角膜交联治疗儿童圆锥角膜的研究进展

圆锥角膜的传统治疗方式包括早期至中期通过配戴框架眼镜、隐形眼镜或角膜基质环植入术以矫正视力,晚期进行角膜移植术。18岁之前儿童圆锥角膜的病情较成人更严重。对儿童圆锥角膜及早诊断和治疗可以有效改善其生活质量,延缓角膜移植术的时间。角膜交联是阻止或延缓该疾病进展的有效手段,近年来广泛应用于儿童圆锥角膜。本文对儿童圆锥角膜常...     

角膜胶原交联术研究进展

目的角膜胶原交联术(corneal collagen cross linking,CXL)是第一种能有效控制圆锥角膜进展的治疗方法,通过核黄素/紫外光介导的角膜胶原交联,增加角膜的机械强度,阻止了圆锥角膜的进展。经过近年来的研究,CXL的安全性得到了广泛的认可,随着技术方法不断改进,治疗范围也有所扩大。本文就近年来对于CXL原理、适应证、并发症、禁忌证的研究进展进行了综述。     

角膜胶原交联治疗进展期圆锥角膜

圆锥角膜是一种以角膜扩张为特征,原因不明的双侧进行性角膜病变,可严重影响患者的视力.目前,使用角膜胶原交联治疗,已经成为可以有效阻止圆锥角膜进展的新方法,本文就角膜胶原交联治疗进展期圆锥角膜的原理、方法、并发症及展望进行综述.     

角膜胶原交联术及不同交联剂的研究进展

角膜胶原交联术是治疗圆锥角膜的有效手段之一,通过角膜交联剂与光照射提高角膜强度,遏制或延缓圆锥角膜进行性发展。基于传统核黄素紫外光交联的创新术式和基于不同交联剂的交联方式不断涌现,包括跨上皮、快速核黄素紫外光交联,玫瑰红绿光交联、京尼平交联和甘油醛交联等。对于以上交联术式和不同交联剂的研究均致力于增加治疗效果和减少患者不适,研究结果将为临床上选择合适的角膜胶原交联术式治疗圆锥角膜提供理论基础和临床依据。     

角膜胶原交联术治疗圆锥角膜的研究进展

角膜胶原交联术(corneal collagen cross-linking,CXL)是一种治疗原发或继发性圆锥角膜、感染性角膜炎及大泡性角膜病变等角膜疾病的新疗法。它利用光化学原理来增加角膜强度,阻止角膜病变进展,现已被广泛应用于临床。目前临床上普遍采用的方法多为经典去上皮角膜交联(dresden protocol),但经典方法耗时较长,可能存在角膜上皮愈合不良、感染等术后并发症。近年来多项研究对经典方式进行了改良,例如核黄素液浸入角膜的多种方式选择,增加紫外光照射能量以缩短照射时间的加速交联以及跨上皮角膜交联等。本文就非经典角膜胶原交联术在治疗圆锥角膜的研究作一综述。     

跨上皮角膜胶原交联手术治疗进展期圆锥角膜的疗效

目的:分析跨上皮角膜胶原交联手术治疗进展期圆锥角膜后1a的疗效并讨论其临床意义。方法:收集2017-01/2018-12于我院进行快速跨上皮角膜胶原交联手术的进展期圆锥角膜患者45例48眼,术后随访1a,分析手术前后视力、角膜最薄点厚度、角膜内皮细胞计数、角膜交联线深度、角膜前表面曲率Km值及角膜生物力学参数等变化情况。结果:与术前比较,本组患者术后裸眼视力明显改善(P<0.05),但最佳矫正视力、角膜最薄点厚度和角膜内皮细胞计数均无明显变化(P>0.05),术后6mo,1a角膜前表面曲率Km值(48.54±2.57、48.77±2.29D)均显著下降,角膜生物力学参数第1次压平宽度(1.52±0.21、1.57±0.22mm)均显著降低(P<0.05),第2次压平速度绝对值(0.82±0.09、0.82±0.18m/s)均显著增加(P<0.05)。结论:快速跨上皮角膜胶原交联手术治疗进展期圆锥角膜对裸眼视力有明显改善,术后角膜生物力学也有改善,但最佳矫正视力改善不明显。     

圆锥角膜行去上皮角膜胶原交联术后角膜微结构的变化

目的：采用共焦显微镜观察进展期圆锥角膜行去上皮角膜胶原交联术后角膜微结构的变化。

方法：选取2016-02/2017-02于我院行上皮角膜胶原交联术治疗的进展期圆锥角膜患者11例15眼,分别于手术前后行共焦显微镜检查,观察角膜微结构变化。

结果：术后早期角膜上皮下神经纤维显著减少或消失; 角膜前基质呈蜂窝状,几乎无典型的角膜基质细胞,术后3mo基质细胞开始出现,术后12mo基质细胞数量几乎恢复到术前水平,但角膜上皮下神经仍稀疏,未达到术前水平; 术后后部角膜基质细胞和内皮细胞大小及形态未受影响。

结论：角膜胶原交联术后角膜微结构发生变化最明显的是上皮下神经纤维和前基质细胞,但随着随诊时间的延长,这种变化呈逐渐减弱趋势。     

圆锥角膜的治疗

圆锥角膜是一种病因不明的双侧进行性角膜病变,以角膜前凸产生不规则散光为特征,常伴有不同程度的视力损伤,多发生于女性.圆锥角膜的治疗可根据病情进展的不同阶段采取不同方法,早期可用框架眼镜、角膜接触镜,晚期则采取角膜移植术来改善视功能.常用手术方法有穿透性角膜移植术、深板层角膜移植术、激光角膜切削术、表面角膜镜片术等.近年来新型治疗方法如紫外光-核黄素交联疗法、角膜基质内环植入术、增视性虹膜切除术等也开始广泛应用.本文就其目前治疗方法综述如下.     

角膜交联术新进展与临床运用

紫外光核黄素角膜交联术(corneal collagen cross-linking,CCL)是一种二十一世纪初应用于临床的最新的角膜成形技术。以核黄素作为光敏剂应用370nm紫外线对角膜进行局部照射,刺激胶原纤维交联,增加角膜硬度。该技术已经在临床崭露头角,有望成为人们比较熟悉的角膜成型技术如传导性角膜成形术和角膜基质环植入术的辅助治疗手段。这些被称为角膜成形学的治疗或手术技术,可望开辟一个新的领域,治疗以往无法治疗的某些角膜疾病。利用CCL,眼科医生可重塑角膜结构,而不需使用如穿透性角膜移植术或板层角膜移植术等创伤性技术。用这种方法代替角膜基质环植入术,或与之相结合,可显著提高圆锥角膜的治疗效果。经过几年的苦心研究,CCL的技术方法得到了改进,治疗范围也有所扩大。不仅用来治疗进展性圆锥角膜,同时也为难治性角膜溃疡、角膜变性、术后角膜扩张病等角膜疾病的治疗带来希望。     

圆锥角膜的诊断与治疗

圆锥角膜是一种双侧非炎性角膜扩张性疾病,其特征主要为中央和旁中央区角膜基质变薄和呈圆锥形突起。早期圆锥角膜的诊断标准并未完全统一。现今用于诊断圆锥角膜的仪器主要有Orbscan角膜地形图、Pentacam眼前节测量分析仪、共焦显微镜、眼反应分析仪等,手术治疗方法主要有角膜移植术、基质环植入术、交联疗法等。本文综述近年来用于圆锥角膜诊断的常用仪器的优缺点及手术治疗方法,为临床上选择更适宜的检测仪器和治疗方法提供依据。     

Current review and a simplified “five-point management algorithm” for keratoconus

Keratoconus is a slowly progressive, noninflammatory ectatic corneal disease characterized by changes in corneal collagen structure and organization. Though the etiology remains unknown, novel techniques are continuously emerging for the diagnosis and management of the disease. Demographical parameters are known to affect the rate of progression of the disease. Common methods of vision correction for keratoconus range from spectacles and rigid gas-permeable contact lenses to other specialized lenses such as piggyback, Rose-K or Boston scleral lenses. Corneal collagen cross-linking is effective in stabilizing the progression of the disease. Intra-corneal ring segments can improve vision by flattening the cornea in patients with mild to moderate keratoconus. Topography-guided custom ablation treatment betters the quality of vision by correcting the refractive error and improving the contact lens fit. In advanced keratoconus with corneal scarring, lamellar or full thickness penetrating keratoplasty will be the treatment of choice. With such a wide spectrum of alternatives available, it is necessary to choose the best possible treatment option for each patient. Based on a brief review of the literature and our own studies we have designed a five-point management algorithm for the treatment of keratoconus.     

飞秒激光在圆锥角膜治疗中的应用进展

圆锥角膜是一种严重影响患者视功能的扩张性角膜病变,目前其治疗方式包括配戴框架眼镜或角膜接触镜、角膜表面镜片术、角膜移植术等。飞秒激光是一种以脉冲形式运转的红外线激光,精确度高,安全性好,操作简便,已在角膜移植、基质环植入及角膜胶原交联等研究领域得到了较好的应用;尤其是在角膜胶原交联中的应用可极大地改善患者的舒适程度,此外飞秒激光与多种圆锥角膜的治疗方法联合应用也会达到更好的效果。就近年来飞秒激光在圆锥角膜治疗中的相关应用进展进行综述。     

Current surgical options for keratoconus

The treatment of keratoconus is partly dependent on the severity of the disease process. When contact lenses fail because the patient is intolerant or they do not provide sufficient acuity to meet the patient's needs, penetrating keratoplasty is the usual surgical modality for adequate visual rehabilitation. Keratoconus is considered a contraindication to incisional refractive surgery such as radial keratotomy and laser in situ keratomileusis because of the corneal instability conferred by these procedures. When the cornea is transparent, intrastromal corneal ring implantation is a refractive modality that may improve visual function and, in select keratoconus patients, obviate the need for corneal transplantation.     

Management of corneal complications in vernal keratoconjunctivitis: A review

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral, allergic conjunctivitis with episodes of acute exacerbations. Although VKC has a self-limiting course, chronic recurrent inflammation can cause long-term visual impairment due to corneal complications including shield ulcers, infectious keratitis, keratoconus, corneal opacities, and limbal stem cell deficiency. The initial step in the management of corneal involvement is medical treatment of the acute stage of VKC and prevention of recurrences. Giant papillae not responding to medical treatment can be removed surgically in the case of corneal involvement. Shield ulcer with no inflammatory plaque usually heals with appropriate medical therapy. For shield ulcer with inflammatory plaque, however, surgical debridement with or without amniotic membrane transplantation might be necessary. Keratoconus may develop in chronic and severe VKC. An annual evaluation of these patients with corneal topography and/or tomography is essential for early detection of keratoconus and its timely management that includes collagen cross-linking and intrastromal corneal ring segment implantation. Corneal transplantation may be required in the advanced stage of keratoconus. Both penetrating keratoplasty and deep anterior lamellar keratoplasty can result in excellent visual outcomes in keratoconic eyes with concomitant VKC. Appropriate management of inflammation in the perioperative period is crucial for achieving successful outcomes after corneal transplantation. Limbal stem cell deficiency, a rare complication of long-standing and severe VKC, might be treated with living-related conjunctival limbal allograft.     

Keratoconus: current surgical options

The treatment of keratoconus is in part dependant on the severity of the disease process. When contact lenses fail because of patient intolerance or insufficient acuity to meet the patient's needs, penetrating keratoplasty is the usual surgical modality considered for satisfactory visual rehabilitation. Keratoconus is considered to be a contraindication for incisional refractive surgery such as radial keratotomies or LASIK because of the corneal instability conferred by these procedures. When the cornea is transparent, INTACS implantation is a refractive modality that may improve visual function and in some instances prevent the need for corneal transplantation in select patients with keratoconus.     

角膜内镜片的发展

圆锥角膜是一种易致盲的眼病，且发病率较高，约为1/2000，目前治疗圆锥角膜的方法主要有配戴硬性透氧性角膜接触镜(rigid gas permeable contact lens，RGP)、角膜交联术、角膜移植术等，上述治疗方法费用高、耗时长、疗效不肯定。随着科学技术的发展，角膜内镜片逐渐成为治疗圆锥角膜的一种新技术。角膜内镜片技术尝试在角膜层间植入一定度数的镜片，在治疗圆锥角膜的同时使视力得到最佳恢复。本文就角膜内镜片的研究进展及发展前景进行综述。     

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.     

Post-laser in-situ keratomileusis ectasia: current understanding and future directions

PURPOSE OF REVIEW: The aim of this article is to review the causes, risk factors, management, and future research directions for corneal ectasia after laser in situ keratomileusis. RECENT FINDINGS: Complex corneal biomechanical processes influence the integrity of the normal and postoperative cornea, and developing an understanding of these processes facilitates recognition of risk factors for ectasia after laser in-situ keratomileusis. Currently identified risk factors include keratoconus, high myopia, low residual stromal bed thickness from excessive ablation or thick flap creation, and defined topographic abnormalities such as forme fruste keratoconus and pellucid marginal corneal degeneration. Ectasia can also rarely occur in patients without currently identifiable risk factors, and future identification of at-risk patients may be facilitated by corneal interferometry and corneal hysteresis measurements. Utilization of intraoperative pachymetry measurements at the time of surgery and confocal microscopy prior to enhancement to measure residual stromal bed thickness should avoid unanticipated low residual stromal bed thickness. Management options for ectasia after laser in situ keratomileusis include intraocular pressure reduction, rigid gas permeable contact lenses, and intracorneal ring segments, in addition to corneal transplantation. In the future, collagen cross-linking may reduce corneal steepening and improve refractive error. SUMMARY: When ectasia develops, early recognition and proper management are essential to prevent progression, to promote visual rehabilitation, and to reduce the need for corneal transplantation for these patients.