Research progress in the diagnosis and treatment of neurotrophic keratitis / 国际眼科杂志(Guoji Yanke Zazhi)

Neurotrophic keratitis(NK)is a degenerative corneal disease caused by impairment of trigeminal innervations. It can lead to spontaneous corneal epithelial defects, corneal ulceration and perforation. Early diagnosis of NK is crucial and requires accurate investigation of clinical history and thorough examination of ocular surface to determine clinical stage. Treatment for NK needs to be divided into stages according to disease severity. In addition to conventional treatments including artificial tears, blepharorrhaphy, and amniotic membrane transplantation, there are also emerging treatments such as targeted drug therapy and corneal neurotization. This article summarized the epidemiology, clinical manifestations and classification, etiology, diagnosis, differential diagnosis and treatment of NK, aiming to provide reference for the early diagnosis and treatment of NK in the future.

Potential of human induced pluripotent stem cells differentiating into corneal epithelial cells in simulated limbal stem cell microenvironment / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the potential of human induced pluripotent stem cells(hiPSCs)differentiating into corneal epithelial cells in the simulated limbal stem cells(LSCs)microenvironment.METHODS: The hiPSC cell lines were established in vitro, and hiPSCs were co-cultured with corneal stromal cells in transwell system, which simulated the LSC microenvironment. Bone morphogenetic protein 4(BMP4)and a specific transforming growth factor β inhibitor(SB431542)were added to improve the differentiation efficacy. The expression of corneal epithelial cell-specific markers CK3 and CK12, corneal epithelial cell precursor CK15, and the limbal stem cell markers ABCG5 were determined by immunofluorescence staining and flow cytometry.RESULTS: The hiPSCs were actively proliferated in vitro, and immunofluorescence staining showed positive stem cell-specific markers OCT4, SOX2, TRA-1-60 and NANOG. Furthermore, hiPSCs co-cultured with corneal stromal cells exhibited LSCs markers ABCG5 and corneal epithelial cell precursor markers CK15 were positive; however, corneal epithelial cell markers CK3 and CK12 were negative. With the addition of BMP4 and SB431542, hiPSCs showed positive expression of CK3, and the CK3 expression increased over the time.CONCLUSION: With the addition of SB431542 and BMP4, hiPSCs cultured in simulated LSCs microenvironment could differentiate into corneal epithelial cells.

Toxicity evaluation of zinc oxide nanoparticles in vitro and in vivo on cornea / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To observe the toxic effects of zinc oxide nanoparticles(ZnO NPs)on cornea by constructing intoxicated model in vivo and in vitro.METHODS:Human corneal epithelial cells(HCEpiC)were cultured in vitro and exposed to different concentrations(0.5, 5, 12.5, 25, 50, 100, 250 μg/mL)of ZnO NPs for 24h. The cell culture medium without nano-solution was used as the blank control group. The viability of the cells was assessed by MTT assay. Three different concentrations(25, 50 and 100 μg/mL)of ZnONPs dispersions were exposed to the conjunctival sac of anesthetized mice three times a day for 7d consecutively. The phosphate buffered saline(PBS)eye group was the PBS control group. Corneal morphology was observed on 1, 3, 5 and 7d, and the eyes were removed on 8d for various laboratory examinations, including corneal pathological changes and expression levels of inflammatory factors(TNF-α, IL-6).RESULTS:After treatment of HCEpiC cells with different concentrations of ZnO NPs for 24h, the MTT results showed that Zno NPs cause damage to cells at 0.5 μg/mL, and the cell survival rate was about 80%(P<0.05). Half of the cells were killed at a dose of 5 μg/mL, the damaging effect on cells in the concentration range of 5～250 μg/mL was concentration-dependent(P<0.0001). After 7d of conjunctival capsule spotting in mice, dot-like staining of fluorescein was seen in the 25 μg/mL ZnO NPs and 50 μg/mL ZnO NPs groups. Localized circular fluorescein stained areas were seen in the corneas of the 100 μg/mL ZnO NPs group. HE staining showed that the corneal epithelial layer, stromal layer thickness and stromal layer immune cell number did not change significantly in the 25 μg/mL and 50 μg/mL ZnO NPs groups(all P>0.05), while the corneal epithelial layer thinned, the corneal stromal layer thickened and the stromal layer immune cells increased significantly in the 100 μg/mL ZnO NPs group(all P<0.05). Immunohistochemical staining showed that the number of corneal stromal immune cells producing TNF-α and IL-6 and the mean integral optical density(IOD)values of TNF-α and IL-6 were significantly higher in the 100 μg/mL ZnO NPs group than in the PBS control group(P<0.05), and the degree of inflammation response was concentration-dependent. Compared with the PBS control group, no significant increase in immune cell count and IOD values in the 25 μg/mL ZnO NPs and 50 μg/mL ZnO NPs groups(P>0.05).CONCLUSION:The toxic damaging effect of ZnO NPs on the cornea was confirmed from both in vitro and in vivo, which provided a theoretical basis for the ocular safety evaluation of ZnO NPs.

Prevalence and risk factors of dry eye patients with corneal epithelial defects: A hospital-based retrospective study / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze the characteristics and correlated risk factors of dry eye patients with corneal epithelial defects.METHODS: Outpatient medical records of dry eye patients with corneal epithelial defects at Peking University Third Hospital from July 2018 to June 2019 were retrospectively analyzed. The patients' data including sex, age, visit date, presence of comorbidities, and meteorological indicators at the same period were statistically analyzed.RESULTS: A total of 291 dry eye patients with corneal epithelial defects, of whom 75.3% were female, were retrospectively analyzed. Young patients aged 21-30 made up the most(26.5%), while the proportion of teenagers(<18 years, 5.8%)and the elderly(≥61 years, 17.2%)was low. However, as the largest proportion of this population, young and middle-aged patients tend to experience fewer visits(5.4±12.4). Spring and winter were the main seasons of complaints. The meteorological indicators at the same period including fine-particulate matter with a median aerometric diameter of less than 10μm(PM10), sulfur dioxide(SO2), nitrogen dioxide(NO2), and reduced average relative humidity were found significantly correlated with dry eye corneal epithelial defects(P<0.05). Conjunctivitis, cataracts, blurred vision, and trichiasis ranked the top four comorbidities.CONCLUSION: Dry eye corneal epithelial defects of young and female population cannot be ignored. PM10, SO2, NO2, and reduced humidity are found significantly correlated with dry eye corneal epithelial defects. For dry eye patients with conjunctivitis, cataracts, blurred vision, and trichiasis, more attention should be paid to their corneal conditions.

Characteristics of early changes in corneal epithelial thickness and related influencing factors after femtosecond assisted laser in situ keratomileusis / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the characteristics of changes in corneal epithelial thickness at the early postoperative stage of femtosecond assisted laser in situ keratomileusis(FS-LASIK)and its related influencing factors.METHOD: Retrospective study. A total of 120 patients(240 eyes)of myopia undergoing FS-LASIK from May 2021 to June 2022 were selected. The corneal epithelium thickness in the central area, inner ring area, and outer ring area of patients before and at 1d, 1wk, 1 and 3mo after operation was recorded. The relationship between the variation of corneal epithelium thickness and spherical equivalent, optical zone diameter, depth of cut and cutting ratio was analyzed by Pearson correlation.RESULTS: There was no statistical significance in corneal epithelial thickness in the central area, inner ring area and outer ring area at 1d after FS-LASIK compared with that before operation(P&#x003E;0.05). At 1wk, 1 and 3mo after surgery, the corneal epithelial thickness in the central area, inner ring area and outer ring area increased compared with that before surgery, and the corneal epithelial thickness in the central area and inner ring area at 1 and 3mo after surgery was greater than that in the outer ring area(all P&#x003C;0.05). The corneal epithelial thickness in the central, inner and outer ring areas of high myopia patients was thicker than that of low and moderate myopia patients before operation. The corneal epithelial thickness in the central, inner and outer ring areas of high myopia patients was thinner than that of low and moderate myopia patients at 1wk after operation(P&#x003C;0.05). At 1 and 3mo after operation, the corneal epithelial thickness in the central, inner and outer ring areas of patients with high myopia was greater than that of patients with low and moderate myopia, and the changes of corneal epithelial thickness in the central, inner and outer ring areas were greater than those of patients with low and moderate myopia(P&#x003C;0.05). The results of Pearson correlation showed that the changes in corneal epithelial thickness in the central and inner ring area were positively correlated with the corneal curvature, depth of cut and cutting ratio at 3mo after surgery, and they were in negative correlation with the age, spherical equivalent and optical zone diameter(P&#x003C;0.05).CONCLUSION: The corneal epithelial thickness of patients thickened after the FS-LASIK operation, and it was correlated with age, corneal curvature, preoperative depth of cut, cutting ratio, spherical equivalent and the optic zone diameter.

A novel biodegradable polymer scaffold for in vitro growth of corneal epithelial cells

The shortage of donor corneal tissue worldwide has led to extensive research for alternate corneal equivalents utilizing tissue engineering methods. We conducted experiments using Poly D, L lactic acid polymer along with a copolymer (Eudragit) in varying concentrations to create a biodegradable scaffold suitable for in vitro growth of corneal epithelial stem cells. It was found that stable, spherical, and porous microparticles can be prepared by combining PDLLA and Eudragit RL100 polymers in the ratio of 90:10 and 70:30. The microparticles can then be fused to form scaffold membranes with porous architecture and good water retention capacity at room temperature using methanol, which can withstand handling during transplantation procedures. The scaffolds made using a 70:30 ratio were found to be suitable for the promotion of growth of laboratory corneal epithelial stem cell lines (SIRC cell lines). This innovation can pave way for further developments in corneal stem cell research and growth, thus providing for viable laboratory-derived corneal substitutes.

Displasia epitelial corneal / Corneal epithelial dysplasia

Las neoplasias intraepiteliales córneo-conjuntival son lesiones premalignas, mal delimitadas, de crecimiento lento y escaso potencial de malignización. Solo el 9 por ciento progresa a carcinoma invasor de células escamosas. Posee varias formas de presentación y tiene múltiples dilataciones vasculares. La displasia epitelial corneal primaria es una forma poco frecuente de neoplasia intraepitelial córnea-epitelial. Se presenta un caso clínico confirmado por estudios anatomopatológicos. En el presente estudio se observó respuesta satisfactoria luego de un mes de tratamiento tópico con 5FU, sin efectos colaterales. El seguimiento durante tres años no ha mostrado signos de recidiva(AU)

Corneal-conjunctival intraepithelial neoplasms are premalignant, poorly demarcated, slow-growing lesions with low malignant potential. Only the 9 percent progresses to invasive squamous cell carcinoma. It appears in several forms and presents multiple vascular dilatations. Primary corneal epithelial dysplasia is a rare form of corneal-epithelial intraepithelial neoplasia. We present a clinical case, confirmed by anatomopathologic studies. In the present study we observed a satisfactory response after one month of topical treatment with 5FU, with no side effects. Follow-up for three years has shown no signs of recurrence(AU)

Corneal and corneal epithelial thickness distribution characteristics in healthy North Indian eyes using spectral domain optical coherence tomography

Purpose: To determine the pattern of corneal thickness and epithelial thickness distribution in healthy North Indian eyes by using spectral domain optical coherence tomography (SD?OCT). Methods: The observational study measured total corneal and epithelial thickness in the central 2 mm zone and eight sectors each in paracentral 2�mm (ring 1) and midperipheral 5�mm (ring 2) zones on SD?OCT. Results: The study included 67 eyes of 67 subjects with a male:female ratio of 32:35 and mean age of 25.04 � 4.54 years. The mean central corneal and epithelial thicknesses were 505.97 � 30.12 ?m and 60.48 � 8.37 ?m, respectively. The epithelium of inferior and infero?nasal sectors in ring 1 and inferior sector in ring 2 was significantly thicker than the radially opposite sectors of the respective rings (P = 0.001; P = 0.01 and P = 0.02, respectively). Sector?wise analysis did not reveal any significant correlation between the total corneal thickness and epithelial thickness (all P > 0.05) except in the outer superior sector where there was a weak positive correlation (r = 0.28, P = 0.02). Central epithelial thickness in males (60.59 � 9.28 ?m) and females (60.37 � 7.58 ?m) was comparable (P = 0.91). Pachymetry was thinnest in the inferior, inferonasal, and inferotemporal sectors in 44.79% of eyes (n = 30), while thinnest epithelium was seen in the superior, superonasal, and superotemporal quadrants in 50.75% of eyes (n = 34). Conclusion: The epithelial thickness distribution in this sample of topographically normal healthy North Indian eyes was nonuniform and independent of the underlying corneal thickness. Epithelium was thinner in the superior cornea, whereas total corneal thickness was minimum in the inferior part

A cross-sectional study to compare the normal corneal epithelial thickness in various age groups of Indian population using 9 mm wide optical coherence tomography scans

Purpose: To compare the corneal epithelial thickness among various age groups of normal Indians with 9?mm?wide optical coherence tomography scans. Methods: This cross sectional, observational study recruited patients in the age groups of 5–20 years (group 1), 21–35 years (group 2), 36–50 years (group 3), and more than 51 years (group 4). They underwent a detailed ophthalmic examination and were excluded if found to have any ocular surface or intraocular disease (except cataract and refractive error), undergone any ophthalmic surgery, corneal topography changes suggestive of corneal ectasias, or been continuously using any topical medication in either eye for a period of 3 months or more with the last instillation being within 1 month of inclusion in the study. Corneal epithelial thickness (CET) was measured using anterior segment optical coherence tomography (AS?OCT). The CET data from 25 sectors in each eye were analyzed for each age group. Results: There were 71 subjects in group 1, 76 subjects in group 2, 59 subjects in group 3, and 57 subjects in group 4. The mean (± standard deviation) ages in the groups 1, 2, 3, and 4 were 14.04 ± 5.10, 26.63 ± 4.71, 42.66 ± 3.92, and 61.65 ± 7.47 years, respectively. The central corneal thickness in all age groups was comparable. Maximum variance in CET parameters was seen in superior cornea. Conclusion: Central corneal thickness remains fairly stable over various age groups. The maximum variance in CET over age is seen in superior cornea. The findings from the Indian population correlate well with racially and geographically distinct subjects.

Study on the protective mechanism of Qishen recipe on corneal epithelial cells induced by hypertonic based on JNK1/ AQP5 pathway / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To observe the protective effect of Qishen recipe on corneal epithelial cells induced by hypertonic fluid, and elucidated its mechanism of action in the treatment of dry eye base on JNK1 / AQP5 pathway.<p>METHODS: Human corneal epithelial cells(HCECs)model was created by osmotic pressure at a concentration of 500mOsm/L for 24h. Serum of rats containing drugs in the blank group, model group, Western medicine group, and Qishen recipe low-dose, medium-dose and high-dose groups were treated on the modeled DE HCECs, and the effects of different drug stimulation on the survival rate of HCECs were tested by CCK-8 method. The expressions of inflammatory factors TNF-α, IL-6 in extracellular fluid were explored by ELISA. The expression of apoptosis factors caspase 1 and AQP5 were detected by immunocytochemistry(ICC). The expressions of AQP5, JNK1, p-JNK1 of HCECs after intervention with different drug concentrations were found by Western blotting.<p>RESULTS: Compared with the blank group, the survival rate of HCECs in each group was significantly reduced(<i>P</i><0.01). The extracellular fluid inflammatory factors TNF-α, IL-6 and caspase-1, p-JNK1, AQP5 protein expression levels increased significantly in each group(all <i>P</i><0.01); In comparison to the model group, the survival rate of HCECs in each medication group increased significantly(all <i>P</i><0.01). The expression levels of TNF-α, IL-6 in the extracellular fluid of each drug group, AQP 5 and p-JNK1 protein expression in HCECs, and the expression of caspase-1 and AQP5 protein in the western medicine group and the Qishen recipe high and medium dose group were all reduced(all <i>P</i><0.05). Compared with the western medicine group, the survival rate of HCECs in the Qishen prescription high-dose group was significantly increased(<i>P</i><0.01). The expression levels of TNF-α and IL-6 in each dose group of Qishen recipe were reduced(all <i>P</i><0.05), while the expression levels of caspase-1 in the high-dose Qishen recipe group and the AQP5 protein expression levels of the high and medium-dose Qishen recipe group saw a decrease(all <i>P</i><0.05). However, there was no statistically significant difference in the JNK1 protein expression of HCECs of all the groups detected by Western blotting method(<i>P</i>>0.05). <p>CONCLUSION: Qishen recipe can not only reduce the JNK1 phosphorylation and AQP5 protein expression of HCECs induced by hypertonicity, but also reduce the expression of inflammatory factors TNF-α, IL-6 and the apoptotic factor caspase-1 of HCECs in the extracellular fluid, thus effectively Inhibit inflammation and apoptosis.

Protective effects of Slit2 on corneal epithelium and nerves in diabetic mice and its mechanism / 中华实验眼科杂志

Objective:To explore the promoting effects of slit guidance ligand 2 (Slit2) on the repair of corneal epithelium and nerve damage in diabetic mice and possible molecular mechanism.Methods:Sixty SPF C57BL/6 mice aged 5-6 weeks were divided into normal control group, diabetes model group and Slit2 injection group according to the random number table method, 20 for each group.Diabectic model was prepared by intraperitoneal injection of streptozotocin in the diabetes model group and Slit2 injection group.A mouse corneal epithelial injury repair model was established using electric epithelial scraper, and Slit2 recombinant protein was subconjunctivally injected immediately following modeling in the Slit2 injection group.The equal volume of phosphate buffer saline (PBS) was used in a same way in the diabetes model group.No intervention was performed in the normal control group.Corneal epithelial healing were examined at 24, 48 and 72 hours after corneal epithelial defect by corneal fluorescin staining.Real-time fluorescent quantitative PCR was used to detect the expression of Slit2 and its related receptors in the corneal epithelium of normal and diabetic model mice.Fluorescence staining of corneal wholemount with β-tubulin Ⅲ was used to observe the changes in corneal nerve morphology.Immunofluorescence staining was performed to detect the expression and distribution of Slit2 in mouse corneal epithelium in normal control group and diabetes model group, as well as the expression and distribution of Slit2, epidermal growth factor receptor (EGFR), extracellular-signal-regulated kinase (ERK), threonine protein kinase (AKT), β-catenin and Ki67 in the healing corneal epithelium of mice after corneal epithelium damage in different groups.The mouse corneal epithelial stem/progenitor cell line (TKE2) was divided into normal control group, high-glucose group and Slit2 treatment group.Western blot was performed to detect the expression of p-EGFR/EGFR and p-AKT/AKT in the TKE2 of the three groups.The expression of p-EGFR/EGFR and p-AKT/AKT in high glucose-cultured TKE2 with 0.01, 0.1 and 0.5 μg/ml Slit2 treatment for 10 minutes, and before and 10, 20, 30, 60, 120 minutes after 0.5 μg/ml Slit2 treatment was detected by Western blot.The effects of Slit2 on the axon regeneration of mouse trigeminal ganglion cells (TGs) were observed by immunofluorescence staining.The use and care of animals complied with the ARVO statement.This study protocol was approved by an Ethics Committee of Qingdao Eye Hospital of Shandong First Medical University (No.[2020]57).Results:At 48 and 72 hours after corneal epithelial scraping, the speed of corneal epithelial repair was significantly slowed down in diabetes model group in comparison with the normal control group and Slit2 injection group.The relative expression levels of Slit2 and its receptors Robo1, Robo2 and Robo4 mRNA in the normal corneal epithelium in the diabetes model group were significantly higher than those of the normal control group (all at P<0.05). The fluorescence intensity of Slit2 in normal corneal epithelium in diabetes model group was similar to the normal control group, and the fluorescence intensity of Slit2 in damaged corneal epithelium in diabetic mice was significantly weaker than that in normal control group.Corneal nerve plexus was denser at 7 days after corneal epithelial injury and the nerve fibers were increased with more branches in Slit2 injection group compared with diabetic group.The fluorescence intensity of p-EGFR, p-ERK, β-catenin and Ki67 in damaged corneal epithelium in normal control group and Slit2 injection group was stronger than that of the diabetes model group.The relative expression levels of p-EGFR/EGFR, p-AKT/AKT, and β-catenin in TKE2 in high-glucose group were significantly lower than those in normal control group and Slit2 treatment group (all at P<0.05). The relative expression levels of p-EGFR/EGFR and p-AKT/AKT in high glucose-cultured TKE2 after Slit2 treatment were significantly increased in comparison with before Slit2 treatment (both at P<0.05), and the relative expression levels of p-EGFR/EGFR and p-AKT/AKT in TKE2 were elevated as the increase of Slit2 concentration.The activation effect of 0.5 μg/ml Slit2 on EGFR and AKT pathways was most obvious.The synapse length of TGs cultured by high glucose was (40.52±5.44) μm, which was significantly shortened than (72.14±9.48) μm in normal control group and (73.04±4.66) μm in Slit2 injection group (both at P<0.05). Conclusions:Slit2 can protect the corneal epithelium by activating EGFR signaling pathway and play a protective role to neurons by increasing the density of corneal subepithelial plexus and promoting the growth of TGs axons in diabetic mice.

Feasibility of corneal epithelial transplantation with polyethylene glycol hydrogel membrane as a carrier for limbal stem cell deficiency / 中华实验眼科杂志

Objective:To investigate whether polyethylene glycol hydrogel films (PHFs) can be used as a carrier for the expansion of corneal epithelial cells (CECs) in vitro and whether PHFs can be used in the treatment of limbal stem cell deficiency (LSCD). Methods:Sebacoyl chloride, dihydroxyl PCL and glycerol ethoxylate were used to synthesize PHFs.The thickness, transmittance and mechanical tensile properties of PHFs were measured.Four clean-grade New Zealand white rabbits were selected to culture primary limbal epithelial cells.The expression of keratin marker AE1/AE3 and stem cell marker p63 in the cultured cells were observed under a fluorescence microscope.The cells were divided into negative control group cultured with common cell culture solution, positive control group cultured with cell culture solution containing 100 μmol/L H 2O 2, and PHFs+ CECs group lined with PHFs cultured with common cell culture solution for 24 hours.The proliferation and apoptosis of cells in the three groups were observed by MTT and TUNEL staining, respectively.Fifteen clean-grade New Zealand white rabbits were divided into control group, PHFs group and PHFs+ CECs group by random number table method, with 5 rabbits in each group.LSCD model was constructed in the three groups.The control group was not given any treatment after modeling.In PHFs group, empty PHFs were placed on the corneal surface of rabbits.In PHFs+ CECs group, tissue-engineered grafts constructed with CECs after passage implanted on PHFs were placed on the corneal surface of rabbits.The corneal defect area of rabbits was detected and scored by fluorescein sodium staining.The histological characteristics of rabbits corneal epithelium was observed by hematoxylin-eosin staining.The use and care of animals complied with Guide for the Care and Use of Laboratory Animals by the U. S.National Research Council.The experimental protocol was approved by the Research and Clinical Trial Ethics Committee of The First Affiliated Hospital of Harbin Medical University (No.2021006). Results:The synthetic PHFs were with a thickness ≤150 μm, a tensile strength about 6 MPa, and a transmittance over than 99% in the range of 400-700 nm.Most of the cells from primary culture of limbal tissue were positive for AE1/AE3 and p63.MTT test results showed that the A490 value of PHFs+ CECs group, negative control group and positive control group was 0.59±0.01, 0.65±0.07 and 0.06±0.04, respectively, showing a statistically significant overall difference ( F=12.25, P<0.05). The A490 values of PHFs+ CECs group and negative control group were significantly higher than that of positive control group, and the differences were statistically significant (both at P<0.05). TUNEL test results showed that there was a significant difference in the TUNEL-positive cell rate among the three groups ( F=13.45, P<0.05), and the rates of TUNEL-positive cells in PHFs+ CECs group and negative control group were significantly lower than that in positive control group (both at P<0.05). Fluorescein sodium staining results showed that with the extension of postoperative period, the corneal fluorescein sodium staining score of the three groups decreased, which decreased successively in control group, PHFs group and PHFs+ CECs group.Hematoxylin-eosin staining showed fewer irregularly shaped corneal epithelial cells in the control group, and sparse single layer of corneal epithelial cells in some areas of the PHFs group.In PHFs+ CECs group, the corneal epithelium coverage was the largest, and the cell layers increased to 3-5, and the cells were with regular morphology and in close arrangement. Conclusions:PHFs have enough toughness, high transmittance and can expand corneal epithelium in vitro.PHFs are suitable for corneal epithelial transplantation and can promote the repair of corneal epithelium in rabbit model of LSCD.

New progress in pathogenesis and diagnosis in the treatment of persistent corneal epithelial defect / 国际眼科杂志(Guoji Yanke Zazhi)

@#Persistent corneal epithelial defect(PED)can occur after corneal herpes simplex virus infection, corneal transplantation, and intraocular surgery in diabetic patients. Although the incidence is not high, it can cause serious consequences if not properly managed, such as corneal infection or exacerbation, stromal ulcers, perforation, scarring, and even loss of vision. The pathogenic causes of PED are diverse and can be mediated by multiple mechanisms. In clinical practice, even with aggressive treatment, the corneal epithelium in PED eyes is difficult to heal and presents a challenge for treatment. At present, the standard treatment for PED management mainly includes the use of bandage soft contact lenses and artificial tears, aiming at the barrier protection for the corneal epithelium. The new treatment mainly focuses on epithelial regeneration and corneal nerve re-innervation. In addition, several drugs and methods with potential therapeutic value have emerged in recent years. In this review, we talk about how are the PEDs spread, what causes them, how are they diagnosed and how are they treated. We also talk about some new therapies and research process.

Protective effects of Resveratrol on inflammation and oxidative stress damage in human corneal epithelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To investigate the protective effects of resveratrol(RSV)on inflammation and oxidative stress damage in human corneal epithelial cells(HCECs).<p>METHODS: The inflammation of HCECs was induced by Tumor necrosis factor-α(TNF-α), and the experiment was divided into: control group, TNF-α group and RSV+TNF-α group. The oxidative stress response of HCECs was induced by H₂O₂, and they were divided into normal group, H₂O₂ group and RSV+ H₂O₂ group. MTT assay was used to detect the viability of HCECs; RT-qPCR and enzyme-linked immunosorbent assay(ELISA)methods were used to detect the expression of IL-1, IL-6 and IL-8; Immunofluorescence staining and Western blot were used to observe the nuclear translocation of NF-κB p65. 2',7'-dichlorofluorescein diacetate(DCFH-DA)fluorescent probe was applied to detect the level of reactive oxygen species(ROS).<p>RESULTS:In the inflammatory response of HCECs, RT-qPCR and ELISA showed that the expression levels of IL-1, IL-6 and IL-8 were increased significantly in the TNF-α group compared with the control group, the above indicators were lower after pretreatment of RSV than those in TNF-α group; Immunofluorescence staining and Western blot showed that the nuclear translocation of NF-κB p65 was increased in TNF-α group, while it was inhibited after pretreatment of RSV. In the oxidative stress response of HCECs, the results of MTT and DCFH-DA fluorescent probe staining showed that H₂O₂significantly decreased the viability of HCECs and increased the production of ROS in HCECs. After pretreatment of RSV, cell viability increased significantly, and RSV inhibited the generation of ROS in HCECs induced by H₂O₂. <p>CONCLUSION: RSV has an inhibitory effect on inflammation and oxidative stress damage in human corneal epithelial cells, and it has been confirmed that RSV inhibits inflammation by inhibiting the activation of the NF-κB pathway.

Effect of recombinant human growth hormone on corneal epithelial wound healing / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To explore the effects of recombinant human growth hormone(rHGH)on early rehabilitation in rabbit corneal epithelial wound. <p>METHODS:Thirty-two New Zealand rabbits were selected to establish the corneal epithelial defects models. One eye was treated with normal saline(NC group)and the other eye was treated with 20nmol/L rHGH(rHGH group)in a randomized double-blinded way. The corneal healing process was monitored by the corneal fluorescein staining scores at 0h, 24h, 48h, and 72h after the surgery. The central corneal sensitivity was detected by Cochet-Bonnet corneal esthesiometer and the concentrations of inflammatory mediators interlecukin-1α(IL-1α), interlecukin-17(IL-17), interlecukin-21(IL-21), Leptin, matrix metalloproteinase-9(MMP-9)and tumor necrosis factor-α(TNF-α)in collected tears were measured by multiplex antibody microarray. <p>RESULTS: The corneal epithelial healing rates of the NC group and rHGH group were(62.52±6.73)% and(79.62±10.62)%(<i>P</i><0.05),(90.56±9.57)% and(98.43±3.65)%(<i>P</i><0.05)at 48h and 72h postoperatively. The central corneal sensitivity of rHGH group(4.22±0.26)cm was better than that in NC group(3.22±0.42)cm at 48h after surgery(<i>P</i><0.05). The expressions of TNF-α and IL-1α increased in both groups at each time point after operation, and the expressions in NC group were higher than those in the rHGH group. Both groups had higher MMP-9 concentrations in the tear fluid at 24 and 48h postoperation in comparison with the point before the operation. The MMP-9 expression in NC group was higher than that in the rHGH group at 48h postoperatively. The expressions of IL-21 in NC group were higher than those in the rHGH group at 24 and 48h postoperation in comparison with the point before the operation(<i>P</i><0.05). No significant differences in tearIL-17 and Leptin were observed between groups before and after surgery(<i>P</i>>0.05).<p>CONCLUSION: Topical application of rHGH can accelerate the early stage of rabbit corneal epithelial wound healing <i>in vivo</i>.

Effect of Diquafosol on Hyperosmotic Stress-induced Tumor Necrosis Factor-α and Interleukin-6 Expression in Human Corneal Epithelial Cells

In vitro culture of human corneal epithelial stem cells using modified explant culture / 中国组织工程研究

BACKGROUND: Corneal epithelial stem cells, also known as limbal stem cells, are distributed in the basal layer of limbal epithelium. It is extremely difficult to deal with limbal stem cell deficiency or dysfunction that is caused by severe thermal burn, chemical burn, and chronic inflammation of ocular surface. At present, in vitro culture of corneal epithelial stem cells using tissue engineering technology followed by clinical transplantation is a new and effective therapeutic direction. OBJECTIVE: To explore the feasibility of serum-free culture of human corneal epithelial stem cells in vitro using modified explant culture method. METHODS: The remaining donor corneal tissues after keratoplasty (less than 8 mm in diameter) were obtained from Henan Eye Bank, and the outer and middle limbus were dissected under surgical microscope. Two culture methods were used to culture human corneal epithelial stem cells. In the conventional explant culture group, the limbal tissues were adhered to the dish with the epithelium being upward, then Keratinocyte-serum free medium (K-SFM) was added into dishes, followed by incubation at 37 °C in a 5% CO2 incubator. In the modified explant culture group, limbal tissues were dissected to immerse in the K-SFM culture medium and incubated at 37 °C in the 5% CO2 incubator for 12 hours. The limbal tissues were then adhered to the dish with the epithelium being downward. The day whenever the cells from the limbal tissues adhered to the dish was marked as the 1st day of culture, and changes in cell morphology and growth were recorded by phase contrast microscopy every day. Immunofluorescent staining was used to detect the expression of K3 and p63 in primary cells on the 5th, 10th and 14th day of the modified explant culture. RESULTS AND CONCLUSION: The mean early stage of growth in the modified explant culture group was shorter than that of the conventional explant culture group (P < 0.05), and the mean growth rate of the modified explant culture group was higher than that of the conventional explant culture group (P < 0.05). In the modified explant culture group, cells had a good growth state, and many cells with small size gathered together on the 10th day of culture. On the 14th day, cell clones were formed, and the cells in the clone showed uniform morphology. On the 5th day, K3 highly expressed, while p63 lowly expressed in primary cells. On the 10th day, both of K3 and p63 had an increased expression. On the 14th day, there was no significant increase in the K3 expression, but the expression of p63 increased significantly. In the in vitro serum-free culture condition, the modified explant culture could significantly promote the growth of corneal epithelial stem cells, and expand corneal epithelial stem cells in vitro, which could provide sufficient seed cells for enriching corneal epithelial stem cells and constructing human limbal multilayered epithelial sheets.

Graft epithelial mapping following penetrating keratoplasty using anterior segment optical coherence tomography / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To evaluate the changes in corneal epithelial thickness in corneal grafts following penetrating keratoplasty(PK)using anterior segment optical coherence tomography(AS-OCT), and to determine the role of epithelial thickness mapping in the early detection of graft rejection.<p>METHODS: This prospective comparative observational study included 20 patients(20 eyes)who underwent PK as study group and 16 patients(16 eyes)as control group. Corneal epithelial thickness mapping using AS-OCT was performed at 2wk, 1 and 3mo postoperatively. The parameters of epithelial thickness and distribution at the 3mo were compared to 16 patients(16 eyes)with allograft rejection following PK.<p>RESULTS: There was significant decline in the superior, inferior, maximum, and minimum epithelial thickness values of the study group at 1mo compared to 2wk(<i>P</i>=0.0004, 0.0001, 0.0001, 0.04 respectively)with no significant differences at 3mo compared to 1mo(<i>P</i>=0.4, 0.1, 0.8)respectively. Percentage of reduction in epithelial thickness was significantly higher than that of stromal thickness at 1mo compared to 2wk(<i>P</i>=0.04). The epithelial thickness maps showed a similar pattern of epithelial thickness distribution in the study group and in the rejection group showing considerable corneal edema. However, the allograft rejection group showed irregular pattern of epithelial thickness distribution in patients showing relatively higher central corneal thickness(CCT)as measured by pachymetry map.<p>CONCLUSION: Quantitative assessment of graft epithelial remodeling following PK shows early changes that contribute to significant corneal graft thickness changes. Changes in corneal epithelial thickness and pattern of distribution could be used as an indicator for corneal graft rejection.

Progress in research on persistent corneal epithelial defects / 国际眼科杂志(Guoji Yanke Zazhi)

@#Persistent corneal epithelial defect(PED/PCEDs)is an eye disease that fails to form corneal epithelium rapidly even after 10-14d of corneal injury. Corneal protective epithelial destruction and stromal layer damage can easily lead to eye infection, stromal ulcer, perforation, scar formation, and even blindness. At present, clinicians still face considerable challenges in treating PED patients. Standard treatments such as wearing bandaged contact lenses and using artificial tears, while newly developed drugs can promote the formation of various growth factors to re-form the cornea, and further cooperate with the corresponding surgery to provide innervation for the cornea. In order to achieve the effect of treatment. In addition, treatment should be carried out as soon as possible after the diagnosis of PED to avoid secondary complications. This article reviews the epidemiology, etiology, diagnosis, clinical manifestation, treatment and prognosis of persistent corneal epithelial defect.

Oxidative damage effect of povidone-iodine on corneal epithelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the oxidative damage effect of povidone iodine on corneal epithelial cells. <p>METHODS:To study the oxidative damage effect of different concentrations of povidone iodine, the cultured epithelial cells were randomly divided into control group, low concentration group, medium concentration group and high concentration group. To study the oxidative damage effect of disinfection time of povidone iodine, the cultured corneal epithelial cells were randomly divided into control group, short time group, medium time group and long time group. Malondialdehyde(MDA)and superoxide dismutase(SOD)were detected by ELISA, cell viability was detected by CCK-8 method and inverted microscope, and apoptotic rate was detected by flow cytometry. <p>RESULTS: The higher concentration of povidone iodine was associated with the higher MDA content, the lower SOD content, the lower cell activities and the higher apoptotic rate of the corneal epithelial cells, which was in a dose-independent manner. The differences among four groups were statistically significant(all <i>P</i><0.01). The longer disinfection time of povidone iodine was related with the higher MDA content, the lower SOD content, the lower cell activities and the higher apoptotic rate of corneal epithelial cells, which was in a time-independent manner. The differences among four groups were statistically significant(all <i>P</i><0.01). <p>CONCLUSION: The oxidative damage of povidone iodine on corneal epithelial cells were in a dose independent and time dependent manner.