The Limbal Niche and Its Role in Maintaining Corneal Regeneration

In recent years, stem cells have been a focal point in research designed to evaluate the efficacy of ophthalmologic therapies, specifically those for corneal conditions. The corneal epithelium is one of the few regions of the body that maintains itself using a residual stem cell population within the adjacent limbus. Stem cell movement has additionally captivated the minds of researchers due to its potential application in different body regions. The cornea is a viable model for varying methods to track stem cell migratory patterns, such as lineage tracing and live imaging from the limbus. These developments have the potential to pave the way for future therapies designed to ensure the continuous regeneration of the corneal epithelium following injury via the limbal stem cell niche. This literature review aims to analyze the various methods of imaging used to understand the limbal stem cell niche and possible future directions that might be useful to consider for the better treatment and prevention of disorders of the cornea and corneal epithelium. .

Surgical approaches to correct corneal astigmatism at time of cataract surgery: a mini-review

Among refractive errors,astigmatism is the most common optical aberration,where refraction changes in different meridians of the eye.It causes blurred vision at any distance and includes corneal,lenticular,and retinal astigmatism.Cataract surgery used to cause a progressive increase in the pre-exisiting corneal astigmatism because of creating a surgically induced astigmatism,for example,a large size surgery incision.The development of surgical techniques during last decades has made cataract surgery interchange to treat preoperative corneal astigmatism at time of surgery.Nowadays,three surgical approaches can be used.By placing a sutureless clear corneal incision on the steep meridian of the cornea,a preoperative corneal astigmatism less than 1.0 D can be corrected.Single or paired peripheral corneal relaxing incisions(PCRIs)provide 1.0-3.0 D corneal astigmatism correction.PCRIs are typically used for treating 1.0-1.5 D of regular corneal astigmatism,if more than 2.0 D,the risk of overcorrection and irregular astigmatism is increased.When toric intraocular lenses(IOLs)are unavailable in markets,PCRIs are still a reasonable option for patients with up to 3.0 D of pre-existing corneal astigmatism.Toric IOLs implantation can correct 1.0-4.5 D of corneal astigmatism.Several IOLs are approved to correct a high degree of corneal astigmatism with cylinder power up to 12.0 D.These approaches can be used alone or in combination.

Clinical associations of corneal neuromas with ocular surface diseases

Corneal neuromas,also termed microneuromas,refer to microscopic,irregula rly-shaped enlargements of terminal subbasal nerve endings at sites of nerve damage or injury.The formation of corneal neuromas results from damage to corneal nerves,such as following corneal pathology or corneal or intraocular surge ries.Initially,denervated areas of sensory nerve fibers become invaded by sprouts of intact sensory nerve fibers,and later injured axons regenerate and new sprouts called neuromas develop.In recent years,analysis of corneal nerve abnormalities including corneal neuromas which can be identified using in vivo confocal microscopy,a non-invasive imaging technique with microscopic resolution,has been used to evaluate corneal neuropathy and ocular surface dysfunction.Corneal neuromas have been shown to be associated with clinical symptoms of discomfort and dryness of eyes,and are a promising surrogate biomarker for ocular surface diseases,such as neuropathic corneal pain,dry eye disease,diabetic corneal neuropathy,neurotrophic keratopathy,Sjogren's syndrome,bullous keratopathy,post-refra ctive surgery,and others.In this review,we have summarized the current literature on the association between these ocular surface diseases and the presentation of corneal microneuromas,as well as elaborated on their pathogenesis,visualization via in vivo confocal microscopy,and utility in monitoring treatment efficacy.As current quantitative analysis on neuromas mainly relies on manual annotation and quantification,which is user-dependent and labor-intensive,future direction includes the development of artificial intelligence software to identify and quantify these potential imaging biomarkers in a more automated and sensitive manner,allowing it to be applied in clinical settings more efficiently.Combining imaging and molecular biomarkers may also help elucidate the associations between corneal neuromas and ocular surface diseases.

Observation on ultrastructure and histopathology of cornea following femtosecond laser-assisted deep lamellar keratoplasty for acute corneal alkaline burns

AIM： To demonstrate the changes in ultrastructure and histopathology of the cornea in acute corneal alkaline burns after femtosecond laser-assisted deep lamellar keratoplasty.·METHODS： The New Zealand white rabbits treated with alkaline corneal burn were randomized into two groups,Group A（16 eyes） with femtosecond laser-assisted deep lamellar keratoplasty 24 h after burn and Group B（16 eyes）without keratoplasty as controls. All eyes were evaluated with transmission electron microscopy（TEM） at 1, 2, 3,and 4wk follow-up, then all corneas were tested by hematoxylin and eosin staining histology.· RESULTS： The corneal grafts in Group A were transparent, while those in Group B showed corneal stromal edema and loosely arranged collagen fibers. One week after treatment, TEM revealed the intercellular desmosomes in the epithelial layers and intact non-dissolving nuclei in Group A. At week 4, the center of the corneas in Group A was transparent with regularly arranged collagen fibers and fibroblasts in the stroma. In Group B, squamous cells were observed on the corneal surface and some epithelial cells were detached.· CONCLUSION： Femtosecond laser-assisted deep lamellar keratoplasty can suppress inflammatory responses, prevent toxic substance-induced injury to the corneal endothelium and inner tissues with quicker recovery and better visual outcomes.

COMPARATIVE STUDIES ON THE CORNEAL STRUCTURE OF MAMMAL ANIMALS：I．ULTRASTRUCTURE OF THE CORNEAL SUBSTANTIA PROPRIA IN GUINEA P

The corneal sutotantia propria in guinea pig is composed of the fibroblasts,fibers andintercelular maxtrix.Tab fibers belong to collagen fibrils.The fibrils are fine(about 37nm in diameter)and form lamelae being parallel to one another.The lamelae are approximately 0.75￣1.5μmthick. The fibrils in adjacent lamelae run across each other at right angles and parallel to the cornealsurface.in fibroblasts are dispersed between the fibril lamelae. Their appearances are extremelyflat. The nucleus is large and located at the canter of the cell.The cytoplasm is abundant in roughendoplasmic reticulum.The corned fibroblasts give out very long processes extended between thelamelae.The cytoplasmic brocades of a cell are in able contant with these of neighboring cells.Thecontant surfaces show irregular and interdigital forms. In some of the intercellular contant regionsthere are gap junctions.

Research progress on animal models of corneal epithelial-stromal injury

A corneal epithelial-stromal defect is recognized as a major contributor to corneal scarring.Given the rising prevalence of blindness caused by corneal scarring,increasing attention has been focused on corneal epithelialstromal defects.Currently,the etiology and pathogenesis of these defects remain inadequately understood,necessitating further investigation through experimental research.Various modeling methods exist both domestically and internationally,each with distinct adaptive conditions,advantages,and disadvantages.This review primarily aims to summarize the techniques used to establish optimal animal models of corneal epithelial-stromal injury,including mechanical modeling,chemical alkali burns,post-refractive surgery infections,and genetic engineering.The intention is to provide valuable insights for studying the mechanisms underlying corneal epithelial-stromal injury and the development of corresponding therapeutic interventions.

A HISTOPATHOLOGIC IMMUNOHISTOCHEMICAL AND ULTRASTRUCTURAL STUDY OF RABBIT CORNEA AFTER EXCIMER LASER PHOTOREFRACTIVE KERATECTOMY

Objective To evaluate the corneal healing of non-epuality diopter response histopathologically, immunohistochemically and ultrastructurally after excimer laser photorefractive keratectomy(PRK) with SVS APEX PLUS(Summit Technology Inc. USA) excimer laser, and the effects of corticosteroid on the healing. Methods PRK on 6 white rabbits(12 eyes) was performed on right eye or the rabbit for an attampted correction or -4.00 diopter and on left eye for an attempted correction of -8.00 diopter. The rabbits were divided into 2 groups randomly and each group included 6 eyes: Group FLM (3 rabbits, 6 eyes) and group CM (3 rabbits, 6 eyes). Fluoromethalone was given to group FLM,and chloromycetin to group CM. On 10d, 30d and 100d,the eyes of one rabbit in each group were enucleated randomly. Half of each cornea was prepared for electron microscope observation (SEM and TEM) and the rest embedded in OCT compound for immunohistochemical study to examine Ⅲ-C and FN. Results All eyes were reepithelialized within 3d after PRK. Subepithelial corneal haze was observed on 15d,which was dominant on 30 or 60d. On 100d postoperatively,corneal hazes of 11 eyes were grades 0 or 0.5,only 1 eye(the left eye or group CM) was denser haze (grade 1). On 3d postoperatively, one or two layers of corneal epithelial cell covered the ablation zone. On 30d after PRK,the epithelial cells showed hyperplastic changes. The cells were larger and increased from normal 5 or 6 layers to 7 or 8 layers of cells on l00d after PRK,epithelium was clear with more bright epithelium. Mi- croplicae and microvilli were less than before. The expression of Ⅲ-C and FN in group CM was significantly more evi- dent than that in group FLM. Conclusion The study show that despite recovery of a continuous and smooth epithelial layer and nearly normal corneal tissues on 100d after PRK,abnormalities of both epithelium and superficial stroma can be detected in the area of ablation. The ablation depth of stroma can influence the appearance of corneal haze af- ter PRK. The microplicae and microvilli of rabbit cornea epithelium become less after PRK,which can be one of cause leading to ocular dry sensation in some patients.

Single-cell RNA sequencing in cornea research:Insights into limbal stem cells and their niche regulation

The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound healing depends on the proliferation and differentiation of limbal stem cells(LSCs),a cell population that resides at the limbus in a highly regulated niche.Dysfunction of LSCs or their niche can cause limbal stem cell deficiency,a disease that is manifested by failed epithelial wound healing or even blindness.Nevertheless,compared to stem cells in other tissues,little is known about the LSCs and their niche.With the advent of single-cell RNA sequencing,our understanding of LSC characteristics and their microenvironment has grown considerably.In this review,we summarized the current findings from single-cell studies in the field of cornea research and focused on important advancements driven by this technology,including the heterogeneity of the LSC population,novel LSC markers and regulation of the LSC niche,which will provide a reference for clinical issues such as corneal epithelial wound healing,ocular surface reconstruction and interventions for related diseases.

Corneal Blindness Caused by Accidental Ocular Use of Chlorhexidine (Hexz) Gel in Two Newborn Born in the Health District of Kati in Mali

Introduction: Corneal opacities in children are relatively common. In children, it is urgent because of the risk of irreversible amblyopia. The causes of these blindnesses vary considerably according to the regions of the world. Chlorhexidine digluconate is a broad-spectrum antiseptic directed against gram-positive and gram-negative bacteria. It has been used as an antiseptic for more than 50 years, both in humans and in animals. However, despite these benefits, it can cause serious damage if applied to the eyes. Incidents of eye damage with 7.1% chlorhexidine have been reported to WHO across Africa. Observation: We report and write two cases of bilateral corneal blindness caused by accidental ocular use of chlorhexidine (HEXZ) GEL 7.1% in two newborns in the health district of Kati in MALI. The ophthalmological examination had revealed corneal opacity, conjunctival hyperaemia and limbic ischemia greater than 50% in 1 eye out of 4, corresponding to stage IV of the ROPPER HALL classification;2 eyes out of 4 were at stage III and 1 eye out of 4 was at stage I of the same classification. Conclusion: It is essential to ensure correct use of chlorhexidine digluconate gel 7%. It is an antiseptic which should not be used on the ocular and auditory mucous membranes, at the risk of most often permanent burns.

The Mean Central Cornea Thickness and Associated Factors among Adult Patients Attending Mulago Hospital Eye Clinic Kampala, Uganda

Background: The mean central corneal thickness (CCT) values are known to have an influence on intraocular pressure measurement and vary widely with age, sex and ethnicity. Little is known about the pattern of CCT in central Uganda. Aim: To determine the mean central corneal thickness and its associated factors among adult patients attending Mulago Hospital eye clinic, Kampala Uganda. Design and Method: A cross sectional study was done from August to October 2016 on 270 adult patients selected by systemic random sampling. The study included all adult patients who attended the eye clinic during the study period and consented to the study excluding those who had conditions causing abnormal thinning, thickening or irregularity of the cornea. The participants were evaluated by history taking and ocular examination including visual acuity assessment, slit lamp examination, central cornea thickness measurement, intraocular pressure measurement and funduscopy. Data were collected using a pretested questionnaire, entered using Epidata and analyzed by STATA11.0. Results: Of the 270 patients examined, 61% were female, 39% male, the mean age being 42 years ranging from 18 to 96 years. The mean central corneal thickness for both eyes was 539.3 (SD ± 41.65 μm) ranging from 332 μm to 701 μm and mean intraocular pressure was 15 (SD ± 5.34) mmHg. Gender, ethnicity, IOP, glaucoma, hypertension, diabetes, refractive error, were not statistically significantly associated with central cornea thickness. However central cornea thickness was statistically significantly associated with systolic blood pressure (r = -0.24, p = 0.025) and age (p = 0.002). A one-year increase in age reduced the mean central cornea thickness by 0.54 μm. Conclusion: The average CCT of Ugandan adult population was 539.3 ± 41.65 μm which falls in the category of normal central cornea thickness. Central corneal thickness reduced with increasing age and increasing systolic blood pressure.

Central Corneal Thickness of Diabetic Patients in Yaoundé: Case Control Study

Background: To compare central corneal thickness (CCT) values measured in diabetic eyes and compare the CCT values in normal patients without diabetes. Methods: A total of 83 diabetic patients and 83 non-diabetic patients were prospectively enrolled in this comparative case series. CCT was measured using a Topcon CT-1P non-contact automated pachymeter, and values were compared. Results: Mean age was 57 ± 11 years, with a range of 23 and 80 years. The mean CCT was 508.87 ± 35.83 μm for diabetic patients and 513.41 ± 37.22 μm for non-diabetic patients. There was no statistically significant difference between the CCT of diabetic patients compared to non-diabetic patients (p = 0.260). We did not find a significant correlation between the CCT of diabetic patients and clinical characteristics of diabetes. However, there was a positive and statistically significant linear correlation between the CCT of diabetic patients and intra ocular pressure (IOP). Conclusion: The mean CCT in diabetic patients was lower than in non-diabetic control patients, although there was no statistically significant difference.

Corneal neurotization: a narrative review of techniques, outcomes, and surgical considerations

Background and Objective:Corneal neurotization is a novel surgical technique used to restore corneal sensation in patients with neurotrophic keratopathy.Neurotrophic keratopathy is a disorder characterized by dysfunction of the ophthalmic division of the trigeminal nerve,which provides sensory innervation to the cornea.Without sensation,the cornea is at risk of infection,ulceration,perforation,and ultimately,vision loss.Corneal neurotization has emerged as an innovative technique to reinnervate anesthetized corneas by transferring a healthy donor nerve to the affected eye around the corneoscleral limbus.As the field of corneal neurotization rapidly grows,there is a need to synthesize the existing body of literature on corneal neurotization and identify important areas for further research.In this review,we will discuss neurotrophic keratopathy and its current management strategies,followed by an overview of corneal neurotization techniques,outcomes,surgical considerations,and future directions.Methods:PubMed and Google Scholar searches were conducted to retrieve and analyze relevant original papers and reviews on neurotrophic keratopathy and corneal neurotization up until April 2022.Key Content and Findings:Currently,numerous techniques for corneal neurotization exist,including direct nerve transfers,as well as indirect neurotization via interposition nerve grafts.So far,corneal neurotization has been shown to be highly successful in restoring corneal sensation,improving visual acuity,and improving corneal epithelial health.To date,there have been no significant differences in outcomes between direct versus indirect neurotization techniques,different donor nerves,or autologous versus allogeneic interposition grafts.However,there is some evidence that corneal neurotization procedures may be more successful in pediatric patients.Conclusions:Corneal neurotization shows great promise in treating neurotrophic corneas and represents the first management option to date that addresses the underlying pathophysiological mechanism of neurotrophic keratopathy by restoring corneal sensation.As the use of corneal neurotization continues to broaden,additional studies will become important to compare techniques in a systematic manner,with larger sample sizes,as well as standardized outcome measures and follow-up time.

角巩膜缘与角膜切口超声乳化术治疗老年白内障疗效对比

目的 对比角巩膜缘与角膜切口超声乳化术治疗老年白内障的临床疗效。方法 随机将80例老年白内障患者分为2组。2组均行超声乳化术,对照组采用角膜切口,观察组采用角巩膜缘切口。比较2组上皮修复时间、切口修复时间、裸眼视力、最佳矫正视力(BCVA)、角膜散光度、手术源性角膜散光度、泪囊破裂时间(BUT)、角膜荧光素染色评分(FLCs)、泪液分泌试验(SIt)水平以及术后并发症发生率。结果 观察组上皮修复、切口修复时间均早于对照组(P<0.05);观察组术后1周、2周、4周时裸眼视力、BCVA水平以及BUT、Sit水平均高于对照组(P<0.05);观察组术后1周、2周、4周时角膜散光度、手术源性角膜散光度以及FLCs水平水平均低于对照组(P<0.05);2组术后并发症发生率(18%与12%)差异无统计学意义(P>0.05)。结论 角巩膜缘切口超声乳化术治疗老年白内障临床疗效较好,患者术后角膜散光度较低,且视力、泪膜功能稳定性恢复较好。

天然高分子基角膜修复材料力学性能研究进展

由于盲人数量庞大、可供移植的捐赠角膜供不应求,人工角膜逐渐成为研究热点,但人工角膜常因力学性能不足而发生植片撕裂,为克服这一问题,国内外研究者开展了一系列研究工作尝试改善人工角膜的力学性能。文章针对胶原蛋白、明胶、丝素蛋白以及壳聚糖这4类常见的天然高分子基角膜修复材料的力学性能相关进展进行了总结。结果发现,通过光交联、热交联等物理方法,1-乙基-3-(3-二甲基氨基丙基)碳二亚胺(EDC)/N-羟基琥珀酰亚胺(NHS)交联、京尼平或戊二醛交联等化学方法以及其他复合方法都可以显著提升角膜材料的力学性能,但这些方法仍存在一些不足之处。因此,进一步开发高质量人工角膜至关重要,文章通过归纳总结希望能够为角膜修复材料的力学性能提升研究提供一些参考和思路。

REG增强的脱细胞猪角膜/聚甲基丙烯酸羟乙酯原位一体式全层复合人工角膜

背景:目前用于全层移植的人工角膜缺乏生物活性及力学适配性,组合式人工角膜存在镜柱和周围组分间的界面问题。目的:在脱细胞猪角膜原位固化制备具有多肽增强、匹配自然角膜机械强度、良好透光性的一体式全层人工角膜。方法:使用非离子型脱细胞试剂Triton X-100与超声冻融及超级核酸酶相结合的方法制备脱细胞猪角膜,将聚甲基丙烯酸羟乙酯单体与光引发剂同时引入脱细胞猪角膜中,通过紫外滤光片遮住除中心区域以外的部分,使用275 nm紫外光引发中央区域聚合,除去未反应的单体及引发剂后得到中央光学区,同理在后板层固化隔水区,最后引入REG活性多肽,得到原位一体式全层人工角膜,表征人工角膜的物理性能、力学性能、透光性、降解性能及体内外生物相容性。结果与结论:①实验在脱细胞猪角膜的中央区域采用聚甲基丙烯酸羟乙酯原位构建了一个具有聚合物和胶原纤维共存的光学区,扫描电镜下可见人工角膜的上表面较为粗糙且轮廓不规则,具有明显的凹陷和突起结构,下表面相对光滑;该人工角膜具有接近于天然角膜的力学性能,光学区透光率达到自然角膜的80%,浸泡于含胶原酶的PBS无菌溶液中可较好地保留固化光学区和隔水区,维持角膜的基本结构;该人工角膜具有良好的细胞相容性,能够为细胞提供适宜的黏附生长环境,有利于角膜上皮细胞的迁移和黏附,促进血管内皮细胞的生长和新生血管的形成,促进上皮化过程;人工角膜植入SD大鼠皮下12周后具有良好的生物相容性和安全性,可降低植入初期的急性炎症反应;②结果表明,实验制备的一体式全层人工角膜具有作为全层人工角膜支架材料的潜力。

2型糖尿病患者角膜透明度变化及其影响因素

目的探讨2型糖尿病患者角膜透明度的变化及其影响因素。方法采用病例对照研究,纳入2020年10月1日至2021年10月30日于安徽医科大学第二附属医院就诊的2型糖尿病患者52例104眼和年龄匹配的健康对照者23例46眼,分别作为糖尿病组和正常对照组。糖尿病患者根据眼底情况分为无糖尿病视网膜病变(DR)组和DR组。采用Pentacam对角膜光密度(CD)进行评估。依据Pentacam仪器自带程序将角膜分为前、中、后层,并以角膜顶点为圆心分为0~2 mm、>2~6 mm、>6~10 mm和>10~12 mm区,仪器自动计算角膜各层和各区域CD值和总CD值。采用多因素线性回归分析模型分析糖尿病组总CD值的影响因素。结果糖尿病组患者受检眼总CD值为20.24±3.10,明显高于正常对照组的18.79±3.31,差异有统计学意义(t=-2.583,P=0.011)。糖尿病组患者受检眼角膜前层、中层、0~2 mm、>2~6 mm区CD值均明显高于正常对照组,差异均有统计学意义(均P<0.05)。无DR组和DR组受检眼前层CD值均高于正常对照组,无DR组受检眼角膜中层和后层CD值和总CD值均高于正常对照组和DR组,差异均有统计学意义(均P<0.05)。0~2 mm和>2~6 mm环区无DR组和DR组受检眼CD值均明显高于正常对照组,>6~10 mm环区无DR组受检眼CD值明显高于DR组和正常对照组,差异均有统计学意义(均P<0.05)。多因素线性回归分析显示,糖尿病患者年龄和糖化血红蛋白(HbA1c)水平是CD值升高的主要影响因素(β=0.266,P<0.001;β=0.423,P=0.003)。结论糖尿病患者的角膜透明度下降先于DR出现,糖尿病患者HbA1c水平控制不佳可引起角膜透明度下降。

电针对干眼大鼠角膜自噬相关蛋白调节作用的研究

目的观察电针对干眼大鼠角膜自噬的调节作用。方法将雄性Sprague-Dawley(SD)大鼠随机分为正常组、模型组、电针组和假针组。除正常组外,其余3组均采用皮下注射东莨菪碱溶液配合吹风制备大鼠干眼模型。电针组和假针组造模后分别予电针及假针刺干预。检测大鼠干预前后泪膜破裂时间和泪液分泌量,并评估角膜荧光素染色的分值;应用透射电镜观察大鼠角膜组织的超微结构;采用蛋白免疫印迹(Western blotting)技术检测大鼠角膜微管相关蛋白轻链3(microtubule-associatedprotein 1 light chain 3,LC3)、P62和Beclin-1的表达,应用实时聚合酶链式反应(real-time polymerase chain reaction,RT-PCR)技术检测角膜LC3 mRNA的表达。结果与正常组比较,模型组大鼠泪液分泌量降低,泪膜破裂时间缩短,角膜荧光素染色评分升高,差异均具有统计学意义(P<0.05);角膜上皮细胞肿胀,线粒体明显损伤;角膜LC3Ⅱ和Beclin-1蛋白表达减少,P62蛋白表达增多,LC3 mRNA表达减少,差异均具有统计学意义(P<0.05)。与模型组比较,电针组大鼠泪液分泌量升高,泪膜破裂时间延长,角膜荧光素染色评分降低,差异均具有统计学意义(P<0.05);角膜上皮细胞轻微肿胀,有自噬小体形成;角膜LC3Ⅱ和Beclin-1蛋白表达增多,P62蛋白表达降低,LC3 mRNA表达增多,差异均具有统计学意义(P<0.05)。与模型组比较,假针组细胞器肿胀明显,线粒体损伤明显;其余指标差异均无统计学意义(P>0.05)。结论电针可以促进干眼大鼠角膜组织中自噬的发生,促进自噬可能是电针治疗干眼的潜在机制。

抗菌肽在眼表感染性疾病中的应用进展

眼表长时间暴露在外部环境下,很容易患各种眼表感染性疾病。近年来,由于病原体对抗菌药物的耐药性问题,眼表感染性疾病患者呈现治疗效果不佳、视力和生活质量严重下降等情况。目前,眼表感染性疾病已成为一个全球性的公共卫生问题,寻找一种安全、有效的治疗药物迫在眉睫。抗菌肽作为抗生素类似物,具有广谱抗菌性,能有效抵抗各种微生物的感染,包括细菌、病毒、真菌和寄生虫。抗菌肽在眼表感染性疾病的治疗中发挥着重要作用。本文就抗菌肽的结构与功能、抗菌肽在眼表感染性疾病中的作用机制、内源性抗菌肽在眼表感染中针对不同病原体的作用、外源性诱导抗菌肽对眼表感染性疾病的作用以及抗菌肽研究的最新进展等进行综述。

通过眼部结构协助诊断早期阿尔茨海默症的研究进展

阿尔茨海默症(AD)是常见的中枢神经系统退行性疾病,其神经病理学变化先于认知功能障碍和行为损害出现。目前,AD的早期诊断是基于有创性和价格昂贵的检测技术,难以在临床上广泛使用。因此,迫切需要新的标志物,以在早期阶段检测AD。眼睛作为大脑的延伸,研究发现,与大脑病理学变化相比,AD患者眼部病理学变化更早出现,如视网膜结构异常、视觉功能障碍、视网膜异常蛋白积聚、脉络膜厚度变化、角膜神经纤维密度降低、晶状体异常Aβ蛋白的沉积和瞳孔光反应敏感度下降等。本文针对近些年AD患者的眼部病理学变化进行综述,为临床早期诊断AD提供新思路。

光学相干断层扫描在角膜塑形镜验配中的应用

目的:通过光学相干断层扫描(OCT)测量角膜塑形镜下泪液间隙厚度,探讨泪液间隙厚度与角膜塑形镜配适度之间的关系,为角膜塑形镜的验配提供一种更直观、量化的临床评估手段。方法:收集2023-01/12在我院验配角膜塑形镜的近视患者。在进行配镜之前,对所有患者都实施了全面的眼科诊断,涵盖了视力检测、裂隙灯检查、非接触眼压测量、眼底检查、双眼眼位检查、测量角膜直径、角膜地形图检查、泪膜破裂时间评估以及综合验光检查等项目。根据个人的检查结果选择试戴片的参数,待患者戴镜适应后进行荧光素染色配适度评估。将被检眼分为镜片过松组、镜片适配组、镜片过紧组。使用OCT测量三组被检眼泪液间隙厚度,评估三组数据之间差异性。结果:本研究共纳入近视患者49例77眼。验配前测得平均球镜度为-3.10±1.25 D,平均柱镜度为-0.43(-0.75,0)D,平均水平子午线角膜曲率(HK)为42.48±0.81 D,平均垂直子午线角膜曲率(VK)为42.98(42.25,43.50)D。镜片适配组21例34眼(13例双眼,8例单眼)、镜片过松组14例22眼(8例双眼,6例单眼)、镜片过紧组14例21眼(7例双眼,7例单眼)。三组受检者的主要基础资料比较无差异(均P>0.05)。使用OCT测量得出,镜片适配组、镜片过松组、镜片过紧组泪液间隙厚度分别为231.18(219.0,243.0)、220.41(214.0,224.3)、249.00(241.5,258.0)μm,三组厚度数值比较有差异(P<0.05)。结论:OCT技术提供了一种安全可靠的测量泪液间隙厚度的方法,它可以帮助评估角膜塑形镜的适配情况,为角膜塑形镜的验配评估提供了一种无创的、更直观和定量的评估手段。