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International Ophthalmology Nov 2023To compare the efficacy of phakic intra-ocular lenses in isolation or in combination with corneal crosslinking (CXL) and/or intra-stromal corneal ring segments (ICRS) in... (Meta-Analysis)
Meta-Analysis Review
The efficacy of 2 different phakic intraocular lens implant in keratoconus as an isolated procedure or combined with collagen crosslinking and intra-stromal corneal ring segments: a systematic review and meta-analysis.
PURPOSE
To compare the efficacy of phakic intra-ocular lenses in isolation or in combination with corneal crosslinking (CXL) and/or intra-stromal corneal ring segments (ICRS) in keratoconus.
METHODS
Data extracted from the publications meeting the selection. The outcome parameters included mean pre- and post-operative uncorrected distance visual acuity, corrected distance visual acuity (CDVA), sphere and cylinder of refraction and complications. Available data analyzed with Cochrane Review Manager.
RESULTS
A total of 23 studies including 464 eyes were included. All the parameters showed significant improvement in all subgroups other than CDVA in ACPIOL + CXL subgroup and cylinder in PIOL + CXL subgroups. There was not a significant difference between PCPIOL and ACPIOL in the outcomes, exception was more improvement of CDVA in "ACPIOL only" than" PCPIOL only" subgroup.
CONCLUSION
Both PCPIOLs and ACPIOLs are comparably safe and efficient options in management of KCN and their efficacy significantly improves when combined with CXL/ICRS.
Topics: Humans; Phakic Intraocular Lenses; Photosensitizing Agents; Keratoconus; Riboflavin; Collagen; Corneal Topography; Cross-Linking Reagents; Corneal Stroma
PubMed: 37470861
DOI: 10.1007/s10792-023-02813-z -
Components of one-carbon metabolism and renal cell carcinoma: a systematic review and meta-analysis.European Journal of Nutrition Dec 2020Little is known about the aetiology of renal cell carcinoma (RCC). Components of one-carbon (1C) metabolism, which are required for nucleotide synthesis and methylation... (Meta-Analysis)
Meta-Analysis
PURPOSE
Little is known about the aetiology of renal cell carcinoma (RCC). Components of one-carbon (1C) metabolism, which are required for nucleotide synthesis and methylation reactions, may be related to risk of RCC but existing evidence is inconclusive. We conducted a systematic review and independent exposure-specific meta-analyses of dietary intake and circulating biomarkers of 1C metabolites and RCC risk.
METHODS
Medline and Embase databases were searched for observational studies investigating RCC or kidney cancer incidence or mortality in relation to components of 1C metabolism and 12 eligible articles were included in the meta-analyses. We used Bayesian meta-analyses to estimate summary relative risks (RRs) and 95% credible intervals (CrIs) comparing the highest versus lowest categories as well as the between-study heterogeneity.
RESULTS
We did not find convincing evidence of an association between any exposure (riboflavin, vitamin B, folate, vitamin B, methionine, homocysteine, choline, or betaine) and RCC risk. However, vitamin B biomarker status did have a protective (RR = 0.62) but imprecise (95% CrI 0.39-1.14) effect estimate and folate intake had a notable association as well (RR = 0.85, 95% CrI 0.71-1.01).
CONCLUSION
There was a lack of precision due largely to the low number of studies. Further investigation is warranted, especially for folate and vitamin B, which had consistent suggestive evidence of a protective effect for both dietary intake and biomarker status. A unique strength of this review is the use of Bayesian meta-analyses which allowed for robust estimation of between-study heterogeneity.
Topics: Bayes Theorem; Carbon; Carcinoma, Renal Cell; Folic Acid; Humans; Kidney Neoplasms; Risk Factors; Vitamin B 12; Vitamin B 6
PubMed: 32162043
DOI: 10.1007/s00394-020-02211-6 -
Indian Journal of Ophthalmology May 2023Corneal cross-linking (CXL), a corneal strengthening procedure, is known to alter anterior stroma swelling behavior and is one of the treatment modalities of bullous... (Review)
Review
Corneal cross-linking (CXL), a corneal strengthening procedure, is known to alter anterior stroma swelling behavior and is one of the treatment modalities of bullous keratopathy (BK). There are multiple studies published on the role of CXL in the treatment of BK. These articles had heterogeneous study population, different protocols used, and variable conclusions. This systematic review aimed to determine the role of CXL in the treatment of BK. The primary outcomes considered were changes in central corneal thickness (CCT) after 1, 3, and 6 months of CXL. The secondary outcome measures were changes in visual acuity, corneal clarity, subjective symptoms, and complications after CXL. We included randomized control trials (RCTs), observational and interventional studies, and case series with reports of more than 10 cases in this review. In RCTs, the mean pre-CXL CCT (794.0 ± 178.5 μm) in the intervention group (n = 37), decreased at 1 month (750.9 ± 154.3 μm) followed by a subsequent increase, but this difference was not significant during the 6-month follow-up (P- value 0.28, 0.82, and 0.82 at 1, 3, and 6 months, respectively). In noncomparative clinical studies (n = 188), the mean pre-CXL CCT (794.0 ± 178.5 μm) decreased at 1 month (710.9 ± 127.2 μm, P < 0.0001). Seven of the 11 articles included in the review reported no significant improvement in vision with CXL. The initial improvement in corneal clarity and clinical symptoms was not sustained. Current evidence suggests that CXL has short-term efficacy in the treatment of BK. More RCTs with high-quality evidence are needed.
Topics: Humans; Corneal Cross-Linking; Photosensitizing Agents; Riboflavin; Ultraviolet Rays; Collagen; Cross-Linking Reagents; Corneal Stroma; Keratoconus; Corneal Topography
PubMed: 37203022
DOI: 10.4103/ijo.IJO_1942_22 -
Nutritional Neuroscience Dec 2023Brain oxygen deprivation causes morphological damage involved in the formation of serious pathological conditions such as stroke and cerebral palsy. Therapeutic methods... (Review)
Review
Brain oxygen deprivation causes morphological damage involved in the formation of serious pathological conditions such as stroke and cerebral palsy. Therapeutic methods for post-hypoxia/anoxia injuries are limited and still have deficiencies in terms of safety and efficacy. Recently, clinical studies of stroke have reported the use of drugs containing riboflavin for post-injury clinical rehabilitation, however, the effects of vitamin B2 on exposure to cerebral oxygen deprivation are not completely elucidated. This review aimed to investigate the potential antioxidant, anti-inflammatory and neuroprotective effects of riboflavin in cerebral hypoxia/anoxia. After a systematic search, 21 articles were selected, 8 preclinical and 12 clinical studies, and 1 translational study. Most preclinical studies used B2 alone in models of hypoxia in rodents, with doses of 1-20 mg/kg (in vivo) and 0.5-5 µM (in vitro). Together, these works suggested greater regulation of lipid peroxidation and apoptosis and an increase in neurotrophins, locomotion, and cognition after treatment. In contrast, several human studies have administered riboflavin (5 mg) in combination with other Krebs cycle metabolites, except one study, which used only B2 (20 mg). A reduction in lactic acidosis and recovery of sensorimotor functions was observed in children after treatment with B2, while adults and the elderly showed a reduction in infarct volume and cognitive rehabilitation. Based on findings from preclinical and clinical studies, we conclude that the use of riboflavin alone or in combination acts beneficially in correcting the underlying brain damage caused by hypoxia/anoxia and its inflammatory, oxidative, and behavioral impairments.
PubMed: 38095869
DOI: 10.1080/1028415X.2023.2288387 -
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 -
Cornea Feb 2023The aim of this study was to compare the outcomes of 18 mW/cm 2 (5 minutes) versus 9 mW/cm 2 (10 minutes) accelerated corneal collagen cross-linking protocols in... (Meta-Analysis)
Meta-Analysis
PURPOSE
The aim of this study was to compare the outcomes of 18 mW/cm 2 (5 minutes) versus 9 mW/cm 2 (10 minutes) accelerated corneal collagen cross-linking protocols in patients with progressive keratoconus.
METHODS
A systematic review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, and electronic information was searched to identify studies comparing the outcomes of 5- versus 10-minute protocols in patients with progressive keratoconus. Mean changes in uncorrected visual acuity, best-corrected visual acuity, cylinder (diopters), thinnest corneal thickness, corneal keratometry values (K1 and K2), corneal high-order aberration (HOA), spherical aberration, coma, and trefoil were the primary outcome measures. Secondary outcome measures included the mean change in central corneal thickness and postoperative complications. Random effects modeling was used for the analysis.
RESULTS
Four studies that enrolled 329 eyes were included. The 10-minute protocol had significantly improved outcomes compared with the 5-minute protocol for the mean changes in K1 and K2 ( P < 0.00001), corneal total HOA ( P = 0.0002), and corneal coma ( P = 0.00001). However, no statistically significant differences were found between the 2 protocols in uncorrected visual acuity, best-corrected visual acuity, cylinder, thinnest corneal thickness, spherical aberration, or trefoil. The 5-minute protocol was associated with a significantly lower mean change in the central corneal thickness for secondary outcomes. In addition, no significant differences were found between the 2 protocols for postoperative complications.
CONCLUSIONS
The 10-minute protocol had better K1, K2, and HOA outcomes than the 5-minute protocol, but no statistically significant differences in the other outcomes.
Topics: Humans; Collagen; Corneal Cross-Linking; Corneal Topography; Cross-Linking Reagents; Keratoconus; Photochemotherapy; Photosensitizing Agents; Postoperative Complications; Riboflavin
PubMed: 36156043
DOI: 10.1097/ICO.0000000000003124 -
Cornea Mar 2016To examine the efficacy of corneal collagen cross-linking (CXL) for the treatment of keratoconus (KCN). (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To examine the efficacy of corneal collagen cross-linking (CXL) for the treatment of keratoconus (KCN).
METHODS
A systemic literature review and meta-analysis of ocular functional and structural parameters of patients with KCN undergoing cross-linking procedures were performed using PubMed and the web of science. A literature search was performed for relevant peer-reviewed publications on population-based studies. Data were analyzed with R software (Meta library), and heterogeneity was assessed with the Cochran Q and I. A random-effects model was used for high heterogeneity; otherwise a fixed model was used. Sensitivity analysis of particular tested groups was used to explain high heterogeneity. The main outcome measures extracted from the articles were corrected distance visual acuity, uncorrected distance visual acuity, and maximum K.
RESULTS
An improvement in visual acuity of 1 to 2 Snellen lines was found 3 months or more after undergoing CXL. Changes were more pronounced in uncorrected visual acuity. Some topography parameters were found to be improved (0.6-1 diopters) 12 to 24 months after CXL. The refractive cylinder improved by 0.4 to 0.7 diopters. Endothelial cell density decreased by 225 cells per square millimeter in the first 3 months and thereafter returned to normal. Corneal thickness was reduced by 10 to 20 μm in the year following CXL but not after 24 months. No changes in intraocular pressure were noted.
CONCLUSIONS
CXL is a safe and effective method for halting the deterioration of KCN, while slightly improving visual function.
Topics: Collagen; Corneal Endothelial Cell Loss; Corneal Topography; Cross-Linking Reagents; Humans; Intraocular Pressure; Keratoconus; Photochemotherapy; Photosensitizing Agents; Riboflavin; Visual Acuity
PubMed: 26751990
DOI: 10.1097/ICO.0000000000000723 -
Cornea Aug 2018To systematically compare standard epithelium-off corneal collagen cross-linking (SCXL) and transepithelial corneal collagen cross-linking (TECXL) for treating... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To systematically compare standard epithelium-off corneal collagen cross-linking (SCXL) and transepithelial corneal collagen cross-linking (TECXL) for treating keratoconus.
METHODS
PubMed, EMBASE, the Cochrane Library, the US trial registry (ClinicalTrials.gov), VIP Database, Wanfang Databse, and China National Knowledge Infrastructure searches up to February 2017 were conducted. Primary outcomes were changes at 1 year in uncorrected distance visual acuity, maximum keratometry (Kmax), and mean keratometry (mean K). Secondary outcomes were changes at 1 year in corrected distance visual acuity, mean refractive spherical equivalent, central corneal thickness, endothelial cell density, and the occurrence of adverse events.
RESULTS
Eight studies with a total of 455 eyes were included. For primary outcomes, SCXL showed a greater reduction in mean K [standardized mean difference (SMD) 0.28; 95% confidence interval (CI), 0.03-0.53; P = 0.03] compared with TECXL. Subgroup analysis indicated that SCXL had a comparable effect on reducing mean K with TECXL protocols using chemical enhancers (SMD 0.05; 95% CI, -0.36 to 0.45; P = 0.82) but a greater reduction in mean K compared with TECXL with current iontophoretic protocols (SMD 0.43; 95% CI, 0.10-0.75; P = 0.01). For the other outcomes, there were no statistically significant differences.
CONCLUSIONS
With the exception of less reduction in mean K with current iontophoretic protocols, analysis of the limited number of comparative studies available seems to demonstrate that SCXL and TECXL have a comparable effect on visual, refractive, pachymetric, and endothelial parameters at 1 year after surgery. Further follow-up is required to determine whether these techniques are comparable in the long-term.
Topics: Collagen; Cornea; Corneal Pachymetry; Corneal Topography; Cross-Linking Reagents; Drug Administration Routes; Epithelium, Corneal; Humans; Keratoconus; Photochemotherapy; Photosensitizing Agents; Riboflavin; Ultraviolet Rays
PubMed: 29847492
DOI: 10.1097/ICO.0000000000001632 -
European Journal of Dentistry Oct 2023Matrix metalloproteinase (MMP) enzymes participate in collagen matrix degradation, including in dentine, potentially compromising bond strength. Therefore, MMP...
Impact of Dentine Pretreatment with Matrix Metalloproteinase Inhibitors on Bond Strength of Coronal Composite Restorations: A Systematic Review and Meta-analysis of In Vitro Studies.
Matrix metalloproteinase (MMP) enzymes participate in collagen matrix degradation, including in dentine, potentially compromising bond strength. Therefore, MMP inhibitors have been hypothesized to improve restoration bond strength and stability. This systematic review aimed to evaluate the influence of different MMP inhibitors applied as dentine surface pretreatments on the immediate (24 hours) and longer term (months) bond strength of direct coronal composite restorations. This systematic literature review followed the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statement. A systematic literature search of three databases (Ovid MEDLINE, Ovid Embase, and Google Scholar) was conducted independently by two reviewers from inception to April 2022. An adapted quality assessment tool was independently applied by two reviewers for risk of bias assessment. RevMan v5.4 software was used for meta-analyses. A randomeffectsmodel was used to generatemean differences with 95% confidence intervals for treatment and control comparisons. The Q-test and I2-test were used to test for heterogeneity. The proportion of total variance across studies attributable to heterogeneity rather than chance was calculated. Overall effects were tested using the Z-test, while subgroup differences were tested using Chi-squared tests. Of 934 studies, 64 studies were included in the systematic review and 42 in the meta-analysis. Thirty-one MMP inhibitors were reported, three of which were included in the meta-analysis: 2% chlorhexidine (CHX), 0.3M carbodiimide (EDC), and 0.1% riboflavin (RIBO). Pretreatment with 2% CHX for 30 and 60 seconds did not significantly improve bond strength compared with controls either immediately or after long-termageing. However, pretreatment with 0.3MEDC and 0.1% RIBO (but not CHX) significantly improved bond strength compared with control groups both immediately and over time. Most studies showed a medium risk of bias. These in vitro findings pave the way for rationale clinical trialing of dentine surface pretreatment with MMP inhibitors to improve clinical outcomes.
PubMed: 36400108
DOI: 10.1055/s-0042-1757582 -
Graefe's Archive For Clinical and... Jun 2024Corneal collagen crosslinking (CXL) is the primary treatment for progressive keratoconus which has a significant impact on vision and quality of life. Our study aimed to... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Corneal collagen crosslinking (CXL) is the primary treatment for progressive keratoconus which has a significant impact on vision and quality of life. Our study aimed to compare the efficacy and safety of epithelium-on versus epithelium-off CXL to treat keratoconus.
METHODS
We searched PubMed, Medline, Embase, Web of Science, and Scopus databases. We included studies that compared standard epithelium-off with epithelium-on CXL. The primary outcome measures were changes in corrected distance visual acuity (CDVA) and maximum keratometry (Kmax), and the secondary outcomes were uncorrected distance visual acuity (UDVA), central corneal thickness (CCT), and adverse events. A meta-analysis was performed on the primary and secondary outcomes based on the weighted mean differences between baseline to 12-month follow-up.
RESULTS
The search retrieved 887 publications with 27 included in the systematic review. A total of 1622 eyes (1399 patients; age 25.51 ± 4.02 years) were included in comparisons of epithelium-off to epithelium-on CXL in keratoconus. Epithelium-off CXL treated 800 eyes and epithelium-on CXL for 822 eyes. At 12-month follow-up, CDVA and Kmax showed no significant difference between the epithelium-off and epithelium-on CXL. The secondary outcomes showed that UDVA was better in epithelium-off CXL (- 0.11D, 95% CI - 0.12, - 0.1; p < 0.001) and there was more thinning in CCT in epithelium-off CXL (- 3.23 μm, 95% CI - 4.64, - 1.81; p <0.001).
CONCLUSION
Epithelium-off and epithelium-on CXL were both effective to treat progressive keratoconus. Further research is needed to compare the long-term outcomes and safety of both CXL protocols for adaptation into clinical practice.
Topics: Keratoconus; Humans; Cross-Linking Reagents; Collagen; Photosensitizing Agents; Epithelium, Corneal; Photochemotherapy; Visual Acuity; Riboflavin; Ultraviolet Rays; Corneal Topography; Corneal Stroma
PubMed: 37938377
DOI: 10.1007/s00417-023-06287-8