Amniotic Membrane Grafts in Pediatric Corneal Limbal Dermoids with Conjunctival Eyelashes: A Case Presentation

Purpose: To report a case of a pediatric corneal limbal dermoid with eyelashes and to describe post-operative changes after excision with reconstruction using amniotic membrane grafting, sutures and fibrinogen-thrombin glue. Case Report: One pediatric patient was identified with a grade II infratemporal corneal-limbal dermoid with conjunctival eyelashes. The dermoid was surgically excised and the cornea reconstructed with amniotic membrane using sutures and fibrinogen/thrombin glue. Preoperative and postoperative measurement of astigmatism, anisometropia and presence of exposure keratopathy were performed.

Transplantation of tissue-engineered human corneal epithelium in limbal stem cell deficiency rabbit models

AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed with DiI-labeled untransfected HCEP cells and denuded amniotic membrane (dAM) in air-liquid interface culture, and their morphology and structure were characterized by hematoxylin-eosin (HE) staining of paraffin-sections, immunohistochemistry and electron microscopy. LSCD models were established by mechanical and alcohol treatment of the left eyes of New Zealand white rabbits, and their eyes were transplanted with TE-HCEPs with dAM surface outside by lamellar keratoplasty (LKP). Corneal transparency, neovascularization, thickness, and epithelial integrality of both traumatic and post transplantation eyes were checked once a week by slit-lamp corneal microscopy, a corneal pachymeter, and periodic acid-Schiff (PAS) staining. At day 120 post surgery, the rabbits in each group were sacrificed and their corneas were examined by DiI label observation, HE staining, immunohistochemistry and electron microscopy. RESULTS: After cultured for 5 days on dAM, HCEP cells, maintaining keratin 3 expression, reconstructed a 6-7 layer TE-HCEP with normal morphology and structure. The traumatic rabbit corneas, entirely opaque, conjunctivalized and with invaded blood vessels, were used as LSCD models for TE-HCEP transplantation. After transplantation, obvious edema was not found in TE-HCEP-transplanted corneas which became more and more transparent, the invaded blood vessels reduced gradually throughout the monitoring period. The corneas decreased to normal thickness on day 25, while those of dAM eyes were over 575 mu m in thickness during the monitoring period. A 45 layer of epithelium consisting of TE-HCEP originated cells attached tightly to the anterior surface of stroma was reconstructed 120 days after TE-HCEP transplantation, which was similar to the normal control eye in morphology and structure. In contrast, intense corneal edema, turbid, invaded blood vessels were found in dAM eyes, and no multilayer epithelium was found but only a few scattered conjunctiva-like cells appeared. CONCLUSION: The TE-HCEP, with similar morphology and structure to those of innate HCEP, could reconstruct a multilayer corneal epithelium with normal functions in restoring corneal transparency and thickness of LSCD rabbits after transplantation. It may be a promising HCEP equivalent for clinical therapy of corneal epithelial disorders.

Simple keratectomy and corneal tattooing for limbal dermoids:results of a 3-year study

AIM:To evaluate and report the efficacy of combined surgical excision and corneal tattooing in patients with limbal dermoids.·METHODS:In a retrospective interventional case series,9 eyes of 8 patients were treated with combined surgery of simple keratectomy and corneal tattooing for limbal dermoids.Medical records,including best-corrected visual acuity,anterior segment photography,demographic,clinical data,and follow-up information were reviewed.·RESULTS:The mean follow up period in this study was 50±15(range 36-77) months.There was no evidence of infection or recurrent limbal dermoids in any of the eyes during the follow-up period.All patients achieved good cosmetic outcomes with no complications.·CONCLUSION:Simple keratectomy and corneal tattooing of limbal dermoids could be an alternative option for surgery,especially when a donor cornea is not available.

Limbal stem cells: Central concepts of corneal epithelial homeostasis

A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal

Preoperative evaluation and outcome of corneal transplantation for limbal dermoids：aten-yearfollow-up study

AIM： To summarize preoperative evaluation and outcome of corneal transplantation for limbal dermoids for ten years.METHODS： Eighty-five patients diagnosed with limbal dermoids and treated with corneal transplantation were analyzed retrospectively. All patients were further divided into two groups according to absence or presence of neovascularization surrounding the dermoids in the corneal stroma. Eighty-two eyes were treated with tumor excision combined with partial lamellar sclerokeratoplasty, and the other three eyes were performed by penetrating keratoplasty. The size and location of the tumor, the associated ocular and systemic anomalies, the depth of the corneal penetration of tumor tissues, the preoperative and postoperative best-corrected visual acuity （BCVA）, graft survival and cosmetic outcome, and surgical complications were recorded respectively.RESULTS： The average age at surgery was 5.3y （range, 3mo-36y）. The mean size of dermoids was 6.1±1.6 mm. The 43.5% of eyes （37/85） were present with hair at the surface of the dermoid and 72.9% of dermoids were located inferotemporal of the eye. Amplyopia was present in 34.1% of patients （29/85） and 9.4% of patients （8/85） had lipodermoids. Eighteen patients suffered from Goldenhar’s syndrome with an accessory ear. The 75% of patients in group 1 had involvement of the corneal deep stroma down to Descemet’s membrane without involving it, but 71.4% of patients had Descemet’s membrane involvement in group 2. Preoperative BCVA ranged from counting fingers to 20/20. Postoperatively 81.1% had a BCVA of 20/800 or better. There was no significant difference between the post-surgical BCVA of the two groups （t=1.584, P〉0.05）. The grafts of 70.5% patients were present as 1＋ opacity, 21.1% as 2＋ opacity, 8.2% as 3＋ opacity and none as 4＋ opacity. Surgical complications included graft rejection, microperforation, prolonged reepithelialization, steroid glaucoma, interface neovascularization, and interface hemorrhage.CONCLUSION： The dermoids with neovascularization surrounding them in the corneal stroma invaded deeper tissues in the cornea than those with no neovascularization surrounding them in the corneal stroma. Therefore, surgeons should take care to avoid corneal perforation during the corneal transplantation operation. The majority of patients markedly improved their cosmetic appearance after surgery.

Cryopreserved limbal lamellar keratoplasty for peripheral corneal and limbal reconstruction

This study aimed to evaluate the outcomes and described the recovery process of cryopreserved limbal lamellar keratoplasty（CLLK） for peripheral corneal and limbal diseases. Thirteen eyes of 12 patients with a mean age of 41±23.9 y were included. The average follow-up was 12.1±5.6 mo. Stable ocular surface was achieved in all eyes at last follow-up. Epithelialization originated from both recipient and graft in 9 eyes. We conclude that CLLK compensates for the shortage of donor corneas and cryopreserved limbal grafts provide epithelialization sources in ocular surface reconstruction.

Quantification of corneal neovascularization after ex vivo limbal epithelial stem cell therapy

AIM: To assess cultured limbal epithelial stem cell transplantation in patients with limbal stem cell deficiency by analyzing and quantifying corneal neovascularization.METHODS: This retrospective, interventional case series included eight eyes with total limbal stem cell deficiency. Ex vivo limbal epithelial stem cells were cultured on human amniotic membrane using an animalfree culture method. The clinical parameters of limbal stem cell deficiency, impression cytology, and quantification of corneal neovascularization were evaluated before and after cultured limbal stem cell transplantation. The area of corneal neovascularization,vessel caliber(VC), and invasive area(IA) were analyzed before and after stem cell transplantation by image analysis software. Best-corrected visual acuity(BCVA),epithelial transparency, and impression cytology were also measured.RESULTS: One year after surgery, successful cases showed a reduction(improvement) of all three parameters of corneal neovascularization [neovascular area(NA), VC, IA], while failed cases did not. NA decreased a mean of 32.31%(P =0.035), invasion area29.37%(P =0.018) and VC 14.29%(P =0.072). BCVA improved in all eyes(mean follow-up, 76 ±21mo).Epithelial transparency improved significantly from 2.00 ±0.93 to 0.88±1.25(P =0.014). Impression cytology showed that three cases failed after limbal epithelial stem cell therapy before 1y of follow-up.CONCLUSION: This method of analyzing andmonitoring surface vessels is useful for evaluating the epithelial status during follow-up, as successful cases showed a bigger reduction in corneal neovascularization parameters than failed cases. Using this method,successful cases could be differentiated from failed cases.

切除联合自体角膜缘干细胞移植术治疗原发性翼状胬肉的研究

目的探讨翼状胬肉切除联合自体角膜缘干细胞移植术治疗原发性翼状胬肉的临床效果及安全性。方法回顾性研究2019年1月至2023年1月在本院接受原发性翼状胬肉手术治疗的66例患者病历资料,将66例患者根据手术方式的不同分为对照组(n=33,翼状胬肉切除联合游离结膜瓣移植术)及试验组(n=33,翼状胬肉切除联合自体角膜缘干细胞移植术)。比较两组临床效果、术后结膜瓣愈合时间、角膜上皮修复时间,记录术前及术后1个月、3个月、6个月泪膜破裂时间(TBUT)变化及术后并发症发生率和术后6个月的复发率。结果试验组患者治疗后的临床疗效高于对照组,术后结膜瓣愈合时间、角膜上皮修复时间明显短于对照组,术后的1月、3月、6月时TBUT时间明显长于对照组(P<0.05);两组术后并发症的发生率及复发率比较,差异无统计学意义(P>0.05)。结论翼状胬肉切除联合自体角膜缘干细胞移植术治疗原发性翼状胬肉具有良好的治疗效果和安全性,可降低术后复发率,且不增加术后并发症发生率。

翼状胬肉切除术联合角膜缘干细胞移植术后应用角膜绷带镜的效果

目的:分析翼状胬肉切除术联合角膜缘干细胞移植术后应用角膜绷带镜的效果。方法:选取2017年1月—2022年12月于双桥医院眼整形科行翼状胬肉切除术联合角膜缘干细胞移植术患者80例(80眼)作为研究对象,随机分为对照组和观察组,各40例。对照组术后应用妥布霉素地塞米松滴眼液、玻璃酸钠滴眼液,观察组在对照组基础上应用角膜绷带镜。比较两组恢复效果。结果:观察组复发率低于对照组,角膜上皮修复时间短于对照组,差异有统计学意义(P<0.05)。术后1 d,两组疼痛评分比较,差异无统计学意义(P>0.05);术后3 d,两组疼痛评分均低于术后1 d,观察组低于对照组,差异有统计学意义(P<0.05)。治疗前,两组症状评分比较,差异无统计学意义(P>0.05);治疗后,观察组畏光、异物感、流泪、眼部充血评分低于对照组,差异均有统计学意义(P<0.05)。结论:角膜绷带镜有利于减轻患者术后疼痛,缓解术后症状,降低复发率。

除风益损汤加减方对翼状胬肉术后眼表损伤修复的作用探究

目的:探讨除风益损汤加减方对翼状胬肉术后眼表损伤修复的影响。方法:纳入研究的100例原发性翼状胬肉患者随机分为观察组和对照组,各50例。2组均接受翼状胬肉切除联合角膜缘干细胞移植手术,其中对照组术后采用常规滴眼液点眼治疗,观察组在对照组的基础上联合口服除风益损汤加减方治疗,用药1周。比较2组术后眼部疼痛评分、眼部体征、泪膜破裂时间、角膜状态及复发率的差异。结果:术后1日、2日、1周2组眼部疼痛评分均优于术后6h,差异均有统计学意义;观察组眼部疼痛评分评分优于对照组,差异有统计学意义;术后2日、1周2组眼部体征积分均优于术后1日,差异均有统计学意义;观察组眼部体征积分优于对照组,差异有统计学意义;术后1周观察组泪膜破裂时间及角膜状态评分均优于对照组,差异均有统计学意义;术后随访6个月,观察组复发率低于对照组,差异有统计学意义。结论:除风益损汤加减方可促进翼状胬肉切除联合角膜缘干细胞移植术后眼表损伤的修复。

翼状胬肉切除与角膜缘干细胞移植联合治疗对翼状胬肉患者角膜散光及视力的影响

目的:探究翼状胬肉切除联合角膜缘干细胞移植对翼状胬肉患者的影响。方法:选取2020年3月—2023年3月镇江市第四人民医院收治的100例翼状胬肉患者作为研究对象,按随机数表法分为两组,各50例。对照组行翼状胬肉切除治疗,观察组在对照组基础上加用角膜缘干细胞移植治疗。比较两组临床疗效、拆线时间、角膜上皮修复时间、视力恢复情况、泪膜功能及并发症发生情况。结果:观察组治疗总有效率高于对照组,拆线时间、角膜上皮修复时间早于对照组,并发症总发生率低于对照组,差异有统计学意义(P<0.05)。术后3个月,观察组最佳矫正视力(BCVA)、角膜水平曲度、角膜垂直曲度高于对照组,角膜散光度低于对照组,泪膜破裂时间(BUT)、泪液分泌试验(SⅠT)长于对照组,差异有统计学意义(P<0.05)。结论:翼状胬肉切除联合角膜缘干细胞移植可修复翼状胬肉患者角膜上皮,改善视力,有利于泪膜功能的提升,且并发症少。

翼状胬肉切除联合角膜缘干细胞移植术治疗翼状胬肉的临床效果探讨

目的探讨翼状胬肉切除联合角膜缘干细胞移植(Corneal Limbal Stem Cell Transplantation,CAT)术治疗翼状胬肉的临床效果。方法随机选取2022年12月—2023年10月新疆伊宁市农四师医院收治的60例翼状胬肉患者作为研究对象,采用随机数表法分为两组。对照组(30例)行翼状胬肉切除+自体结膜瓣缘干细胞移植术(Autologous Conjunctival Flap Stem Cell Transplantation,LCAT)处理,观察组(30例)行翼状胬肉切除+CAT术处理。对比两组的泪膜功能[泪膜破裂时间(Break-up Time,BUT)、泪液分泌试验(Schirmer Test,SIT)]、视力水平[裸眼视力(Naked Vision,UCVA)、角膜屈光度]以及术后并发症发生状况。结果术后3个月,两组的BUT与SIT泪膜功能指标均高于术前,但组间对比,差异无统计学意义(P均>0.05)。术后3个月,两组UCVA值高于术前,角膜屈光度小于术前,但组间对比,差异无统计学意义(P均>0.05)。观察组与对照组术后并发症发生率对比(10.00%vs 6.67%),差异无统计学意义(P>0.05)。结论翼状胬肉切除+CAT术式用于翼状胬肉患者的处理,其安全性、视力及泪膜功能改善效果与翼状胬肉切除+LCAT术式相当。

不同方法及术后干预对翼状胬肉患者舒适度及疗效的影响

目的:探讨不同球结膜移植术及术后干预对翼状胬肉患者舒适度及疗效的影响。方法:选取2017年1月—2019年12月样本医院收治的200例(200眼)翼状胬肉患者作为研究对象,按随机数表法分为A、B、C、D 4组,每组50例(50眼)。A、B组采用切除术联合自体游离结膜瓣移植术,C、D组采用切除术联合角膜缘干细胞移植,B、D组术后佩戴角膜绷带镜。观察对比4组患者术后眼部不适、视力、角膜上皮愈合时间、治愈率及复发率情况。结果:4组患者术后均出现不同程度的眼部不适,3 d后缓解,2周后基本消失。术后1 d、3 d、7 d B组患者眼部不适较A组轻,D组患者眼部不适较C组轻,而A组与C组、B组与D组之间比较,差异无统计学意义(F=0.083,P>0.05);术后1 d、3 d 4组患者的裸眼视力均有不同程度的下降。术后1 d、3 d B组患者视力较A组高,D组患者视力较C组高,差异有统计学意义(F=3.026、3.088,P<0.05);4组患者术后角膜上皮愈合约需4~6 d,B组角膜上皮愈合时间较A组短,D组较C组短,差异有统计学意义(F=35.800,P<0.05);4组患者术后治愈率和术后翼状胬肉复发情况比较,差异无统计学意义(χ^(2)=0.632、1.031,P>0.05)。结论:切除术联合角膜缘干细胞移植对翼状胬肉患者治疗效果显著,复发率较低。佩戴角膜绷带镜可减轻术后眼部不适,有利于角膜上皮愈合和早期视力的稳定,对翼状胬肉的治疗具有积极意义。

聚乙烯醇滴眼液在复发性翼状胬肉患者术后的应用效果分析

目的:探讨人工泪液治疗复发性翼状胬肉的临床效果;方法:选取2022年1月—2023年2月深圳市南山区人民医院收治的复发性翼状胬肉患者100例(100眼)作为研究对象,随机分为试验组与对照组,各50例。患者均采用翼状胬肉切除伴角膜缘干细胞移植术,术后,对照组给予常规药物治疗,试验组在对照组基础上给予聚乙烯醇滴眼液治疗。结果:术前,两组滤纸浸湿长度、泪膜破裂时间比较,差异无统计学意义(P>0.05)。术后12个月,两组滤纸浸湿长度比较,差异无统计学意义(P>0.05);两组泪膜破裂时间长于术前,且试验组长于对照组,差异有统计学意义(P<0.05)。试验组移植片成活时间早于对照组,胬肉复发率低于对照组,差异有统计学意义(P<0.05)。结论:聚乙烯醇滴眼液在复发性翼状胬肉患者术后的应用效果显著,可促进移植片成活,降低胬肉复发率,延长泪膜破裂时间。

翼状胬肉切除联合角膜缘干细胞移植术治疗翼状胬肉的效果分析

研究分析采取翼状胬肉切除联合角膜缘干细胞移植术治疗翼状胬肉的临床效果。选取2021年1月-2022年12月于医院就诊的60例翼状胬肉患者为研究对象,采用奇偶数分组法将其分为常规组和试验组,每组各30例。常规组行翼状胬肉切除术治疗,试验组行翼状胬肉切除联合角膜缘干细胞移植术治疗,对比两组治疗效果。结果显示,治疗后,试验组视觉功能、泪膜功能改善程度优于常规组(P<0.05);试验组术后并发症总发生率、翼状胬肉复发率均低于常规组(P<0.05);试验组除手术时间长于常规组外,术后各指标恢复时间均短于常规组(P<0.05);试验组术后各时间段结膜体征评分均低于常规组(P<0.05)。研究发现,翼状胬肉切除联合角膜缘干细胞移植术治疗翼状胬肉的效果显著。

优质护理用于翼状胬肉切除加角膜缘干细胞移植术患者护理中的效果研究

分析优质护理用于翼状胬肉切除加角膜缘干细胞移植术患者护理中的效果。选取2022年9月—2023年9月瓮安县中医医院收治的76例行翼状胬肉切除加角膜缘干细胞移植术的患者为研究对象。采用随机数字表法将患者分为两组,分别为参照组和试验组,每组各38例。参照组实施常规护理,试验组实施优质护理,比较两组患者护理效果。结果显示,护理后,试验组各项眼部舒适度评分均低于参照组,疼痛程度和不良情绪评分均低于参照组,手术时间短于参照组,呼吸频率、血压指标低于参照组,指端血氧饱和度高于参照组,并发症总发生率低于参照组,各项生活质量评分均高于参照组。上述指标比较,差异均具有统计学意义(P<0.05)。研究发现,翼状胬肉切除加角膜缘干细胞移植术治疗过程中,选择优质护理作为配合方案,对提高患者眼部舒适度,减轻其疼痛感作用显著。

连续缝合埋线法在翼状胬肉切除联合角膜缘干细胞移植术中的应用

目的探讨连续缝合埋线法在翼状胬肉切除联合角膜缘干细胞移植术中的应用疗效。方法70例原发性翼状胬肉患者随机分为观察组和对照组。两组均采用翼状胬肉切除联合角膜缘干细胞移植原位缝合术治疗,对照组采用间断缝合法,观察组采用连续缝合埋线法。比较两组的疼痛评分、眼表体征评分、泪膜破裂时间、并发症及复发率。结果(1)术后6小时两组疼痛评分无统计学差异(Z=-0.314,P=0.754);术后1日、2日观察组疼痛评分均低于对照组(Z_(术后第1日)=-2.842,P_(术后第1日)=0.004;Z_(术后第2日)=-2.403,P_(术后第2日)=0.016)。(2)术后1日、2日观察组眼表体征均优于对照组(Z_(术后第1日)=-2.446,P_(术后第1日)=0.014;Z_(术后第2日)=-2.526,P_(术后第2日)=0.012);术后1周两组眼表体征无统计学差异(Z=-1.358,P=0.175)。(3)术后1周观察组泪膜破裂时间优于对照组(t=2.135,P=0.036),术后4周两组泪膜破裂时间无统计学差异(t=0.989,P=0.326)。(4)术后4周及术后3个月观察组眼表并发症评分均优于对照组(Z_(术后第4周)=-2.019,P_(术后第4周)=0.044;Z_(术后第3月)=-2.945,P_(术后第3月)=0.003)。(5)两组复发率无统计学差异(P=0.607)。结论翼状胬肉切除及角膜缘干细胞移植术中采用连续缝合埋线法,可缓解术后的眼部刺激症状、减轻眼表炎症、促进眼表重建。

Evaluating alternative stem cell hypotheses for adult corneal epithelial maintenance

In this review we evaluate evidence for three different hypotheses that explain how the corneal epithelium is maintained. The limbal epithelial stem cell(LESC)hypothesis is most widely accepted. This proposes that stem cells in the basal layer of the limbal epithelium, at the periphery of the cornea, maintain themselves and also produce transient(or transit) amplifying cells(TACs). TACs then move centripetally to the centre of the cornea in the basal layer of the corneal epithelium and also replenish cells in the overlying suprabasal layers. The LESCs maintain the corneal epithelium during normal homeostasis and become more active to repair significant wounds. Second, the corneal epithelial stem cell(CESC) hypothesis postulates that, during normal homeostasis, stem cells distributed throughout the basal corneal epithelium, maintain the tissue. According to this hypothesis, LESCs are present in the limbus but are only active during wound healing. We also consider a third possibility, that the corneal epithelium is maintained during normal homeostasis by proliferation of basal corneal epithelial cells without any input from stem cells. After reviewing the published evidence, we conclude that the LESC and CESC hypotheses are consistent with more of the evidence than the third hypothesis, so we do not consider this further. The LESC and CESC hypotheses each have difficulty accounting for one main type of evidence so we evaluate the two key lines of evidence that discriminate between them. Finally, we discuss how lineage-tracing experiments have begun to resolve the debate in favour of the LESC hypothesis. Nevertheless, it also seems likely that some basal corneal epithelial cells can act as long-term progenitors if limbal stem cell function is compromised. Thus, this aspect of the CESC hypothesis may have a lasting impact on our understanding of corneal epithelial maintenance, even if it is eventually shown that stem cells are restricted to the limbus as proposed by the LESC hypothesis.

Acellular porcine corneal matrix as a carrier scaffold for cultivating human corneal epithelial cells and fibroblasts in vitro

AIM：To investigate the feasibility of corneal anterior lamellar reconstruction with human corneal epithelial cells and fibroblasts,and an acellular porcine cornea matrix（APCM） in vitro.·METHODS：The scaffold was prepared from fresh porcine corneas which were treated with 0.5%sodium dodecyl sulfate（SDS）solution and the complete removal of corneal cells was confirmed by hematoxylin-eosin（HE）staining and 4’,6-diamidino-2-phenylindole（DAPI）staining.Human corneal fibroblasts and epithelial cells were cultured with leaching liquid extracted from APCM,and then cell proliferative ability was evaluated by MTT assay.To construct a human corneal anterior lamellar replacement,corneal fibroblasts were injected into the APCM and cultured for 3d,followed by culturing corneal epithelial cells on the stroma construction surface for another 10d.The corneal replacement was analyzed by HE staining,and immunofluorescence staining.·R ESULTS：Histological examination indicated that there were no cells in the APCM by HE staining,and DAPI staining did not detect any residual DNA.The leaching liquid from APCM had little influence on the proliferation ability of human corneal fibroblasts and epithelial cells.At 10d,a continuous 3 to 5 layers of human corneal epithelial cells covering the surface of the APCM was observed,and the injected corneal fibroblasts distributed within the scaffold.The phenotype of the construction was similar to normal human corneas,with high expression of cytokeratin 12 in the epithelial cell layer and high expression of Vimentin in the stroma.·CONCLUSION：Corneal anterior lamellar replacement can be reconstructed in vitro by cultivating human corneal epithelial cells and fibroblasts with an acellular porcine cornea matrix.This laid the foundation for the further transplantation in vitro.

Correction of low corneal astigmatism in cataract surgery

· AIM: To evaluate and compare aspheric toric intraocular lens(IOL) implantation and aspheric monofocal IOL implantation with limbal relaxing incisions(LRI) to manage low corneal astigmatism(1.0-2.0 D) in cataract surgery.· METHODS: A prospective randomized comparative clinical study was performed. There were randomly recruited 102 eyes(102 patients) with cataracts associated with corneal astigmatism and divided into two groups. The first group received toric IOL implantation and the second one monofocal IOL implantation with peripheral corneal relaxing incisions. Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, the need for spectacles, and patient satisfaction. To determine the postoperative toric axis, all patients who underwent the toric IOL implantation were further evaluated using an OPD Scan III(Nidek Co, Japan). Follow-up lasted 6mo.· RESULTS: The mean uncorrected distance visual acuity(UCVA) and the best corrected visual acuity(BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically better in the patients with toric IOL implants compared to those patients who underwent implantation of monofocal IOL plus LRI. The mean residual refractive astigmatism was of 0.4 D for the toric IOL group and 1.1 D for the LRI group(P 【0.01). No difference was observed in the postoperative endothelial cell count between the two groups.· CONCLUSION: The two surgical procedures demonstrated a significant decrease in refractive astigmatism. Toric IOL implantation was more effective and predictable compared to the limbal relaxing incision.