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.

Effect of amnion membrane transplantation on corneal neovascularization in 10 patients with alkali burn

By observing clinical cases, we studied the curative effect of amnion membrane transplantation on decreasing corneal neovascularization (CNV). It was a non-randomized retrospective case-control study. Among 17 cases (21 eyes) of third-degree alkali burns from 2007 to 2010, 10 cases (12 eyes) were performed with amnion membrane transplantation operation, and others were not. Amnion membrane transplantation was performed at the 3rd day after burn in the treatment group. Areas of CNV in double groups were measured at the 14th day and 60th day after burn. Area of CNV in the treatment group was (66.207±7.251)mm2 at the 14th day after burn, and was 18.27% lower than that in the control group. Area of CNV in the treatment group was (120.046±13.812)mm2 at the 60th day after burn, and was 11.35% lower than that in the control group. There was both statistical significance (P<0.05). Amnion membrane transplantation operation can inhibit the growth of corneal neovascularization induced by alkali burn.

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.

The lived experiences of patients undergoing acellular porcine corneal stroma transplantation

To explore the lived experiences of patients undergoing acellular porcine corneal stroma（APCS）transplantation,a descriptive,qualitative design was performed.A purposive sample of 13 patients who underwent APCS transplantation to treat progressive infectious keratitis were enrolled in the semi-structured,open-ended interviews.The taped and transcribed interviews were analyzed using a thematic analysis approach.Alterations in the transparency of APCS grafts were accompanied by a gradual improved visual acuity（before surgery：1.38±0.91 logMAR;3mo postoperatively ：0.40±0.24 logMAR, respectively）.Accordingly,in terms of lived experiences,the patients generally reported＂negative＂experiences before the operation and during the early postoperative period,but this was greatly improved 3mo after surgery.Four main themes were derived：anxiety and fear,stigma,lifestyle change,and gratitude and insights. Conclusively,health care professionals should provide holistic care for patients,proactively promoting patients’physical and mental health.

Organ transplantation scandal influencing corneal donation rate

~ In the majority of countries, there is a shortage of donor corneas for corneal transplantations. This study investigated the impact of organ transplantation scandals on corneal donation rate at the University Hospital T/ibingen. Each deceased patient was considered as a potential corneal donor. An ophthalmic resident handled with stable methods of procedures the corneal donor procurement from 2009 to 2015. The rates of corneal donation were examined and analyzed. Among the 5712 hospital deaths, consent for corneal donation was obtained in 711 cases. The mean annual corneal donation rate was 12.4%. Since 2009, the donation rate per year could be increased with exception of 2013 and 2015. In the end of 2012 and 2014 two huge organ donation scandals were known in Germany. In the following years 2013 and 2015 corneal donation rate decreased significantly （P=0.0181 and P=0.0006）. We concluded that transplantation scandals have a significant impact on corneal donation rate. Improving professional＇s performance through full transparency and honesty is very important to earn trust of potential donors and their families.

Amniotic membrane transplantation in a patient with impending perforated corneal ulcer caused by Streptococcus mitis: A case report and review of literature

BACKGROUND Streptococcus mitis(S.mitis)is an opportunistic pathogen that can lead to severe ocular infections.In previous reports,penetrating keratoplasty(PK)was usually adopted for the treatment of persistent corneal ulcers.This report describes an unusual case of nonhealing descemetocele caused by S.mitis treated by antibiotics plus amniotic membrane transplantation(AMT).CASE SUMMARY A 63-year-old woman presented with a right persistent corneal ulcer that she had suffered from for the past 9 mo.The culture of a corneal scraping yielded S.mitis.The right eye descemetocele decreased in diameter from 3 to 0.8 mm after the continuous administration of topical vancomycin and ceftriaxone for 2 wk.Due to the slow healing,AMT was performed.Her corneal erosion healed and gradually became clear.Her visual acuity recovered from initially counting fingers to 100/200 at the last follow-up,67 mo after AMT.CONCLUSION Antibiotics plus AMT may be an effective alternative treatment other than PK to promote epithelializationand to reduce inflammation in the corneas complicated by S. mitis keratitis.

A 60-Year-Male Post Corneal Transplantation with Acute Pneumonia

Pneumonia is a common complication in organ transplantation patients. Multiple respiratory pathogens such as bacteria, viruses and fungi are potentially coexisted. A 60-year-old male with left eye post corneal transplantation developed acute severe pneumonia caused by Pneumocystis jiroveci (PJP) coinfection with Nocardia spp. and Cytomegalovirus (CMV). He was hospitalized due to acute respiratory failure. Chest radiographs and chest Computed Tomography (CT) revealed extensive ground-glass opacities. PJP was diagnosed from Bronchoalveolar Lavage Fluid (BALF). The pneumonia was persistent despite of receiving intravenous cotrimoxazole. Tracheal aspirate showed faint gram-positive filamentous beaded branching organisms. Consequently Nocardia spp. was proven. Intravenous cotrimoxazole was continued and intravenous imipenem was added. After a course of dual antibiotics, pneumonia was gradually improved. A week after, he developed the worsened acute respiratory failure. The bronchoscopy was performed. The new pathogens were not detected from BALF microbiology. The BALF cytology was unremarkable. PJP was detected by Polymerase Chain Reaction (PCR) from BALF. CMV antigenemia was detected from BALF and blood. Intravenous ganciclovir was given. This report describes PJP coinfected with Nocardia spp. and CMV in post corneal transplantation patient suffering from severe pneumonia. Multiple respiratory pathogens are common among transplantation patients representing host immunosuppression and inadequate antimicorbial prophylaxis.

Simultaneous tectonic Descemet stripping endothelial keratoplasty and tectonic Bowman layer transplant for the management of corneal perforation

AIM:To report the outcomes of three cases of corneal perforation managed with simultaneous tectonic Descemet stripping endothelial keratoplasty(t-DSEK)and tectonic Bowman layer transplant(t-BLT)as an alternative to tectonic penetrating keratoplasty(t-PKP).METHODS:Three eyes of three patients receiving simultaneous t-DSEK and t-BLT for corneal perforation were included.The technique for DSEK was modified depending on individual requirements.The t-BLT technique was standardised using an 8 mm graft and fixated with a running suture.Success was measured by the ability of this procedure to close a corneal perforation.RESULTS:All three cases achieved tectonic eye globe restoration and remained stable during the minimum 3-month observation period.Reinterventions were relatively common:2 cases required amniotic membrane transplant for persistent epithelial defects.One case required DSEK rebubbling.One case developed angle closure glaucoma requiring surgical peripheral iridectomy.CONCLUSION:Simultaneous t-DSEK and t-BLT may be a useful strategy for the management of corneal perforation as an alternative management to t-PKP for selected cases.

Treatment of superficial corneal opacities with corneal stromal lenticule obtained through SMILE surgery

AIM:To evaluate the clinical efficacy and feasibility of superficial corneal opacities treated by excimer laser phototherapeutic keratectomy(PTK)combined with small incision lenticule extraction(SMILE)-derived corneal stromal lenticule transplantation.METHODS:A retrospective interventional case series of nine patients aged 12-59y with superficial corneal opacity caused by different pathologies who underwent standardized PTK combined with SMILE-derived corneal stromal lenticule transplantation was examined.Lenticule patches were fixed with fibrin glue.All patients underwent pre-and post-operative clinical assessments at different times for up to 12mo.Slit lamp microscopy,corneal density,uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),and anterior segment optical coherence tomography(AS-OCT)were examined.RESULTS:The patients’mean age was 36.00±5.80(12-59)y.Seven eyes(77.8%)gained UDVA and CDVA at the last measurement compared to their preoperative levels.The densities of the total cornea,the total anterior corneal layer,and the anterior corneal layers of 0-2 and 2-6 mm decreased significantly by 12.4%,27.5%,46.7%,and 32.8%,respectively.After human allogeneic transplantation,the implanted lenticules of all eyes were clearly visible by AS-OCT and remained transparent without displacement or graft rejection.The thickness of the central cornea and corneal lenticule transplants were stable throughout the entire postoperative period.One case experienced the postoperative complication of delayed corneal epithelial healing.CONCLUSION:PTK combined with SMILE-derived corneal lenticule transplantation improves long-term visual acuity.Therefore,it is a new,safe,and effective method for treating superficial corneal opacity.

Transplantation of corneal stem cells cultured on amniotic membrane for corneal burn: experimental and clinical study

OBJECTIVE: To investigate the proliferation and differentiation of cultured corneal stem cells and determine the effect of corneal stem cells cultured on amniotic membranes on the limbal area for treating corneal burns. METHODS: The proliferation and differentiation of corneal stem cells in vitro had been examined using colony-forming efficiency and immunohistochemistry. The stem cells had been cultured on amniotic membranes and transplanted to the limbal area for treating corneal burns. RESULTS: Corneal stem cells had a high proliferation capacity in primary and first passage, cytokeratin 3 was not expressed in primary culture but partly in first passage. The stem cells could proliferate to form cell layer on an amniotic membrane. When transplanted, stem cells could survive on limbus. After transplantation, ocular inflammation resolved, the cornea re-epithelialized, the stromal opacity reduced, the superficial neovascularity was lessened and the conjunctival fornix re-established. CONCLUSIONS: Ocular surface conditions could be improved by allograft of corneal stem cells cultured on amniotic membranes.

In Vivo Confocal Microscopic Observation of Lamellar Corneal Transplantation in the Rabbit Using Xenogenic Acellular Corneal Scaffolds as a Substitute

Background： The limiting factor to corneal transplantation is the availability of donors. Research has suggested that xenogenic acellular corneal scaffolds （XACS） may be a possible alternative to transplantation. This study aimed to investigate the viability of performing lamellar corneal transplantation （LCT） in rabbits using canine XACS. Methods： Fresh dog corneas were decellularized by serial digestion, and LCT was performed on rabbit eyes using xenogeneic decellularized corneal matrix. Cellular and morphological changes were observed by slit-lamp, light, and scanning electron microscopy at 7, 30 and 90 days postoperatively, lmmunocytochemical staining for specific markers such as keratin 3, vimentin and MUC5AC, was used to identify cells in the graft. Results： Decellularized xenogenic corneal matrix remained transparent for about l-month after LCT. The recipient cells were able to survive and proliferate into the grafts. Three months after transplantation, grafts had merged with host tissue, and graft epithelialization and vascularization had occurred. Corneal nerve fibers were able to grow into the graft in rabbits transplanted with XACS. Conclusions： Xenogenic acellular corneal scaffolds can maintain the transparency of corneal grafts about 1-month and permit growth of cells and nerve fibers, and is, therefore, a potential substitute or carrier for a replacement cornea.

Tocilizumab promotes corneal allograft survival in rats by modulating Treg-Th17 balance

AIM: To examine the therapeutic effects of tocilizumab on experimental corneal transplantation and its effect on Treg/Th17 balance. METHODS: Allograft corneal graft was performed between host Sprague Dawley and Wistar donor rats.The rats were randomly divided into four groups: normal,autograft, allograft, and allograft treated with tocilizumab.Kaplan-Meier was performed to draw the survival curve.The protein levels of interleukin-17A(IL-17A), vascular endothelial growth factor(VEGF), and forkhead box protein3(Foxp3) were measured by immunohistochemistry.The mRNA levels of IL-17A, VEGF, retinoid-related orphan receptor gammat(RORγt), interleukin-6(IL-6) and Foxp3 were detected by reverse transcription real-time polymerase chain reaction(RT-PCR). The Treg and Th17 cells were investigated by flow cytometry. RESULTS: The survival time of tocilizumab group was(24±1.27 d) longer than that of allograft group(10±0.55 d).Moreover, immunohistochemical examination revealed that IL-17A and VEGF protein levels in the allograft group were significantly higher than that of tocilizumab group(P<0.01),while Foxp3 levels in the allograft group was significantly lower than that of the tocilizumab treated group(P<0.001).Flow cytometry showed that the number of Th17 cellsin allograft group was significantly higher than that in tocilizumab group(P<0.001). Meanwhile, the number of Tregs was significantly lower than in tocilizumab group(P<0.001). Simultaneously, Foxp3 m RNA expression level in corneal tissues of tocilizumab treated group was significantly higher than other groups(P<0.001). CONCLUSION: These findings suggest that tocilizumab may promote corneal allograft survival, possibly by modulating Treg-Th17 balance.

Ipsilateral Lymphadenectomy to Inhibit Corneal Allograft Rejection in Rats

In order to investigate the ipsilateral lymphadenectomy for inhibiting rejection in rat corneal transplantation, corneal allogenic transplantation models were established in rats. Eighteen female Wister rats were used as donors, and 36 Sprague Dawley rats as recipients. After penetrating corneal transplantation, recipients were randomly divided into 3 groups: group A (control group); group B, the ipsilateral lymphadenectomy group; group C, the bilateral lymphadenectomy group. Among 12 rats in each group, the corneas of 2 rats in each group were used for pathological study at day 14 after the transplantation, and the remaining 10 rats were used for studying corneal rejection by a slit lamp. The time points when allograft rejection occurred were recorded and mean survival time (MST) was compared. The results showed that MST in groups B and C was 46 30±9 464 days and 44 43±7 604 days, respectively, which was significantly prolonged as compared with that in group A (10 71±1 567 days, P<0.01). There was no significant difference in MST between groups B and C (P>0.05). It was concluded that both bilateral and ipsilateral lymphadenectomy therapies could effectively inhibit the corneal allograft rejection. Ipsilateral lymphadenectomy is a less complex surgical procedure and is just as effective in preventing rejection.

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.

Observation of Long-term Efficacy of Corneal Limbal Conjunctival Autografts in Microscopy Treatments of Pterygium

Purpose: To compare the long-term efficacy of a corneal limbal conjunctival autograft combined with pterygium excision in the treatment of primary pterygium. Methods: This random control study included 63 patients (63 eyes) with primary pterygium. These were randomly divided into a group with corneal limbal conjunctival autograft combined with pterygium excision (group A) and a group with pterygium excision with exposed sclera (group B) and subjected to long-term follow up. The surgical outcomes were classified and evaluated (grade Ⅰ-Ⅳ). Several indexes were analyzed, including ocular surface irritation symptom,tear film stability, surgical complication, and recurrence rate. Results: The follow up ranged from 24 to 38 months, (26.9± 3.4) months on average. No recurrence was noted at 6 weeks postoperatively. At 6 months postoperatively, the recurrence rate of pterygium was 5.2% in group A and 8.0% in group B. At 1 year postoperatively, the recurrence rate in group A was 10.5% and 20.0% in group B. At the end of follow up, the recurrence rates were 13.1% in group A and 24.0% in group B. No statistical significance was found between two groups regarding the recurrence rates at each time point (P>0.05). After the follow up. (> 2 years),the severity of ocular surface conditions was significantly milder in patients in group A than in group B (P <0.01).No statistically significant differences were noted between the two groups at 6 weeks,6 months, and 1 year after surgery. No statistically significant differences were observed between the two groups regarding postoperative tear film break-up time. Fewer postoperative complications and milder ocular surface irritation symptoms occurred in patients in group A. Conclusion: Corneal limbal conjunctival autograft combined with pterygium excision yields sound long-term efficacy and a low recurrence rate and induces only mild damage on the ocular surface when used as a treatment for pterygium.

An Association between Corneal Inflammation and Corneal Lymphangiogenesis after Keratoplasty

Purpose:.To examine the relationship between corneal inflammation and corneal lymphangiogenesis after keratoplasty.Methods:.Rat corneal lymphangiogenesis was examined by lymphatic vessel endothelial receptor(LYVE-1) immunohistochemistry and whole mount immunofluorescence at 1, 3, 7,10, and 14 days after corneal transplantation. Corneal inflammation was evaluated by inflammation index(IF) grading and NF-κB immunohistochemistry at the same time points. The association between lymphatic vessel counting(LVC) and the IF scores was then examined.Results:.LYVE-1 positive lymphatic vessels occurred in the corneal stroma on day 3,.developed throughout days 7 and10,.and peaked in number at day 14 after keratoplasty.Corneal inflammation was strong on day 3, and then resolved gradually,.but increased again from days 7 to 14 after the transplantation..LVC was strongly and positively correlated with IF after keratoplasty(r=0.41;P<0.05). However, changes in IF scores and LVC were not parallel.Conclusion:.A close,.but not parallel,.relationship was found between corneal lymphangiogenesis and corneal inflammation after corneal transplantation.

Lymphocyte infiltration and activation in iris-ciliary body and anterior chamber of mice in corneal allograft rejection

AIM: To investigate the infiltration and activation of lymphocyte in iris-ciliary body and anterior chamber after allogenic penetrating keratoplasty (PK), for further revealing the role of iris-ciliary body in corneal allograft immune rejection. METHODS: In the mice models of PK, BALB/C mice received orthotopic isografts (n =35) or C57BL/6 donor allografts (n=25). Grafts were examined daily for 3 weeks by slit-lamp microscopy and scored for opacity. The infiltration of CD4(+) T lymphocyte in iris-ciliary body and anterior chamber was examined by immunohistology and the mRNA of CD80 and CD86 in both cornea graft and iris-ciliary body by RT-PCR was analyzed in allograft recipient at days 3, 6, 10 and the day when graft rejection occurred. Isograft recipients were examined as control at the corresponding time points. Transmission electron microscope was used to study the ultrastructure, especially cell infiltration, of iris-cilary body and corneal graft at day 3, 7 and the day when rejection occurred after allogenic PK. RESULTS: Rejection was observed in all the allograft recipients followed more than 10 days, at a median time of 15 days (range 12-18 days), but not in any of isografts. CD4(+) T cells were first detected at day 6 after transplantation in limbus and Ciliary body, and then in the stroma of recipient, iris, anterior chamber and corneal allograft with an increased number until graft rejection occurred. CD80 and CD86 mRNA were detected under RT-PCR examination in both graft and iris-ciliary body of allograft recipient, but not in any of isograft recipient. Three days after operation, lymphocytes and monocytes macrophages were visible in iris blood vessels and the anterior chamber, and vascular endothelial cell proliferation and activation were significant under transmission electron microscopy examination. At day 7, corneal endothelial cells became thinner. Lymphocytes and mononuclear macrophages were found with great number in the anterior chamber and adhered to the corneal endothelium. Blood vessels in iris increased and were filled with lymphocytes. And lymphocytes were detected to migrate through endothelial cell gap out of vessels. When allograft rejection occurred, macrophages attached to endothelial cells with large number of lymphocytes and macrophages infiltrating in iris. CONCLUSION: Lymphocyte infiltration and activation occurred in iris-ciliary body after allogenic PK, and the lymphocytes could migrate from iris blood vessel to the anterior chamber, which might play an important role in corneal allograft immune rejection.

Effects of CTLA4-Ig Gene-modified Dendritic Cells on the Corneal Allografts

In order to investigate the effects of mouse CTLA4Ig gene-modified dendritic cells （DCs） on the survival of the corneal allografts in rats, the plasmid PG／CTLA4Ig was transfected into DCs of F344 rats mediated by Lipofectamine^TM 2000. The expression of CTLA4Ig was detected by immunofluorescent microscopy. The effects of donor DCs on the proliferation of T cells in Lewis rats （recipients） were tested by by CCK8. Corneal transplantation was performed from F344 rats to Lewis rats. The DCs modified with CTLA4Ig gene were injected into the Lewis rats on the day 0 and 3 after transplantation. The movement of the DCs after modification in vivo was observed by immunofluorescent microscopy, and the survival of corneal allografts was evaluated by Holland criterion. The results showed that the CTLA4Ig-modified DCs could restrain the proliferation of allogenetic T cells. The CTLA4Ig-modified DCs prolonged survival of corneal allografts. （P〈0.01）. It was suggested that the injection of CTLA4Ig gene-modified DCs could obviously inhabit the allograft rejection and prolong the survival of corneal allografts.

Evaluation of corneal graft survival in mice model

AIMTo investigate the characteristics and criterion of graft rejection in mice model.

Evaluation of corneal graft survival in mice model

·AIM: To investigate the characteristics and criterion of graft rejection in mice model. ·METHODS: C57BL/6 or BALB/c mice corneal grafts were grafted onto BALB/c hosts. Each group was divided into two subgroups according to the corneal opacity scores 12d after transplantation. The characteristics of opacity and neovascularization were observed. Mice of the 12 th , 50 th day after transplantation, the grafts biopsy of mice in allogeneic group 1, which opacity score exceed 3, were prepared for histological observation and those restore transparent were endothelial stained. ·RESULTS: There was no difference of corneal opacity score on the 7 th and 12 th day after operation; the histological results had no disparity between syngeneic group and allogeneic group. On the 12 th day after surgery, the turbidity curve was apparent in grafts with opacity score 【2. Mononuclear cells were shown in grafts with opacity score reached 3 in allogeneic group 1. Different rejection performance was observed in tissue sections on the 50 th day after surgery. ·CONCLUSION: Grafts, opacity score exceeds 3 from the 7 th to the 12 th day after operation could not be judged as a rejection. We should pay more attention to the variation of grafts opacity since 12d after corneal transplantation.·