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Purpose: To evaluate various factors affecting the integrity of human donor corneal epithelium. Methods: Donor corneal buttons were evaluated for epithelial defect (ED) and exposure. The slit?lamp photographs were taken on day 01, and the data such as age and gender of the donor, cause of death, refrigeration of cadavers, death?to?preservation time (DPT), experience of technician, and distance from site of collection to eye bank were collected. Results: A total of 100 consecutive corneal buttons belonging to 56 donors were evaluated. The median age of donors was 50 years. Males constituted 45 (80.4%). The mean DPT was 9.7 ± 5.3 hours. After death, 34 donors (60.7%) were refrigerated before the collection/retrieval. Most of the corneas (80%) were recovered by technicians having an experience of 0–5 years. Thirty?one donors (55.3%) were located at 1–50 km from the eye bank. The mean area of exposure was 15 ± 4.3 mm2. The mean area of ED was 28.7 ± 5.9 mm2. ED was significantly associated with refrigeration of cadavers and longer DPT. On multivariate analysis, only DPT was found to be significantly associated (P = 0.006; odds ratio [OR] = 1.54 ± 0.24) with the presence of ED. After transplantation, only two corneas had persistent epithelial defects and were treated successfully using various interventions. Conclusion: Integrity of donor corneal epithelium is mainly influenced by the refrigeration of cadavers and DPT.
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Objective:To investigate the inhibitory effect of miR-497 on the corneal epithelial healing in diabetic mice and its possible mechanism.Methods:Forty healthy clean-grade wild-type C57BL/J6 mice were randomly divided into a blank control group and a model control group, with 20 mice in each group.Another 20 CRISPR/Cas9-mediated miR-497 knockout mice and miR-497 overexpression mice were taken as miR-497 knockout and miR-497 overexpression groups, respectively.The diabetes model was constructed by continuous intraperitoneal injection of streptozotocin (STZ) to the mice in model control, miR-497 knockout and miR-497 overexpression groups, and the mice in blank control group were injected with an equal amount of citrate buffer, followed by 8-week normal feeding.After the establishment of diabetes model, the corneal epithelial injury model was further constructed by scraping off part of the corneal epithelium with a central diameter of 2 mm.The corneal epithelial defect area of mice in 0, 12, 24 and 36 hours after corneal epithelial injury was observed by corneal fluorescein sodium staining.The expression of Wnt3a and β-catenin proteins in mice corneal tissues was detected by Western blot.The expression of miR-497 as well as the mRNA expression levels of cell proliferation-associated factor genes CyclinD1, c-Myc, and Ki-67 mRNA was detected by real-time quantitative fluorescence PCR.The targeting relationship between miR-497 and wnt3a was detected by a dual luciferase reporter gene assay.Human corneal epithelial cells (HCEC) were cultured in vitro and transfected with miR-497 mimics, miR-497 mimics negative control, miR-497 inhibitor, and miR-497 inhibitor negative control by Lipo8000 as miR-497 mimics group, mimics negative control group, miR-497 inhibitor group, andmiR-497 inhibitor negative control group, respectively, all of which were cultured in high glucose medium containing 25% glucose.Another two groups of HCEC were taken and cultured in medium containing 5% and 25% glucose as control and high glucose groups, respectively.The cell proliferation viability was determined by CCK8 method.The use and care of animals complied ith the ARVO statement.The study protocol was approved by the Ethics Committee of Renmin Hospital of Wuhan University (2019K-K010). Results:Eight weeks after STZ injection, the blood glucose of mice was significantly higher and the weight was significantly lower in each diabetic model group than those of blank control group (all at P<0.05). At 12, 24 and 36 hours after the corneal epithelial injury, the percentages of corneal epithelial defect area observed by slit-lamp microscopy in model control group were significantly higher than those in blank control group and miR-497 knockout group and lower than those in miR-497 overexpression group, and the differences were statistically significant (all at P<0.05). The relative expressions of wnt3a and β-catenin proteins in the corneal tissues of model control group were significantly lower than those of blank control group and miR-497 knockout group, but higher than those of miR-497 overexpression group, and the differences were statistically significant (all at P<0.05). The relative expressions of CyclinD1, c-Myc and Ki-67 mRNA in model control group were lower than those in miR-497 knockout group, but higher than those in miR-497 overexpression group, and the differences were statistically significant (all at P<0.05). The relative expression of miR-497 in model control group, miR-497 knockout group and miR-497 overexpression group was 1.00±0.02, 0.63±0.06 and 1.48±0.03, respectively, with a statistically significant difference ( F=19.62, P<0.01). The luciferase activity of miR-497-5p mimics group in wild-type wnt3a transfected cells was lower than that of miR-497-5p negative control group and empty vector group, and the differences were statistically significant (all at P<0.05). In the mutant wnt3a transfected cells, there was no significant difference in the luciferase activity among various groups ( F=0.73, P=0.59). The cell proliferation A value of high glucose group was 0.59±0.03, which was significantly lower than 0.59±0.03 of normal control group and 0.88±0.08 of miR-497 inhibitor group, but significantly higher than 0.48±0.11 of miR-497 mimics group (all at P<0.05). Conclusions:The silencing of miR-497 may promote the repair of diabetic corneal epithelial defects by targeting wnt/β-catenin pathway.
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AIM: To observe the epithelial remodeling of femtosecond laser-assisted stromal lenticule addition keratoplasty combined with corneal collagen cross-linking(SLAK-CXL)in patients with progressive keratoconus, investigate the remodeling rules of corneal epithelial and influencing factors, and provide clinical data for further refractive correction.METHODS: Retrospective and observational study. A total of 28 keratoconus patients(29 eyes)who received SLAK-CXL from September 2020 to October 2021 were included. Preoperative and postoperative visual acuity, intraocular pressure(IOP), diopter, keratometry and corneal epithelial thickness(CET)were recorded. The trend of CET change was observed. The factors affecting CET were analyzed according to the thickness and depth of the lenticule.RESULTS: Flattest meridian keratometry(Kf)and steepest meridian keratometry(Ks)at 1mo postoperatively were significantly larger than those preoperatively(P<0.05). The thinnest corneal thickness(TCT)at 1, 2, 6mo and 1a postoperatively were significantly larger than preoperative(P<0.05). The CET changed with time, with the central CET showing a larger variation tendency. The CET of superior, superior nasal, nasal, superior temporal in paracentral area were thinned, the CET of superior, temporal, superior temporal in midperipheral area were thinned, while the CET of superior nasal was thickened in peripheral area at 1, 2, 6mo and 1a postoperatively. The variation of CET was not correlated with the thickness or depth of lenticule at 1a postoperatively(P>0.05).CONCLUSIONS: It is firstly found that the corneal morphology has changed after SLAK-CXL. CET decreases and then increases and then decreases again. At 1a postoperatively, the CET of the central and paracentral areas is thinner, while the CET of the midperipheral and peripheral areas is thicker. The degree of epithelial remodeling is not correlated with lenticule thickness or depth.
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AIM: To investigate the influencing factors of punctate staining of corneal epithelium in patients wearing orthokeratology.METHOD: Data of 280 cases wearing orthokeratology were collected, including 185 cases in the group without corneal staining and 95 cases in the group with corneal staining. All patients were examined for general distant vision, intraocular pressure, slit lamp, fundus examination after mydriasis, comprehensive optometry, corneal topography, corneal thickness, corneal endothelium, axial length, Schirmer Ⅰtest(SⅠt)before wearing lenses, meibomian gland loss score before wearing lenses, eccentric distance, interleukin-2(IL-2)in tear, tumor necrosis factor-α(TNF-α)content analysis and so on. The influencing factors of corneal epithelium punctate staining were analyzed by univariate and multivariate Logistic regression.RESULTS: There were significant differences in preoperative diopter, preoperative meibomian gland deletion score, IL-2, TNF-α and lens sediment between the two groups(all P<0.05). Logistic regression analysis showed that diopter before wearing lenses was a protective factor for corneal epithelium punctate staining. Before wearing lenses, the loss of meibomian gland score, IL-2, TNF-α and lens deposits were the risk factors of corneal epithelium punctate staining. In the detection of corneal epithelium punctate staining, the comprehensive advantage of lens deposits was obvious, the specificity of lens deposits was higher, and the sensitivity of IL-2 was the highest. CONCLUSIONS: Before wearing lenses, diopter is the protective factor of corneal epithelium punctate staining, and the loss of meibomian gland score, IL-2, TNF-α and lens deposits are the risk factors of corneal epithelium punctate staining.
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Neurotrophic keratopathy (NK) is a relatively rare degenerative corneal disease.Over time, it can cause varying degrees of ocular surface damage, leading to corneal ulcers, perforations and even blindness.The best opportunity to reverse ocular surface damage is in the earliest stage of NK.However, patients experience few typical symptoms and diagnosis is often delayed.In 2021, BMC Ophthalmology published the Expert Consensus on the Identification, Diagnosis and Treatment of Neurotrophic Keratopathy in Volume 21.Through the interpretation of the consensus, this paper hopes to further improve ophthalmologists' understanding of the screening and treatment of NK, and optimize the management norms of NK diagnosis and treatment.
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Laser corneal refractive surgery is an effective way for the correction of myopia, and its long-term stability is a common concern of surgeons and patients. However, refractive regression is still one of the most common postoperative long-term complications, which has a great impact on postoperative refractive state and visual quality. Refractive regression may be related to many factors, such as the remodeling of corneal epithelium and stroma, and the imbalance between corneal biomechanics and intraocular pressure. Although enhancement surgery could be a useful way to correct refractive regression, there is a risk of corneal ectasia and other complications. Some intraocular pressure lowering medications can be used to rebuild the balance of intraocular pressure and corneal biomechanics, and to prevent postoperative refractive regression by affecting the thickness of corneal epithelium. To a certain extent, the type, the timing and the way of intraocular pressure lowering medications application may have an impact on the prevention and treatment effect of refractive regression.
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Purpose: To evaluate the role of McCarey-Kaufman (MK) medium in maintaining the integrity of donor corneal epithelium. Methods: Nineteen corneal buttons were harvested and stored in MK media at 2°C–8°C for four days. Serial photographs were done every day till the 3rd day, and images were then analyzed with ImageJ software (LOCI, University of Wisconsin, USA). The area of exposure and epithelial defect (ED) was calculated every day for each corneal button. Results: The average age of the donors was 56.5 ± 22.7 years and mean time from death to preservation of the corneal buttons was 7.7 ± 3.1 hours. The average corneal area was 145.6 ± 18.8 mm2. The total mean area of exposure was 3.6 ± 4.8, 7.2 ± 9.2, and 9.0 ± 11.9 mm2, and ED was 1.7 ± 4.6, 2.8 ± 5.3, and 3.3 ± 5.9 mm2 on days 1, 2, and 3, respectively. The percentage of increase in the area of exposure and ED in MK media was 3.71% and 1.1% from day 1 to day 3, respectively. Six out of 19 corneal buttons (31.57%) were utilized for keratoplasties, of which two were utilized in house and four were distributed outside. Of the two utilized corneas, none had epithelial defect on postoperative day 1. Rest 13 corneas were either used for training and research purposes, stored in glycerol media, or discarded. Conclusion: Since the percentage change in area of exposure/ED is not much at the end of day 3, corneas stored in MK media can be safely used even after three days of storage. Hence, MK medium serves as an excellent medium in maintaining the integrity of donor corneal epithelium
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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.
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@#AIM: To explore the value of corneal epithelial thickness parameters in the diagnosis of early keratoconus by Fourier domain optical coherence tomography(FD-OCT).<p>METHODS: Retrospective control study. Patients with early keratoconus who were admitted to the Department of Ophthalmology of the First Affiliated Hospital of Soochow University from January 2015 to October 2020 and patients who received laser refractive surgery for myopia during the same period were included in this study. Using FD-OCT to measure the cornea in circle centralized by the pupil and with diameter of 9mm in the early-keratoconus group and the control group. This was to obtain the thickness parameter of corneal epithelium with diameter of 7mm, the respective averaged thickness value of corneal epithelium and the respective averaged thickness value of the full corneal layer on each of the 25 divisions. The parameter value differences between the early-keratoconus group and the control group were compared, and the diagnosis value of parameters that hold difference was analyzed. <p>RESULTS: The Min-e value in early-keratoconus group was significantly lower than that of the control group. On contrary, the value of Std.Dev, Max-Min-e, and Max-e were significantly higher in early-keratoconus group than that in latter one(all <i>P</i><0.001). The value of Std.Dev and Max-Min-e hold a greater diagnostic efficiency on diagnosis of early keratoconus(AUC=0.937, 0.928), while Max -e value and Min-e value performed a medium diagnostic efficiency(AUC=0.871, 0.797). Analysis on thickness of corneal epithelium on the 25 divisions found that the thickness of corneal epithelium at infratemporal region of inner ring(EIT1)became thinner most obviously in early-keratoconus group, with greatest diagnostic efficiency(AUC=0.827). The average corneal thickness of the 25 zones of the early keratoconus group was significantly thinner than that in the normal control group. Averaged corneal thickness at infratemporal region of inner ring(CIT1)hold a relatively high diagnostic efficiency among the 25 divisions(AUC=0.903).<p>CONCLUSION: The parameter values of corneal epithelium thickness including Std.Dev, Max-Min-e, Max-e, Min-e, the averaged thickness value of corneal epithelium at infratemporal region of inner ring, and the thickness value of full corneal layer at infratemporal region of inner ring can all be used for diagnosis of early keratoconus.
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@#The epithelial ingrowth under corneal flap is one of the complications after keratorefractive surgery, of which the incidence has declined dramatically with the improvement of relevant facilities and surgical techniques. However, epithelial ingrowth results from traumatic flap displacement has been describing in the literatures from time to time. If the prompt and efficient treatment cannot be taken, the severe complications of epithelial ingrowth will occur such as the alternation of refraction and cornea keratolysis. In this article, we reviewed the research progress of epithelial ingrowth after keratorefractive surgery.
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@#AIM: To observe the curative effect of pterygium resection and autologous limbal stem cell transplantation(LSCT)combined with amniotic membrane transplantation(AMT)in the treatment of pterygium.<p>METHODS: Totally 177 patients(187 eyes)with pterygium treated in ophthalmology clinic of the hospital between January 2017 and January 2020 were selected and randomly divided into group A(59 cases, 64 eyes), group B(59 cases, 60 eyes), and group C(59 cases, 63 eyes). All were treated with pterygium resection. On this basis, patients in the three groups were treated with autologous LSCT, AMT, and autologous LSCT combined with AMT, respectively. All subjects were followed up for 12mo after surgery. Visual acuity, corneal epithelial repair, and neovascularization of the three groups were comparatively analyzed. Postoperative recurrence rate, ocular symptoms, complications, and survival of grafts were statistically analyzed.<p>RESULTS: Visual acuity changes and repair time of corneal epithelial defect showed no statistically significant difference among the three groups(<i>P</i>>0.05). 1mo after surgery, the corneal fluorescein staining(FL)value of group C was significantly lower than that of group A or group B(all <i>P</i><0.05). No angiogenesis or recurrent true pterygium was observed. 6mo and 12mo after surgery, the grades of conjunctival fibroplasia in group A and group C were significantly different from that in group B(<i>P</i><0.05). There was no statistically significant difference in the wet length of the filter paper in Schirmer I test in terms of time, inter-group and interaction effects(<i>P</i>>0.05). 1mo after surgery, the tear film breakup time(BUT)of group C was significantly longer than that of group A or group B(all <i>P</i><0.05). There were different degrees of conjunctival edema in the three groups after surgery, which disappeared within 2wk after suture removal. Grafts all survived, vascularization of amniotic membrane grafts ended.<p>CONCLUSION:Autologous LSCT, AMT and autologous LSCT combined with AMT all are effective in the treatment of pterygium. However, autologous LSCT combined with AMT can achieve better short-term effect, with milder conjunctival fibroplasia and dry eye symptoms.
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@#Delayed healing of diabetic corneal epithelial wound is a commonly encountered condition, and persistent corneal epithelial defects may give rise to recurrent epithelium erosion, corneal ulceration, and subsequent perforation as well as affecting visual loss. The current review focused on the pathological basis, updates of the pathogenesis, and recent advances in the treatment of delayed healing of diabetic corneal epithelial wounds, wherein the roles of hyperglycemia, tear film, proteases, cytokines, corneal nerves and genes were elaborated, and the latest views on treatment strategies, for the delayed healing were summarized as well. Recent advances in research on delayed corneal epithelial wound healing in diabetes mellitus.
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@#AIM: To explore the clinical value of Tuiyi Mingmu decoction combined with autologous limbal stem cell transplantation in the treatment of pterygium.<p>METHODS: A retrospective analysis was performed to collect 80 patients(98 eyes)with pterygium admitted to the hospital from January 2016 to January 2018. The patients were divided into transplantation group(autologous limbal stem cell transplantation, <i>n</i>=34 cases, 39 eyes)and combined group(Tuiyi Mingmu decoction + autologous limbal stem cell transplantation, <i>n</i>=46 cases, 59 eyes). The uncorrected visual acuity(UCVA), corneal diopter, corneal astigmatism, tear break-up time(BUT)and Schirmer I test(S I t)tear secretion were compared between the two groups before operation and at 1mo after operation, and the corneal epithelial repair time, incidence rate of complications and recurrence rate at 12mo of follow-up were counted.<p>RESULTS: Before operation, there were no significant differences in the UCVA, corneal diopter and corneal astigmatism between the two groups(<i>P</i>>0.05). At 1mo after operation, the UCVA was increased while the corneal diopter and corneal astigmatism were decreased in the two groups, and the UCVA in combined group was higher than that in transplantation group while the corneal diopter and corneal astigmatism were lower than those in transplantation group(<i>P</i><0.05). Before operation, there were no statistically significant differences in the BUT and S I t between the two groups(<i>P</i>>0.05). At 1mo after operation, the BUT and S I t were increased in the two groups, and the indexes in combined group were higher than those in transplantation group(<i>P</i><0.05). The corneal epithelial repair time in combined group was shorter than that in transplantation group(<i>P</i><0.05), and the incidence rate of postoperative complications and recurrence rate at 12mo of follow-up were lower than those in transplantation group(<i>P</i><0.05).<p>CONCLUSION: Tuiyi Mingmu decoction combined with autologous limbal stem cell transplantation can improve the visual acuity of patients with pterygium, reduce corneal astigmatism, promote the repair of corneal epithelial cells, and reduce the recurrence rate, with few complications and definite safety.
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As the outermost part,cornea plays a critical role in protecting the eyeball and functions as main component of the dioptric media. Trauma,inflammation,malnutrition,inherited diseases,tumors,contact lens problems and complications of refractive surgeries may cause corneal injury. However,there are still no perfect treatments for severe corneal damage. Progresses have been made in the research field of corneal stem cells in recent years. Epithelial stem cells play an important role in corneal wound healing, whereas the contribution of stromal and endothelial stem cells is less studied. Moreover, corneal cells differentiated from alternative cell sources have a brilliant prospect in transplantation. This article reviewed the recent research progress of stem cells in the corneal epithelial,stromal and endothelial wound healing.
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Objective To investigate the histopathological and ultrastructural changes in the corneal epithelium in TgAPPswePS1 transgenic mice.Methods TgAPPswePS1 transgenic mice were randomly divided into experimental group (A and B sub-group) and control group.There were 15 APPswe/PSEN1dE9 transgenic mice (15-18 months old) with Alzheimer's disease (AD) in the experimental A group,and 15 APPswe/PSEN1 dE9 transgenic AD mice (8 months old) mice in the experimental B group,as well as 10 wild-type mice (8 months old) in the control group.Then,the histopathological and ultrastructural changes and the expression of amyloid β-protein (Aβ) in the corneal epithelium of the mice were detected,and finally,the apoptosis of corneal epithelial cells were observed by TUNEL assay.Results The thickness of corneal epithelium in the control group,A and B sub-group of the experimental group was (23.567 ± 2.123) μm,(15.456 ± 1.439) μm and (20.104 ± 1.763) μm,respectively.Meanwhile,murine corneal epithelial cells presented the histopathological changes of disorderly arrangement,decreased layers of cells and irregular morphology in the experimental group compared with the control group.Under transmission electron microscope,the microvilli on the surface of corneal epithelium was flat and significantly decreased in the A and B sub-group when compared with the control group.Moreover,Aβ positive expression in the experimental group was significantly upregulated compared with the control group;and the apoptotic number of the corneal epithelium in the B sub-group [(5.631 ± 2.471) cells] was smaller than that in the A sub-group [(16.329 ±3.542) cells],with the significant difference(P ＜ 0.05).Conclusion There are changes in the histopathology and ultrastructure of the corneal epithelium and the expression of Aβ in TgAPPswePS1 transgenic mice compared with wild-type mice,which are associated with the age of mice.
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Objective To investigate the effects of the eye drops containing deproteinized calf blood extract on the ocular surface and tear film at the early stage of orthokeratology treatment in myopic adolescents.Methods Together 59 myopia (118eyes) who received vision correction by orthokeratology lens between June 2016 and October 2016 were included in this study,and they were randomly assigned into two groups:the treatment group,29 patients (58 eyes) receiving the eye drops containing deproteinized calf blood extract to presumably promote the repair of corneal epithelium,and the control group,30 patients (60 eyes) without receiving such eye drops.For each subject,the surface regularity index (SRI) and objective scattering index (OSI)were recorded;lipid layer thickness (LLT) and tear film break-up time (BUT) were measured,and finally fluorescein stain of corneal epithelium and the ocular surface disease index (OSDI) questionnaire were performed before treatment and 1 week and 1 month after lens wearing.Results The treatment group showed significantly lower rate of corneal staining than the control group at 1 week (10.3％ vs.33.3％,all P ＜0.05) and 1 month after treatment (8.6％ vs.26.7％,all P ＜ 0.05).There was no significant difference in LLT at 1 week and 1 month after treatment and before treatment (all P ＞ 0.05).Both corneal curvature and BUT were decreased,while SRI,OSI,and OSDI score were increased significantly after 1-week lens wearing (all P ＜ 0.05),but there was no significant difference at 1 week and 1 month after lens wearing (all P ＞ 0.05).Moreover,there was no significant difference in corneal curvature,SRI,BUT,LLT,OSI,and OSDI score at different time points between the treatment group and the control group (all P ＞ 0.05).Conclusion Eye drops containing deproteinized calf blood extract can protect and repair the corneal epithelium at the early stage of orthokeratology treatment.
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Objeetive To compare the thickness of corneal epithelium and full-thickness of the cornea among New Zealand rabbits,cats and the human using optical coherence tomography angiography (OCTA) technology as to explore the morphological basis for different animals as experimental models of xenocorneal transplantation.Methods Totally selected 12 New Zealand male rabbits and 12 male cats were included in this study and divided into group A and B.Then the thickness of corneal epithelium and full-thickness of the cornea of both eyes in the two groups were measured with OCTA technology,and according to the distance from the center of the cornea,the cornea was divided into 17 areas by System software.The center of the cornea was a diameter of 2 mm around the center of the cornea,with the inner ring and outer ring of 5 mm and 6 mm in diameter,respectively;and the inner and outer ring region was again divided into 8 areas,including superior side (S),superior nose side (SN),nasal side (N),inferior nose side (IN),inferior side (I),inferior temporal side (IT),temporal side (T),superior temporal side (ST).Then the thickness of corneal epithelium and full-thickness of the cornea in each region were measured for comparing the difference of New Zealand rabbits' and cats' corneal thickness with the human's.Results The thickness of corneal epithelium and full-thickness of the cornea of cats were both thicker than those of rabbits.The full-thickness of the cats' cornea became thinner from the central to the peripheral side,and the difference of thickness between the T5,ST5,S5,SN5,N5 areas and the central of the cornea was statistically significant (all P ＜0.05);the thickness of corneal epithelium in the ST5,S5,SN5 areas was significantly thicker than the central area (all P ＜0.05);And this was true of the rabbits' full-thickness of the cornea,and the difference in the full-thickness of the cornea between the T5,IT5,IN5,N5,T6,N6 area and the central region was statistically significant (all P ＜ 0.05);meanwhile there were also significant difference in the thickness of corneal epithelium between the ST5,S5,SN5,ST6,S6,SN6 areas and the central area (all P ＜ 0.05).Additionally,there were significant differences in the thickness of corneal epithelium and full-thickness of the cornea between the two experimental animals and humans (all P ＜ 0.05).Conclusion The cornea of cats possesses similar regions in corneal full-thickness and epithelial thickness as well as the distribution to human cornea,so cats have superiority to the rabbits for the potential donor of xenocorneal transplantation in human beings.
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PURPOSE: To investigate the effect of human serum on corneal epithelial cells. METHODS: Changes of corneal epithelial cells were evaluated after 1, 4, 12, and 24 hours (hrs) of exposure to various concentrations of human serum (3, 5, 8, and 16%). Cellular metabolic activity and the extent of cellular damage were measured. Effect of human serum on cell migration was also examined. Concentration of procollagen type-I COOH-terminal peptide (PIP), epidermal growth factor (EGF), and laminin after exposure to human serum was further observed. RESULTS: In every concentration of human serum, metabolic activity of the corneal epithelial cells temporarily decreased at 4 hrs of exposure and recovered to baseline levels afterward. With the same exposure time, there was no statistically significant difference in metabolic activity between the human serum-exposed group and the control group. Cellular toxicity of human serum exhibited a time- and dose-dependent relationship. Cellular migration was observed after 24 hrs of exposure to 5% concentration of human serum and after 12 hrs of exposure to 8% and 16% concentration of human serum. The PIP, EGF, and laminin titers increased in time- and dose-dependent manners. CONCLUSIONS: Human serum does not decrease the metabolic activity of corneal epithelial cells as the concentration and exposure time increase, but it can induce cytotoxicity. Considering cellular migration, a serum concentration of 5% or higher should be used.
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Humans , Cell Movement , Epidermal Growth Factor , Epithelial Cells , Epithelium, Corneal , In Vitro Techniques , Laminin , ProcollagenABSTRACT
PURPOSE: To compare preoperative and postoperative thickness and to investigate the difference in the thickness change of corneal epithelium and stroma after cataract surgery through scleral tunnel incision. METHODS: Forty eyes of forty patients who were 40 years old or older and underwent small-incision superior scleral tunnel cataract surgery with phacoemulsification were included. Using the RTVue instrument (Optovue Inc., Fremont, CA, USA), corneal epithelial (ET) and stromal thicknesses (ST) of all subjects were measured preoperatively and at 3 days, 1 week, and 1 month postoperatively. Thicknesses were classified into 3 zones according to the distance from the vertex: central zone (within 2 mm), paracentral zone (2-5 mm diameter) and midperipheral zone (5-6 mm diameter). RESULTS: Mean central ST was 486.68 ± 25.15 µm, 535.16 ± 48.13 µm, 515.98 ± 44.07 µm, and 502.28 ± 34.87 µm preoperatively, and at 3 days, 1 week, and 1 month postoperatively, respectively (p < 0.001 for all). ST showed significant thickening in all three zones from 3 days to 1 month postoperatively (p < 0.001 for all). Mean central, paracentral, and midperipheral ET was 52.13 ± 3.41 µm, 50.42 ± 2.97 µm, 49.12 ± 3.05 µm at preoperatively and 51.03 ± 3.63 µm, 48.96 ± 3.62 µm, 47.67 ± 3.81 µm at 1 month postoperatively, respectively (p = 0.061, 0.006, 0.001, respectively), while there were no signficant changes in all three zones at 3 and 7 days postoperatively. Changes in ET and ST were prominent at the superotemporal incision site. CONCLUSIONS: After scleral tunnel cataract surgery, corneal edema was observed in the stroma immediately after surgery. There was no significant change at early times after surgery in the epithelium, and there was a decrease in the peripheral cornea at 1 month postoperatively. The change in ET was considered a compensatory change due to stromal edema and appeared between 1 week to 1 month postoperatively.
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Humans , Cataract , Cornea , Corneal Edema , Corneal Stroma , Edema , Epithelium , Epithelium, Corneal , PhacoemulsificationABSTRACT
Ginseng gintonin is an exogenous ligand of lysophosphatidic acid (LPA) receptors. Accumulating evidence shows LPA helps in rapid recovery of corneal damage. The aim of this study was to evaluate the therapeutic efficacy of gintonin in a rabbit model of corneal damage. We investigated the signal transduction pathway of gintonin in human corneal epithelium (HCE) cells to elucidate the underlying molecular mechanism. We next evaluated the therapeutic effects of gintonin, using a rabbit model of corneal damage, by undertaking histochemical analysis. Treatment of gintonin to HCE cells induced transient increases of [Ca²⁺](i) in concentration-dependent and reversible manners. Gintonin-mediated mobilization of [Ca²⁺](i) was attenuated by LPA1/3 receptor antagonist Ki16425, phospholipase C inhibitor U73122, inositol 1,4,5-triphosphate receptor antagonist 2-APB, and intracellular Ca²⁺ chelator BAPTA-AM. Gintonin facilitated in vitro wound healing in a concentration-dependent manner. When applied as an eye-drop to rabbits with corneal damage, gintonin rapidly promoted recovery. Histochemical analysis showed gintonin decreased corneal apoptosis and increased corneal cell proliferation. We demonstrated that LPA receptor activation by gintonin is linked to in vitro and in vivo therapeutic effects against corneal damage. Gintonin can be applied as a clinical agent for the rapid healing of corneal damage.