Progress of corneal collagen cross-linking combined with refractive surgery

As a photochemical reaction that can stiffen the cornea,corneal collagen cross-linking(CXL) is the only promising method of preventing the progress of keratectasia,such as keratoconus and secondary ectasia following refractive surgery. The aim of CXL is to stabilize the underlying condition,with a small chance of visual improvement. Combining CXL with refractive surgery targeting both stabilization and reshaping of the corneal tissue for visual function improvement is a good treatment option. This review aims to provide a comprehensive and unbiased summary of the published research regarding combined CXL and refractive surgery,including measures and results,to help elucidate the future direction of CXL.

Experimental study on the treatment of rabbit corneal melting after alkali burn with Collagen cross-linking

AIM: To evaluate the effect of Collagen cross-linking on the prevention of melting in rabbit corneas after alkali burn. METHODS: Twenty New Zealand white rabbits were randomly divided into model control group and collagen cross-linking treatment group. The second group of rabbits received collagen cross linked treatment. Both groups were applied with antibiotic eye drops to prevent infection. The corneas were evaluated for melting, opacity, pathological and immunohistochemistry, record the changes when 28 days after the animals were killed. RESULTS: In the control group, 6 out of 8 rabbits showed corneal melting after injury (14 +/- 4) days, while two corneal perforated. In collagen cross-linking treatment group, one rabbit showed corneal melting after injury 23 days, without corneal perforation; corneal dissolution rate between the two groups was significantly different (P <0.05). Pathological examination suggested that in the treatment group, mild corneal edema, mild damage to collagen fibers, inflammatory cell infiltration was significantly less than the control group. Immunohistochemistry showed that corneal collagen fibers arranged in neat rows in the control group. CONCLUSION: Collagen cross-linking treatment not only can prevent and delay the corneal melting after alkali burn, but also can reduce the destruction of corneal collagen fibers and infiltration of inflammatory cells in the corneal tissue.

A short-term study of corneal collagen cross-linking with hypo-osmolar riboflavin solution in keratoconic corneas

AIM: To report the 3mo outcomes of collagen crosslinking(CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium.METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure.RESULTS: The mean thinnest thickness of the cornea was 408.5 ±29.0 μm before treatment and reduced to369.8 ±24.8 μm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0 ±26.5 μm before CXL and recover to 412.5 ±22.7 μm at 3mo after treatment, P =0.659). Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6 ±4.0 diopters, and slightly decreased(54.7±4.9 diopters) after surgery(P =0.085). Mean best-corrected visual acuity was 0.55 ±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery(P =0.879).The endothelial cell density was 2706.4 ±201.6 cells/mm2 before treatment, and slightly decreased( 2641. 2 ±218.2 cells/mm2) at last fellow up(P =0.002).CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.

Corneal collagen cross-linking and liposomal amphotericin B combination therapy for fungal keratitis in rabbits

AIM： To observe the therapeutic effect of corneal collagen cross-linking（CXL） in combination with liposomal amphotericin B in fungal corneal ulcers.METHODS： New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B（n =5 each）. The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28 d after treatment. The corneas were examined with transmission electron microscopy（TEM） at 4wk.RESULTS： A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d（P 〈0.05）. The corneal epithelium defect areas of the combined group was smaller than that of the CXL group（P 〈0.05） on 7 and 14 d, but there were no statistical differences on 3, 21 and 28 d. The corneal epithelium defects of the two treatment groups have been healed by day 21. The corneal epithelium defects of the control group were healed on 28 d. The diameters of the corneal collagen fiber bundles（42.960 ±7.383 nm in the CXL group and 37.040±4.160 nm in the combined group） were thicker than that of the control group（24.900±1.868 nm）,but there was no difference between the two treatment groups. Some corneal collagen fiber bundles were distorted and with irregular arrangement, a large number of fibroblasts could be seen among them but no inflammatory cells in both treatment groups. CONCLUSION： CXL combined with liposomal amphotericin B have beneficial effects on fungal corneal ulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease.

Scheimpflug imaged corneal changes on anterior and posterior surfaces after collagen cross-linking

AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 30.6±8.9y).Prior to treatment and an average 7mo after therapy,Scheimpflug analysis was performed using Pentacam HR.In addition to corneal thickness assessments,corneal radius,elevation,and aberrometric measurements were performed both on anterior and posterior corneal surfaces.Data obtained before and after surgery were statistically analyzed.RESULTS:In terms of horizontal and vertical corneal radius,and central corneal thickness no deviations were observed an average 7mo after operation.Corneal higher order aberration showed no difference neither on anterior nor on posterior corneal surfaces.During follow-up period,no significant deviation was detected regarding elevation values obtained by measurement in mm units between the 3.0-8.0 mm-zones.CONCLUSION:Corneal stabilization could be observed in terms of anterior and posterior corneal surfaces,elevation and higher order aberration values 7mo after collagen cross-linking therapy for keratoconus.

Riboflavin-UVA collagen cross-linking for the treatment of acanthamoeba keratitis

In this review,recent studies regarding riboflavin-ultraviolet A(UVA)collagen cross-linking for the treatment of acanthamoeba keratitis(AK)were reviewed.English written studies about acanthamoeba,keratitis,riboflavin and collagen cross-linking were retrieved from PubMed search engine(www.ncbi.nlm.nih.gov/pubmed).Although there were significant numbers of cases reporting the effectiveness of riboflavin-UVA collagen cross-linking in AK,experimental studies(in vivo and in vitro)failed to verify amoebicidal or cysticidal effect of riboflavin-UVA collagen cross-linking.In conclusion,the efficacy of riboflavin-UVA collagen cross-linking for the treatment of AK is still debatable.It is necessary to conduct a prospective case-control study for clear guidance for clinicians.

Clinical outcomes at one year following keratoconus treatment with accelerated transepithelial cross-linking

This study evaluated the clinical outcomes in keratoconus corneas following accelerated transepithelial corneal collagen cross-linking（CXL）（Avedro KXL system,Waltham,MA,USA） over one year of follow-up.The mean depth of the demarcation line measured by optical coherence tomography（OCT） was 205.19 μm.One month after surgery,a non-statistically significant change was noted in sphere（P= 0.18） and in spherical equivalent（P= 0.17）,whereas a significant improvement was observed in corrected distance visual acuity（P=0.04）.A significant change was observed in topographic astigmatism（P= 0.03） and posterior corneal a sphericity（P= 0.04）.Accelerated transepithelial CXL may be a useful technique for the management of progressive keratoconus.

Analysis of the effective dose of ultraviolet light in corneal cross-linking

AIM: To analyze the efficacy of ultraviolet (UV) light initiating corneal cross-linking (CXL). METHODS: The time-dependent absorption of UV light due to the depletion of the initiator (riboflavin) was calculated. The effective dose of CXL with corneal surface covered by a thin layer of riboflavin was derived analytically. The cross linking time was calculated by the depletion level of the riboflavin concentration. A comprehensive method was used to derive analytic formulas. RESULTS: The effective dose of CXL was reduced by a factor (R) which was proportional to the thickness (d) and concentrations (C-0) of the riboflavin surface layer. Our calculations showed that the conventional dose of 5.4 J/cm(2) had a reduced effective dose of 4.3 and 3.45 J/cm(2), for d was 100 and 200 pm, respectively, and C-0=0.1%. The surface cross linking time was calculated to be T*=10.75s, for a depletion level of 0.135 and UV initial intensity of 30 mW/cm(2). The volume T* was exponentially increasing and proportional to exp (bdC(0)), with b being the steady state absorption coefficient. CONCLUSION: The effective dose of CXL is reduced by a factor proportional to the thickness and concentrations of the riboflavin surface layer. The wasted dose should be avoided by washing out the extra riboflavin surface layer prior to the UV light exposure.

Topography versus non-topography-guided photorefractive keratectomy with corneal cross-linking variations in keratoconus

AIM:To compare the visual results of non-topographyguided and topography-guided photorefractive keratectomy(PRK)applying sequential and simultaneous corneal crosslinking(CXL)treatment for keratoconus.METHODS:Interventional and comparative prospective study.Sixty-nine eyes(36 patients)suffering from keratoconus(stages 1 Amsler-Krumeich classification)were divided into four groups:sequential topography-guided photorefractive keratectomy with CXL,simultaneous topography-guided photorefractive keratectomy with CXL,simultaneous nontopography guided photorefractive keratectomy with CXL,and sequential non-topography guided photorefractive keratectomy with CXL.The main outcome measures were pre-and postoperative uncorrected distance visual acuity(UDVA),best corrected distance visual acuity(CDVA),manifest refraction,contrast sensitivity,and keratometry.RESULTS:All analyzed visual,contrast sensitivity,and refractive parameters showed a significant improvement in the four groups(all P<0.05).A noticeable improvement was seen in keratometry in all the groups,and a remarkable difference was observed between topography-guided groups in comparison to non-topography-guided groups(P<0.05).Interestingly,the improvement in all parameters showed a degree of stability to the end of the follow-up.CONCLUSION:The treatment priorities in all four groups are safety,efficacy,and predictability in the correction of the sphero-cylindrical errors in mild and moderate keratoconus.No significant differences among groups in the recorded objective outcomes were found.

FSLASIK联合快速角膜交联术后角膜透明度的临床观察

目的研究飞秒激光辅助准分子激光原位角膜磨镶术(FSLASIK)联合快速角膜交联手术(CXL)矫正近视手术术后患者早期的角膜光密度(CD)、视力、屈光度的变化特点。方法回顾性临床研究。本研究筛选了2019年至2021年在本院行FSLASIK联合快速角膜交联手术矫正近视和散光的30例(60只眼)患者,进行回顾性的分析,分别于术前、术后1个月、术后3个月进行常规检查,检查项目包括屈光度、裸眼视力(UCVA)、裂隙灯检查和Pentacam眼前节分析仪。观察记录手术前后角膜光密度的变化;观察记录等效球镜度数(SE)的变化,数据统计完成后,采用IBM SPSS 24.0统计软件进行分析,通过KolmogorovSmirnov测试对各组数据进行正态性检验。对符合正态分布的数据进行重复方差检验,进一步两两比较采用LSDt检验,对于不符合正态分布的采用Friedman检验分析。结果(1)术后1个月UCVA与术前最佳矫正视力(BCVA)相比,略微降低(P<0.05)。术后3个月UCVA与术后1个月UCVA相比差异无统计学意义(P>0.05)。术后3个月UCVA与术前BCVA相比,差异无统计学意义(P>0.05)。(2)术后等效球镜度明显降低,较术前差异有统计学意义(P<0.05),术后1个月与术后3个月的SE之间差异无统计学意义(P>0.05)。(3)从整体光密度上看,术后1个月的角膜光密度与术前相比差异无统计学意义。术后3个月的角膜光密度与术前相比略微降低(P<0.05),术后3个月与术后1月相比略微降低(P<0.05)。(4)从不同直径范围的角膜光密度上看,术后1个月,角膜直径0~2 mm、2~6 mm区域内的角膜光密度与术前相比略微提高(均P<0.05),角膜直径6~10 mm内的角膜光密度与术前相比略降低(P<0.05);术后3个月,在角膜直径0~2 mm、2~6 mm区域内的角膜光密度与术前比差异均无统计学意义;角膜直径6~10 mm区域内的角膜光密度与术前相比略微降低(P<0.05)。(5)从不同分层的角膜光密度上看,术后1个月,角膜前层(前120μm)和角膜后层(后60μm)的角膜光密度与术前相比差异无统计学意义(P>0.05);角膜中央层的角膜光密度与术前相比略微降低(P<0.05)。术后3个月,角膜前层、中央层、后层角膜光密度与术前相比均略微降低(均P<0.05)。结论FSLASIK Xtra术后早期可以维持较好的角膜透明度,具有较好的安全性、有效性与准确性。

Bio-Oss Collagen治疗牙周炎骨下袋的临床疗效观察

目的评价Bio—OssCollagen治疗牙周骨下袋的临床效果。方法选择全身健康的牙用基础治疗后6周左右的慢性牙周炎患者10例,男性6例,女性4例,平均年龄40．8岁,共有18处骨下袋,试验组9处骨下袋17个位点。对照组9处骨下袋15个位点。牙周翻瓣术分别植入Bio-Om Collagen(试验组)和Bio-Oss(对照组)。分别在手术前和手术后6个月检查牙周袋探诊深度(PD)、牙龈出血指数(BI)、牙龈退缩(GR)和临床附着水平(C地),拍摄术区平行定位X线片评价植骨前后骨缺损处牙槽骨的修复情况。结果植骨前两组的各项指标阃无显著性差异。Bio-Om CoUagen组植骨前的PD(6．6±1．2mm)、BI(2．7±0．8)、GR(2．2±0．8mm)和CAl．,(8．8±1．3mm),植骨后6个月分则为PD(3．8±0．9ram)、BI(1．9±0．7)、GR(2．4±1．Imm)和CAL(6．2士1．2mm);Bio -Oss组植骨前的PD(6．1±1．0mm)、BI(2．2±0．7)、GR(1．9±1．5mm)和CAL(8．0±2．0mm),植骨后6个月分别为PD(4．0±0．7mm)、BI(1．9±0．7)、GR(1．9±1．2mm)和CAL(5．9±1．6mm),两组PD和CAL以及试验组BI的改变均有明显的统计学意义(P<O．05),GR在治疗前后均无显著差异。Bio一Oss Collagen组PD的降低(2．8±0．9mm)要明显大于Bio-Oss组(2．0±1．0mm)(P<0．05)。余指标则均无显著性差异。比较治疗前后的X线片。膏缺损处牙槽骨均明显增加。结论Bio-Oss CoUagen和Bio—Oss两种骨材料均可明显地降低牙周袋探诊深度和减少附着丧失,奉研宽中Bio-Oss CoHagen要优于Bio-0ss,而且临床操作较方便。

Corneal collagen cross-linking epithelium-on vs. epithelium-off: a systematic review and meta-analysis

Background The purpose of the study was to determine the advantages and disadvantages of epi-on corneal cross-linking(CXL)techniques compared with standard epi-off CXL.Methods We searched MEDLINE and EMBASE for randomized controlled trials(RCTs)and non-randomized studies of interventions(NRSIs)and we evaluated the selected papers according to the Cochrane risk of bias tool.We considered,as primary outcomes,average Kmax flattening,changes in uncorrected and corrected distance visual acuity(UDVA and CDVA);as secondary outcomes,we considered changes in pachymetry values and endothelial cell density(ECD).We also investigated adverse events related to the treatments and treatment failure.Meta-analysis was conducted with a fixed or random-effects model using weighted mean difference(MD)with 95%confidence interval(CI)as the effect size.Results A total of 15 studies were included and among these 15 trials,9 were RCTs and 6 were NRSIs,but only 4 studies showed no high risk of bias and were included in this meta-analysis.Our analysis revealed significant postoperative differences in CDVA(MD=0.07;95%CI 0.04 to 0.10;P<0.001),and no significative differences in UDVA,Kmax,central corneal thickness(CCT)and ECD(P>0.05).Epi-on CXL protocol was found to be significantly less prompt to have risks of delay in epithelial healing(P=0.035)and persistent stromal haze(P=0.026).Conclusion Epi-on CXL is as effective as epi-off CXL.Except for a higher significant improvement in CDVA with current epi-on protocols,our meta-analysis demonstrates that epi-on and epi-off CXL have comparable effects on visual,topographic,pachymetric,and endothelial parameters.Epi-on CXL has clinical advantages in terms of comfort and avoidance of complications as it reduces the risk of developing delay in epithelial healing and persistent stromal haze.

跨上皮快速角膜胶原交联术治疗进展期圆锥角膜患者的效果

目的探讨跨上皮快速角膜胶原交联术(CXL)治疗进展期圆锥角膜患者的效果。方法选取2017年10月至2021年3月于哈尔滨爱尔眼科医院诊治的60例(65眼)进展期圆锥角膜患者,均行跨上皮快速CXL,比较患者治疗前后裸眼视力(UCVA)、最佳矫正视力(BCVA)、屈光状态、角膜透明及眼压。结果术后3、6个月,患者UCVA均高于术前及术后1、12个月,且术后12个月高于术后1个月,差异有统计学意义(P<0.05)。术后3、6个月,患者BCVA高于术前及术后1、12个月,且术后6个月高于术后3个月,术后12个月高于术后1个月,差异有统计学意义(P<0.05)。术前及术后不同时间点的球镜度比较差异无统计学意义;术后1个月柱镜度低于术前,术后12个月柱镜度高于术后1、3、6个月,差异有统计学意义(P<0.05)。术前及术后1、3、6、12个月,患者眼压比较差异无统计学意义。随访期间,所有患者未出现角膜感染,晶状体保持透明。结论跨上皮快速CXL治疗进展期圆锥角膜效果显著,可有效改善患者视力水平,具有较高应用价值。

Corneal collagen crosslinking in keratoconus and other eye disease

Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen crosslinking(CXL) with riboflavin and Ultraviolet-A(UVA) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. Studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative spherical equivalent(SEQ) was reduced by an average of more than 1 D and refractive cylinder decreased by about1 D. The major indication for the use of CXL is to inhibit the progression of corneal ecstasies, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photo ablation. This treatment has been used to treat infectious corneal ulcers with apparent favorable results. Most recent studies demonstrate the beneficial impact of CXL for iatrogenic ecstasies, pellucid marginal degeneration, infectious keratitis, bullous keratopathy and ulcerative keratitis. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subject to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze,permanent scars, endothelial damage, treatment failure,sterile infiltrates, bullous keratopathy and herpes reactivation are the other reported complications of this procedure.

Covalent and Ionic Bonding between Tannin and Collagen in Leather Making and Shrinking:A MALDI-ToF Study

Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract.The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions,if any,did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin.The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight(MALDI ToF)mass spectrometry.Reactions between the two materials did appear to occur,with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the disappearance of ionic bonds.The linkages between the two materials appeared to be by amination of the phenolic–OHs of the tannin by the amino groups of the non-skeletal side chains of arginine,and by esterification by the–COOH groups of glutamic and aspartic acid of the aliphatic alcohol-OH on the C3 site of the flavonoid units heterocycle of the tannin.The proportion of covalent linkages increases markedly and predominate with increasing temperatures.This tightening of the tannin-protein covalent network formed may be an additional contributing factor both to leather wear resistance and performance as well to leather shrinking when this is subjected to excessive temperatures.

5-year follow-up of combined non-topography guided photorefractive keratectomy and corneal collagen cross linking for keratoconus

AIM： To evaluate the visual outcomes of simultaneous non-topography guided photorefractive keratectomy（PRK） and corneal collagen cross-linking（CXL） in eyes with keratoconus 5 y after the procedure.METHODS： Prospective, interventional, non-randomized, and non-controlled case series design was used. Sixty eyes of 30 patients（16 males and 14 females; age： 21-41 y） with mild, non-progressive（stages 1-2） keratoconus were enrolled. Refraction, uncorrected distance visual acuity（UDVA） and corrected distance visual acuity（CDVA）, flat and steep keratometry readings, and adverse events were evaluated preoperatively and postoperatively. Data were collected preoperatively and postoperatively at 3 mo, 1, 2, 3, 4, and 5 y follow-up visits after combined non-topography-guided PRK with CXL was performed. All patients had at least 5 y of follow-up.RESULTS： All study parameters showed a statistically significant improvement at 5 y over baseline values. The mean follow-up time was 68.20±4.71 mo（range： 60-106 mo）. Patients showed a significant improvement in UDVA from 1.24±0.79 log MAR prior to combined non-TG-PRK＋CXL to 0.06±0.15 log MAR postoperatively at the time of their last follow-up visit. CDVA significantly increased from 0.06±0.19 log MAR preoperatively to 0.03±0.12 log MAR postoperatively. A significant decrease in the mean spherical equivalent（SE） refraction was observed from-2.28±1.8 to-0.79±0.93 diopters（D）（P〈0.05）, and the manifest sphere decreased from-1.62±1.23 to-0.27±0.21 D（P=0.001）. The manifest cylinder significantly decreased from-1.73±0.86 to-0.29±0.34 D postoperatively（P=0.001）. The mean steep keratometry was 45.13±1.32 vs 47.28±2.12 D preoperatively（P〈0.05）, and the preoperative mean steepest keratometry（Kmax） 48.6±3.1 was reduced significantly to 46.8±2.9 postoperatively（P〈0.05）. CONCLUSION： Combined non-TG-PRK with 15 min CXL is an effective and safe option for correcting mild refractive error and improving visual acuity in patients with mild stable keratoconus.

水解胶原蛋白肽联合乳清蛋白对改善胃肠手术患者营养状况的研究

目的探讨乳清蛋白联合水解胶原蛋白肽对胃肠道患者围术期营养支持的临床应用价值。方法选取2020年1月至2022年6月该院胃肠外科择期行胃肠道手术患者80例作为研究对象,并将其随机分为观察组和对照组,每组40例。两组患者入院时采用营养风险筛查2002量表进行营养风险筛查,当评分≥3分,对照组患者围术期口服或管饲输注乳清蛋白,观察组患者使用乳清蛋白联合水解胶原蛋白肽,对比两组患者入院时、术前1 d、术后7 d的总蛋白、清蛋白、前清蛋白水平及出院前营养状况及切口愈合率。结果两组患者入院时、术前1 d、术后7 d的总蛋白、清蛋白、前清蛋白水平随时间而改变,差异均有统计学意义(F_((时间)=1548.752,P_(时间)<0.05;F_(时间)=172.897,P_(时间)<0.05;F_(时间)=271.346,P_(时间)<0.05);观察组和对照组患者入院时、术前1 d、术后7 d的总蛋白、清蛋白水平组间效应差异均有统计学意义(F_(组间)=5.268,P_(组间)<0.05;F_(组间)=5.619,P_(组间)<0.05),但前清蛋白水平组间效应差异无统计学意义(F_(组间)=1.782,P_(组间)>0.05)。时间因素对总蛋白、清蛋白、前清蛋白水平的影响随着治疗方法不同而有所不同,差异均有统计学意义(F_(交互)=56.965,P_(交互)<0.05;F_(交互)=40.911,P_(交互)<0.05;F_(交互)=0.837,P_(交互)<0.05)。观察组营养正常率为32.5%,高于对照组的10.0%,差异有统计学意义(P<0.05)。观察组甲级切口愈合率为100.0%,高于对照组的90.0%,差异有统计学意义(P<0.05)。结论使用乳清蛋白联合水解胶原蛋白肽对有营养风险的胃肠手术患者围术期进行肠内营养支持,疗效具有优势。

Association of bone turnover biomarkers with severe intracranial and extracranial artery stenosis in type 2 diabetes mellitus patients

BACKGROUND Intracranial and extracranial artery stenosis is associated with cerebral infarction.Vascular calcification and atherosclerosis are the main causes of stenosis and major risk factors for cardiovascular and cerebrovascular events in patients with type 2 diabetes mellitus(T2DM).Bone turnover biomarkers(BTMs)are associated with vascular calcification,atherosclerosis,glucose,and lipid metabolism.AIM To investigate the association of circulating BTM levels with severe intracranial and extracranial artery stenosis in patients with T2DM.METHODS For this cross-sectional study including 257 T2DM patients,levels of the BTMs serum osteocalcin(OC),C-terminal cross-linked telopeptide of type I collagen(CTX),and procollagen type I N-peptide were measured by electrical chemiluminescent immunoassay,and artery stenosis was assessed by color Doppler and transcranial Doppler.Patients were grouped according to the existence and location(intracranial vs.extracranial)of artery stenosis.Correlations between BTM levels,previous stroke,stenosis location,and glucose and lipid metabolism were analyzed.RESULTS T2DM patients with severe artery stenosis had a higher frequency of previous stroke and levels of all three tested BTMs(all P<0.05)than patients without.Some differences in OC and CTX levels were observed according to the location of artery stenosis.Significant associations were also observed between BTM levels and some glucose and lipid homeostasis parameters.On multivariate logistic regression analysis,all BTMs were significant predictors of artery stenosis in T2DM patients with and without adjustment for confounding factors(all P<0.001),and receiver operating characteristic curve analysis demonstrated the ability of BTM levels to predict artery stenosis in T2DM patients.CONCLUSION BTM levels were found to be independent risk factors for severe intracranial and extracranial artery stenosis and were differentially associated with glucose and lipid metabolism in patients with T2DM.Therefore,BTMs may be promising biomarkers and potential therapeutic targets for artery stenosis.

Collagen cross-linking:when and how?A review of the state of the art of the technique and new perspectives

Since the late 1990s corneal crosslinking(CXL)has been proposed as a new possibility to stop progression of keratoconus or secondary corneal ectasia,with the promising aim to prevent progressive visual loss due to the evolution of the pathology and to delay or avoid invasive surgical procedures such as corneal transplantation.The possibility of strengthening corneal tissue by means of a photochemical reaction of corneal collagen by the combined action of Riboflavin and ultraviolet A irradiation(UVA),radically modified the conservative management of progressive corneal ectasia.This is a review of the state of the art of CXL,reporting basic and clinical evidence.The paper describes basic principles,advantages and limits of different CXL techniques and possible future evolution of the procedure.

FS-LASIK与FS-LASIK Xtra矫正近视术后角膜上皮重塑状态及角膜像差变化比较

目的探讨飞秒激光辅助准分子激光角膜原位磨镶术(FS-LASIK)与FS-LASIK联合角膜胶原交联(FS-LASIK Xtra)术后角膜上皮重塑状态和角膜像差,分析角膜上皮厚度(CET)与角膜像差的关系。方法采用队列研究方法,纳入2021年6月至2022年2月于成都中医大银海眼科医院接受FS-LASIK的近视患者172例172眼,按手术方式不同分为FS-LASIK组94眼和FS-LASIK Xtra组78眼,共随访6个月。以角膜中央为基点将角膜分为中央2 mm环区和2~5 mm环区,分别于术前及术后1、3和6个月采用眼前节光学相干断层扫描测量角膜中央0~5 mm范围内9个区域的CET,采用iTrace视觉功能分析系统测量角膜高阶像差(HOA),研究主要结局为术后6个月CET增加量(ΔCET)及角膜HOA,分析角膜中央ΔCET与角膜像差的关系。结果FS-LASIK Xtra组术眼术后1、3和6个月角膜中央、上方、鼻上、鼻侧、鼻下、下方、颞下、颞侧、颞上ΔCET均明显低于FS-LASIK组,差异均有统计学意义(均P<0.05)。FS-LASIK Xtra组术眼术后6个月角膜中央、上方、鼻上、下方、颞下ΔCET明显高于术后1个月,术后3个月和6个月颞侧ΔCET均明显高于术后1个月,术后6个月颞上ΔCET均明显高于术后1个月和3个月,差异均有统计学意义(均P<0.05)。FS-LASIK组术眼术后3个月和6个月角膜中央、上方、下方、颞下ΔCET均明显高于术后1个月,术后6个月鼻上ΔCET明显高于术后3个月,术后6个月鼻侧、鼻下、颞侧、颞上ΔCET均明显高于术后1个月和3个月,差异均有统计学意义(均P<0.05)。FS-LASIK Xtra组和FS-LASIK组术眼术后不同时间点垂直三叶草、垂直彗差、水平彗差变化量总体比较差异均无统计学意义(垂直三叶草:χ^(2)_(分组)=4.27,P=0.118;χ^(2)_(时间)=0.01,P>0.05.垂直彗差:χ^(2)_(分组)=5.74,P=0.057;χ^(2)_(时间)=0.08,P=0.957.水平彗差:χ^(2)_(分组)=3.97,P=0.137;χ^(2)_(时间)=0.51,P=0.773)。FS-LASIK Xtra组术眼术后1、3和6个月倾斜三叶草变化量均明显高于FS-LASIK组,差异均有统计学意义(均P<0.05)。FS-LASIK Xtra组术眼术后6个月球差变化量明显高于术后1个月,FS-LASIK组术眼术后6个月明显高于术后1个月和3个月,差异均有统计学意义(均P<0.05)。FS-LASIK组术眼术后6个月总HOA变化量明显低于术后1个月和3个月,差异均有统计学意义(均P<0.05)。FS-LASIK组术后1个月和6个月,角膜中央ΔCET与球差均呈弱正相关(r_(s)=0.257,P=0.008;r_(s)=0.244,P=0.012),与总HOA均呈弱正相关(r_(s)=0.253,P=0.009;r_(s)=0.279,P=0.004)。结论与FS-LASIK相比,FS-LASIK Xtra术后ΔCET明显较小,但2个组各区域CET增加的均一性相似。2种手术方法术后角膜HOA变化趋势接近,上皮整体分布与角膜像差有一定联系。