Corneal stem cells and tissue engineering: Current advances and future perspectives

Major advances are currently being made in regenerative medicine for cornea. Stem cell-based therapies represent a novel strategy that may substitute conventional corneal transplantation, albeit there aremany challenges ahead given the singularities of each cellular layer of the cornea. This review recapitulates the current data on corneal epithelial stem cells, corneal stromal stem cells and corneal endothelial cell progenitors. Corneal limbal autografts containing epithelial stem cells have been transplanted in humans for more than 20 years with great successful rates, and researchers now focus on ex vivo cultures and other cell lineages to transplant to the ocular surface. A small population of cells in the corneal endothelium was recently reported to have self-renewal capacity, although they do not proliferate in vivo. Two main obstacles have hindered endothelial cell transplantation to date: culture protocols and cell delivery methods to the posterior cornea in vivo. Human corneal stromal stem cells have been identified shortly after the recognition of precursors of endothelial cells. Stromal stem cells may have the potential to provide a direct cell-based therapeutic approach when injected to corneal scars. Furthermore, they exhibit the ability to deposit organized connective tissue in vitro and may be useful in corneal stroma engineering in the future. Recent advances and future perspectives in the field are discussed.

Profile of biological characterizations and clinical application of corneal stem/progenitor cells

Corneal stem/progenitor cells are typical adult stem/progenitor cells.The human cornea covers the front of the eyeball,which protects the eye from the outside environment while allowing vision.The location and function demand the cornea to maintain its transparency and to continuously renew its epithelial surface by replacing injured or aged cells through a rapid turnover process in which corneal stem/progenitor cells play an important role.Corneal stem/progenitor cells include mainly corneal epithelial stem cells,corneal endothelial cell progenitors and corneal stromal stem cells.Since the discovery of corneal epithelial stem cells(also known as limbal stem cells)in 1971,an increasing number of markers for corneal stem/progenitor cells have been proposed,but there is no consensus regarding the definitive markers for them.Therefore,the identification,isolation and cultivation of these cells remain challenging without a unified approach.In this review,we systematically introduce the profile of biological characterizations,such as anatomy,characteristics,isolation,cultivation and molecular markers,and clinical applications of the three categories of corneal stem/progenitor cells.

Mesenchymal stem cells: Potential role in corneal wound repair and transplantation

Corneal diseases are a major cause of blindness in the world. Although great progress has been achieved in the treatment of corneal diseases, wound healing after severe corneal damage and immunosuppressive therapy after corneal transplantation remain prob-lematic. Mesenchymal stem cells(MSCs) derived from bone marrow or other adult tissues can differentiate into various types of mesenchymal lineages, such as osteocytes, adipocytes, and chondrocytes, both in vivo and in vitro. These cells can further differentiate into specific cell types under specific conditions. MSCs migrate to injury sites and promote wound healing by secreting anti-inflammatory and growth factors. In ad-dition, MSCs interact with innate and acquired immune cells and modulate the immune response through their powerful paracrine function. Over the last decade, MSCs have drawn considerable attention because of their beneficial properties and promising therapeutic prospective. Furthermore, MSCs have been applied to various studies related to wound healing, autoim-mune diseases, and organ transplantation. This review discusses the potential functions of MSCs in protecting corneal tissue and their possible mechanisms in corneal wound healing and corneal transplantation.

Corneal stromal mesenchymal stem cells: reconstructing a bioactive cornea and repairing the corneal limbus and stromal microenvironment

Corneal stroma-derived mesenchymal stem cells(CS-MSCs) are mainly distributed in the anterior part of the corneal stroma near the corneal limbal stem cells(LSCs). CS-MSCs are stem cells with self-renewal and multidirectional differentiation potential. A large amount of data confirmed that CS-MSCs can be induced to differentiate into functional keratocytes in vitro, which is the motive force for maintaining corneal transparency and producing a normal corneal stroma. CS-MSCs are also an important component of the limbal microenvironment. Furthermore, they are of great significance in the reconstruction of ocular surface tissue and tissue engineering for active biocornea construction. In this paper, the localization and biological characteristics of CS-MSCs, the use of CS-MSCs to reconstruct a tissue-engineered active biocornea, and the repair of the limbal and matrix microenvironment by CS-MSCs are reviewed, and their application prospects are discussed.

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

Anti-inflammatory potential of human corneal stroma-derived stem cells determined by a novel in vitro corneal epithelial injury model

BACKGROUND An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells(hCEC).AIM To investigate whether corneal-stroma derived stem cells(CSSC) seeded on an amniotic membrane(AM) construct manifests an anti-inflammatory, healing response.METHODS Treatment of hCEC with ethanol and pro-inflammatory cytokines were compared in terms of viability loss, cytotoxicity, and pro-inflammatory cytokine release, in order to generate the in vitro injury. This resulted in an optimal injury of 20%(v/v) ethanol for 30 s with 1 ng/mL interleukin-1(IL-1) beta. Co-culture experiments were performed with CSSC alone and with CSSC-AM constructs.The effect of injury and co-culture on viability, cytotoxicity, IL-6 and IL-8 production, and IL1 B, TNF, IL6, and CXCL8 mRNA expression were assessed.RESULTS Co-culture with CSSC inhibited loss of hCEC viability caused by injury. Enzyme linked immunosorbent assay and polymerase chain reaction showed a significant reduction in the production of IL-6 and IL-8 pro-inflammatory cytokines, and reduction in pro-inflammatory cytokine mRNA expression during co-culture with CSSC alone and with the AM construct. These results confirmed the therapeutic potential of the CSSC and the possible use of AM as a cell carrier for application to the ocular surface.CONCLUSION CSSC were shown to have a potentially therapeutic anti-inflammatory effectwhen treating injured hCEC, demonstrating an important role in corneal regeneration and wound healing, leading to an improved knowledge of their potential use for research and therapeutic purposes.

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.

The Preliminary Experimental Study of Induced Differentiation of Embryonic Stem Cells into Corneal Epithelial Cells

Purpose:To study preliminarily induced differentiation of embryonic stem cells intocorneal epithelial cells in vitro.Methods: Murine embryonic stem cells were co-cultured with Rabbit limbal cornealepithelial cells in Transwell system to induce differentiation. Mophological andimmunohistochemical examination were implemented.Results: The induced cells from embryonic stem cells have an epithelial appearance.The cells formed a network and were confluent into film gradually after beingco-cultured with rabbit limbal corneal epithelial cells for 24 ～ 96 hours. The cells rangedmosaic structure and localized together with clear rim. Most of the cells showedpolygonal appearance. Transmission electron microscope showed lots of microvilli on thesurface of induced cells and tight junctions between them. These epithelial-like cellsexpressed the corneal epithelial cell specific marker cytokeratin3/cytokeratinl2.Conclusion: The potential mechanism of the differentiation of murine embryonic stemcells into corneal epithelial cells induced by limbal corneal epithelial cell-derivedinducing activity is to be further verified.

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.

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.

Induced pluripotent stem cells as a potential therapeutic source for corneal epithelial stem cells

Corneal blindness caused by limbal stem cell deficiency(LSCD) is one of the most common debilitating eye disorders. Thus far, the most effective treatment for LSCD is corneal transplantation, which is often hindered by the shortage of donors. Pluripotent stem cell technology including embryonic stem cells(ESCs) and induced pluripotent stem cells(iPSCs) have opened new avenues for treating this disease. iPSCs-derived corneal epithelial cells provide an autologous and unlimited source of cells for the treatment of LSCD. On the other hand, iPSCs of LSCD patients can be used for iPSCs-corneal disease model and new drug discovery. However, prior to clinical trial, the efficacy and safety of these cells in patients with LSCD should be proved. Here we focused on the current status of iPSCs-derived corneal epithelial cells used for cell therapy as well as for corneal disease modeling. The challenges and potential of iPSCs-derived corneal epithelial cells as a choice for clinical treatment in corneal disease were also discussed.

Cell viability and extracellular matrix synthesis in a co-culture system of corneal stromal cells and adipose-derived mesenchymal stem cells

AIM：To investigate the impact of adipose-derived mesenchymal stem cells（ADSCs） on cell viability and extracellular matrix（ECM） synthesis of corneal stromal cells（CSCs）. METHODS：ADSCs and CSCs were obtained from the corneas of New Zealand white rabbits and indirectly cocultured in vitro. The proliferative capacity of CSCs in the different groups was assessed by CCK-8 assays. Annexin V-fluorescein isothiocyanate（FITC）/proliferation indices（PI） assays were used to detect the apoptosis of CSCs. The expression levels of matrix metalloproteinase（MMP）, such as MMP1, MMP2, MMP9, and collagens were also evaluated by Western blot. RESULTS：ADSCs significantly promoted proliferation and invasion of CSCs in the indirect co-culture assays. The co-cultural group displayed much higher ability of proliferation, especially under the co-culture conditions of ADSCs for 3d, compared with that CSCs cultured alone. The PI of CSCs in the co-culture system were increased approximately 3-8-fold compared with the control group. A significant change was observed in the proportions of cells at apoptosis（early and late） between the negative control group（6.34% and 2.06%） and the ADCSs-treated group（4.69% and 1.59%）. The expression levels of MMPs were down regulated in the co-culture models. Compared with the control group, the decrease intensities of MMP-1, MMP-2 and MMP-9 in CSCs/ADSCs group were observed, 3.90-fold, 1.09-fold and 3.03-fold, respectively. However, the increase intensities of collagen type（I, II, III, IV, and V） in CSCs were observed in CSCs/ADSCs group, 3.47-fold,4.30-fold, 2.35-fold, 2.55-fold and 2.43-fold, respectively, compared to that in the control group. The expressions of aldehyde dehydrogenase and fibronectin in CSCs were upregulated in the co-culture models.CONCLUSION：ADSCs play a promotive role in CSCs＇ growth and invasion, which may be partially associated with MMPs decrease and collagens increase, resulting in a positive participation in the plasticity and ECM synthesis of CSCs. This provided a new insight into the extensive role of ADSCs in CSCs and a potential molecular target for corneal therapy.

Keratinocyte Growth Factor-2 on the Proliferation of Corneal Epithelial Stem Cells in Rabbit Alkali Burned Cornea

Purpose: To determine whether the topical application of keratinocyte growth factor-2 (KGF-2) can enhance corneal epithelial healing in rabbit alkali burned cornea. In addition, the distribution and proliferation of corneal epithelial stem cells in KGF-2-treated and control corneas were investigated to explain their mechanisms of effects on the epithelium. Methods: Twenty-four New Zealand eyes were divided into four groups, treated with KGF-2 solution (1, 50, 100 μg/ml) and PBS solution. Eighth millimeter filter paper discs, produced by standard paper punch, were soaked for 15 sec in 0.5N NaOH solution. The alkali-soaked discs were applied to the central cornea, centered on the pupil and held gently in position with forceps for 1 min. The cornea was finally irrigated over 1 min with 100 ml balanced salt solution (BSS). Keratinocyte growth factor-2 was then applied topically three times a day. The phosphate-buffered saline (PBS) group was served as a control. Each corneal epithelial defect was subsequently photographed every 24 hours with a slit lamp and was measured by computer-assisted digitizer. In each group, two rabbits were sacrificed for light microscopic examination after the interval of 7, 14 and 21 days. Meanwhile, the cornea epithelium was examined by immunohistochemistry for P63, AE5, EGFR. Results: Topical application of 10 μg/ml to 100 μg/ml KGF-2 significantly accelerated corneal epithelial wound healing when compared with controls. After 24 hours, epithelial healing rate of the 100 μg/ml KGF-2 group and the PBS treated group was (74±6)% and (40±8)% (P < 0.05). After 48 hours, the rate of the C group was (94±6)%, whereas in the control group it was (73±12)% (P < 0.05). Epithelial defects were often recurrent, which happened only two times in the 100 μg/ml KGF-2-treated group, but many times in the control group. In the corneal epithelial stem cell analysis, the number of the P63 positive cells was higher in the KGF-2-treated corneal epithelium than in the controls. The P63 positive cells in the alkali burned epithelium were found not only in the limbal area but also in the central cornea. In addition, the number of stem cells in each group came to the maximum on the 14th day. For example, on the 7th day after alkali injury, it was 40.3±2.1 NPC in the non-limbal area of 50 μg/ml KGF-2-treated group; whereas, it was 84.8±2.7 NPC on the 14th day(P = 0.000). Conclusions: From the daily evaluation of the corneal surface as well as the microscopic examinations at the end of the three periods of observation, we concluded that KGF-2 provided a beneficial effect in the treatment of alkali burns of the cornea. Furthermore, the results of epithelial stem cell analysis demonstrated that KGF-2 accelerated the corneal epithelial healing by markedly stimulating epithelial stem cells proliferation and making them migrate to the central cornea.

Differentiation of human embryonic stem cells derived mesenchymal stem cells into corneal epithelial cells after being seeded on decellularized SMILE-derived lenticules

AIM: To evaluate the feasibility of mesenchymal stem cells(MSCs) to differentiate into corneal epithelial cells after being seeded on the decellularized small incision lenticule extraction(SMILE)-derived lenticules. METHODS: The fresh lenticules procured from patients undergoing SMILE for the correction of myopia were decellularized. The MSCs were subsequently cultivated on those denuded lenticules. The MSCs without lenticules were used as a control. The proliferation activity of the MSCs after seeding 24 h was quantitatively determined with the Cell Counting Kit-8(CCK-8) assay. Immunofluorescence staining and quantitative reverse transcription polymerase chain reaction(qRT-PCR) were used to assess the marker expression in differentiated MSCs. RESULTS: The data showed that both fresh and decellularized lenticules could significantly promote the proliferation of MSCs, compared to that in control(P=0.02 for fresh lenticules, P=0.001 for decellularize ones, respectively). The MSCs seeded on both lenticules were positive for cytokeratin 3(CK3) staining. The expression of CK3 increased 5-fold in MSCs seeded on fresh lenticules and 18-fold on decellularized ones, compared to that in control. There was a significant difference in the expression of CK3 in MSCs seeded on fresh and decellularized lenticules(P<0.001). The expression of CK8 and CK18 was similar in pure MSCs and MSCs seeded on fresh lenticules(P>0.05), while the expression of these markers was decreased in MSCs seeded on decellularized ones. CONCLUSION: These results suggest that the decellularized lenticules might be more suitable for MSCs to differentiate into corneal epithelial cells, which offersthe prospect of a novel therapeutic modality of SMILEderived lenticules in regenerative corneal engineering.

Keratinocyte growth factor-2 and autologous serum potentiate the regenerative effect of mesenchymal stem cells in cornea damage in rats

AIM:To investigate the healing process after severe corneal epithelial damage in rats treated with mesenchymal stem cells(MSCs)cultured with or without keratinocyte growth factor(KGF-2)and autologous serum(AS)on amniotic membrane(AM).Many patients are blind and devastated by severe ocular surface diseases due to limbal stem cell deficiency.Bone marrow-derived MSCs are potential sources for cellbased tissue engineering to repair or replace the corneal tissue,having the potential to differentiate to epithelial cells.METHODS:The study included 5 groups each including 10 female'Sprague Dawley'rats in addition to20 male rats used as bone marrow donors.Group I rats received AM+MSCs,Group II rats AM+MSCs cultured with KGF-2,Group III rats AM+MSCs cultured with KGF-2+AS,Group IV rats only AM and Group V rats,none.AS was derived from blood drawn from male rats and bone marrow was obtained from the femur and tibia bones of the same animals.Therapeutic effect was evaluated with clinical,histopathological and immunohistochemical assessment.MSC engraftment was demonstrated via detection of donor genotype(Y+)in the recipient tissue(X)with polymerase chain reaction.RESULTS:Corneal healing was significantly better in Groups I-III rats treated with MSC transplantation compared to Group IV and Group V rats with supportive treatment only.The best results were obtained in Group III rats with 90%transparency,70%lack of neovascularization,and 100%epithelium damage limited to less than 1/4 of cornea.CONCLUSION:We suggest that culture of MSCs with KGF-2 and AS on AM is effective in corneal repair in case of irreversible damage to limbal stem cells.

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。

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。

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。

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。

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。