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Journal of Global Health 2021To investigate the prevalence and time trends of refractive error (RE) among Chinese children under 18 years old. (Meta-Analysis)
Meta-Analysis
BACKGROUND
To investigate the prevalence and time trends of refractive error (RE) among Chinese children under 18 years old.
METHODS
PubMed, Embase, Web of Science were searched for articles that estimated prevalence of RE in Chinese children. Data of identified eligible studies was extracted by two investigators independently. Pooled prevalence of RE and its 95% confidence interval (95% CI) and the time trends of RE were investigated using Meta-analysis methods.
RESULTS
Of the 41 studies covering 1 051 784 subjects, the pooled prevalence of myopia, high myopia, hyperopia and astigmatism in Chinese children was 38.0% (95% confidence interval (CI) = 35.1%-41.1%), 2.8% (95% CI = 2.3%-3.4%), 5.2% (95% CI = 3.1%-8.6%) and 16.5% (95% CI = 12.3%-21.8%), respectively. Subgroup analysis show that children living in urban were at higher risk of RE. Prevalence of myopia and hyperopia were higher in Northern China compared with Southern China and high myopia and astigmatism were higher in Hong Kong, Macau and Taiwan than in mainland China. Regression analysis showed an upward trend in myopia and hyperopia and a downward trend in high myopia and astigmatism with years.
CONCLUSIONS
The prevalence of RE is higher in urban areas than in rural for Chinese children. The much higher prevalence of myopia and astigmatism in China compared with foreign countries indicates the important role played by environment and genetic factors. Considering the large magnitude of refractive errors, much more attention should still be paid to RE prevention and treatment strategy development in China.
Topics: Child; China; Humans; Prevalence; Refractive Errors; Time Factors
PubMed: 34327000
DOI: 10.7189/jogh.11.08006 -
Annals of Palliative Medicine Jan 2022Cataract is one of the common eye diseases. At present, Phacoemulsification combined with traditional intraocular lens (IOL) implantation can achieve satisfactory... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Cataract is one of the common eye diseases. At present, Phacoemulsification combined with traditional intraocular lens (IOL) implantation can achieve satisfactory rejuvenation effects. However, the correction of corneal astigmatism is limited, while Toric IOL implantation can provide good astigmatism correction treatment.
METHODS
We retrieved randomized controlled trials (RCTs) on the treatment of cataracts published in the PubMed, EBSCO, MEDLINE, EMBASE, Science Direct, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu databases. Professional journals were searched manually to avoid omissions. The research subject search terms included cataract, astigmatism, IOL, and intraocular lens. The observation indicators search terms included uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), residual corneal astigmatism, and cataract cure rate.
RESULTS
A total of 12 articles were included. The articles were tested for heterogeneity of UDVA measured using the Logarithm of Mininal Angle Resolution (LogMAR) visual acuity chart, and the results showed that Chi-squared test (Chi2) =75.21, degree of freedom (df) =11, and I2=85%>50%, so the random effects model (REM) was adopted for analysis. The results indicated that the differences between the Toric and Non-Toric IOL groups statistically significant, and the Toric IOL group had a significant therapeutic effect [Z =2.18, mean difference (MD) =-0.05, 95% confidential interval (CI): -0.09, -0.00, P=0.03]. The fixed effects model (FEM) was adopted to analyze the determination of BDVA by LogMAR visual acuity chart in 6 articles. The results suggested that the difference between the Toric IOL and non-Toric IOL groups was not statistically significant (Z =0.29, MD =-0.00, 95% CI: -0.02, 0.01, P=0.77). Heterogeneity analysis was performed on three articles in terms of residual corneal astigmatism, which showed that Chi2=75.55, df =3, I2=96%>50%, and P<0.00001. The REM analysis results revealed that the difference between the two groups was not statistically significant, and the Toric IOL group had low residual corneal astigmatism (Z =1.35, MD =-0.34, 95% CI: -0.83, 0.15, P=0.18).
DISCUSSION
The meta-analysis results confirmed that Toric IOL implantation showed obvious advantages in improving UDVA and corneal residual astigmatism in cataract patients.
Topics: Astigmatism; Cataract; Humans; Lens Implantation, Intraocular; Lenses, Intraocular; Phacoemulsification
PubMed: 35144417
DOI: 10.21037/apm-21-3767 -
Frontiers in Medicine 2022This study aimed to evaluate the efficacy of small-incision lenticule extraction (SMILE) in improving vision and visual quality and correcting astigmatism for the...
PURPOSE
This study aimed to evaluate the efficacy of small-incision lenticule extraction (SMILE) in improving vision and visual quality and correcting astigmatism for the treatment of high astigmatism.
METHODS
Eligible studies and studies comparing the efficacy of SMILE with femtosecond laser-assisted laser keratomileusis (FS-LASIK) or transepithelial photorefractive keratectomy (T-PRK) for high astigmatism (≥2.00 D) were identified in PubMed, Embase, and the Cochrane Central Register of Controlled Trials, searched from their inception to 29 May 2022. The references of all searched studies were checked as supplements. The risk of bias was evaluated for each eligible study. The literature was screened according to the inclusion and exclusion criteria, and relative data were extracted. Data were extracted and analyzed by ReviewManager 5.4. The primary outcome was post-operative uncorrected distance visual acuity (UDVA). The secondary outcomes included corneal aberrations and vector parameters. The weight mean difference (WMD) and their 95% confidence intervals (95% CI) were used to assess the strength of the association.
RESULTS
A total of six studies including 380 astigmatism eyes were involved, with 211 high-astigmatism eyes and 31 low-astigmatism eyes undergoing SMILE surgery, 94 high-astigmatism eyes undergoing FS-LASIK surgery, and 44 high-astigmatism eyes undergoing T-PRK surgery. Compared with non-SMILE, SMILE induced more astigmatism (weighted mean difference [WMD] = -0.07, 95% CI [-0.12 to -0.02], = 0.005) and fewer sphere aberrations (WMD = -0.12, 95% CI [-0.17 to -0.08], < 0.00001). The post-operative UDVA, sphere, spherical equivalent (SE), and higher order aberrations in different surgeries were likewise equivalent. The difference vector and index of success were significantly higher, and the surgically induced astigmatism vector, correction index, and magnitude of error were significantly lower in SMILE.
CONCLUSION
This meta-analysis suggests that SMILE, FS-LASIK, and T-PRK show excellent efficacy, predictability, and safety for myopia. SMILE exhibited less astigmatism refraction predictability and less surgically induced spherical aberrations. There may be more under-correction in SMILE. More randomized, prospective, and large sample-sized studies are needed to confirm these conclusions in the long term.
PubMed: 36743675
DOI: 10.3389/fmed.2022.1100241 -
BMJ Open Ophthalmology 2022The purpose of this paper is to review the basic principles of linear optics. A paraxial optical system is represented by a symplectic matrix called the transference,... (Review)
Review
The purpose of this paper is to review the basic principles of linear optics. A paraxial optical system is represented by a symplectic matrix called the transference, with entries that represent the fundamental properties of a paraxial optical system. Such an optical system may have elements that are astigmatic and decentred or tilted. Nearly all the familiar optical properties of an optical system can be derived from the transference. The transference is readily obtainable, as shown, for Gaussian and astigmatic optical systems, including systems with elements that are decentred or tilted. Four special systems are described and used to obtain the commonly used optical properties including power, refractive compensation, vertex powers, neutralising powers, the generalised Prentice equation and change in vergence across an optical system. The use of linear optics in quantitative analysis and the consequences of symplecticity are discussed. A systematic review produced 84 relevant papers for inclusion in this review on optical properties of linear systems. Topics reviewed include various magnifications (transverse, angular, spectacle, instrument, aniseikonia, retinal blur), cardinal points and axes of the eye, chromatic aberrations, positioning and design of intraocular lenses, flipped, reversed and catadioptric systems and gradient indices. The optical properties are discussed briefly, with emphasis placed on results and their implications. Many of these optical properties have applications for vision science and eye surgery and some examples of using linear optics for quantitative analyses are mentioned.
Topics: Astigmatism; Eyeglasses; Humans; Lenses, Intraocular; Optics and Photonics; Refraction, Ocular
PubMed: 35452208
DOI: 10.1136/bmjophth-2021-000932 -
Frontiers in Medicine 2024To examine the causes and factors that lead to high order aberration (HOA) during the treatment of myopia using small incision lenticule extraction (SMILE), as well as...
OBJECTIVE
To examine the causes and factors that lead to high order aberration (HOA) during the treatment of myopia using small incision lenticule extraction (SMILE), as well as the differences between SMILE and other corneal refractive surgeries through a systematic review and meta-analysis.
METHODS
A systematic search was conducted from January 2015 to February 2023 in Pubmed, Embase, Web of Science, and Google Scholar databases to gather relevant studies on SMILE and HOA. Studies meeting specific criteria were chosen, and clinical data was retrieved for analysis.
RESULTS
This meta-analysis resulted in the inclusion of 19 studies involving 1,503 eyes. Pooled results showed significant induction of total HOA (tHOA, = -0.21, < 0.001), spherical aberration (SA, = -0.11, < 0.001) and coma aberration (CA, = -0.18, < 0.001) after SMILE compared to pre-SMILE, while no significant change in trefoil aberration (TA) was observed ( = -0.00, = 0.91). There was a significantly lower induction of tHOA after SMILE compared to femtosecond laser-assisted keratomileusis (FS-LASIK, = 0.04, < 0.001), and no significant difference was observed compared to wavefront aberration-guided (WFG) refractive surgery ( = 0.00, = 0.75). There was also a significant association between different levels of myopia and astigmatism, duration of follow-up, lenticule thickness, and preoperative central corneal thickness (CCT) on the induction of tHOA after SMILE ( < 0.05), while the higher preoperative myopia group (sphere > -5D), lower preoperative astigmatism group (cylinder ≤ -1D), larger lenticule thickness group (lenticule thickness > 100 μm), shorter follow-up group (follow-up 1 month postoperatively) and the thicker CCT group (CCT > 550 μm) brought a significant induction of tHOA compared to the opposite comparison group ( < 0.001).
CONCLUSION
While SMILE can induce HOA significantly, it induces less HOA than FS-LASIK. Postoperative HOA following SMILE can be affected by factors such as myopia, astigmatism, lenticule thickness, CCT, and duration of follow-up. Future research should continue to explore techniques to decrease the induction of HOA by using this methodology.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/.
PubMed: 38601117
DOI: 10.3389/fmed.2024.1274101 -
Oxygen in Corneal Collagen Crosslinking to Treat Keratoconus: A Systematic Review and Meta-Analysis.Asia-Pacific Journal of Ophthalmology... Sep 2022Keratoconus is a disorder that results in visual loss from increased corneal high-order aberrations and irregular astigmatism and reduces quality of life. The primary... (Meta-Analysis)
Meta-Analysis
PURPOSE
Keratoconus is a disorder that results in visual loss from increased corneal high-order aberrations and irregular astigmatism and reduces quality of life. The primary treatment for progressive keratoconus is crosslinking (CXL). Recently, it has been suggested that oxygen enhances the type II photodynamic reaction of CXL that is oxygen dependent. Our study investigated the effect of increased oxygen availability in epithelium-on CXL on visual acuity and corneal curvature.
METHODS
We searched PubMed, EMBASE, Medline, Web of Science, and Scopus databases on November 3, 2021. We included studies that reported increased oxygen availability during CXL in patients with keratoconus published within the last 10 years. A meta-analysis on the primary outcomes, maximum keratometry, and corrected distance visual acuity, was conducted.
RESULTS
The search yielded 108 publications which were screened and assessed for eligibility. Six studies were included in the systematic review and 5 studies were included in our meta-analysis of the outcomes of increased oxygen availability in accelerated CXL. The meta-analysis on data after 6 months of follow-up found a significant decrease in mean maximum keratometry of 1.2 diopter (95% confidence interval: 0.2-2.3; P =0.02) and an improvement in mean corrected distance visual acuity by 0.08 logMAR (95% confidence interval, 0.02-0.13; P =0.01). There were no serious adverse events reported.
CONCLUSIONS
Increasing oxygen during epithelium-on CXL improved visual acuity and produced corneal flattening without any serious adverse events in patients with keratoconus. The demarcation line depth was significantly higher with oxygen compared to the control group. Further data are required with a control group and long-term follow-up across a range of CXL protocols for implementation into standard clinical practice.
Topics: Collagen; Corneal Stroma; Corneal Topography; Cross-Linking Reagents; Humans; Keratoconus; Oxygen; Photosensitizing Agents; Quality of Life; Riboflavin; Ultraviolet Rays
PubMed: 36094374
DOI: 10.1097/APO.0000000000000555 -
PloS One 2022Globally, the prevalence of refractive error was 12%, and visual impairment due to refractive error was 2.1%. In sub-Saharan Africa, the prevalence of refractive error... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Globally, the prevalence of refractive error was 12%, and visual impairment due to refractive error was 2.1%. In sub-Saharan Africa, the prevalence of refractive error and visual impairment due to refractive error was 12.6% and 3.4%, respectively. In Ethiopia, the prevalence of visual impairment due to refractive error varies from 2.5% in the Gurage zone to 12.3% in Hawassa city. Hence, this Meta-analysis aimed to summarize the pooled prevalence of visual impairment due to refractive error in Ethiopia.
METHODS
A systematic search of the literature was conducted by the authors to identify all relevant primary studies. All articles on the prevalence of visual impairment due to refractive error in Ethiopia were identified through a literature search. The databases used to search for studies were PubMed, Science Direct, POPLINE, HENARI, Google Scholar, and grey literature was searched on Google until December 15, 2021. In this meta-analysis, the presence of publication bias was evaluated using funnel plots and Begg's tests at a significance level of less than 0.05. The sensitivity analysis was conducted to check for a single study's effect on the overall prevalence of refractive error.
RESULT
About 1664 studies were retrieved from initial electronic searches using international databases and google searches. A total number of 20,088 children and adolescents were included in this meta-analysis. The pooled prevalence of visual impairment due to refractive error in Ethiopia using the random effects model was estimated to be 6% (95% CI, 5-7) with a significant level of heterogeneity (I2 = 94.4%; p < 0.001). The pooled prevalence of visual impairment due to refractive was analyzed by subtypes, and pooled prevalence was estimated to be 4%, 5.2%, and 1% for myopia, hyperopia, and astigmatism, respectively.
CONCLUSION
The pooled prevalence of visual impairment due to refractive error was high in Ethiopia. About one in twenty-five Ethiopian children and adolescents are affected by visual impairment due to myopia.
Topics: Adolescent; Child; Ethiopia; Humans; Myopia; Prevalence; Refractive Errors; Vision, Low
PubMed: 35980970
DOI: 10.1371/journal.pone.0271313 -
Ophthalmology and Therapy May 2024Small incision lenticule extraction (SMILE) has made notable advancements in addressing myopic astigmatism. Nevertheless, the potential impact of cyclotorsion on...
INTRODUCTION
Small incision lenticule extraction (SMILE) has made notable advancements in addressing myopic astigmatism. Nevertheless, the potential impact of cyclotorsion on surgical outcomes cannot be overlooked. This study aims to assess the effectiveness of cyclotorsion compensation technology in SMILE surgery for the correction of myopic astigmatism, examining its influence on postoperative visual quality.
METHODS
A systematic review and meta-analysis were conducted. A comprehensive literature search was performed using databases, including PubMed, Web of Science, EMBASE, Cochrane Library, EBSCO, Scopus, CNKI, VIP, and Wan Fang. Studies meeting the criteria were selected and included. Data were independently extracted by three authors. Clinical outcome parameters were analyzed using Review Manager version 5.3.
RESULTS
This meta-analysis included ten studies. The results showed that, compared with the control group (cyclotorsion compensation was not performed in SMILE), the following indicators in the cyclotorsion compensation group were: residual astigmatism (RA) [weighted mean difference (MD) = 0.73, 95% confidence interval (CI) + 0.26 to + 1.19, P = 0.002], spherical equivalent (SE) (MD = 1.99, 95% CI + 0.77 to + 3.21, P = 0.001), coma (MD = -0.06, 95% CI -0.08 to -0.04, P < 0.00001), higher-order aberrations (HOAs) (MD = -0.04, 95% CI -0.06 to -0.02, P < 0.0001), follow-up 6-month angle of error (AE) (MD = -2.67, 95% CI -3.71 to -1.63, P < 0.00001), and follow-up 6-month uncorrected distance visual acuity (UDVA) (MD = -0.05, 95% CI -0.08 to -0.01, P = 0.005), and the differences in results were statistically significant. However, the differences among correction index, index of success (IOS), targeted induced astigmatism (TIA), magnitude of error (ME), and spherical aberration (SA) were not statistically significant.
CONCLUSION
Cyclotorsion compensation proves to be effective and predictable for correcting myopic astigmatism. The cyclotorsion compensation group demonstrated advantages over the control group in terms of postoperative residual astigmatism, and it induced fewer coma aberrations. Whether cyclotorsion compensation can lead to better visual quality remains to be seen, and further research on correcting myopic astigmatism through cyclotorsion compensation is warranted.
PubMed: 38498276
DOI: 10.1007/s40123-024-00921-2 -
American Journal of Medical Genetics.... Feb 2022The 22q11.2 deletion syndrome (22q11.2DS) is a multisystem disorder with an estimated prevalence of 1:3000 live births. Manifestations show a marked variability in...
The 22q11.2 deletion syndrome (22q11.2DS) is a multisystem disorder with an estimated prevalence of 1:3000 live births. Manifestations show a marked variability in expression and include speech- and language delay, intellectual disability, and neuropsychiatric disorders. We aim to provide an overview of ocular findings in 22q11.2DS in order to optimize recommendations for ophthalmic screening. We combined results from a systematic literature review with results from a multicenter cross-sectional study of patients with 22q11.2DS who were assessed by an ophthalmologist. Our systematic literature search yielded four articles, describing 270 patients. We included 132 patients in our cross-sectional study (median age 8.9 [range 0-56] years). Most reported ocular findings were retinal vascular tortuosity (32%-78%), posterior embryotoxon (22%-50%), eye lid hooding (20%-67%), strabismus (12%-36%), amblyopia (2%-11%), ptosis (4%-6%), and refractive errors, of which hyperopia (6%-48%) and astigmatism (3%-23%) were most common. Visual acuity was (near) normal in most patients (91%-94%). Refractive errors, strabismus, and amblyopia are treatable conditions that are frequently present in patients with 22q11.2DS and should be corrected at an early stage. Therefore, in 22q11.2DS, we recommend ophthalmic and orthoptic screening at the age of 3 years or at diagnosis, and a low-threshold referral in adults.
Topics: Adolescent; Adult; Child; Child, Preschool; Cross-Sectional Studies; DiGeorge Syndrome; Eye Abnormalities; Humans; Infant; Infant, Newborn; Intellectual Disability; Language; Middle Aged; Multicenter Studies as Topic; Young Adult
PubMed: 34773366
DOI: 10.1002/ajmg.a.62556 -
American Journal of Ophthalmology Mar 2024To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation. (Review)
Review
PURPOSE
To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation.
METHODS
We investigated how current IOLs influence peripheral visual function, peripheral optical quality, and visual perception and performance, in patients following cataract surgery. Peripheral vision is described as vision outside the central foveal region of the eye (beyond 4-5° of eccentricity). We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and gray literature for relevant references. Randomized controlled trials and observational studies were eligible for inclusion. Finally, 47 studies with a total of 5963 participants were eligible for this review, of which 15 were included in the meta-analysis.
RESULTS
Regarding visual fields, the meta-analysis showed that the pooled estimate of mean deviation (MD) measured with perimetry tests (standard automated perimetry [SAP], short-wavelength automated perimetry [SWAP], and frequency doubling technology [FDT]) appears to be lower than the mean of healthy age-matched controls, regardless of IOL design. Results for pooled estimate show that localized defects (pattern standard deviation [PSD]) were higher than those in the healthy age-matched controls for FDT. We also collected evidence demonstrating that pseudophakia increases peripheral astigmatism and a myopic shift from 20° onward, leading to decreased peripheral image quality compared with that in phakic eyes. Patient-reported outcomes on peripheral vision showed a pooled score estimate of 95.19, indicating high satisfaction, and for the Steps & Stairs questions, a pooled score estimate at 0.23, indicating no to little difficulty seeing steps and stairs.
CONCLUSIONS
Peripheral image quality is degraded in eyes after cataract surgery. Nevertheless, whether this degradation leads to impaired visual function in the periphery requires further investigation.
PubMed: 38521156
DOI: 10.1016/j.ajo.2024.03.016