Epidemiologie der Myopie

Prospective clinical study of retinal microvascular alteration after ICL implantation

Purpose: To evaluate the retinal microvascular alteration after implantable collamer lens (ICL) implantation in moderate to high myopia patients using quantitative optical coherence tomography angiography (OCTA). Methods: This prospective cohort study included 50 eyes of 25 patients with preoperative spherical equivalent ≥ -3.00 D. Patients underwent bilateral ICL implantation at the Department of Ophthalmology, Peking University Third Hospital, from November 2018 to July 2019. OCTA was used to image the superficial and deep retinal capillary plexuses before ICL implantation surgery and at 3 months follow-up. Results: There was no significant difference in the microvascular density within each annular zone and all quadrantal zones of the superficial and deep layers found in myopia patients before and after ICL surgery. Conclusion: Levels of microvascular density in retinal capillary plexuses were stable, as detected by the OCTA, showing the high security of ICL implantation, which would not leave adverse effects on retinal microvasculature in myopia patients.

[Direct assessment of changes in biomechanical properties of the cornea after ReLEx SMILE and FemtoLASIK surgeries]

The aim of this study was to evaluate corneal biomechanical properties in myopic patients after ReLEx SMILE and FemtoLASIK surgeries using the Corvis ST analyzer.

MATERIAL AND METHODS

The SMILE group comprised 23 patients (46 eyes) with spherical refraction -3.8±1.8 diopters (D), the FemtoLASIK group included 18 patients (36 eyes) with spherical refraction -3.5±1.3 D. Analysis of the biomechanical properties of the cornea was carried out using the CORVIS ST device (Oculus, Germany) before and seven days after corneal refractive surgery.

RESULTS

In the SMILE group, with intraoperative decrease in corneal thickness of 91.43±19.43 µm, a significant increase in the following parameters was observed: deformation coefficient (DA ratio; p=0.0001), peak distance (PD; p=0.02) and inverse concave radius (ICR; p=0.003); a decrease in the stiffness parameter at first applanation (SP-A1; p=0.0001), Corvis biomechanical index (CBI; p=0.0001), intraocular pressure (IOP; p=0.001). In the FemtoLASIK group, with intraoperative decrease in corneal thickness of 75.33±32.3 µm, we observed a significant increase in DA ratio (p=0.0002), PD (p=0.04), ICR (p=0.0002), a decrease in SP-A1 (p<0.0001), IOP values (p=0.0003). In comparison with the FemtoLASIK group, the deformation amplitude DA changed significantly less in the SMILE group (p=0.04). In the FemtoLASIK group, in comparison with the SMILE group, the DA ratio (p=0.0009) and SP-A1 (p=0.0003) significantly increased. Intraoperative corneal thickness change correlates with ICR both in SMILE (R=0.52) and in FemtoLASIK (R=0.65).

CONCLUSION

Corneal biomechanical properties determined with CORVIS ST in eyes with mild to moderate myopia change to a lesser extent after ReLEx SMILE compared to FemtoLASIK.

Research trends and hotspots in the relationship between outdoor activities and myopia: A bibliometric analysis based on the web of science database from 2006 to 2021

Objectives

This study aimed to explore the current status, hotspots, and emerging research trends regarding the relationship between outdoor activities and myopia.

Methods

Publications on the relationship between outdoor activities and myopia from 2006 to 2021 were collected from the Web of Science Core Collection database. CiteSpace (version 6.1.R2) was used to performed a bibliometric analysis, and R software (version 4.1.0) was used to visualize the trends and hot map of publications.

Results

A total of 640 publications were collected and analyzed in the present study. China was the major contributor (n = 204), followed by the United States of America (n = 181) and Australia (n = 137). The United States of America had the most extensive foreign cooperation (centrality = 0.25), followed by Australia (centrality = 0.20). The National University of Singapore contributed the largest number of publications (n = 48), followed by Sun Yat-Sen University (n = 41) and the Australian National University (n = 41). Among institutions, Cardiff University in the United Kingdom had the most extensive foreign cooperation (centrality = 0.12), followed by the National University of Singapore (centrality = 0.11). Saw S from Singapore had the largest number of publications (n = 39), followed by Morgan I from Australia (n = 27) and Jonas J from Germany (n = 23). Investigative ophthalmology & visual science is the most important journal to study the relationship between outdoor activities and myopia. "Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050" published by Holden BA was the most cited paper in this field with 177 citations. Co-occurrence and burst analyses of keywords showed that research trends and hotspots in this field focused mainly on "risk," "prevention" and "school".

Conclusions

The influence of outdoor activities on myopia remains a concern. In the future, deeper cooperation between countries or institutions is required to explore the effects of outdoor activities on myopia. Outdoor activities for the prevention of myopia and reduction of the risk of myopia among school students may be the focus of future research.

A comparative study of the prevalence of myopia and behavioral changes in primary school students

Objective

To analyze the changes in the prevalence of myopia and its relation to ocular biological parameters, and behaviors among primary school students in China, and understand the prevention and control of myopia.

Methods

Cross-sectional surveys were performed on 7–9-year-old children in the yrs. 2012 and 2019. In addition, spherical equivalent refraction (SER), axial length (AL), and AL/corneal radius ratio (AL/CR ratio) were collected without cycloplegia. Participants completed detailed questionnaires on behavior related to myopia.

Results

Data was collected on 623 children (8.02 ± 0.57 years old) in 2012 and 536 students in 2019 (8.09 ± 0.65 years old). The prevalence of myopia was 37.7% in 2012 and 39.9% in 2019. The SER was -0.25 (0.92) D in 2012 and -0.25 (1.25) in 2019. There was no statistical difference in the prevalence of myopia and SER over the 7 years (all P > 0.05). In 2019, the prevalence of myopia among girls demonstrated an increasing trend (33.8% vs. 37.8%), but there was no statistical difference (P > 0.05). The mean AL and AL/CR ratio of boys were decreasing (all P < 0.05). The proportion of children reading more than 2 h and using digital devices for more than 2 h per day after their classes in the 2019 group both decreased (all P < 0.05). However, the proportion of activities performed outdoors for more than 2 h./day decreased significantly (P = 0.001).

Conclusion

Compared with 2012, the prevalence of myopia in primary school students in 2019 was under control, which may be related to the improvement of children's near-work behavior, but there was the problem of insufficient outdoor activity time. In terms of ocular biological parameters, the risk of myopia for boys in 2019 was lower.

Temporal and spatial characterization of myopia in China

Purpose

The aim of this study was to characterize the temporal and spatial distribution of myopia among students aged 7-18 years, by analyzing the aggregation area and providing the basis for the prevention and control of myopia in China.

Methods

A database for the spatial analysis of myopia in China during 1995-2014 was established using ArcGIS10.0 software as a platform for data management and presentation. A spatial autocorrelation analysis of myopia was undertaken, and a temporal and spatial scan analysis was performed using SaTScan9.5 software.

Results

Our data demonstrated that the prevalence of myopia in China in 1995, 2000, 2005, 2010, and 2014 was 35.9, 41.5, 48.7, 57.3, and 57.1%, respectively, thus indicating a gradual upward trend. The prevalence of myopia was analyzed in various provinces (municipalities and autonomous regions), and the highest was found in Jiangsu Province, with an average Moran's I index of 0.244295 in China (P ≤ 0.05). According to the local Moran's I autocorrelation analysis, there was a spatial aggregation of myopia prevalence among students in the entire country, with Shandong, Jiangsu, Anhui, and Shanghai being classified as high-high aggregation areas, while Hainan and Guangxi were classified as low-low aggregation areas. In addition, the Getis-Ord General G results of the global hotspot analysis showed a countrywide myopia prevalence index of 0.035020 and a Z score of 1.7959 (P = 0.07251). Because the myopia prevalence correlation difference was not statistically significant, there were no "positive hotspots" or "negative hotspots." The local hotspot analysis shows that Shandong and Jiangsu belong to high-value aggregation areas, while Hainan and Guizhou belong to low-value aggregation areas. Further analysis using time-space scanning showed 15 aggregation regions in five stages, with four aggregation regions having statistically significant differences (P ≤ 0.05). However, the aggregation range has changed over time. Overall, from 1995 to 2014, the aggregation areas for the myopia prevalence in Chinese students have shifted from the northwest, north, and northeast regions to the southeast regions.

Conclusion

Our data demonstrate that, from 1995 to 2014, the prevalence of myopia increased in students aged 7-18 years in China. In addition, the prevalence of myopia is randomly distributed in various provinces (municipalities and autonomous regions) and exhibits spatial aggregation. Also, the gathering area is gradually shifting to the southeast, with the existence of high-risk areas. It is, therefore, necessary to focus on this area and undertake targeted prevention and control measures.

Erworbene Katarakte

Weitaus seltener und daher weniger bekannt als die altersbedingte Katarakt ist die sekundär erworbene Katarakt, die eine diagnostische und chirurgische Herausforderung darstellen kann. Dieser Beitrag gibt einen Überblick über die häufigsten Subtypen vor allem bei Erwachsenen und beleuchtet die chirurgischen Besonderheiten einschließlich perioperativer Charakteristika.

Erworbene Katarakte

Weitaus seltener und daher weniger bekannt als die altersbedingte Katarakt ist die sekundär erworbene Katarakt, die eine diagnostische und chirurgische Herausforderung darstellen kann. Dieser Beitrag gibt einen Überblick über die häufigsten Subtypen vor allem bei Erwachsenen und beleuchtet die chirurgischen Besonderheiten einschließlich perioperativer Charakteristika.

Efficacy and safety of acupuncture for patients with pseudomyopia: A protocol for systematic review and meta-analysis

BACKGROUND

Myopia are common health problems that people experience in daily life. Pediatric myopia has become a major international public health concern that has a negative impact on physical, mental health of patients, and quality of life. Currently, there is no cure available. Press needle as an adjuvant therapy is currently undergoing clinical trials in different medical centers. However, no relevant systematic review or meta-analysis has been designed to evaluate the effects of press needle patching on early myopia. There is also a lack of systematic evaluation and analysis of acupoints and thumbtack needle.

METHODS

We will electronically search Medline, Embase, PubMed, Web of Science, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, Chinese Scientific Journal Database, and Wan-Fang Database from their inception to October 2021. In addition, we will manually retrieve other resources including the reference lists of identified publications, conference articles, and gray literature. The clinical randomized controlled trials or quasi-randomized controlled trials related to press needle for the treatment of early myopia will be included in the study. The language is limited to Chinese and English. Research selection, data extraction, and research quality assessment will be independently completed by 2 researchers. Data were synthesized by using afixed effect model or random effect model depend on the heterogeneity test. The total effective rate was the primary outcomes. RevMan V.5.3 statistical software will be used for meta-analysis. If it is not appropriate for a meta-analysis, then a descriptive analysis will be conducted. Data synthesis will use the risk ratio and the standardized or weighted average difference of continuous data to represent the results.

RESULTS

This study will analyze the clinical effective rate, pesudomyopia outcomes, quality of life, improvement of clinical symptoms of pesudomyopia, and validity of thumbtack needle for patients with pesudomyopia.

CONCLUSION

This systematic review will provide evidence to judge whether thumbtack needle is an effective intervention for patients with early myopia.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021243151.

Non-coding RNAs and related molecules associated with form-deprivation myopia in mice

The role of miRNAs and its regulatory mechanism in myopia are indeterminate. Our study aimed to investigate potential myopia‐associated non‐coding RNAs and related molecules by performing a comprehensive bioinformatic analysis of miRNA expression profile of mice with form‐deprivation myopia (FDM). Differentially expressed miRNAs in two raw microarray data sets (GSE58124 and GSE84220) from Gene Expression Omnibus (GEO) database were comprehensively analysed using GEO2R. Target genes were predicted using miRDB and enriched with Metascape online tool. Protein‐protein interaction (PPI) networks were constructed utilizing STRING and Cytoscape. Significant differentially expressed miRNAs were validated by real‐time polymerase chain reaction (qRT‐PCR) using RNA extracted from monocular FDM ocular tissues. As result, we identified three upregulated miRNAs (mmu‐miR‐1936, mmu‐miR‐338‐5p, and mmu‐miR‐673‐3p) significantly associated with myopia in the two microarray data sets (p < 0.05 and |Log (Fold Change) |>1). GO functional analysis suggested these three miRNAs were targeted in genes mostly enriched in morphogenesis and developmental growth of retinal tissues. Enrichment analysis revealed top eight transcription factors, including PAX6 and Smad3, related to myopia. Ten hub genes, including Rbx1, Fbxl3, Fbxo27, Fbxl7, Fbxo4, Cul3, Cul2, Klhl5, Fbxl16 and Klhl42, associated with ubiquitin conjugation were identified. qRT‐PCR confirmed the increased expression of mmu‐miR‐1936 and mmu‐miR‐338‐5p (p < 0.05), but no statistical difference was observed in mmu‐miR‐673‐3p expression in myopic retinas. Our findings indicated mmu‐miR‐1936, mmu‐miR‐338‐5p and mmu‐miR‐673‐3p upregulation may be associated with myopia development via post‐transcriptional gene regulation, and identified potential molecules that could be further explored in future studies of the mechanism in myopia.

Prevalence of Refractive Error and Visual Acuity Among School Children in the Plateau Region of Qinghai, China

Purpose

This study aimed to investigate the prevalence of refractive error and visual acuity among school children in the plateau region of Qinghai, China.

Methods

The school-based, cross-sectional study was performed in Menyuan, Qinghai, China. Three kindergartens and three primary schools were randomly enrolled from both rural areas and county towns. The participants had undergone ophthalmic examinations of the intraocular pressure (IOP), uncorrected visual acuity (UCVA), presenting visual acuity (PVA) and best corrected visual acuity (BCVA), cycloplegic refraction, and axial length (AL). Regression analysis was applied to investigate the potential risk factors affecting the prevalence of various refractive errors.

Results

A total of 3770 children were invited to participate, and 3524 (93.5%) had undergone examination. Among the 3524 children (51.8% boys) with a mean age of 8.3±2.3 years, 1049 (29.8%) had myopia, 30 (0.9%) had high myopia, 1692 (48.0%) had mild hyperopia, 152 (4.3%) had medium to marked hyperopia and 925 (26.2%) had astigmatism. The mean SER was −0.16±1.86 D and decreased with age. The AL increased with age from 21.80±0.59 mm at 4-years to 23.53±1.05 mm at 12-years. The myopia prevalence increased with age from 2.0% at 4 years to 62.8% at 12-years. Myopia was associated with increasing age, county town habitation and girls. Among the 723 participants with PVA 20/40 or worse in one eye, 564 (78.0%) were due to uncorrected refractive error, and 83 (22.0%) were due to undercorrected refractive error. Among the 1049 children with myopia, only 254 wore glasses, and 151 children with PVA had a worse BCVA and did not have accurate spectacles.

Conclusion

The prevalence of myopia is very high among school children in Menyuan. Only 24.2% of myopic children wore glasses, and 59.4% of children did not have accurate spectacles. Strategies to improve access to eye care and affordable glasses are needed.

Corneal curvature-associated MTOR variant differentiates mild myopia from high myopia in Han Chinese population

BACKGROUND

Myopia is the most prevalent ocular disorder in the world, and corneal parameters have been regarded as key ocular biometric parameters determining the refractive status. Here, we aimed to determine the association of genome-wide association study-identified corneal curvature (CC)-related gene variants with different severity of myopia and ocular biometric parameters in Chinese population.

METHODS

Total 2,101 unrelated Han Chinese subjects were recruited, including 1,649 myopia and 452 control subjects. Five previously reported CC-associated gene variants (PDGFRA, MTOR, WNT7B, CMPK1 and RBP3) were genotyped by TaqMan assay, and their association with different myopia severity and ocular biometric parameters were evaluated.

RESULTS

Joint additive effect analysis showed that MTOR rs74225573 paired with PDGFRA rs2114039 (P = .009, odds ratio (OR) = 4.91) or CMPK1 rs17103186 (P = .002, OR = 13.03) were significantly associated with higher risk in mild myopia. Critically, mild myopia subjects had significantly higher frequency in MTOR rs74225573 C allele than high myopia subjects (P = .003), especially in male subjects (P = .001, OR = 0.49). High myopia subjects carrying MTOR rs74225573 C allele have significant flatter CC (P = .035) and longer corneal radius (P = .044) than those carrying TT genotype.

CONCLUSION

This study revealed that male high myopia subjects are more prone to carry CC-related MTOR rs74225573 T allele, whereas mild myopia subjects are prone to carry the C allele. MTOR rs7422573 variant could be a genetic marker to differentiate mild from high myopia in risk assessment.

ABBREVIATIONS

ACD: anterior chamber depth; AL: axial length; AL/CR: axial length/corneal radius ratio; ANOVA: analysis of variance; CC: corneal curvature; CCT: central corneal thickness; C.I.: confidence interval; CMPK1: cytidine/uridine monophosphate kinase 1; CR: corneal radius; D: diopter; GWAS: genome-wide association studies; HWE: Hardy-Weinberg equilibrium; LT: lens thickness; MIPEP: mitochondrial intermediate peptidase; MTOR: mechanistic target of rapamycin kinase; OR: odds ratio; PDGFRA: platelet-derived growth factor receptor-α; RBP3: retinol-binding protein 3; SD: standard deviation; SE: spherical equivalence; SNTB1: syntrophin beta 1; VCD: vitreous chamber depth; VIPR2: vasoactive intestinal peptide receptor 2; WNT7B: wingless/integrated family member 7B.

Sleep time and homework hours/daily are associated with reduced visual acuity among school students aged 9-18 in Shenyang in 2016

PURPOSE

The purpose of this survey was to explore the prevalence of reduced visual acuity and its associated factors among school students in Shenyang in 2016.

METHODS

This was a cross-sectional study using data from the Ministry of Education' Student Physical Fitness (MESPF) monitoring in 2016. A total of 13,642 students aged 9-18 years were surveyed in Shenyang. The unaided distance visual acuity was measured, and questionnaire on lifestyle behaviors that may affect visual acuity was investigated among students. The prevalence of reduced visual acuity and its associated factors were analyzed.

RESULTS

The average prevalence of reduced visual acuity among students aged 9-18 years was 65.8%, and severe reduced visual acuity was main (42.9%), and there were statistical effect of age, gender, and region on the prevalence of reduced visual acuity. Binary and multi variable logistic regression results revealed that students sleeping <8 h, homework hours ⩾1 h, and parental myopia had an increased risk of reduced visual acuity.

CONCLUSIONS

Sleep time <8 h and homework time ⩾1 h may be associated with reduced visual acuity among students in Shenyang. Therefore, it is benefit for student to get enough sleep and decreasing studying time in order to prevent and reduce poor vision.

Clinical observations of acute onset of myopic optic neuropathy in a real-world setting

AIM

To describe the clinical features of acute myopic onset of optic neuropathy and observe the effects of retrobulbar and systemic glucocorticoid therapy in a real-world setting.

METHODS

A retrospective observational case series included 18 patients with a clinical diagnosis of acute onset of myopic optic neuropathy in a real-world setting. While the patients were using retrobulbar and systemic glucocorticoid therapy, various imaging examination data were analysed, and the clinical features of myopic optic neuropathy were summarized for 6mo to 2y.

RESULTS

The included group of patients with acute onset of myopic optic neuropathy consisted mostly of females (n=11). The visual field (VF) showed abnormalities in bilateral eyes, including the spread of physiological blind spots, central and paracentral dark spots, and centripetal peripheral VF reduction; but central vision with no subjective changes. The visual evoked potential (VEP) was abnormal in all eyes with vision loss. The best corrected visual acuity (BCVA) was improved from 1.04±0.63 to 0.47±0.57 (logMAR) after glucocorticoid treatment (P<0.05). In patients with a short course (within 1wk), recovery was fast and achieved the same BCVA as recorded before the onset within 6d. However, in patients with the long course (1 to 2wk), recovery was slow and did not achieve the BCVA recorded before the onset within 10d. The changes of intraocular pressure (IOP) were not obvious before and after treatment (18.68±5.30 vs 19.55±5.34 mm Hg, P>0.05). There was no recurrence during long-term follow-up observation.

CONCLUSION

The acute onset of myopic optic neuropathy is characterized by BCVA and VF abnormalities in bilateral eyes. Retrobulbar and systemic glucocorticoid therapy is effective.

Open schools! Weighing the effects of viruses and lockdowns on children

This review weighs the risk of infection with SARS-CoV-2 against the side effects of school closures on physical and mental health, education, and well-being of those affected by the school closures. Whereas short term effects - decreased learning and food security, and increased anxiety, violence against children, child labor and teen pregnancies - are frequently discussed, the long-term effects of school closures will be much more detrimental across the lifespan of the "Generation Corona": Existing pandemics of inactivity and myopia, already affecting billions of people, are worsening due to less physical exercise and less time spent outdoors, poor diet, weight gain, and increased screen time during lockdowns, causing future increases of stroke, heart attack, cancer, and blindness. Socio-emotional complications of isolation, learned helplessness, economic and existential insecurity will include increased depression and suicide, decreased empathy and increased loneliness. Together with decreased educational attainment and economic productivity, the amount of ensuing increased future global morbidity and mortality justifies immediate action of school reopening.

The Effects of 0.01% Atropine on Adult Myopes' Contrast Sensitivity

Purpose

Atropine at a low concentration is considered a safe and effective treatment to mitigate myopia progression. However, the potential unwanted side effects of administering atropine at a low dose on visual functions other than best corrected visual acuity has not been investigated. In this study, we investigate the short-term (12,16, and 20 h) and long-term (1, 2, and 4 weeks) effects of 0.01% atropine (i.e., 0.1 mg/ml) on contrast sensitivity (CS) in patients with myopia.

Methods

Thirty adults (23.33 ± 2.93 years old) with myopia between -1.00 and -6.00 diopters (D), astigmatism of -1.50 D or less, and anisometropia of 1.00 D or less, participated in this prospective, masked, placebo-controlled, randomized study. The participants were randomly assigned to receive 0.01% atropine or polyvinyl alcohol eye drops once nightly to both eyes for four weeks. CS was measured binocularly at baseline and 12, 16, 20 h, 1, 2, and 4 weeks after the first use of the eye drops.

Results

There was no statistically significant differences of CS found between atropine and placebo-controlled groups in both short-term and long-term. There was no statistically significant interaction effect found between the time and group.

Conclusion

We demonstrated no significant deleterious effect of 0.01% atropine on adult myopes’ CS.

Schielen oder nicht Schielen? – Strabismus divergens intermittens, eine besondere Schielform

Hintergrund

Schielen tritt bei ca. 5–7 % der gesunden Kinder auf. Außenschielen ist mit 1,24 % weltweit seltener als Innenschielen. Der Strabismus divergens intermittens stellt mit 40–90 % die häufigste divergente Schielform dar. Das klinische Bild wurde von vielen AutorInnen beschrieben. Dennoch stellt es durch die Variabilität der Befunde eine therapeutische Herausforderung dar.

Material und Methode

Es wurden im Rahmen einer Literaturrecherche die Ergebnisse von Studien zum Strabismus divergens intermittens mit Fokus auf klinisches Bild, Untersuchungskriterien und Therapieansätze gesammelt und die Ergebnisse dargestellt.

Resultate

Der Strabismus divergens intermittens zeichnet sich durch eine besondere Binokularsituation und bisher ursächlich nicht vollends geklärte Symptome (Photophobie, Kneifen) aus. Konservative Therapien dienen der Entlastung des visuellen Systems, in vielen Fällen ist aber eine Schieloperation nötig. In der präoperativen Beurteilung ist der Stabilität des Schielwinkels besonderes Augenmerk zu schenken, als Entscheidungshilfe hinsichtlich Schieloperation hat sich der New Castle Control Score bewährt.

Schlussfolgerung

Die klinischen Charakteristika des Strabismus divergens intermittens sind klar beschrieben. Hinsichtlich therapeutischer Ansätze zeigen sich im internationalen Vergleich Unterschiede. Die Bedeutung der Einbeziehung der Eltern („shared decision making“) bei der Beurteilung der Schielhäufigkeit und bei der Operationsentscheidung ist zu betonen.

Prevalence of reduced visual acuity among school-aged children and adolescents in 6 districts of Changsha city: a population-based survey

Background

To calculate and evaluate the prevalence of reduced uncorrected distant visual acuity (UCDVA) in primary, middle and high schools in 6 districts of Changsha, Hunan, China.

Methods

A population-based retrospective study was conducted in 239 schools in 6 districts of Changsha. After routine eye examination to rule out diseases that can affect refraction, 250,980 eligible students from primary, middle and high schools were enrolled in the survey. Then the uncorrected distant and near visual acuity of each eye were measured. Categories of schools, districts, grades, eye exercises and sports time were also documented and analyzed.

Results

The overall prevalence of reduced UCDVA was 51.8% (95% confidence interval [CI]: 51.6–52.0%) in 6 districts of Changsha. Results of individual districts were as follows: Furong district 59.9%(95% CI: 57.9–61.8%), Tianxin district 62.3%(95% CI: 60.5–64.0%), Wangcheng district 47.8%(95% CI: 46.8–48.8%), Kaifu district 58.5%(95% CI: 58.0–58.9%), Yuhua district 47.0%(95% CI: 46.7–47.4%) and Yuelu district 52.6%(95% CI: 52.3–52.9%). The proportion of normal VA is seen to decrease from primary grade 3. The proportion of mildly reduced UCDVA is higher in primary grade 1 and 2. The proportion of moderately reduced UCDVA remains similar during 12 grades. The proportion of severely reduced UCDVA increases with grades. Multivariate analysis shows that the prevalence of reduced UCDVA is higher in key schools (risk ratio [RR] = 1.47, 95% CI 1.44–1.50) than non-key schools.

Conclusions

According to the existing data analysis results, the prevalence of reduced UCDVA among primary, middle and high school students in Changsha is very high. Some effective measures need to be taken to prevent it.

Association of 5p15.2 and 15q14 with high myopia in Tujia and Miao Chinese populations

BACKGROUND

The polymorphisms rs6885224 and rs634990 have been reported to be associated with high myopia in many populations. As there is still no report on whether these two SNPs are associated with myopia in the Tujia and Miao minority areas of China, we conducted a replication study to evaluate the association of single-nucleotide polymorphisms in the regions 5p15.2 and 15q14 with high myopia in Tujia and Miao Chinese populations.

METHODS

We performed a comprehensive meta-analysis of 5831 cases and 7055 controls to assess whether rs6885224 in the 5p15.2 region and rs634990 in the 15q14 region are associated with high myopia. Our replication study enrolled 804 individuals. Genomic DNA was extracted from venous leukocytes, and these two SNPs were genotyped by Sanger sequencing. Allele and genotype frequencies were analysed using χ² tests, and ORs and 95% CIs were calculated.

RESULTS

According to the results of the meta-analysis, rs6885224 in the CTNND2 gene showed no association with myopia [p = 0.222, OR = 1.154, 95% CI (0.917-1.452)]. Conversely, rs634990 in the 15q14 region did exhibit a significant correlation with myopia [p = 7.270 × 10^- 7, OR = 0.817, 95% CI (0.754-0.885)]. In our replication study, no association with high myopia in the Tujia and Miao populations was found for rs634990 or rs6885224. The following were obtained by allele frequency analysis: rs6885224, p = 0.175, OR = 0.845, and 95% CI = 0.662-1.078; rs634990, p = 0.087, OR = 0.84, and the 95% CI = 0.687-1.026. Genotype frequency analysis yielded p = 0.376 for rs6885224 and p = 0.243 for rs634990.

CONCLUSIONS

Our meta-analysis results show that rs634990 was significantly associated with myopia but that rs6885224 was not. Nevertheless, in our replication study, these two SNPs showed no association with myopia in the Tujia and Miao Chinese populations. This is the first report involving Tujia and Miao ethnic groups from Enshi minority areas. However, the sample size needs to be expanded and more stringent inclusion and exclusion criteria need to be formulated to verify the findings.

Performance of Topological Perception in the Myopic Population

Purpose: Discriminating objects' topological property (TP) is a primitive function of visual representation, which is reported to be associated with magnocellular (M) visual pathway, temporal lobe (TL), and superior colliculus (SC)-pulvinar subcortical pathway. Previous studies have shown that M pathway and TL were affected in high myopia (HM) subjects. The study was accordingly designed to explore whether topological perception performance was abnormal in HM subjects. Methods: 30 mildly myopic, 25 moderately myopic, 35 highly myopic, and 20 emmetropic subjects were enrolled. All participants underwent a comprehensive ophthalmological assessment including automated refraction, intraocular pressure, Humphrey 10-2 standard automated perimetry, ocular fundus photography and swept-source optical coherence tomography. Defined by differences in hole, TP and non-TP discrimination with letters "E", "S", "P", "d" as stimuli in the central and peripheral regions was performed using the MATLAB 2017 software. d-primes extracted from the software were analyzed within each group. The correlation of peripheral TP/non-TP deficit with spherical equivalent (SE), axial length (AL) and average peripapillary retinal nerve fiber layer (RNFL) thickness was performed. Results: The patterns of topological perception performance were similar among the groups. TP discrimination peripherally was significantly better than that centrally in the mild myopia (P < .001), moderate myopia (P < .001), high myopia (P < .001) and emmetropia groups (P = .001). In the peripheral region, TP d-prime scores were significantly better than non-TP d-prime scores (all P < .001). The main and interaction effects of eccentricity and stimulus type were statistically significant(P < .05). There was no statistically significant correlation between peripheral TP/non-TP deficit and SE, AL or average RNFL thickness (P > .05). Conclusions: The current study first showed that patterns of topological perception among the myopic population were similar and not affected by the severity of myopia.

Genetic association study of SOX2 gene polymorphisms with high myopia in a Chinese population

PURPOSE

The aim of this study is to investigate whether SOX2 gene variants were associated with high myopia in a Chinese population.

METHODS

This study is conducted using case-control association analysis. This study recruited 83 healthy controls (with binocular spherical equivalent between -0.50 and +0.50 D) and 117 high myopia cases (spherical equivalent > -6.00 D in both eyes). Three single-nucleotide polymorphisms were selected from HapMap database for genotyping by direct sequencing. Statistical software (SPSS 22.0) was used for statistical analysis. The chi-square test was used to examine the difference in the frequency between cases and controls.

RESULTS

Genotype distributions in the three single-nucleotide polymorphisms were all in accordance with the Hardy-Weinberg equilibrium. The differences of rs4575941 locus genotype frequency and allele frequency between the case group and the control group were statistically significant (p = .043 and p = .029, respectively). The rs4575941 allele G frequency in the high myopia group was significantly higher than that in the control group with an odds ratio value of 1.579. However, the value of a chi-square test for the trend was 0.029, and after Bonferroni test, the p value was .087.

CONCLUSION

In Chinese population, rs4575941 in SOX2 gene was likely to play some roles in the genetic susceptibility to high myopia; the rs4575941 allele G might be a risk gene for high myopia.

Myopia genetics in genome-wide association and post-genome-wide association study era

Genome-wide association studies (GWAS) of myopia and refractive error have generated exciting results and identified novel risk-associated loci. However, the interpretation of the findings of GWAS of complex diseases is not straightforward and has remained challenging. This review provides a brief summary of the main focus on the advantages and limitations of GWAS of myopia, with potential strategies that may contribute to further insight into the genetics of myopia in the post-GWAS or omics era.

Results of pars plana vitrectomy for primary rhegmatogenous retinal detachment with PVR grades A and B in high-myopic eyes

PURPOSE

To evaluate the results of pars plana vitrectomy (PPV) without adjuvant buckling procedures for the primary rhegmatogenous retinal detachment (RRD) with PVR grades A and B in high-myopic eyes.

METHODS

A retrospective review included 291 eyes treated for primary RRD from 2008 to 2016. The single surgery success rate (SSSR), the total number of surgeries, outcomes and complications were analysed between group of 67 eyes with high axial myopia (group A) and group of 224 eyes without high myopia (group B).

RESULTS

The mean follow-up was 30.6 ± 22.8 months. The SSSR in group A was 82.1% and in group B was 86.2% (p > 0.05). The final reattachment rate and number of required surgeries were in group A 96.3% (3.1 surgeries) and in group B 96.0% (2.8 surgeries). The initial BCVA improved in group A from 1.58 to 0.58 LogMAR at year 3; and in group B from 1.21 to 0.34 LogMAR. In match-pair analysis of macula-off RRD, no significant difference of the CRT between groups A and B was observed within 3 years of follow-up.

CONCLUSION

The anatomical success of primary PPV for RRD did not differ between high-myopic and non-high-myopic eyes in PVR grades A and B. However, functional results of high-myopic eyes are worse compared to eyes without high axial myopia.

Corneal Stiffness and Its Relationship With Other Corneal Biomechanical and Nonbiomechanical Parameters in Myopic Eyes of Chinese Patients

PURPOSE

To investigate corneal stiffness and analyze its possible influence on other corneal biomechanical and nonbiomechanical parameters in myopic eyes of Chinese patients.

METHODS

A total of 387 healthy (right) myopic eyes were included in this study. Corneal visualization Scheimpflug technology was used to measure the corneal stiffness parameter at the first applanation (SP-A1), deformation amplitude ratio at 1.0 and at 2.0 mm, biomechanically corrected intraocular pressure (bIOP), and corneal deformation parameters during the first applanation (A1: A1-time, A1-length, and A1-velocity), second applanation (A2; A2-time, A2-length, and A2-velocity), and highest concavity (HC; HC-time, HC-radius, HC deformation amplitude, and HC peak distance). The Pentacam was used to evaluate central corneal thickness, mean corneal curvature (Km), anterior corneal central elevation, and corneal asphericity (Q value) of the anterior cornea.

RESULTS

The mean SP-A1 and bIOP values were 90.46 ± 15.39 mm Hg/mm and 13.5 ± 1.85 mm Hg, respectively. The SP-A1 increased with age (β = 0.41 [95% CI, 0.28%-0.54%]; P < 0.0001). Corneal stiffness was positively correlated with central corneal thickness, uncorrected intraocular pressure, and bIOP and was also significantly correlated with all corneal deformation parameters (P < 0.05), except A1-length, HC-time, and HC peak distance. Corneal stiffness was negatively correlated with central corneal elevation of the anterior surface (r = -0.124, P = 0.014) and mean corneal curvature (r = -0.114, P = 0.025) and positively correlated with the Q value of the anterior surface (r = 0.109, P = 0.032).

CONCLUSIONS

Corneal stiffness increased with age. Stronger corneal stiffness may be related to flattening of the cornea and higher intraocular pressure.

The increasing prevalence of myopia and high myopia among high school students in Fenghua city, eastern China: a 15-year population-based survey

BACKGROUND

Myopia is the leading cause of preventable blindness in children and young adults. Multiple epidemiological studies have confirmed a high prevalence of myopia in Asian countries. However, fewer longitudinal studies have been performed to evaluate the secular changes in the prevalence of myopia, especially high myopia in China. In the present study, we investigated trends in the prevalence of myopia among high school students in Fenghua city, eastern China, from 2001 to 2015.

METHODS

This was a population-based, retrospective study. Data were collected among 43,858 third-year high school students. Noncycloplegic autorefraction was used to determine refractive error, which was defined as low myopia, moderate myopia, high myopia and very high myopia according to the spherical equivalent from the worse eye of each participant. The prevalence of myopia was calculated and the annual percentage change (APC) was used to quantify the time trends. All analyses were conducted using the SPSS, Stata and Graphpad Prism software.

RESULTS

From 2001 to 2015, the prevalence of overall myopia increased from 79.5% to 87.7% (APC =0.59%), with a significant increase of moderate myopia (38.8% to 45.7%, APC = 0.78%), high myopia (7.9% to 16.6%, APC = 5.48%) and very high myopia (0.08% to 0.92%, APC = 14.59%), while the prevalence of low myopia decreased from 32.7% to 24.4% (APC = - 1.73%). High myopia and very high myopia contributed the major part of the increasing trend of myopia prevalence (contribution rate 27.00% and 69.07%, respectively).

CONCLUSIONS

During the 15-year period, there was a remarkable increase in the prevalence of high and very high myopia among high school students, which might become a serious public health problem in China for the next few decades.

Comparison of peripapillary retinal nerve fiber layer thickness between myopia severity groups and controls

AIM

To compare the peripapillary retinal nerve fiber layer (RNFL) thickness measured via optical coherence tomography (OCT) between different groups of myopia severity and controls.

METHODS

This was a prospective cross-sectional study. All subjects underwent a full ophthalmic examination, refraction, visual field analysis and A-scan biometry. Myopic patients were classified as low myopia (LM) [spherical equivalent (SE) from greater than -0.5 D, up to -3.0 D], moderate myopia (MM; SE greater than -3.0 D, up to -6.0 D) and high myopia (HM; SE greater than -6.0 D). The control group consisted of emmetropic (EM) patients (SE from +0.5 D to -0.5 D). A Zeiss Cirrus HD-OCT machine was used to measure the peripapillary RNFL thickness of both eyes of each subject. The mean peripapillary RNFL thickness between groups was compared using both analysis of variance and analysis of covariance.

RESULTS

A total of 403 eyes of 403 subjects were included in this study. The mean age was 31.48±10.23y. There were 180 (44.7%) eyes with EM, 124 (30.8%) with LM, 73 (18.1%) with MM and 26 (6.5%) with HM. All groups of myopia severity had a thinner average RNFL than the EM group, but after controlling for gender, age, and axial eye length, only the HM group differed significantly from the EM group (P=0.017). Likewise, the superior, inferior and nasal RNFL was thinner in all myopia groups compared to controls, but after controlling for confounders, only the inferior quadrant RNFL was significantly thinner in the HM group, when compared to the EM group (P=0.017).

CONCLUSION

The average and inferior quadrant RNFL is thinner in highly myopic eyes compared to emmetropic eyes. Refractive status must be taken into consideration when interpreting the OCT of myopic patients, as RNFL thickness varies with the degree of myopia.