Previous studies have yielded contradictory conclusions on the relationship between intermittent exotropia (IXT) and the magnitude of myopia, especially in children. The aim of this study was to determine the clinical characteristics of IXT in children with myopia and myopic anisometropia. We retrospectively evaluated the clinical data of patients (4-15years of age) with convergence insufficiency (CI)-IXT and basic IXT who underwent surgery between 2022 and 2023. All patients underwent cycloplegia before the examinations and surgery. The degree of strabismus was measured when the patient viewed from the center of the glasses. Ocular dominance was routinely tested in children with IXT via the "hole-in-card test" after best-corrected visual acuity was obtained. Children were subsequently grouped into 2 groups (anisometropia and nonanisometropia) according to the difference in binocular spherical equivalent (SE) values (≥ 1.0 diopters [D]). A total of 197 patients were included in the study. The preoperative deviation at near was significantly lower in the basic IXT group than in the CI-IXT group, whereas the distance exodeviation was significantly greater in the basic IXT group than in the CI-IXT group (P < 0.05). Patients with anisometropia were older than those without anisometropia (P < 0.001). The dominant eyes had significantly less myopia than the nondominant eyes did in the CI-IXT and anisometropia groups (P = 0.049 and P = 0.003, respectively). High myopia was more prevalent in middle school students with IXT (16.67%) than in preschool students (4.55%) and primary schoolchildren (3.18%). The percentage of individuals with anisometropia (≥ 3.0 D) varied in the low (1.68%), moderate (8.7%), and high myopia groups (22.22%). Binomial logistic regression analysis revealed that age and SE of the dominant eye were independent factors related to anisometropia in children with IXT (P < 0.001 and P < 0.001, respectively). Patients with IXT, especially those with anisometropia and CI-IXT, were shown to have less myopia in the dominant eye. Age and SE of the dominant eye were found to be independent factors related to anisometropia in children with IXT.

To determine the efficacy of five types of myopia control glasses (MCG) among Indian children. A retrospective cohort study with 1-year follow-up was done in 397 eyes of 216 children aged 4 to 17 years, with myopia between -0.75 and -10.00 diopters (D), astigmatism of 4.00 D or less, and baseline progression of 0.50 D or greater. Data from children prescribed type I (defocus incorporated multiple segments), type II (highly aspherical lenslet target), type III (cylindrical annular refractive elements), type IV (peripheral defocus reducing lenses), and type V (pediatric progressive addition lenses) MCG were analyzed. Mean change in spherical equivalence of refractive error (SER) and axial length (AL) and percentage efficacy in reducing SER and AL progression to physiological levels were compared. Subgroup analysis was done by age, gender, and amount of myopia. Mean change in SER and AL at 6 and 12 months with all MCG combined was -0.05 ± 0.23 D, -0.26 ± 0.43 D, 0.07 ± 0.11 mm, and 0.16 ± 0.18 mm, respectively. No statistically significant difference was noted between types I, II, and III. Axial and refractive efficacy at 6 and 12 months of all MCG combined was 42.34%, 43.99%, 90.41%, and 68.91%, respectively. There was no significant difference among boys and girls. The older group showed significantly better axial efficacy (P < .01) at 6 and 12 months. Refractive efficacy was significantly higher at 12 months (P < .01) among children with low myopia. Types I, II, and III MCG are equally efficacious in controlling myopia progression among Indian children, with better results among older children and those with low myopia.

Long-Term Outcomes of Iris-Fixated Phakic Intraocular Lenses in Low Myopia: A Retrospective Analysis With Over a Decade of Follow-up.

Choroidal Volume Decrease Associated with Stromal Regression in Adult Myopia: A High-Resolution Optical Coherence Tomography Angiography Study [R2-C1

To evaluate retinal hemoglobin oxygen saturation in myopic eyes by scanning laser ophthalmoscope (SLO) and to assess its correlations with different severity of myopia. Sixty-one eyes from 61 patients were included and subdivided into three groups according to their refractive errors: high myopia group [20 eyes, spherical equivalent (SE)≤-6 D]; low and moderate myopia (22 eyes, -6.0<SE≤-0.5 D); normal (19 eyes, -0.5<SE<+0.5 D). All subjects underwent SLO imaging with dual lasers (532 nm and 633 nm). The oxygen saturations of hemoglobin in arteries (SO2A) and veins (SO2V), and their differences (SO2AV) were estimated from the optical densities of the vessels on the images at the two wavelengths. Pearson's or Spearman's rank correlation coefficient were calculated to assess the correlation between retinal hemoglobin oxygen saturation and refractive error/axial length (AL). For the retinal oxygen saturation, the SO2V in high myopia group (73.21%±21.42%) was significantly higher than that in normal group (55.81%±21.69%) and low and moderate myopia group (56.88%±13.83%, P<0.05). The SE was significantly correlated with SO2A (r=-0.30) and SO2V (r=-0.36; P<0.05), and AL was also significantly correlated with SO2A (r=0.27) and SO2V (r=0.30; P<0.05). No significant correlations were found between SO2AV and SE and AL (P>0.05). SO2A and SO2V increased in more myopic eye based on SLO measurements. Further studies are warranted to investigate the changes of retinal hemoglobin oxygen saturation in myopia with different methods.

To analyze the two-year visual and refractive outcomes as well as the safety, and efficacy of photorefractive keratectomy (PRK) surgery for myopia. In this prospective cohort study, 63 eligible patients were recruited, including 45 women (71.4%) and 18 men (28.6%). Demographic characteristics along with pre- and post-operative clinical data including visual acuity, refraction, maximum ablation, spherical and cylindrical error, and residual stromal bed (RSB) were evaluated. The mean age of the patients was 35.42±8.16y (range 22 to 55y). The mean spherical and cylindrical error before surgery were -2.23±1.58 D (range -5 to +0.25) and -1.24±0.94 D, respectively (range -3.75 to 0.00). The mean efficacy and safety of PRK surgery at 2y follow-up were 0.98±0.06 and 1.01±0.04 respectively. The lower age was significantly correlated with a higher amount of efficacy index (P<0.001, r=-0.42). Also, the lower amount of preoperative myopia and spherical equivalent (SE) were correlated with a higher safety index (P<0.001, r=-0.44; P<0.001, r=-0.46). The two-year efficacy and safety of PRK for the treatment of low myopia is excellent. Younger age and lower amount of refractive error are correlated with higher efficacy and safety indices of the surgery.

Currently, the mainstream methods for myopia control include atropine, orthokeratology lenses(OK lens), and repeated low-level red light (RLRL). In-depth exploration of different intervention methods are of great significance. 600 participants aged 8-16 years with a spherical equivalent (SE) of - 0.50 to - 7.50 D (D) completed 8 months treatment. They were divided into four groups: the RLRL, 1% atropine, OK lens and control (single-vision spectacles [SVS]) group. Each group comprised 150 patients . At baseline, the difference was not statistically significant in the AL of the RLRL, 1% atropine, OK, and SVS groups (P > 0.05); After 8 months, significant differences were observed between the OK group and the RLRL, 1% atropine, SVS groups (P < 0.05). However, no statistically significant difference was found between the RLRL and 1% atropine groups. In the RLRL group, the difference in axial length (AL) progression between low myopia(LM) and high myopia(HM) subgroups was statistically significant (P < 0.05). the corneal curvature KI and K2 were statistically nonsignificant before and after the intervention(P > 0.05).At baseline, the SEs were not significantly different (P > 0.05). After 8 months. the OK, RLRL, and 1% atropine groups showed statistically significant differences in SE compared to the SVS group (P < 0 0.05). RLRL, 1% atropine, and OK lenses were effective in controlling AL and SE increase compared with SVS, with RLRL and 1% atropine exhibiting better outcomes than OK lenses. WHAT IS KNOWN: Repeated low-level red light (RLRL), 1% atropine, and OK lenses were effective in controlling AL and SE increase in children and adolescents, and RLRL therapy has emerged as a novel therapy for myopia control with unexpected efficacy in axial shortening. Comprehensively analyzed the effectiveness and safety of three different myopia control strategies. RLRL was effective at controlling myopia progression according to different myopia regions, the decreases in AL in the longer AL group were greater than those in the shorter group. At the same time, our study further demonstrates that the differential efficacy of three myopia intervention regimens in patients with low, moderate, and high myopia.

Individualized Estimation of Baseline Retinal Nerve Fiber Layer Thickness Using Conditional Variational Autoencoder.

BackgroundMyopia is a growing global health issue. This study aims to determine the current status and determinants of primary and secondary school students with myopia in the Shekou District, and to propose reforms in myopia prevention.MethodsFour thousand seven hundred and sixty-three students were involved in this retrospective study, and categorized by spherical equivalent into normal, low myopia, moderate myopia, and high myopia. Multinomial logistic regression and multiple linear regression analyses were conducted to examine factors on the severity of myopia and axial length [AL], respectively.ResultsThe multinomial logistic regression model indicated, compared to the normal group, each additional year of age significantly increased the odds for low myopia (odds ratio [OR] = 1.285, 95% confidence interval [CI]: 1.122–1.472), moderate myopia (OR = 1.271, 95% CI: 1.074–1.502), and high myopia (OR = 1.411, 95% CI: 1.090–1.826). Compared to the Grade 1, the OR for low myopia showed a gradual increase across grades: Grade 3 (OR = 2.065, 95% CI: 1.394–3.058), Grade 4(OR = 2.184, 95% CI: 1.338–3.562), Grade 5(OR = 2.640, 95% CI: 1.438–4.850) and Grade 6 (OR = 2.239, 95% CI: 1.077–4.657); The OR for moderate myopia rose significantly from Grade 2 (OR = 2.239, 95% CI: 1.077–4.657), peaked at Grade 9 (OR = 90.445, 95% CI: 14.325–571.040), and remained elevated at Grade 12 (OR = 72.069, 95% CI: 3.818–1360.260); The OR for high myopia was significantly elevated in Grade 6 (OR = 11.490, 95% CI: 1.082–122.077) and Grade 9 (OR = 26.259, 95% CI: 1.429–482.616). The multiple linear regression model indicated that longer AL was significantly associated with older age (β = 0.109, 95% CI: 0.065–0.141), males(β = 0.533, 95% CI: 0.482–0.583), and higher grade level (the largest effect observed at Grade 9, β = 1.124, 95% CI: 0.792–1.455).ConclusionMost myopic students in Shekou District exhibited low or moderate myopia. Alleviating educational stress and implementing AL monitoring are the essential measures for myopia prevention. A comprehensive myopia prevention necessitates a two-pronged strategy combining educational reforms and medical interventions.

To investigate the choroidal vascular area (VA) and stromal area (SA) in the small vascular layer (SVL), Sattler's layer (SL), and Haller's layer (HL) in myopia. A total of 280 myopic eyes from 150 subjects were enrolled, including low myopia (LM), moderate myopia (MM), and high myopia (HM). Two scans (one horizontal and one vertical) passing through the fovea were obtained from the cube data of spectral-domain optical coherence tomography (SD-OCT), the choroidal area (CA), VA, SA, and choroidal vascularity index (CVI) of the SVL, SL, and HL were acquired using the Niblack's method. The choroidal parameters were compared among groups. Compared to LM, CA decreased significantly in all subregions of MM and HM (P < 0.05), with HM showing a greater decline. SVLCA decreased in fovea and superior regions in MM and HM, but only decreased in the superior region when comparing HM with MM. Relative to LM and MM groups, SLCA demonstrated significant reductions across all subregions in HM (P < 0.05). Similarly, HLCA, HLVA, and HLSA exhibited decreased levels in foveal and nasal regions. Notably, the HM group presented elevated HLCVI in temporal and superior regions, along with higher foveal SLCVI compared to other groups (P < 0.05). After adjusting for age as confounding factor, generalized estimating equation analysis demonstrated a significant association between SLSA and HM (P < 0.05). Notably, the reduction in SLSA within the nasal region exerted the most pronounced influence on the HM (accuracy = 0.64). Different choroidal vascular layers exhibit distinct responses to varying degrees of myopia, and the reduction in SA may precede that in VA. Reduced SVLCA, SLCA and HLCA in MM may signal early myopia progression; fundus changes in MM also warrant focus. Trial registration number and date of registration for prospectively registered trials: 2022-SR-544, December 6, 2022. Key messages What is Known: • Choroid may be involved in refractive adjustment and axial growth and is related to the alterations in Haller's and Sattler's layers. • Different choroidal vascular layers exhibit distinct responses to varying degrees of myopia, and the reduction in stromal area may precede that in vascular area. • Reduced choroidal small vascular layer area, Sattler's layer area and Haller's layer area in moderate myopia may signal early myopia progression; fundus changes warrant focus. • The reduction in stromal area of Sattler's layer was highly associated with high myopia, especially prominent on the nasal region.

BackgroundDespite parents’ pivotal role in myopia mitigation, published studies investigating parental awareness and knowledge are limited in Ghana.AimAssess parental awareness and knowledge of myopia and related factors to mitigate myopia progression.SettingParticipants were parents from the Kumasi Metropolis and Bekwai Municipality in the Ashanti region of Ghana.MethodsA descriptive cross-sectional study was conducted using a semi-structured questionnaire. Participants were selected through a double-staged cluster sampling.ResultsOf 747 participants, 500 (66.93%), reported no prior information about myopia, while 247 (33.07%) indicated awareness. Most of those aware (n = 182, 93.81%) demonstrated adequate knowledge. Predictors of awareness included male gender (odds ratio [OR] = 0.534, p = 0.023), training college (OR = 11.041, p < 0.001) and university education (OR = 21.536, p < 0.001), lower monthly income (Ghanaian cedi [Gh¢] 500.00 – Gh¢999.00; OR = 0.389, p = 0.038) and difficulty seeing afar (OR = 1.90, p = 0.023). Knowledge correlated with male gender (p = 0.036), monthly income (p < 0.001), type of work (p = 0.046) and age group (p = 0.042). Community-based approach was most preferred for myopia awareness creation.ConclusionThere was low myopia awareness but adequate knowledge levels, which significantly correlated with demographic factors. Community-based approach was the preferred myopia awareness creation mode.ContributionThe study provides insight into parental perspectives on myopia and reveals the preferred mode of myopia awareness and education in the Ghanaian context.

Retinal curvature in myopia: correlation with ocular physiological parameters.

Migraine is among the most prevalent neurological disorders afflicting adolescents. One possible contributing factor to the development of migraines is refractive errors such as myopia, hypermetropia, and astigmatism. Purpose – to evaluate Doppler criteria in refractive disorders associated with migraine in adolescents and to investigate the relationship between ocular blood flow changes and visual disturbance. Material and methods The study was included 87 patients (174 eyes), aged 11–17 years, with headaches and diagnosed refractive errors, were included. Participants were divided into three groups: patients with myopia without migraine (n=31), patients with migraine without refractive errors (n=19), patients with combined myopia and migraine (n=37). The control group organized 20 healthy volunteers. Patients with myopia were subdivided based on refractive error severity. Low myopia (from (–)0.25 to (–)3.0 D) included 39 patients (44.8%), moderate myopia (from (–)3.25 to (–)6.0 D) included 30 patients (34.5%), and high myopia (more than (–)6.0 D) included 18 patients (20.7%). The hemodynamic parameters – maximum systolic velocity (Vmax), minimum diastolic velocity (Vmin), and resistance index (RI) – were studied in the ophthalmic artery (OA), central retinal artery (CRA), and posterior short ciliary arteries (PSCA) using color Doppler imaging (CDI). The degree of blood flow asymmetry was also assessed. Results Statistically significant differences were found in all studied parameters of the three arteries. In migraine patients, reduced Vmax, Vmin in the OA and increased RI were observed, suggesting a vascular role in migraine pathogenesis. The most pronounced changes appeared in patients with both myopia and migraine, particularly in RI and Vmin. These alterations may result from the combined effects of visual strain and vascular dysregulation. Conclusion The results of our research support the idea that vasomotor disturbances play an important role in the mechanisms of migraine pain, and dopplerographic criteria can be used to objectively identify vascular dysfunctions in adolescents. Key words: myopia, migraine, color Doppler imaging, adolescents

To compare corneal deflection characteristics during air-puff before and after keratorefractive procedures using a mathematical method. The authors collected Corvis ST (Oculus Optikgeräte GmbH) corneal images from 86 eyes after photorefractive keratectomy (PRK), 93 eyes after laser in situ keratomileusis (LASIK), and 76 eyes after small incision lenticule extraction (SMILE). Using these images, corneal deflection was quantified and modal coefficients obtained over time through a decomposition method. The results were then compared among individual patients to identify differences before and after surgery. SMILE surgery increased corneal deflection by a quantifiable amount with less dependence on the depth of removed tissue, demonstrating up to 1.46 times (maximum) greater modal deflection changes compared with other surgeries. In contrast, in PRK and LASIK, corneal deflection was increased with greater ablation depth. Inter-patient variability was the largest in PRK, particularly in lower-order modes, which affected a large central area. Higher-order modes of the decomposition method in the central area demonstrated that SMILE and PRK exhibited similar patterns before air-puff, whereas SMILE and LASIK exhibited similar deflection patterns during air-puff. A significant difference between LASIK and SMILE was observed in transient deflection during the early air-puff phase and the ending phase. This computational method could comprehensively analyze the overall corneal bending over time. The results suggest the use of LASIK and PRK for patients with low myopia and SMILE for patients with high myopia.

AimsTo develop a multidimensional imaging model to detect primary open-angle glaucoma (POAG) by combining fundus photographs with the retinal nerve fibre layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness maps and deviation maps.Methods1054 eyes of 546 patients were included. Images were randomly divided into training, validation and test datasets at 64%, 16% and 20%. Four basic convolutional neural network algorithms were used to develop the multidimensional imaging model by combining fundus photographs, RNFL and GCIPL deviation maps, with RNFL and GCIPL thickness maps. POAG structure damage was defined as RNFL and GCIPL thinning with neuroretinal rim thinning.ResultsMultidimensional imaging model obtained an area under the receiver operating characteristic curve (AUC) of 0.970 (95% CI 0.958 to 0.979), which was superior to the fundus photographs model (AUC, 0.945 (95% CI 0.929 to 0.958); p＜0.05), RNFL and GCIPL deviation maps model (AUC, 0.931 (95% CI 0.915 to 0.946); p＜0.001), RNFL and GCIPL thickness maps model (AUC, 0.958 (95% CI 0.944 to 0.969)) in the test dataset. There was a significant difference between the multidimensional imaging model (AUC, 0.969 (95% CI 0.934 to 0.988)) and three glaucoma ophthalmologists (attending ophthalmologist 1: AUC, 0.847; attending ophthalmologist 2: AUC, 0.842; resident ophthalmologist: AUC, 0.755; p＜0.001 for both) in one fold of the test dataset. Furthermore, the overall AUCs were lower in the myopic group than in the non-myopic group. The overall AUC for lesion detection by each model (p=0.159) was: low myopia group (AUC, 0.968 (95% CI 0.940 to 0.985)) > moderate myopia group (AUC, 0.966 (95% CI 0.936 to 0.984)) >high myopia group (AUC, 0.958 (95% CI 0.927 to 0.978)). The multidimensional imaging model outperformed unimodal models in diagnosing myopia combined with POAG.ConclusionThe multidimensional imaging model, combining fundus photographs, RNFL and GCIPL deviation maps, with RNFL and GCIPL thickness maps, could perform better than unimodal models. Its potential to improve the diagnostic accuracy of myopia combined with POAG for various myopia levels is promising. This means it could be a valuable tool for assisting with POAG diagnosis in the clinic, offering hope for improved patient care.

This comparative cross-sectional study in an indigenous black population demonstrated that high myopic eyes have a significantly thinner retinal nerve fibre layer when compared to emmetropic and other myopic subgroups. To compare the peripapillary retinal nerve fibre layer (RNFL) thickness in myopes and emmetropes and determine the relationship between age and sex and RNFL thickness in myopes and emmetropes in an African population. This was a hospital-based observational cross-sectional study in which both myopic and emmetropic subjects were recruited. Myopic subjects were classified into low (-0.5D to -3.0 diopters[D]), moderate (>-3.0D to -5.0D), and high myopia (>-5.0D) based on spherical equivalent. Myopic and emmetropic groups were further sub-divided into subgroups based on age as follows: 20-29, 30-39, 40-49, 50-591 to recruit subjects across the age groups. Consecutive subjects presenting to the eye clinic that met the eligibility criteria were recruited into the study until the sample size in each group was completed. All participants underwent full ophthalmic examination, refraction, visual fields analysis, and A-scan biometry. The peripapillary RNFL thickness of the retina was measured using the Optovue iScan Spectral Domain Optical Coherence Tomography (SD-OCT). Measurements from one eye (right) of participants were used for analysis. Quantitative data were descriptively summarized and compared using T-test, ANOVA and ANCOVA. A total of 116 participants were recruited, 28 (24.1%) subjects were emmetropes, while 33 (28.5%) had low myopia, 27 (23.3%) moderate myopia and 28 (24.1%) high myopia.. The mean age of all subjects was 36.0±11.4years. All subgroups of myopia had thinner RNFL [Low=103.8±8.6µm (P=0.582); Moderate=101±6.5µm (P=0.171); High=94.4±7.9µm (P=<0.001)] compared to emmetropes (105.2±10.7µm). There was a decrease in the mean global RNFL thickness with increasing myopia. RNFL thickness was negatively correlated with age (r= -0.303). The rate of reduction per year was higher in emmetropes (0.66µm) compared to myopes(0.25µm). The rate of decline of RNFL per year is associated with thicker mean global RNFL thickness seen in emmetropes as compared to myopes. High myopes in this population have thinner peripapillary RNFL values compared to emmetropes, low and moderate myopes. RNFL thickness was negatively correlated with age in both emmetropes and myopes.

Background. Myopia is the most common refractive disorder of the eye globally. One of the methods for surgical correction of myopia is ReLEx® SMILE (Small Incision Lenticule Extraction). The impact of baseline myopia severity on postoperative outcomes remains debated due to inconsistent literature findings. Purpose: To assess the association between the outcomes of ReLEx® SMILE and baseline myopia severity. Materials and methods. This prospective study included 78 patients (156 eyes) aged 18 to 35 years who underwent refractive correction using the ReLEx® SMILE procedure. Patients were stratified into three groups by myopia severity: Group I – low myopia (n = 31 eyes), Group II – moderate myopia (n = 87 eyes), Group III – high myopia (n = 38 eyes). The follow-up period was six months. Results. Uncorrected visual acuity (UCVA) of 0.9–1.0 was achieved in 100% (Group I), 93% (Group II), and 82% (Group III) of eyes, with statistically significant differences between the groups (p &lt; 0.017). No statistically significant differences in the efficacy index were observed (p = 0.78): efficacy was 100% in Groups I and II, and 97.1% in Group III. The safety index was 100% in Groups I and III and 98% in Group II, with no statistically significant difference (p = 0.458). Refractive regression occurred in one case each in Groups I and III, while no cases of regression were observed in Group II. Conclusion. Refractive correction using the ReLEx® SMILE technique provides predictable and stable correction for all degrees of myopia and myopic astigmatism, with no significant differences in complication rates across severity groups.

Background. In individuals with myopic refractive error—particularly high myopia—ocular anatomy undergoes changes, most notably an increase in axial length (AL) exceeding 24.5 mm. Several studies have reported alterations in the scleral shell among patients with varying degrees of myopia. Increased myopia is associated with reduced corneal hysteresis and decreased acoustic density of the sclera. Differences in intraocular pressure (IOP) between individuals with myopia, emmetropia, and hyperopia have also been described. However, the available literature provides no conclusive evidence on the relationship between intraocular pressure (IOP) and central corneal thickness (CCT) across different degrees of myopia. Purpose: To assess how intraocular pressure and central corneal thickness vary across different degrees of myopia. Materials and methods. We retrospectively analyzed medical records of 500 patients (1000 eyes) aged 18 years and older, all diagnosed with myopic refractive error. Patients were stratified into three groups based on myopia severity. The cohort included 290 females (58%) and 210 males (42%). Pachymetry was performed using the ALLEGRO Oculyzer (WaveLight Oculyzer II), autorefractometry using TONOREF (Nidek II), and IOP was measured with four tonometers: a non-contact tonometer (TONOREF Nidek II), Maklakov tonometer, Schiøtz tonometer, and Goldmann applanation tonometer. Statistical analysis was conducted using R software (version 4.2.2). Results. A statistically significant positive correlation was observed between increasing myopia and IOP measurements obtained using the non-contact tonometer TONOREF (Nidek II) (p = 0.001) and the Goldmann applanation tonometer (p &lt; 0.001). No such association was found for IOP values measured with the Maklakov (p = 0.978) or Schiøtz (p = 0.262) tonometers. The analysis revealed a statistically non-significant (p = 0.065) trend toward increased central corneal thickness with greater myopia. Mean CCT values were 539.8 ± 32.5 µm in low myopia, 544.1 ± 33.9 µm in moderate myopia, and 546.5 ± 37.9 µm in high myopia. Conclusions. No statistically significant association was found between central corneal thickness (CCT) and the degree of myopia (p = 0.065). The effect of myopia severity on intraocular pressure (IOP) measurements varied depending on the tonometry method used. Statistically significant associations between IOP and myopia severity were observed when measured using the TONOREF (Nidek II) noncontact tonometer (p = 0.001) and the Goldmann applanation tonometer (p &lt; 0.001). In contrast, no such association was found with the Maklakov (p = 0.978) or Schiøtz (p = 0.262) tonometers.

The global prevalence of high myopia is rising, posing a significant public health concern. Limited research exists on risk factors for prelaminar schisis (PLS) and its impact on visual field changes in highly myopic eyes. Herein, we investigated clinical features of prelaminar schisis (PLS) in highly myopic eyes. This cross-sectional study included 245 eyes with high myopia and 64 eyes with emmetropia and low myopia. PLS was classified on a 3-point scale (0-2), and clinical characteristics were compared between two groups and three sub-groups. Factors associated with PLS presence and severity were evaluated in highly myopic eyes. Highly myopic eyes had a higher frequency (P = 0.008) and severity (P = 0.001) of PLS than controls. Among them, 33.47% (82/245) had Grade 0, 56.33% (138/245) had Grade 1, and 10.20% (25/245) had Grade 2. The presence of Bergmeister papilla (OR = 2.181, 95% CI: 1.080-4.406, P = 0.030), larger Bruch's membrane opening (BMO) (OR = 1.927, 95% CI: 1.279-2.904, P = 0.002) and longer axial length (OR = 1.723, 95% CI: 1.186-2.499, P = 0.004) correlated with PLS severity. Eyes with Grade 2 PLS were more prone to visual field defect than eyes with Grade 0 (P = 0.005) and Gade 1 (P = 0.013) PLS. Bergmeister papilla presence, larger BMO, and longer axial length were associated with the PLS severity, suggesting ONH prelaminar schisis may indicate traction and myopic deformation of the ONH. PLS with peripapillary retinoschisis suggests a possibility of functional damage.

BackgroundMyopia has shown a sharp upward trend worldwide and has become a global public health concern. However, there were insufficient correction rates all over the world. This study aimed to investigate the prevalence of myopia and spectacle-wearing rate in primary and high school students in Yicheng, as well as analyze the risk factors of myopia onset and development. Additionally, we introduced a novel concept to reflect Relative Visual Acuity Insufficiency (RVAI) in myopia students.MethodsA school-based cross-sectional study was conducted in 2022, involving 37,908 students in Yicheng. The refractive error was measured using an autorefractor without cycloplegia and recorded as a spherical equivalent refraction (SER). Visual acuity was recorded as uncorrected visual acuity (UCVA). Only worse SER and UCVA values between the two eyes were analyzed. Myopia was defined as SER < -0.50 D and UCVA > 0.2 using the logarithm of the minimum angle of resolution. Multivariance logistic regression identified risk factors for myopia. Correction rate (CR) referred to the proportion of myopic students wearing spectacles. Required Visual Acuity (RVA) and Actual Visual Acuity (AVA) were proposed to calculate the ratio of RVA to AVA (RAR) to assess RVAI.ResultsA total of 37,908 primary and high school students were included (16,826 girls, mean age of 11.68 ± 3.04 years). The overall myopia prevalence was 41.6%, with 5.4% classified as high myopia. Older age, girls, and schooling in urban areas were risk factors for myopia. CR increased with grade (13.0% in Grade 1 to 85.8% in Grade 11) but remained low overall (48.2% uncorrected). RAR analysis revealed RVAI of myopia students in Yicheng.ConclusionsThe myopia and high myopia prevalence was high among the students in Yicheng. The proportion of students with uncorrected myopia was high. Further research should be conducted to identify specific socioeconomic factors that contribute to myopia and to lower the incidence of myopia by lowering the exposure to these factors. The RAR metric highlights unmet visual needs even in low and moderate myopia, offering a novel tool for prioritizing interventions.Trial registrationNot applicable.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-025-24064-6.