foveal and mean GCC thickness, did not differ significantly no matter the degree of myopia, while the index of circularity was lower in highly myopic subjects. The minimal thickness of the GCC was also lower in the high myopia group. Conclusions: High and moderate myopia led to a loss of blood vessels in the macular region. Perfusion and vascular densities were preserved in the foveal region and were not affected by different degrees of myopia. The FAZ was not significantly larger in myopic subjects, but its circularity was lower in subjects with high myopia.

Higher-Order Aberrations of Topography-Guided LASIK and Wavefront-Optimized LASIK in High- and Low-Myopic Eyes: A Non-Randomized Controlled Trial

We aimed to investigate high-order aberration (HOA) change between topography-guided (TG) and wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) in patients with different degrees of myopia. A non-randomized clinical trial was conducted, in which 40 eyes of 20 patients aged 20-50 years old were included. Participants received TG-LASIK in one eye and WFO-LASIK on the alternate eye. Corneal topography and HOAs including coma, trefoil, spherical aberration (SA), and contrast sensitivity (CS) were collected. Moreover, a quality of vision (QoV) questionnaire was completed by each participant. Non-parametric tests were used to infer the difference in HOAs and CS between the TG-LASIK and WFO-LASIK groups, and subgroup analyses stratified by myopia degree were performed. The high-myopia patients with TG-LASIK showed more coma and SA compared to low-myopia individuals (all 95% CI lower limits > 0), and subjects who received WFO-LASIK exhibited more SA in high-myopia status (both 95% CI lower limits > 0). The TG-LASIK group showed lower postoperative trefoil compared to the WFO-LASIK group in the high-myopia population (mean difference: -0.1267, 95% CI: -0.24 to -0.01). The TG-LASIK group yielded less surgically induced haze, better clarity at night, and better total quality scores (all p < 0.05). In conclusion, TG-LASIK might yield less postoperative trefoil in high-myopia patients and higher QoV in the general population compared to the WFO-LASIK procedure.

Progression of myopia among undergraduate students in central China.

To investigate the progression of myopia and risk factors among university students in central China. A total of 7359 first-year undergraduate students at Huazhong University of Science and Technology in central China were recruited to the study and invited to a centralized clinic for medical examination, including optometry, and re-examined after one year. Correlation analyses were performed to assess the associations between one-year myopia progression and various parameters. The spherical equivalent refraction for the overall population was -3.14±2.28 D at baseline. The rate of myopia progression over 0.50 D after one year was 41.9%, and the 1-year progression of myopia was -0.47±0.58 D. There was no difference of mean 1-year myopia progression between male and female or difference among age group. The myopia progression of original myopia was severer than progression of new-onset myopia. There was also difference of mean myopia progression among different degrees of myopia at baseline. The under corrected eyes had a higher percentage of myopia progression than well corrected eyes (χ 2=7.90, P<0.01). There was no correlation between myopia progression and height, weight, body mass index, hemoglobin (Spearman correlation, ρ=-0.078, -0.152, -0.170, -0.096, respectively, all P>0.05). Myopes still progress in undergraduate students, especially in high myopes.

ASSOCIATION OF INTRAOCULAR PRESSURE CHANGES IN DIFFERENT DEGREES OF MYOPIA

Introduction: Myopia, also known as “short-sightedness” or “near-sightedness,” is an increasingly widespread condition around the world. Myopia is commonly defined as a spherical equivalent (SE) ≤ 0.5 dioptres (D) and develops mainly during childhood and early adulthood when excessive elongation of the eye causes images of distant objects to fall in front of the retina with the eye at rest, resulting in a blurred distance vision. Myopia can be classified according to age of onset, clinical variety, etiology, and degree. According to the degree, myopia can be classified as mild/low myopia (-0.25D to -2.75D);moderate/medium myopia (-3.00D to -6.00D) and high myopia (Above -6.00D).Aim and Objective: To investigate the intraocular pressure changes in the different degrees of myopia. Material and Methods: This study was a clinical study carried out at the department of ophthalmology, rukmani birla hospital,Jaipur. An informed consent was gotten from all the subjects who were part of the study.Clinical tests performed on the subjects include case history, visual acuity, external eye examination, ophthalmoscopy, static retinoscopy and subjective refraction. The subjects with myopia were grouped into three according to the degree of myopia. Their intraocular pressure was measured using the indentation tonometry. Data was collected and uploaded into the Statistical Package for Social Sciences (SPSS) version 21 and the one-way ANOVA was used to test the null hypotheses at 0.05% level of significance and 95% confidence interval. Result: The study included a Sample size of 100 Patients.The table showed that 50 (50.00%) of the subjects had mild myopia;42 (42.00%) had moderate myopia and 8 (8.00%) had high myopia.IOP of 10 - 15 were 20 (20.00%);16 -20,26 (26.00%);21 – 25,4 (4.00%);26 – 30,0 (0.00%).Minimum,maximum and mean IOP values for low myopes were 10.3,30.6 and 17.13 mmHg respectively.For medium myopes,the minimum,maximum and mean IOP values were 11, 22 and 16.63 mmHg respectively. For high myopes, the minimum, maximum and mean IOP values were 18.8, 22 and 20.15 mmHg respectively. SPSS data analysis using the one-way ANOVA at 0.05 level of significance showed that there was a significant difference [P(0.036) &lt; 0.05] in the IOP values between the different degrees of myopia. Conclusion: In conclusion, there was a significant difference in the IOP of different degrees of myopia.Eye care practitioners are advised to closely monitor the IOP of their myopic patients.For young children,as the myopia progresses,the IOP should also be monitored.

Objective Characteristics of Accommodation in Present-Day Schoolchildren with Different Levels of Myopia

Purpose: We study the state of the accommodative function in present-day schoolchildren using the method of computer accomodography. Patients and methods: 74 children (10–16 years old), 54 of them with different degrees of myopia and 20 children (control group) with emmetropia were tested on the computer accomodography devise Righton Speedy-K ver. MF-1. The strength of the accommodative response accorded to the presented accommodative stimulus was determined by calculating the accommodative coefficient response (CAO) and the contraction’s nature of the ciliary body fibers by determining the microfluctuation coefficient (KMF).