Myopia Group Research Articles

Changes of Choroidal Thickness in Children after Short-Term Application of 1% Atropine Gel

Introduction: The aim of the study was to assess changes in choroidal thickness (ChT) after administration of 1% atropine for 1 week in myopic, emmetropic, and hyperopic children. Methods: A total of 235 children aged 4–8 years, which included 46 myopia, 34 emmetropia, and 155 hyperopia patients, were recruited and divided into three groups according to the spherical equivalent with the use of 1% atropine twice a day for 1 week. The ChT was measured at baseline and 1 week. Results: In the myopia and emmetropia groups, following administration of 1% atropine gel, the ChT thickened significantly under the fovea (i.e., from 278.29 ± 53.01 μm to 308.24 ± 57.3 μm, p < 0.05; from 336.10 ± 78.60 μm to 353.46 ± 70.22 μm, p < 0.05, respectively), and at all intervals from the fovea, while in the hyperopia group, there was no significant difference in the ChT except the nasal side (p < 0.05). Conclusion: Topical administration of 1% atropine gel for 1 week significantly increased the subfoveal and parafoveal ChT in children with myopia and emmetropia. Atropine did not increase the ChT in hyperopic children, except on the nasal side.

Vascular Changes of the Choroid and Their Correlations With Visual Acuity in Pathological Myopia.

Photoreceptor loss plays a role in visual impairment in pathological myopia. As the nutrition and oxygen demands of photoreceptors are mainly supported by the choroidal vessels, we aimed to investigate changes in the choroidal vasculature and their correlations with visual acuity in pathological myopia. The cohort was composed of 136 eyes from 80 participants, including 42 eyes from 21 participants with emmetropia/low myopia, 48 eyes from 26 participants with simple high myopia, and 46 eyes from 33 participants with pathological myopia. Swept-source optical coherence tomography (OCT) was used to image the eyes with a 12-mm radial line scan protocol. The parameters for 6-mm diameters of macula area centered on the fovea were analyzed. A custom deep learning algorithm based on a modified residual U-Net architecture was used to segment the choroidal boundaries. Then, the distance between the two boundaries was determined and choroidal thickness (CT), luminal area (LA), and stromal area (SA) were demarcated based on Niblack's auto-local threshold algorithm after binarization of the OCT images. Finally, the ratio of LA and total choroidal area was defined as the choroidal vascularity index (CVI). The choroidal parameters in three groups were compared, and correlations of the choroidal parameters with age, gender, axial length, and best-corrected visual acuity (BCVA) were analyzed. The CVI, CT, LA, and SA values were lower in pathological myopia than in emmetropia/low myopia and simple high myopia (P < 0.05). The CT, LA, and SA values were lower in simple high myopia than in emmetropia/low myopia (P < 0.05), whereas there was no difference between the CVIs in the emmetropia/low myopia and high myopia groups (P > 0.05). The CVI was nonlinear with increases in axial length (AL), and there was a critical AL flexion point, approximately 27.26 mm; however, the CT, LA, and SA were negatively correlated with AL. Further analysis showed that only younger subjects (40 years old or less) showed significant AL flexion points. Simple and multiple regression models showed that the CVI was correlated with BCVA (P < 0.05). Choroidal vascular alterations, especially decreased CVI, occurred in patients with pathological myopia. The CVI decreased with axial elongation beyond the flexion point and was correlated with visual impairment, indicating that the CVI might be a reliable imaging biomarker to monitor the progression of pathological myopia.

Evaluating early-stage disk halo changes after small incision lenticule extraction.

To investigate early changes in the disk halo under different light conditions after myopic small incision lenticule extraction (SMILE). This prospective study included 70 eyes of 70 myopic patients aged 18-33 years, with a spherical equivalent (SE) of -5.87 ± 1.86 D, who underwent SMILE. The subjective refraction, higher-order aberrations (HOAs), pupillometry, and halo were measured preoperatively and postoperatively to analyse disk halo variations and correlated factors. At 5 cd/m2 and 1 cd/m2 luminance, the halo radius in the high myopia (HM) group reached a postoperative peak after 1 week (p = 0.000 and 0.019, respectively), and recovered to baseline after 3 months. In the low-to-moderate (LM) myopia group, the halo radius did not differ 1 week postoperatively compared to the preoperative level (p = 0.015), but significantly improved after 3 months (p = 0.000). The halo radius correlated with SE, uncorrected distance visual acuity (UDVA), ocular HOAs, coma, and the pupillary light reflex in the LM group at all time points, but there were no correlations in the HM group. Halo symptoms occurred early after SMILE, but recovered within 3 months. The recovery process was slower in the HM group than in the LM group, and the halo radius correlated with SE, UDVA, ocular HOAs, coma, and the pupillary light reflex.

Effect of myopia and astigmatism deepening on the corneal biomechanical parameter stress-strain index in individuals of Chinese ethnicity.

Purpose: To investigate the differences in corneal biomechanical parameter stress-strain index (SSI) among different degrees of myopic eyes in Chinese individuals and to analyze the relevant factors of the SSI. Methods: This study analyzed the right eyes of 240 participants (240 eyes) aged 18-34years. The participants were divided into low-, moderate-, high-, and ultra-high myopia groups according to their spherical equivalent (SE), with 60 eyes included in each group. Spherical, cylinder, and SE were measured via automatically integrated optometry. Intraocular pressure (IOP) was measured using a non-contact tonometer. AL was measured using an IOLMaster device. Corneal curvature and central corneal thickness (CCT) were measured using a Pentacam. SSI and biomechanical corrected IOP (bIOP) were measured via corneal visualization Scheimpflug technology (Corvis ST). The statistical analyses included one-sample Kolmogorov-Smirnov tests and normal distribution histogram methods, Levene variance homogeneity tests, Pearson's correlation analyses, multiple linear stepwise regression analyses, one-way ANOVA, and LSD t-tests. Results: The mean (±SD) age of the 240 participants was (24.97 ± 4.16) years. The SSI was positively correlated with spherical, cylinder, SE, CCT, IOP, and bIOP and negatively correlated with K1 and AL (r = 0.475, 0.371, 0.497, 0.169, 0.291, 0.144, -0.154, and -0.464, respectively; all p < 0.05), but were not correlated with age, K2, or Km (all p > 0.05). Multiple linear regression analysis performed with SSI as the dependent variable, and spherical, cylinder, K1, CCT, and IOP as independent variables produced the following regression equation: SSI = 0.989 + 0.017 spherical + 0.042 cylinder +0.018 IOP (R 2 = 0.402, F = 31.518, p < 0.001). The SSI values in the low-, moderate-, high-, and ultra-high myopia groups were 0.945 ± 0.135, 0.940 ± 0.128, 0.874 ± 0.110, and 0.771 ± 0.104, respectively. The values decreased sequentially, and the differences between pairs were statistically significant (all p < 0.05), except for that between the low- and moderate-myopia groups (p > 0.05). Conclusion: SSI decreased with increasing myopia and astigmatism in the Chinese participants. The SSI was significantly lower in high and ultra-high myopia, especially ultra-high myopia. These findings indicate that increased corneal elasticity may be related to the pathogenesis of high and ultra-high myopia.

Impact of Dry Eye Disease on Visual Function and Quality after Femtosecond LaserAssisted In-Situ Keratomileusis

Purpose: The purpose of this study was to determine how objective and subjective parameters of dry eye disease correlate with objective vision quality changes following femtosecond laser in-situ keratomileusis (FS-LASIK) surgery in low and high myopes. Methods and Materials: This prospective, observational case series recruited patients undergoing bilateral FS-LASIK. Patients were divided into low/moderate and high myopia groups based on pre-operative assessment. Objective and subjective measurements of dry eye, as well as measurements of vision quality were obtained pre-operatively, 1-week, 1 month, and 3 months post-operatively. Thirty patients were included. The low/moderate and high myopia groups each contained 15 patients. Results: Non-invasive keratography tear break up time (NIKBUT) decreased after FS-LASIK in both groups. Objective scatter index (OSI) improved in the L/M myopia group but worsened in the H myopia group post-operatively. Modulation transfer function (MTF) cutoff improved in both groups post-operatively. A negative correlation was identified between the NIKBUT and both the OSI and MTF results. Changes in ocular surface disease index (OSDI) scores support these objective findings. Conclusion: The results of our study provide evidence that ocular surface changes associated with dry eye contribute to reduced subjective vision quality after FS-LASIK. Refractive surgeons should address dry eye pre-operatively and manage its sequalae post-operatively

TGF-β2 levels in the aqueous humor are elevated in the second eye of high myopia within two weeks after sequential cataract surgery

Transforming growth factor-β (TGF-β) is the critical regulator of physiological and pathological conditions in lens. The TGF-β signaling pathway is closely associated with high myopia patients. Thirty eyes from fifteen patients with high myopia who received sequential cataract surgery were enrolled in this prospective study. Ten cataract patients with non-myopia were chosen as a control group. Aqueous humor (AH) samples were used to detect the levels of TGF-β1, TGF-β2, and TGF-β3 in both groups. Compared with the non-myopic cataracts patient group, the highly myopic cataracts group had a significantly higher TGF-β2 (P = 0.019). Besides, the level of TGF-β2 of the second eye was significantly higher than that in the first eye in high myopia cataract patients group (P = 0.037). And TGF-β1 showed significant differences with age and axial length of high myopia cataract patients. Therefore, TGF-β2 may contribute to the development of high myopia and cataract surgery increased the expression of TGF-β2.

Influence of optical zone on myopic correction in small incision lenticule extraction: a short-term study

Background:To evaluate the influence of preoperative optical zone on myopic correction in small incision lenticule extraction.Methods:In this retrospective clinical study, 581 eyes from 316 patients underwent SMILE were selected, including 117 eyes in the small optical zone group (range from 6.0 to 6.4 mm) and 464 eyes in the large optical zone group (range from 6.5 to 6.8 mm). The measurements included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical, and cylinder were measured preoperatively and 3 months postoperatively. Propensity score match (PSM) analysis was performed with age, gender, eye (right/left), keratometry and preoperative spherical equivalent between two different groups. The influence of optical zones on postoperative refractive outcomes were evaluated using univariate regression analysis.Results:In total, 78 pairs of eyes were selected by PSM (match ratio 1:1). There were no differences in the age, gender, eye (right/left), keratometry or preoperative spherical equivalent between the small and large optical zone groups. However, the difference of postoperative spherical equivalent was significantly between groups. Patients with larger optical zones had a trend towards less undercorrection (P = 0.018). Univariate linear regression model analysis found that each millimeter larger optical zone resulted in 8.13% or 0.39D less undercorrection (P < 0.001). The dependency between the optical zones and postoperative spherical equivalent was significant in the higher preoperative myopia group (r = 0.281, P < 0.001), but not significant in the lower myopia group (r = 0.028, P = 0.702).Conclusion:The diameter of optical zones would affect postoperative refractive outcomes in small incision lenticule extraction. This study indicated that larger optical zones induced less undercorrection, especially in patients with high myopia.

Comparison of visual outcomes of a diffractive trifocal intraocular lens and a refractive bifocal intraocular lens in eyes with axial myopia: a prospective cohort study

BackgroundTo assess and compare the efficacy, safety, accuracy, predictability and visual quality of a diffractive trifocal intraocular lens (IOL) and a refractive rotationally asymmetric bifocal IOL in eyes with axial myopia.MethodsThis prospective cohort study enrolled patients with implantation of the diffractive trifocal IOL or the refractive bifocal IOL. Eyes were divided into four groups according to the IOL implanted and axial length. Manifest refraction, uncorrected and corrected visual acuity at far, intermediate and near distances, prediction error of spherical equivalent (SE), contrast sensitivity and aberrations were evaluated three months after surgery.ResultsIn total, 80 eyes of 80 patients were included: 20 eyes in each group. Three months postoperatively, the corrected distance visual acuity of two trifocal groups were significantly better than the axial myopia bifocal group (P = 0.007 and 0.043). There was no significant difference of postoperative SE (P = 0.478), but the SE predictability of the trifocal IOL was better, whether in axial myopia groups (P = 0.015) or in control groups (P = 0.027). The contrast sensitivity was similar among four groups. The total aberration, higher order aberration and trefoil aberration of bifocal groups were significantly higher (all P < 0.001).ConclusionsThe diffractive trifocal IOL and the refractive bifocal IOL both provided good efficacy, accuracy, predictability and safety for eyes with axial myopia. By contrast, the trifocal IOL had a better performance in corrected distance visual acuity and visual quality.Trial registrationThe study was retrospectively registered and posted on clinicaltrials.gov at 12/02/2020 (NCT04265846).

Evaluation of Blood Flow Parameters of the Macular Area and Optic Disc in Patients with Combination of Glaucoma and Axial Myopia

Purpose. To analyze the indicators of blood flow in the macular region and the peripapillary region in patients with a combination of glaucoma and axial myopia.Patients and methods. The paper analyzes the results of a study of 186 patients (343 eyes): 51 patients (92 eyes) with axial myopia (mean AVR 26.3 ± 1.9 mm) and diagnosed with primary open-angle glaucoma of various stages (Glaucoma + Myopia group), 42 patients (78 eyes) with axial myopia (mean AVR 26.5 ± 1.8 mm) without other ophthalmopathology (Myopia group), 48 patients (86 eyes) with refraction close to emmetropic and primary open-angle glaucoma of various stages (Glaucoma group), 45 patients (87 eyes) without any ophthalmopathology and refraction close to emmetropic (Emmetropia group).Results. With the development of glaucoma, a decrease in the density of capillary perfusion and the density of vessels of the superficial plexus in the macular region was revealed, with a predominant decrease in the parameter in the lower sector, with a progressive decrease with the glaucoma severity. More pronounced deviations from the indicators of the control groups were recorded in the group of combined glaucoma and axial myopia. In the peripapillary region of patients with glaucoma, a decrease in capillary perfusion density and capillary flow index in the upper and especially in the lower sector was recorded, with more pronounced changes in the combination of the disease with axial myopia.Conclusion. The tomographic indicators of blood flow in the macular and peripapillary areas from this study can be used to obtain the most complete picture of the course of the glaucoma process in patients with different types of refraction, as well as for differential diagnosis and staging of glaucoma in high myopic eyes.

Changes in Anterior Chamber After Myopic and Hyperopic FS-LASIK.

This study evaluated the changes and explored influential factors in the anterior chamber after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) on the basis of patients with different degrees of myopia, refractive status, and age. Patients underwent uneventful FS-LASIK for the treatment of ametropia. All patients with myopia were classified into a low age group (18-40years) or high age group (> 40years). Patients in the low age group (18-40years) were subdivided into myopia and hyperopia groups. According to the preoperative spherical equivalent values, the myopia group was further divided into low myopia, moderate myopia, and high myopia groups. We measured the magnitude of anterior chamber depth (ACD), angle (ACA), volume (ACV), lens rise, central corneal thickness (CCT), and mean pupil power (MPP) of all patients using Sirius (version 3.2, CSO, Italy) before and 3months post operation. A total of 140 eyes of 87 patients were evaluated. The magnitudes of ACD, ACA, and ACV decreased significantly postoperatively in both low age (P < 0.001, P < 0.001, P < 0.001, respectively) and high age group (P < 0.001, P < 0.001, P < 0.001, respectively) of patients with myopia, while an increasing tendency of ACD (2.85 ± 0.38mm preoperatively vs 2.89 ± 0.09mm postoperatively) and ACA (39.16° ± 7.30° preoperatively vs 39.37° ± 7.68° postoperatively) was found in hyperopia. There was no correlation between different degrees of myopia and the changes in the anterior chamber. Anterior chamber parameters decreased significantly and approximately in the same degree in low and high age groups postoperatively, while an increasing tendency of ACD and ACA was found in hyperopia, indicating that it is probably a corneal magnification effect that influences changes in the anterior chamber.

Assessing the contrast sensitivity function in myopic parafovea: A quick contrast sensitivity functions study.

PurposeCompare peripheral contrast sensitivity functions (CSF) between myopes and emmetropes to reveal potential myogenic risks during emmetropization.Materials and methodsThis observational, cross-sectional, non-consecutive case study included data from 19 myopes (23.42 ± 4.03 years old) and 12 emmetropes (22.93 ± 2.91 years old) who underwent central and peripheral quick CSF (qCSF) measurements. Summary CSF metrics including the cut-off spatial frequency (cut-off SF), area under log CSF (AULCSF), low-, intermediate-, and high-spatial-frequency AULCSFs (l-, i-, and h-SF AULCSFs), and log CS at 19 SFs in the fovea and 15 peripheral locations (superior, inferior, temporal, and nasal quadrants at 6, 12, 18, and 24° eccentricities, excluding the physiological scotoma at 18°) were analyzed with 3-way and 4-way between-subjects analysis of variance (ANOVA) (α = 0.05).ResultsThree-way ANOVA showed that myopes had significantly increased AULCSF at 6° (mean difference, 0.08; 95% CI, 0.02–0.13; P = 0.007) and 12° (mean difference, 0.09; 95% CI, 0.03–0.14; P = 0.003). Log CS at all 19 SFs were higher in the myopia group compared to the normal group (mean differencesuperior, 0.02; 95% CI, 0.01–0.20; P = 0.02 and mean differenceinferior, 0.11; 95% CI, 0.02–0.21; P = 0.01) at 12°. The h-SF AULCSF at 6° (mean differenceinferior, 1.27; 95% CI, 0.32–2.22; P = 0.009) and i-SF AULCSF at 12° (mean differencesuperior, 5.31; 95% CI, 4.35–6.27; P < 0.001; mean differenceinferior, 1.14; 95% CI, 0.19–2.10; P = 0.02) were higher in myopia vs. normal group.ConclusionWe found myopia increased contrast sensitivity in superior and inferior visual field locations at 6° parafoveal and 12° perifoveal regions of the retina. The observation of increased contrast sensitivities within the macula visual field in myopia might provide important insights for myopia control during emmetropization.

Regression-Based Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and OCT Angiography.

PurposeThe purpose of this study was to correct refractive error-associated bias in optical coherence tomography (OCT) and OCT angiography (OCTA) glaucoma diagnostic parameters.MethodsOCT and OCTA imaging were obtained from participants in the Hong Kong FAMILY cohort. The Avanti/AngioVue OCT/OCTA system was used to measure the peripapillary nerve fiber layer thickness (NFLT), peripapillary nerve fiber layer plexus capillary density (NFLP-CD), macular ganglion cell complex thickness (GCCT), and macular superficial vascular complex vascular density (SVC-VD). Healthy eyes, including ones with axial ametropia, were enrolled for analysis.ResultsA total of 1346 eyes from 792 participants were divided into 4 subgroups: high myopia (<−6D), low myopia (−6D to −1D), emmetropia (−1D to 1D), and hyperopia (>1D). After accounting for age, sex, and signal strength, multivariable regression showed strong dependence in most models for NFLT, GCCT, and NFLP-CD on axial eye length (AL), spherical equivalent (SE) refraction, and apparent optic disc diameter (DD). Optical analysis indicated that AL-related transverse optical magnification variations predominated over anatomic variations and were responsible for these trends. Compared to the emmetropic group, the false positive rates were significantly (Chi-square test P < 0.003) elevated in both myopia groups for NFLT, NFLP-CD, and GCCT. Regression-based adjustment of these diagnostic parameters with AL or SE significantly (McNemar test P < 0.03) reduced the elevated false positive rates.ConclusionsMyopic eyes are biased to have lower NFLT, GCCT, and NFLP-CD measurements. AL- and SE-based adjustments were effective in mitigating this bias.Translational RelevanceAdoption of these adjustments into commercial OCT systems may reduce false positive rates related to refractive error.

Long-term changes in corneal densitometry and associated factors following small incision lenticule extraction for moderate and high myopia.

PurposeTo investigate long-term trends in corneal densitometry and associated influencing factors following small incision lenticule extraction (SMILE).MethodsA comparative study was performed among 72 eyes of 38 patients undergoing SMILE. Eyes were divided into moderate myopia [mean spherical equivalent (SE),−4.22 ± 0.68D] and high myopia (mean SE,−7.63 ± 1.09 D) groups. Visual acuity, manifest refraction, corneal topography and corneal densitometry (CD) were evaluated preoperatively and 3 years postoperatively.ResultsThe efficacy indices at last postoperative follow-up (42.47 ± 0.51 months) were 0.92 ± 0.21 and 0.97 ± 0.22, the safety indices were 1.12 ± 0.17 and 1.14 ± 0.21 for high and moderate myopia, respectively (all P > 0.05). CD values in the 0–6 mm zone of the posterior corneal layer was statistically significantly lower than the preoperative values in both groups. Postoperative CD values (0–2 mm zone) in the posterior layer of the high myopia group were statistically significantly lower than in the moderate myopia group (P = 0.025); CD values (2–6 mm zone) in the anterior layer were higher in the high myopia group (P = 0.026). Correlation analyses showed that CD values in the 0–2 mm middle layer were negatively correlated with lenticule thickness in high myopia (r = −0.411, P = 0.016); there was a negative correlation between the CD values (0–6 mm) and corneal oblique trefoil in this group (P < 0.05).ConclusionCorneal transparency in the 0–6 mm zone of the posterior cornea increased following SMILE in moderate and high myopia. Long-term CD values in high myopia may be correlated with oblique trefoil and lenticule thickness.

Analysis of Characteristic Eye Movement Behaviors of Young Adults with Different Degrees of Myopia

To measure the parameters of eye movement of young adult patients of myopia, to compare the differences in the parameters of patient groups with varied degrees of myopia, and to analyze the correlation between eye movement parameters and axial length (AL) and spherical equivalent refraction (SER). A total of 91 young adult patients of myopia were recruited. The subjects were divided into three groups of low, moderate, and high myopia according to their SER. Information on the subjects' age and sex was collected and general clinical examination was completed. The subjects' binocular fixation, reflexive saccade, and antisaccade were measured with eye tracker. One-way ANOVA or Kruskal-wallis test was used to compare the general data and eye movement parameters of the three groups of myopic patients. Pearson or Spearman correlation analysis was used to analyze AL and SER's correlation with 95% bivariate contour ellipse area (BCEA) and saccadic parameters. The 95% BCEA for mild, moderate, and high myopia groups were 2.08 (0.54, 14.69) deg 2, 4.99 (0.94, 49.22) deg 2, and 5.79 (2.18, 64.91) deg 2, respectively. There was significant difference between the 95% BCEA of the three groups ( P=0.029). The 95% BCEA of the mild myopia group was significantly smaller than that of the high myopia group ( P=0.01). There were no significant differences in saccadic parameters among the three groups ( P>0.05). There was a significant positive correlation between 95% BCEA and AL ( r=0.342, P=0.001). There was a significant negative correlation between 95% BCEA and SER ( r=-0.322, P=0.002). There was no significant correlation between the parameters of saccadic movement and the AL or SER ( P>0.05). For young adult myopic patients, the longer the AL is, the higher the degree of the myopia and the worse the fixation stability becomes. The fixation stability of patients with high myopia was significantly worse than that of patients with mild myopia. There was no significant difference in saccadic parameters in patients with different degrees of myopia.

Expression of Osteopontin and Integrin αvβ3 Receptor in Retina of Diabetic Guinea Pigs with High Myopia

Introduction: The study aimed to investigate the effect of high myopia on the expression of retinal osteopontin (OPN) and integrin αvβ3 receptor in guinea pigs and determine the relationship between high myopia and diabetic retinopathy (DR). Methods: Ninety-three-week-old male guinea pigs were randomly divided into four groups that included normal control group (NOR, n = 18), high myopia group (HM, n = 24), diabetes group (DR, n = 24), and diabetes with high myopia group (DR+HM, n = 24). HM was induced by form deprivation (FDHM) in the right eye. The DR group was injected with 5% streptozotocin 280 mg/kg intraperitoneally in the lower left abdomen of guinea pigs. The DRHM group was subjected to the same treatment as the HM and DR groups. Eighteen guinea pigs in each group were randomly selected to complete the experimental measurement. After enucleation of eyeballs, HE and immunohistochemical staining were performed to observe the retina morphology and count the positive rate of OPN and integrin αvβ3 receptor. Results: Diabetic retinal changes were found in group DR and HM+DR. The degree of retinal change in group HM+DR was less than that in group DR. In the DR group, the morphology of retinal tissue was loose, the number of cells decreased, retinal microaneurysms were increased, and a small amount of small artery embolism and venous thrombosis were observed. Although the retinal structure in the HM+DR group also became thinner, looser, and disordered, only a small number of microaneurysms were observed compared with the diabetic group. Immunohistochemical staining showed that the expression of OPN and integrin αvβ3 receptors in the diabetic groups (DR, HM+DR) was significantly higher than in the HM and NOR groups. The positive expression rates of OPN and integrin αvβ3 receptors in group HM+DR were significantly lower than those in group DR (p < 0.05). Conclusion: The expression of OPN and integrin αvβ3 receptor in the retina of diabetic guinea pigs with high myopia was lower than that of diabetic models, which may be due to the influence of high myopia on neovascularization in DR.

Myopia in Chinese Adolescents: Its Influencing Factors and Correlation with Physical Activities.

Purpose The study is conducted to analyze the risk factors and the protective factors of myopia in Chinese adolescents and its correlation with physical activities and then to provide 2 formulas to predict the probability of becoming myopic and the probability of preventing myopia. Methods This is a cross-sectional study in which a questionnaire survey was conducted among 650 students aged 14-17 from 5 schools in Beijing in 2021. The students were divided into two groups: nonmyopia group and myopia group. Statistically significant variables were selected after the univariate analysis for a binary logistic regression analysis. Results In the univariate analysis, 18 risk factors of myopia were found and 14 physical-activity-related protective factors were found. In the multivariate analysis, 5 independent factors were found to be positively related to myopia and could be used for calculating the probability of becoming myopic. The 5 factors are gender, staying up late playing smartphones, parental myopia, daily time spent on digital devices, and regular eye examinations. Five physical-activity-related factors were found to be positively related to the prevention of myopia and can be used for the calculation of the probability of preventing myopia. The 5 factors are regular physical activities, attitude towards physical education, daily time spent on in-school physical activities, daily time spent on after-school physical activities, and eye exercises. Conclusions The influencing factors of myopia in adolescents mainly include heredity, habits of using eyes, and environment. Physical activities can effectively reduce the probability of becoming myopic in adolescents and promote eye health. Therefore, taking part in physical activities is an effective way to reduce the prevalence of myopia in adolescents.

Clinical Observation of Macular Vessel Density in Type 2 Diabetics with High Myopia

Introduction: The aim of this study was to compare the macular retinal vessel density (VD) of diabetics with high myopia, diabetics without high myopia, and healthy controls. Methods: This cross-sectional study recruited type 2 diabetic (T2D) people with no history of ocular treatment in our hospital. Thirty T2D people with high myopia (30 eyes) were included in group A, while 30 T2D people (30 eyes) without myopia were included in group B. Another 30 healthy volunteers (30 eyes) were included in group C. The superficial and deep capillary plexuses VD of the macula were measured in all subjects by optical coherence tomography angiography. In T2D people with high myopia, the correlation between VD in macular regions and baseline data was investigated. Results: (1) Overall comparison of the 3 groups: no statistically significant differences in macular central superficial vessel density (SVD) were found in the three groups (p > 0.05). There were significant differences in the temporal, superior, nasal, inferior SVD between the 3 groups (p < 0.05). There were significant differences in macular central, temporal, superior, nasal, and inferior deep vessel density (DVD) between the three groups (p < 0.05). (2) Comparison of B (no myopia, T2D group) and C (healthy control group): inferior SVD in group B was lower than that in group C (p < 0.05). Temporal, superior, nasal, and inferior DVD in group B were lower than those in group C (p < 0.05). (3) A (high myopia group, T2D) compared with B (no myopia, T2D group), A group compared with C (healthy control group): temporal, superior, nasal, inferior SVD and DVD in group A were all lower than those in group B and C (p < 0.05), DVD in group B was lower than those in group C (p < 0.05). (4) The mean SVD and DVD were not correlated with age, IOP, anterior chamber depth, corneal curvature, but they were negatively correlated with axial length and duration of diabetes in the T2D people with high myopia. Conclusion: Myopia and diabetes are two important factors affecting macular retinal VD. Comparing with the eyes of T2D people without high myopia, the VD in macular regions shows a higher decline in the eyes of T2D people with high myopia.

A Study on the Association Between Myopia and Elevated Intraocular Pressure Conducted at a Tertiary Care Teaching Hospital in Gujarat, India.

IntroductionGlaucoma is characterized by the loss of retinal nerve fiber tissues and the loss of the neuroretinal rim of the optic nerve head is termed glaucomatous optic neuropathy (GON). The early diagnosis of glaucoma requires measurement of intraocular pressure (IOP) by tonometry. The gold standard method widely used in clinical settings to measure IOP is Goldmann applanation tonometry (GAT). Myopia is also considered a risk factor for glaucoma. Population-based and hospital-based evidence suggests that the prevalence of GON is higher in high myopic eyes than in emmetropic eyes. The present study aims to document the association between myopia and elevated IOP.Materials and methodsA total of 400 medium and high myopic patients attending the ophthalmology outpatient department, in a tertiary care hospital, were measured for IOP using GAT and underwent a detailed clinical evaluation. All the patients also underwent slit lamp biomicroscopic examination and fundus examination. Other data included details on demographic, socio-economic, and occupational history.ResultsA detailed refractive error examination revealed that amongst 400 right eyes, 67.5% had medium myopia, while 66.75% of the left eye were medium myopic. Amongst the medium myopic eyes, the average IOP was 15.51±3.68 mm of Hg, while in high myopic, the average IOP was 16.19±3.33 mm of Hg. A difference of 0.68 mm of Hg with high myopic eyes having higher IOP values than medium myopic eyes was observed, and it was significant statistically with a p-value <0.05.ConclusionThere is a statistically significant association between elevated IOP and the high myopic group. In comparison to IOP measured in medium myopic and high myopic patients, elevated IOP was observed in the high myopic group than in the medium myopic group.

Analysis of White and Dark without Pressure in a Young Myopic Group Based on Ultra-Wide Swept-Source Optical Coherence Tomography Angiography.

Purpose: This study aimed to investigate the incidence of white without pressure (WWOP) and dark without pressure (DWOP) in a young myopic group based on multimode imaging and to explore the quantitative changes in DWOP based on ultra-wide swept-source optical coherence tomography angiography (SS-OCTA). Methods: A total of 138 patients with high myopia (SE < −6.00 D) were recruited. Examinations, including indirect ophthalmoscope, ultra-wide color fundus photograph, and ultra-wide SS-OCTA, were conducted for each eye. A total of 50 of the 138 patients were selected for further analysis since their DWOP lesions in SS-OCTA could be well quantified. Results: The incidence rates of WWOP and DWOP in the young myopic group were 35.24% and 29.96%, respectively. The patients with a lower spherical equivalent (SE) showed a tendency to have a higher axial length (AL) and higher prevalence of WWOP. Multivariate regression analysis illustrated that a more serious SE and a longer AL were risk factors for both WWOP and DWOP. Eyes with DWOP lesions had lower vessel density (VD) in the whole retina (p < 0.001) and a deep vascular complex (DVC) (p < 0.001), and lower thickness of the outer retina (p < 0.001) compared with healthy counterparts. Conclusion: Ultra-wide SS-OCTA provided new insights into myopic-related peripheral retinal degenerations. DWOP was characterized by thinning of the outer retina and lower perfusion in DVC.

The Anterior Segment Biometrics in High Myopia Eyes

Introduction: The aim of this study was to investigate and compare the anterior segment biometrics in high myopia and control groups. Methods: Thirty-four eyes of 34 high myopia patients and 42 eyes of 42 control subjects were included. Schlemm’s canal (SC) area, trabecular meshwork (TM) thickness and length, scleral spur (SS) length, and anterior scleral thickness (AST) were measured using swept-source optical coherence tomography. Associations between SC area, TM thickness, TM length, SS length, and AST were also estimated. Results: SC area, TM thickness, and SS length were significantly associated with AST0 (AST at 0 mm from SS) in both high myopia and control groups. AST0 (702.61 ± 78.05 vs. 729.12 ± 95.87 μm, p = 0.085) and SS length (206.25 ± 52.25 vs. 212.09 ± 51.86 μm, p = 0.556) were not significantly different between high myopia and control groups, whereas SC area (6,622.68 ± 1,130.06 vs. 6,105.85 ± 1,297.84 μm2, p = 0.015) was significantly greater and TM thickness (96.15 ± 34.40 vs. 107.93 ± 29.97 μm, p = 0.048) was significantly thinner in high myopia group than in control group. Conclusion: SC area and TM thickness were significantly associated with AST0, while AST0 and SS length were not significantly different between high myopia and control groups. The changes in SC and TM dimensions in high myopia eyes might be caused by factors other than AST0 and SS length.