准分子激光治疗性角膜切削术联合角膜胶原交联术治疗原发性圆锥角膜

目的：评估准分子激光治疗性角膜切削术（PTK）联合角膜胶原交联术（CXL）治疗原发性圆锥角膜的临床效果。方法：前瞻性自身对照临床研究。2014年9-10月期间在温州医科大学附属眼视光医院接受PTK联合CXL治疗的进展期圆锥角膜患者11例（11眼）,评估比较术前与术后12个月裸眼视力（UCVA）、最佳矫正视力（BCVA）、屈光状态、角膜形态、角膜最薄点厚度和角膜内皮细胞密度的差异。手术前后数据的比较采用配对t检验。结果：术后12个月时,UCVA较术前有所提高（t=3.692,P=0.008）,球镜度、等效球镜度（SE）、角膜前表面最大曲率值较术前均有所改善（t=-1.397,P=0.039;t=-2.363,P=0.040;t=2.941,P=0.007）,角膜最薄点厚度较术前降低（t=3.839,P=0.003）,内皮细胞计数无明显变化（t=-1.615,P=0.172）。结论：PTK联合CXL治疗进展中的原发性圆锥角膜是安全和有效的。     

紫外光A核黄素介导角膜交联治疗感染性角膜炎

角膜胶原交联（CXL）技术是一种治疗圆锥角膜、准分子激光术后角膜扩张、难治性角膜溃疡、角膜炎等角膜疾病的有效方法。它通过紫外光A和感光剂核黄素,介导角膜基质内胶原纤维相互交联而提高角膜机械硬度和角膜基质的生物力学稳定性,从而阻止圆锥角膜等角膜扩张性疾病和难治性角膜炎等的发展。本文就紫外光A核黄素介导角膜交联术治疗感染性角膜炎的基本原理、实验和临床研究现状及其相关安全性等问题进行综述。     

CXL治疗圆锥角膜的中期效果及术后RGPCL配适参数变化的研究

目的:探讨圆锥角膜患眼行角膜胶原交联术（CXL）后1年的治疗效果及术后硬性透气性角膜接触镜（RGPCL）适配参数的改变。方法:前瞻性队列研究。纳入自2018年5至12月于山东第一医科大学附属青岛眼科医院门诊接受快速CXL的进展期圆锥角膜患者41例（53只眼）,其中男性31例,女性10例,年龄（20.46±4.15）岁。...     

圆锥角膜行角膜胶原交联联合不规则角膜激光切削术的思考

如今圆锥角膜的诊疗理念不断更新,人们不仅关注于如何延缓圆锥角膜进展,也在努力提高患者的视觉质量。随着准分子激光和飞秒激光技术在眼科的应用,角膜胶原交联术联合不规则角膜准分子激光切削术的治疗方案已成为圆锥角膜治疗的新策略。然而已逐渐变薄的圆锥角膜患眼是否可再进一步行准分子激光切削、该方案两种手术同期和分期执行孰优孰劣等关...     

儿童高度远视性屈光参差手术治疗进展

远视性屈光参差是造成儿童弱视的常见原因之一。近年来屈光手术矫正儿童远视性/近视性屈光参差越来越受到关注,成为重度屈光参差性弱视治疗中的重要途径。本文就准分子激光角膜表面切削术、准分子激光原位角膜磨镶术、准分子激光上皮下角膜磨镶术及屈光性人工晶状体植入等目前已应用于儿童远视性屈光参差的屈光手术进行综述,着重探讨其术式有效性。     

角膜地形图对亚临床期圆锥角膜筛选的作用

目的 介绍用Ｈｏｌｌａｄａｙ角膜地形图诊断软件（ＨＤＳ）在角膜屈光性手术中对亚临床期圆锥角膜筛选的作用。方法 对１９９６年３月至１９９７年１０月来我院准分子激光中心欲进行准分子激光屈光性角膜切削术（ＰＲＫ）及准分子激光原位角膜磨削术（ＬＡＳＩＫ）的１２００例术前病人２４００只眼行角膜地形图检查,用ＨＤＳ软件进行判别,以筛选亚临床期圆锥角膜,结果 共筛选出２仍２眼亚临床期圆锥角膜（占０．０７８％）,     

屈光性手术前ORBSCAN-Ⅱ角膜地形图40838例筛选分析

目的 对40838例屈光性手术前,进行 Orbscan-Ⅱ角膜地形图检查结果的筛选分析,为临床诊断角膜病及应用提供可靠依据.方法 通过Orbscan-Ⅱ角膜地形图检测,针对角膜地形,全角膜厚度,角膜前、后表面高度及角膜屈率的数据进行分析,筛选出821例(1368眼),由8种特殊原因进行的结果分析.结果 (1)进行选择性的治疗方式:后巩膜加固术,屈光性晶状体摘出联合人工晶状体置入术,有晶状体眼前房型人工晶状体植入矫治高度近视术.(2)避免一些手术禁忌症进行准分子激光屈光性手术:圆锥角膜、后圆椎角膜.(3)筛选450例1468项不正常的数据,不能进行任何治疗.结论 Orbscan-Ⅱ角膜地形图检查对手术方式的选择、术前手术方案的设计、术后疗效的评价、避免一些手术禁忌症的病例进行手术是至关重要的检查工具.     

去上皮和经上皮快速角膜交联术紫外光脉冲输出模式治疗进展期圆锥角膜患者的临床效果

目的　探讨去上皮快速角膜交联术紫外光脉冲输出模式（pl-快速CXL）和经上皮pl-快速CXL治疗进展期圆锥角膜患者的临床效果。方法　选取2018年1月至2019年6月在河北省眼科医院行pl-快速CXL治疗的进展期圆锥角膜患者16例31眼;根据术式将患眼分为两组,去上皮pl-快速CXL组7例13眼和经上皮pl-快速CXL组9例18眼。术前及术后3个月和6个月进行随访。记录患眼最佳矫正远视力、散光度、角膜前表面最大曲率、角膜前表面最小曲率、角膜最薄点厚度、角膜内皮细胞计数、交联线深度,对各指标进行统计学分析。结果　去上皮pl-快速CXL组和经上皮pl-快速CXL组患者术后3个月和术后6个月最佳矫正远视力、散光度、角膜前表面最大曲率、角膜前表面最小曲率、角膜内皮细胞计数与术前相比,差异均无统计学意义（均为P>0.05）;术后3个月和术后6个月时两组角膜最薄点厚度均较术前变薄,差异均有统计学意义（均为P<0.05）。两组患者交联线深度术后3个月与术后6个月相比,差异均无统计学意义（均为P>0.05）。术后3个月和术后6个月时,去上皮pl-快速CXL组患者角膜交联线深度均较经上皮pl-快速CXL组更深,差异均有统计学意义（均为P<0.05）。对于相同时间点的其他参数而言,两组间差异均无统计学意义（均为P>0.05）。结论　无论是去上皮pl-快速CXL还是经上皮pl-快速CXL都安全可行,在术后6个月内均能够稳定圆锥角膜病情。     

基质金属蛋白酶对圆锥角膜的影响

圆锥角膜以进行性角膜前突和变薄,导致不规则散光和视功能损害为特征.大量研究表明,基质金属蛋白酶(matrix metalloproteinases,MMPs)在圆锥角膜基质降解和变薄过程中起关键性作用.紫外光A/核黄素角膜交联术(corneal crosslinking,CXL)是近年来发展起来的唯一能够延缓甚至阻止圆锥角膜病情进展的保守治疗方法.CXL对角膜生物力学和结构的影响研究较多,而对MMPs的影响研究较少.研究表明,CXL后患者泪液中的MMPs出现变化,而对基质中MMPs的影响尚无报道.进一步研究CXL后MMPs的变化有助于理解CXL后圆锥角膜的病理生理进程,以及CXL稳定圆锥角膜病情的作用机制.     

角膜胶原交联中核黄素浓度检测方法的研究进展

角膜胶原交联术（CXL）可以用于治疗进展期圆锥角膜、感染性角膜炎、角膜融解和角膜基质水肿等病变。临床上常用的CXL方案为核黄素-紫外光交联,角膜中的核黄素浓度和分布是影响疗效和安全性的重要因素之一。目前对角膜中核黄素浓度进行检测的方法主要包括荧光显微镜成像、高效液相色谱法、分光光度法、无创实时检测、眼前节裂隙灯显微镜观...     

Corneal cross-linking (CXL) combined with refractive surgery for the comprehensive management of keratoconus: CXL plus

The past two decades have witnessed an unprecedented evolution in the management of keratoconus that demands a holistic approach comprising of inhibiting the ectatic progression as well as visual rehabilitation. The advent of corneal cross-linking (CXL) in the late 1990s resulted in long-term stabilization of the ectatic cornea along with limited reduction in corneal steepening and regularization of corneal curvature. However, CXL as a standalone procedure does not suffice in rehabilitating the functional vision especially in patients who are unwilling or intolerant towards contact lenses. The concept of “CXL plus” was proposed which incorporates adjunctive use of refractive procedures with CXL in order to overcome the optical inefficiency due to corneal irregularity, decrease the irregular astigmatism, correct the residual refractive error and improve functional visual outcome in keratoconus. Several refractive procedures such as conductive keratoplasty (CK), photorefractive keratectomy (PRK), transepithelial phototherapeutic keratectomy (t-PTK), intrastromal corneal ring segments (ICRS) implantation, phakic intraocular lens (PIOL) implantation and multiple other techniques have been combined with CXL to optimize and enhance the CXL outcome. This review aimed to summarize the different protocols of CXL plus, provide guidelines for selection of the optimum CXL plus technique and aid in decision-making for the comprehensive management of cases with primary keratoconus in addition to discussing the future and scope for innovations in the existing treatment protocols.     

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

AIM: To compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (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 non-topography 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.     

Corneal collagen cross-linking: An introduction and literature review

BackgroundThis literature review analyzes the scientific evidence available regarding corneal collagen cross-linking (CXL) as a treatment option for progressive keratectasia.MethodsA literature search was performed using dates from 1990 to August 2010 regarding CXL Specific areas of focus for the literature review include safety and efficacy of the procedure as a stand-alone treatment or when used in conjunction with Intacs^® corneal implants (Addition Technology?) or photorefractive keratectomy (PRK).ResultsA total of 50 clinical trials and studies were identified, 20 of which met the inclusion criteria. Results of the included literature support the conclusion that CXL is a safe and efficacious treatment for progressive keratectasia. The results of CXL alone have shown stabilization or improvement in the maximum keratometry readings, best-corrected visual acuity, uncorrected visual acuity, and spherical and cylinder refractive measurements. CXL has been shown to enhance the effects of Intacs and has been proven successful when used in conjunction with PRK.ConclusionCXL is an effective treatment for limiting the progression of keratectasia, thus reducing the need for penetrating keratoplasty. CXL has a similar side-effect profile and similar risk level as PRK.     

Corneal refractive surgery combined with simultaneous corneal cross‐linking: Indications,protocols and clinical outcomes—A review

Corneal refractive surgery is one of the most common approaches for correction of refractive errors. Combined corneal refractive surgery and corneal cross‐linking (CXL) has been proposed as a method to achieve better refractive stability and to prevent iatrogenic corneal ectasia. However, there are concerns regarding its indications, surgical safety, standardization of protocols and long‐term effect on corneal tissue. This review article aims to discuss the current knowledge and recent updates on combination of CXL and refractive surgery.     

Corneal collagen cross-linking in patients with keratoconus from the Dresden protocol to customized solutions: theoretical basis

Keratoconus is an ectatic condition characterized by gradual corneal thinning, corneal protrusion, progressive irregular astigmatism, corneal fibrosis, and visual impairment. The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages, gas-permeable rigid contact lenses, scleral lenses, implantation of intrastromal corneal ring or corneal transplants for most advanced stages. In keratoconus cases showing disease progression corneal collagen crosslinking (CXL) has been proven to be an effective, minimally invasive and safe procedure. CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation, resulting in stromal crosslinks formation. The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models, from the original Dresden protocol to the most recent developments in the technique, reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols. Finally, the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.     

Visual rehabilitation in low-moderate keratoconus:intracorneal ring segment implantation followed by same-day topography-guided photorefractive keratectomy and collagen cross linking

AIM:To present the results of same-day topography-guided photorefractive keratectomy (TG-PRK) and corneal collagen crosslinking (CXL) after previous intrastromal corneal ring segment (ISCR) implantation for keratoconus.METHODS:An experimental clinical study on twenty-one eyes of 19 patients aged 27.1±6.6y (range 19-43y), with low to moderate keratoconus who were selected to undergo customized TG-PRK immediately followed by same-day CXL, 9mo after ISCR implantation in a university ophthalmology clinic. Refraction, uncorrected distance visual acuities (UDVA) and corrected distance visual acuities (CDVA), keratometry (K) values, central corneal thickness (CCT) and coma were assessed 3mo after TG-PRK and CXL.RESULTS:After TG-PRK/CXL:the mean UDVA (logMAR) improved significantly from 0.66±0.41 to 0.20±0.25 (P<0.05); Kflat value decreased from:48.44±3.66 D to 43.71±1.95 D; Ksteep value decreased from 45.61±2.40 D to 41.56±2.05 D; Kaverage also decreased from 47.00±2.66 D to 42.42±2.07 D (P<0.05 for all). The mean sphere and cylinder decreased significantly post-surgery from, -3.10±2.99 D to -0.11±0.93 D and from -3.68±1.53 to -1.11±0.75 D respectively, while the CDVA, CCT and coma showed no significant changes. Compared to post-ISCR, significant reductions (P<0.05 or all) in all K values, sphere and cylinder were observed after TG-PRK/CXL.CONCLUSION:Same-day combined topography-guided PRK and corneal crosslinking following placement of ISCR is a safe and potentially effective option in treating low-moderate keratoconus. It significantly improves all visual acuity, reduced keratometry, sphere and astigmatism, but causes no change in central corneal thickness and coma.     

PTK、PRK和CXL联合治疗LASIK术后角膜膨隆的临床疗效

目的联合准分子激光治疗性角膜切削术（PTK）、准分子激光屈光性角膜切削术（PRK）和核黄素诱导的长波紫外线角膜胶原交联术（CXL）对准分子激光原位角膜摩镶术（LASIK）术后角膜膨隆进行交联和屈光重建,评价该方法对LASIK术后角膜膨隆的临床疗效。方法前瞻性自身对照研究。选择早中期LAISK术后角膜膨隆患者14例（16眼）,均采用PTK+PRK+CXL进行治疗,记录术前及术后1、3、6个月的裸眼视力（UCVA）、最佳矫正视力（BCVA）、角膜前表面最大曲率（Kmax）值、中央角膜厚度（CCT）、角膜内皮细胞密度（ECD）。应用Wilcoxon符号秩和检验行数据分析。结果16只患眼术前的LogMAR UCVA中位数为0.50,术后l、3、6个月的logMAR UCVA中位数分别为0.10、0.10和0.00,与术前相比均提高（P＜0.01）;术后1、3、6个月Kmax的中位数值分别为44.80、44.85、45.20 D,均较术前（47.15 D）降低（P＜0.05）;角膜厚度的中位数值在术后1、3、6个月分别为450、422、420 µm,与术前差异均有统计学意义（P＜0.01）。而术后1、3、6个月的BCVA、ECD与术前差异均无统计学意义。结论PTK+PRK+CXL治疗LAISK术后角膜膨隆安全、有效,术后UCVA提高、Kmax降低。     

Intacs implantation with sequential collagen cross-linking treatment in postoperative LASIK ectasia

PURPOSE: To report the postoperative course and refractive results of each eye of a patient with postoperative LASIK ectasia for whom Intacs SK (severe keratoconus, Addition Technology Inc) implantation and collagen crosslinking (CXL) treatments were performed. METHODS: A 27-year-old man with postoperative LASIK ectasia with best spectacle-corrected visual acuity (BSCVA) of 20/60 and 20/80 in the right and left eyes, respectively, was operated for Intacs SK implantation for both eyes. Spherical equivalent refraction and mean keratometric values in the right and left eyes were -14.50 diopters (D) and -10.50 D and 56.20 D and 50.70 D, respectively. Following bilateral Intacs SK implantation, CXL was performed after 1 day in the left eye and 1 month in the right eye. RESULTS: During follow up, there was an improvement in visual acuity and decrease in manifest refraction and keratometric values in both eyes. A slight regression of these values was noted in the right eye 1 month after Intacs SK implantation, which was reversed by CXL. Eight months postoperatively, BSCVA was 20/25 and 20/25, manifest refractions were -1.50 x 170 and -1.25 x 50, and mean keratometric values were 47.20 and 44.20 D in the right and left eyes, respectively. CONCLUSIONS: Intacs SK implantation and subsequent CXL may be alternatived in the treatment of postoperative LASIK ectasia.     

Corneal collagen cross‐linking for infectious keratitis: an update of clinical studies

Collagen cross‐linking (CXL) with ultraviolet light‐activated riboflavin is a corneal surface procedure developed for the treatment of keratoconus and corneal ectasia. With the known microbicidal and corneal stiffening effects of ultraviolet irradiation and photoactivated riboflavin, it has recently been introduced for the management of infectious keratitis, especially for ulcers resistant to antimicrobial therapy or associated with corneal melting. Various authors have attempted to use CXL as an adjunctive, salvage or even as the sole treatment for infectious corneal ulcers. The aim of this review was to provide a summary of the clinical studies in the literature. It is worth noting that there is still no consensus on the treatment protocol of CXL against infectious keratitis. The disparities in outcome measures, treatment protocol and study design can confound the interpretation and hamper the generalization of the study results. Based on current evidence, the role of CXL in infectious keratitis remained unclear despite the reported success in some clinical cases. Further investigations are warranted concerning the efficacy and safety of treating infectious keratitis with CXL.     

Phototherapeutic keratectomy versus mechanical epithelial removal followed by corneal collagen crosslinking for keratoconus

ObjectiveTo compare the visual outcomes of patients with keratoconus treated with either phototherapeutic keratectomy (PTK) or mechanical epithelial removal prior to corneal collagen crosslinking (CXL).DesignComparative study.ParticipantsThe records of 34 patients (34 eyes) who had PTK (17 eyes) or mechanical (17 eyes) epithelial removal prior to CXL for keratoconus were reviewed retrospectively.MethodsCXL was performed by 1 of 3 surgeons (G.M., W.B.J., or K.B.). Of the eyes, 17 had undergone mechanical epithelial removal prior to CXL and were consecutively selected, after matching with the 17 eyes in the PTK group, for the variables of procedure date, average keratometry, and pachymetry. All eyes had central cones. Manifest refraction spherical equivalent, sphere, cylinder, best-corrected distance visual acuity, and pachymetry were measured and compared preoperatively and in follow-up.ResultsThe mean change between the pre- and postoperative manifest refraction spherical equivalent for the PTK and mechanical groups was 1.68 ± 0.80 and 0.26 ± 0.90, respectively (p < 0.05). The mean change between pre- and postoperative cylinder for the PTK and mechanical groups was 0.53 ± 0.28 and 0 ± 0.18, respectively (p < 0.05). The mean number of lines of improvement in the PTK and mechanical groups were 0.33 ± 0.82 and ?0.58 ± 0.45 lines, respectively (p > 0.05).ConclusionsEarly results suggest that CXL with laser epithelial removal is superior to CXL with mechanical epithelial removal because it reduces refractive error in qualified patients. Although not statistically significant, there was also a trend for PTK CXL patients to have better visual outcomes.