27 research outputs found
Part-time versus full-time occlusion therapy for treatment of amblyopia: A meta-analysis
YesPurpose: To compare full-time occlusion (FTO) and part-time occlusion (PTO) therapy in the treatment of amblyopia, with the secondary aim of
evaluating the minimum number of hours of part-time patching required for maximal effect from occlusion.
Methods: A literature search was performed in PubMed, Scopus, Science Direct, Ovid, Web of Science and Cochrane library. Methodological
quality of the literature was evaluated according to the Oxford Center for Evidence Based Medicine and modified Newcastle-Ottawa scale.
Statistical analyses were performed using Comprehensive Meta-Analysis (version 2, Biostat Inc., USA).
Results: The present meta-analysis included six studies (three randomized controlled trials [RCTs] and three non-RCTs). Pooled standardized
difference in the mean changes in the visual acuity was 0.337 [lower and upper limits: 0.009, 0.683] higher in the FTO as compared to the PTO
group; however, this difference was not statistically significant (P ¼ 0.056, Cochrane Q value ¼ 20.4 (P ¼ 0.001), I2 ¼ 75.49%). Egger's
regression intercept was 5.46 (P ¼ 0.04). The pooled standardized difference in means of visual acuity changes was 1.097 [lower and upper
limits: 0.68, 1.513] higher in the FTO arm (P < 0.001), and 0.7 [lower and upper limits: 0.315, 1.085] higher in the PTO arm (P < 0.001)
compared to PTO less than two hours.
Conclusions: This meta-analysis shows no statistically significant difference between PTO and FTO in treatment of amblyopia. However, our
results suggest that the minimum effective PTO duration, to observe maximal improvement in visual acuity is six hours per day
Induced vertical disparity effects on local and global stereopsis
Purpose: Although significant amounts of vertical misalignment could have a noticeable effect on visual performance, there is no conclusive evidence about the effect of very small amount of vertical disparity on stereopsis and binocular vision. Hence, the aim of this study was to investigate the effects of induced vertical disparity on local and global stereopsis at near. Materials and Methods: Ninety participants wearing best-corrected refraction had local and global stereopsis tested with 0.5 and 1.0 prism diopter (Δ) vertical prism in front of their dominant and non-dominant eye in turn. This was compared to local and global stereopsis in the same subjects without vertical prism. Data were analyzed in SPSS.17 software using the independent samples T and the repeated measures ANOVA tests. Results: Induced vertical disparity decreases local and global stereopsis. This reduction is greater when vertical disparity is induced in front of the non-dominant eye and affects global more than local stereopsis. Repeated measures ANOVA showed differences in the mean stereopsis between the different measured states for local and global values. Local stereopsis thresholds were reduced by 10s of arc or less on average with 1.0Δ of induced vertical prism in front of either eye. However, global stereopsis thresholds were reduced by over 100s of arc by the same 1.0Δ of induced vertical prism. Conclusion: Induced vertical disparity affects global stereopsis thresholds by an order of magnitude (or a factor of 10) more than local stereopsis. Hence, using a test that measures global stereopsis such as the TNO is more sensitive to vertical misalignment than a test such as the Stereofly that measures local stereopsis. © 2014 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted
Association of C677T (rs1081133) and A1298C (rs1801131) Methylenetetrahydrofolate Reductase Variants with Breast Cancer Susceptibility Among Asians: A Systematic Review and Meta-Analysis
This systematic review and meta-analysis were conducted to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with breast cancer (BC) in Asians. Systematic searches were conducted in PubMed, EMBASE, Web of Science, and Scopus by May 2020. Inter-study heterogeneity was also assessed with a Q test, along with I2 statistics. Random-effects models were applied to pooled crude ORs with corresponding 95% CIs for the genetic models. A total of 1097 identified results, along with 36 qualified studies were included: for MTHFR C677T polymorphism, a total of 36 studies was comprised of 11,261 cases and 13,318 controls and for MTHFR A1298C polymorphism, a number of 19 studies contained 7424 cases and 8204 controls. Likewise, for C677T polymorphism, an increased risk of BC was seen for the allelic (OR 1.21, 95% CI 1.09–1.33, P < 0.01, I2 = 78.9%), dominant (OR 1.17, 95% CI 1.05–1.30, P < 0.01, I2 = 71.8%), recessive (OR 1.43, 95% CI 1.23–1.67, P < 0.01, I2 = 55.8%), and homozygous models (OR 1.48, 95% CI 1.25–1.75, P < 0.01, I2 59.9%) among BC patients compared to controls. Also, in terms of A1298C polymorphism, an association was found between the allelic (OR 1.15, 95% CI 1.04–1.28, P < 0.01, I2 70.4%) and homozygous models (OR 1.38, 95% CI 1.15–1.66, P < 0.01, I2 44.2%) with the risk of BC. In conclusion, findings revealed that MTHFR C677T variant might be a factor that predisposes BC in Asians. Furthermore, it was found that A1298C variant acts as a BC risk factor, particularly in a Western Asia population
Refractive characteristics of keratoconus eyes with corneal Vogt's striae: A contralateral eye study
Purpose: The aim of this study was to assess and compare clinical characteristics of bilateral keratoconus patients with unilateral Vogt's striae. Methods: In this contralateral eye study, refractive status were evaluated in patients with bilateral keratoconus whose corneas had definite slit-lamp biomicroscopic evidence of unilateral Vogt's striae. All cases underwent a comprehensive ophthalmic examination. Some refractive errors components provided by autorefraction were converted to vectorial notation for power vector analysis. Finally, the outcomes were compared between keratoconus eyes with and without Vogt's striae. Results: Fifty patients aged 20 to 38 years (27.43 ± 5.5) were recruited in this study. The results showed a significant difference in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), non-cycloplegic and cycloplegic autorefraction including sphere, cylinder, spherical equivalent, and J0, between keratoconus eyes with and without Vogt's striae (all P < 0.05), except for J45 (P = 0.518 in non-cycloplegic autorefraction and P = 0.574 in cycloplegic autorefraction). Comparison of cycloplegic and non-cycloplegic autorefraction in both study groups showed significant differences in the sphere and spherical equivalent (all P < 0.001), but no significant difference was found in cylinder, J0, and J45 between the study groups (all P > 0.05). Conclusions: Comparison of the cycloplegic and non-cycloplegic autorefraction in keratoconus eyes with and without Vogt's striae showed significant differences in UDVA, CDVA, and some refractive errors components provided by autorefraction between the two groups, with a worse condition in KCN eyes with Vogt's striae. © 2020 Spanish General Council of Optometr
Corneal Biomechanical Properties in Varying Severities of Myopia
Purpose: To investigate corneal biomechanical response parameters in varying degrees of myopia and their correlation with corneal geometrical parameters and axial length. Methods: In this prospective cross-sectional study, 172 eyes of 172 subjects, the severity degree of myopia was categorized into mild, moderate, severe, and extreme myopia. Cycloplegic refraction, corneal tomography using Pentacam HR, corneal biomechanical assessment using Corvis ST and Ocular Response Analyser (ORA), and ocular biometry using IOLMaster 700 were performed for all subjects. A general linear model was used to compare biomechanical parameters in various degrees of myopia, while central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were considered as covariates. Multiple linear regression was used to investigate the relationship between corneal biomechanical parameters with spherical equivalent (SE), axial length (AXL), bIOP, mean keratometry (Mean KR), and CCT. Results: Corneal biomechanical parameters assessed by Corvis ST that showed significant differences among the groups were second applanation length (AL2, p = 0.035), highest concavity radius (HCR, p < 0.001), deformation amplitude (DA, p < 0.001), peak distance (PD, p = 0.022), integrated inverse radius (IR, p < 0.001) and DA ratio (DAR, p = 0.004), while there were no significant differences in the means of pressure-derived parameters of ORA between groups. Multiple regression analysis showed all parameters of Corvis ST have significant relationships with level of myopia (SE, AXL, Mean KR), except AL1 and AL2. Significant biomechanical parameters showed progressive reduction in corneal stiffness with increasing myopia (either with greater negative SE or greater AXL), independent of IOP and CCT. Also, corneal hysteresis (CH) or ability to dissipate energy from the ORA decreased with increasing level of myopia. Conclusions: Dynamic corneal response assessed by Corvis ST shows evidence of biomechanical changes consistent with decreasing stiffness with increasing levels of myopia in multiple parameters. The strongest correlations were with highest concavity parameters where the sclera influence is maximal. © Copyright © 2021 Sedaghat, Momeni-Moghaddam, Azimi, Fakhimi, Ziaei, Danesh, Roberts, Monfared and Jamali
Effect of Exposure to Pill Contraceptive Low-dose Levels of Homocysteine and Nitric Oxide in Healthy Women
Introduction: Cardiovascular disease is one of the public health priorities. Consumption of oral contraceptives increase the risk of cardiovascular disease and it still remains a concern. This study aimed to investigate the effect of exposure on pill contraceptive low-dose levels on homocysteine and nitric oxide.
methods: In this cohort ( retrospective+ prospective) study, 100 women with normal menstrual cycle aged betwen 20-35 years old refered to health care centers of Yazd, Iran in 2015. This study was conducted through face to face interviews by the researcher who asked for demographic and anthropometric characteristics. Anthropometic indices was measured and the levels of homosysteine and nitric oxide was determined. The data were analyzed using t-test, chi- square test and ANOVA by SPSS 21.
Results: The mean and standard deviation of homocysteine levels in the exposed group acompared to non-exposed group were (3/848±2/357 μmol/L) and (3/284±1/616 μmol/L) as well as the mean and standard deviation of nitric oxide in the exposed group were (p-value=0/41) and (181/360±90/44μM) and in the non-exposed group were (162/654±90/913 μM) and (p-value=0/29) , respectively.According to these results, there was not found any statistical significant difference among these results.
Conclusion: Taking low dose oral contraceptives in healthy women did not change any differences in homocysteine and nitric oxide levels as a modifiable risk factors for cardiovascular disease
CD36 gene polymorphism rs1761667 (G > A) is associated with hypertension and coronary artery disease in an Iranian population
Document details - A Systematic Review and Meta-analysis on Blood Lead Level in Opium Addicts: an Emerging Health Threat
This meta-analysis was conducted aiming to summarize the results obtained from the previous studies so that the effect of opium on blood lead levels (BLLs) can be investigated. Scopus, Embase, PubMed, and Web of Science (ISI) were systematically searched up to June 2020. Heterogeneity of the included studies was evaluated using Cochrane’s Q test and the I2 statistic. A random-effects model was used to pool the weighted mean differences (WMDs) and their 95% confidence intervals (CIs). Out of a total of 2372 citations, eleven articles with 916 participants (487 opium addicts and 429 controls) were included in the study. The meta-analysis results showed that there were higher lead levels (WMD = 14.59 μg/dL, 95% CI = 11.59 to 17.92, Z = 8.60, P < 0.001) in opium addicts than in the control group. The degree of heterogeneity observed (P < 0.001, I2 = 98.1%) might be mainly the result of the type of sampling and of consumption. Moreover, the findings of meta-regression analyses indicated that publication year (β = 1.23, P = 0.287), total sample size (β = 0.05, P = 0.728), and quality scores (β = − 2.91, P = 0.546) had no effects on lead levels in opium addicts. In the sensitivity analysis, it was found that the pooled WMDs remained stable after excluding one by one study. Oral opium consumption increased the amount of lead in the bloodstream, and the measurement of lead levels in opium addicts’ blood may be regarded as a useful test to diagnosis and prognosis of disorders that may lead poisoning causes