Figueroa-Ortiz, L C; Martín Rodríguez, O; García-Ben, A; García-Campos, J
To analyse the length and area of corneal surface occupied by vessels, and their location in an experimental model of alkali burn-induced corneal neovascularization. An injury to the central cornea of the right eye in 91 Sprague-Dawley rats was induced using a silver nitrate pencil. The rats were divided in 7 groups that were sacrificed 2, 4, 6, 8, 10, 12 and 14 days post-injury, and then perfused with a mixture of Chinese ink in PBS -phosphate buffer saline-. Corneas were flat-mounted processed and divided in 4 quadrants. Corneal neovascular growth parameters (length and area) and the location of these vessels were performed blind. The results were statistically analysed. Neovascular growth was observed from day 2, reaching its maximum peak in length and area on the 12th day post-injury. A slight reduction in corneal neovascularization was observed after this day. The vessels were initially located in the middle third of the stroma and tended to be observed in the anterior third during the course of the experiment. Neovascularisation was observed on day 2 post-injury in all sectors of corneal surface. Neovascular growth was uniform during the experiment. Neovessels were located in the middle and anterior third of the cornea. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.
Full Text Available AIM: To study the effect of diallyl trisulfide(DATSon experimental corneal neovascularization(CNVin rats induced by corneal suture and detect the expression of vascular endothelial growth factor(VEGFand p-AKT in rats cornea. METHODS: The rat model of corneal neovascularization(CNVwas induced by corneal suture. Rats were randomly divided into Group A: physiological saline control group containing DMSO(10 rats; Group B: 25μmol/L DATS treatment group(10 rats; Group C: 50μmol/L DATS treatment group(10 rats; Group D: 100μmol/L DATS treatment group(10 rats; Group E: 200μmol/L DATS treatment group(10 rats. The occurrence and development of CNV were observed by slit-lamp microscope at 7d after suture, and the area of CNV were calculated.Two weeks later, HE staining was used to observe the pathological organization form of each cornea, and RT-PCR and Western blot were used to detect the expression of VEGF mRNA and protein expression of VEGF and p-AKT between each groups. RESULTS: The blood vessel area of Group C, D and E was compared with that of Group A, the difference was statistically significant(PPPCONCLUSION: DATS can inhibit corneal neovascularization of the rats induced by suture. Its mechanism may be associated with suppression of VEGF secretion, down-regulation of VEGF and inactivation of p-AKT.
Lee, Jung Eun; Kim, Koung Li; Kim, Danbi; Yeo, Yeongju; Han, Hyounkoo; Kim, Myung Goo; Kim, Sun Hwa; Kim, Hyuncheol; Jeong, Ji Hoon; Suh, Wonhee
Pathological angiogenesis is one of the major symptoms of severe ocular diseases, including corneal neovascularization. The blockade of vascular endothelial growth factor (VEGF) action has been recognized as an efficient strategy for treating corneal neovascularization. In this study, we aimed to investigate whether nanoparticle-based delivery of apatinib, a novel and selective inhibitor of VEGF receptor 2, inhibits VEGF-mediated angiogenesis and suppresses experimental corneal neovascularization. Water-insoluble apatinib was encapsulated in nanoparticles composed of human serum albumin (HSA)-conjugated polyethylene glycol (PEG). In vitro angiogenesis assays showed that apatinib-loaded HSA-PEG (Apa-HSA-PEG) nanoparticles potently inhibited VEGF-induced tube formation, scratch wounding migration, and proliferation of human endothelial cells. In a rat model of alkali burn injury-induced corneal neovascularization, a subconjunctival injection of Apa-HSA-PEG nanoparticles induced a significant decrease in neovascularization compared to that observed with an injection of free apatinib solution or phosphate-buffered saline. An in vivo distribution study using HSA-PEG nanoparticles loaded with fluorescent hydrophobic model drugs revealed the presence of a substantial number of nanoparticles in the corneal stroma within 24 h after injection. These in vitro and in vivo results demonstrate that apatinib-loaded nanoparticles may be promising for the prevention and treatment of corneal neovascularization-related ocular disorders.
Sener, Ender; Yuksel, Nusen; Yildiz, Demir Kursat; Yilmaz, Bulent; Ozdemir, Ozdemir; Caglar, Yusuf; Degirmenci, Esra
To investigate the inhibitory effect of subconjunctival application of VEGF antibodies bevacizumab, ranibizumab, pegaptanib, and HER2 antibody trastuzumab on corneal neovascularization in a rat model of experimental corneal neovascularization. Thirty male Wistar albino rats were included in the study. A chemical burn was induced in central cornea of one eye of the rats by a 75% silver nitrate and 25% potassium nitrate stick. Rats were randomly divided into five groups so that each group contained 6 subjects. Right after the chemical burn, 0.1 ml serum physiologic was injected subconjuctivally in control group (group 1). 1.25 mg/0.05 ml bevacizumab was injected in group 2; 1.2 mg/0.1 ml trastuzumab was injected in group 3; 0.5 mg/0.05 ml ranibizumab was injected in group-4; and 0.3 mg/0.1 ml pegaptanib was injected in group 5. On the 8th day of the experiment, rat corneas were photographed by digital photo-camera. Later, eyes of the sacrificed rats were enucleated and corneal speciements were histopathologically analyzed. The percentages of neovascularization on corneal photographs were examined with digital image analysis. The percentage of corneal neovascularization in all treatment groups was found to be significantly lower than the control group (p 0.05). In all treatment groups, fibroblast intensity was significantly lower than the control group. In terms of corneal thickness, no significant difference was observed between treatment and control groups (p > 0.05). Bevacizumab, ranibizumab, pegaptanib, and trastuzumab were found effective for the inhibition of corneal NV. In our study we detected that the most effective agent was bevacizumab.
V. R. Mamikpnyan
Full Text Available Results of comparative experimental and morphological study of activity on corneal neovascularization in rabbit’s eye of photodynamic therapy with Photosense and antiangiogenic therapy with Avastin (bevacizumab alone, and in its combination are represented. The treatment was performed in regimens: 1 photodynamic therapy with Photosense (single intravenous injection in dose of 0.3 mg/kg 72 h prior to laser irradiation, power density of irradiation 500 mW/cm2, wavelength 675 nm; 2 drug antiangiogenic therapy with Avastin (single subconjuctival introduction at dose of 1.25 mg; 3 photodynamic therapy with Photosense (in described regimen in combination with subconjuctival introduction of Avastin at dose of 1.25 mg immediately prior to irradiation. Combined photodynamic therapy with antiangiogenic therapy allows to obtain almost complete occlusion in all regions of corneal neovascular bed with shorter time interval comparing with those for monoregimens. In case of blood flow retention in great vessels courses of combined modality treatment may be repeated. The absence of side-effects on surrounding tissues and the recovery of optical characteristics of cornea may allow to use this upcoming method in clinical practice.
Purpose: To investigate the effect of hydrazinocurcumin on a human vascular endothelial growth factor (VEGF)-induced corneal neovascularization in rabbit model. Methods: Murine corneal neovascularization (CorNV) was induced via two intrastromal implantations of VEGF polymer 2 mm from the limbus.
Purpose: To investigate the effect of hydrazinocurcumin on a human vascular endothelial growth factor. (VEGF)-induced corneal neovascularization in rabbit model. Methods: Murine corneal neovascularization (CorNV) was induced via two intrastromal implantations of. VEGF polymer 2 mm from the limbus.
Full Text Available Purpose: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. Methods: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8, subconjunctival bevacizumab treatment (n=8, and topical bevacizumab treatment (n=8. Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. Results: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730. The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05. The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05. Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05. Conclusions: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn.
Zakaria, Nadia; Van Grasdorff, Sigi; Wouters, Kristien; Rozema, Jos; Koppen, Carina; Lion, Eva; Cools, Nathalie; Berneman, Zwi; Tassignon, Marie-José
Corneal neovascularization results from the encroachment of blood vessels from the surrounding conjunctiva onto the normally avascular cornea. The aim of this study is to identify factors in human tears that are involved in development and/or maintenance of corneal neovascularization in humans. This could allow development of diagnostic tools for monitoring corneal neovascularization and combination monoclonal antibody therapies for its treatment. In an observational case-control study we enrolled a total of 12 patients with corneal neovascularization and 10 healthy volunteers. Basal tears along with reflex tears from the inferior fornix, superior fornix and using a corneal bath were collected along with blood serum samples. From all patients, ocular surface photographs were taken. Concentrations of the pro-angiogenic cytokines interleukin (IL)-6, IL-8, Vascular Endothelial Growth Factor (VEGF), Monocyte Chemoattractant Protein 1 (MCP-1) and Fas Ligand (FasL) were determined in blood and tear samples using a flow cytometric multiplex assay. Our results show that the concentration of pro-angiogenic cytokines in human tears are significantly higher compared to their concentrations in serum, with highest levels found in basal tears. Interestingly, we could detect a significantly higher concentration of IL- 6, IL-8 and VEGF in localized corneal tears of patients with neovascularized corneas when compared to the control group. This is the first study of its kind demonstrating a significant difference of defined factors in tears from patients with neovascularized corneas as compared to healthy controls. These results provide the basis for future research using animal models to further substantiate the role of these cytokines in the establishment and maintenance of corneal neovascularization.
This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, http://publicationethics.org/resources/guidelines). Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...
This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, http://publicationethics.org/resources/guidelines). Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...
Full Text Available Corneal transparency is the basis of the normal physiological functions.However, corneal neovascularization(CNVmay occur in the infection, mechanical and chemical injury or under other pathological conditions,which make the cornea lose original transparency and severe visual impairment. In recent years, along with the development of immunology, molecular biology, biochemistry and other disciplines, there is more in-depth understanding on the CNV, and clinical treatment of CNV has made new breakthroughs. This article provides an overview of the inhibition of CNV.
Full Text Available Objective. To investigate the effects of topical and subconjunctival tigecycline on the prevention of corneal neovascularization. Materials and Methods. Following chemical burn, thirty-two rats were treated daily with topical instillation of 1 mg/mL tigecycline (group 1 or subconjunctival instillation of 1 mg/mL tigecycline (group 3 for 7 days. Control rats received topical (group 2 or subconjunctival (group 4 0.9% saline. Digital photographs of the cornea were taken on the eighth day after treatment and analyzed to determine the percentage area of the cornea covered by neovascularization. Corneal sections were analyzed histopathologically. Results. The median percentages of corneal neovascularization in groups 1 and 3 were 48% (95% confidence interval (CI, 44.2–55.8% and 33.5% (95% CI, 26.6–39.2%, respectively. The median percentages of corneal neovascularization of groups 1 and 3 were significantly lower than that of the control group (P=0.03 and P<0.001, resp.. Histologic examination of samples from groups 1 and 3 showed lower vascularity than that of control groups. Conclusion. Topical and subconjunctival administration of tigecycline seems to be showing promising therapeutic effects on the prevention of corneal neovascularization. Furthermore, subconjunctival administration of tigecycline is more potent than topical administration in the inhibition of corneal neovascularization.
Wang, Ting; Shi, Wei-yun; Li, Su-xia; Liu, Ming-na
To study the relationship between corneal neovascularization and various biological factors in corneal stroma of rats. It was an experimental study. Corneal neovascularization was induced by alkali burn in 40 rats. Transforming growth factor-beta1 (TGF-beta1), alpha-smooth muscle actin (alpha-SMA) and fibroblast activation protein (FAP) in the stroma surrounding corneal neovascularization were detected by immunohistochemical studies on day 1, 3 and 7 after chemical burn. Platelet-endothelial cell adhesion molecule-1 (CD31) was used to identify the vascular endothelial cells. RT-PCR was used to identify FAP in the cornea 3 and 7 days after chemical burn. Picrosirius staining and polarization microscopy were used to detect changes of collagen types I and III in the cornea. After alkali burn, TGF-beta1 was first expressed in the cornea stroma. Then, some stroma cells expressed both alpha-SMA and FAP. The FAP(+) keratocytes were found surrounding the CD31(+) endothelium of angiogenesis. RT-PCR study showed that FAP mRNA was only present in neovascularized cornea and not in normal cornea. Polarization microscopy revealed that the collagen types I and III were rearranged in neovascularized cornea. Various biological factors in corneal stroma are changed when the cornea shows neovascularization. FAP(+) keratocytes are present in the stroma, and the appearance of these cells parallels the growth of vascular endothelial cells. Collagen types I and III are rearranged during the process of angiogenesis.
Conclusions: SiNPs is an effective modality for inhibiting corneal neovascularization following chemical burn in an experimental model. Further investigations are suggested for evaluation of its safety and efficacy in human eyes.
Full Text Available AIM: To observe the expression of erythropoietin(EPOon the corneal of rabbit and evaluate the inhibition effect of EPO siRNA on corneal neovascularization(CNV. METHODS: Totally 22 healthy rabbits were randomly divided into 2 groups, which were experimental group and normal control group. Both eyes of rabbits in experimental group were chosen to establish corneal neovascularization model by alkali burn. The morphologic change of corneal was observed with slit lamp microscope and the area of CNV was calculated every day. After alkali burn, the right eye of the experimental group was accepted EPO siRNA injection under the conjunctiva, and the left eye was assigned to be experimental control group. The corneal with CNV was collected for immunohistochemistry at 3d, 7d, 14d, 21d after alkali burn, and the expression of EPO was measured. RESULTS: CNV began growing at the 3d after alkali burn in experimental group, and it was vigorous growing at 7d-14d period. The result of immunohistochemistry shows that the expression of EPO increased after the operation. Compared with experimental group, the rabbits who were treated by EPO siRNA was found with less neovascularization on their corneal, and the expression of EPO decreased. There were statistical significance between the two group at different time(PCONCLUSION: EPO is likely to play an important role on CNV growth, and EPO siRNA can inhibit the growth of CNV by restraining the expression of EPO.
Kim, Yoo C; Grossniklaus, Hans E; Edelhauser, Henry F; Prausnitz, Mark R
This study tested the hypothesis that highly targeted intrastromal delivery of bevacizumab using coated microneedles allows dramatic dose sparing compared with subconjunctival and topical delivery for treatment of corneal neovascularization. Stainless steel microneedles 400 μm in length were coated with bevacizumab. A silk suture was placed in the cornea approximately 1 mm from the limbus to induce corneal neovascularization in the eyes of New Zealand white rabbits that were divided into different groups: untreated, microneedle delivery, topical eye drop, and subconjunctival injection of bevacizumab. All drug treatments were initiated 4 days after suture placement and area of neovascularization was measured daily by digital photography for 18 days. Eyes treated once with 4.4 μg bevacizumab using microneedles reduced neovascularization compared with untreated eyes by 44% (day 18). Eyes treated once with 2500 μg bevacizumab using subconjunctival injection gave similar results to microneedle-treated eyes. Eyes treated once with 4.4 μg subconjunctival bevacizumab showed no significant effect compared with untreated eyes. Eyes treated with 52,500 μg bevacizumab by eye drops three times per day for 14 days reduced the neovascularization area compared with untreated eyes by 6% (day 18), which was significantly less effective than the single microneedle treatment. Visual exam and histological analysis showed no observable effect of microneedle treatment on corneal transparency or microanatomical structure. This study shows that microneedles can target drug delivery to corneal stroma in a minimally invasive way and demonstrates effective suppression of corneal neovascularization after suture-induced injury using a much lower dose compared with conventional methods. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Full Text Available The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV. A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS or minocycline twice a day (60 mg/kg or 30 mg/kg for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathological examination was performed to assess morphological change and the infiltration of polymorphonuclear neutrophils (PMNs. The mRNA expression levels of vascular endothelial growth factor (VEGF and its receptors (VEGFRs, basic fibroblast growth factor (bFGF, matrix metalloproteinases (MMPs, interleukin-1α, 1β, 6 (IL-1α, IL-1β, IL-6 were analyzed using real-time quantitative polymerase chain reaction. The expression of MMP-2 and MMP-9 proteins was determined by gelatin zymography. In addition, enzyme-linked immunosorbent assay was used to analyze the protein levels of VEGFR1, VEGFR2, IL-1β and IL-6. Minocycline at a dose of 60 mg/kg or 30 mg/kg significantly enhanced the recovery of the corneal epithelial defects more than PBS did. There were significant decreases of corneal neovascularization in the group of high-dosage minocycline compared with the control group at all checkpoints. On day 14, the infiltrated PMNs was reduced, and the mRNA expression of VEGFR1, VEGFR2, bFGF, IL-1β, IL-6, MMP-2, MMP-9, -13 as well as the protein expression of VEGFR2, MMP-2, -9, IL-1β, IL-6 in the corneas were down-regulated with the use of 60 mg/kg minocycline twice a day. Our results showed that the intraperitoneal injection of minocycline (60 mg/kg b.i.d. can significantly inhibit alkali burn-induced corneal neovascularization in mice, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors, inflammatory cytokines and MMPs.
Gonzalez, Lilian; Loza, Raymond J; Han, Kyu-Yeon; Sunoqrot, Suhair; Cunningham, Christy; Purta, Patryk; Drake, James; Jain, Sandeep; Hong, Seungpyo; Chang, Jin-Hong
Nanotechnology is an up-and-coming branch of science that studies and designs materials with at least one dimension sized from 1-100 nm. These nanomaterials have unique functions at the cellular, atomic, and molecular levels. The term "nanotechnology" was first coined in 1974. Since then, it has evolved dramatically and now consists of distinct and independent scientific fields. Nanotechnology is a highly studied topic of interest, as nanoparticles can be applied to various fields ranging from medicine and pharmacology, to chemistry and agriculture, to environmental science and consumer goods. The rapidly evolving field of nanomedicine incorporates nanotechnology with medical applications, seeking to give rise to new diagnostic means, treatments, and tools. Over the past two decades, numerous studies that underscore the successful fusion of nanotechnology with novel medical applications have emerged. This has given rise to promising new therapies for a variety of diseases, especially cancer. It is becoming abundantly clear that nanotechnology has found a place in the medical field by providing new and more efficient ways to deliver treatment. Ophthalmology can also stand to benefit significantly from the advances in nanotechnology research. As it relates to the eye, research in the nanomedicine field has been particularly focused on developing various treatments to prevent and/or reduce corneal neovascularization among other ophthalmologic disorders. This review article aims to provide an overview of corneal neovascularization, currently available treatments, and where nanotechnology comes into play.
Nizar Saleh Abdelfattah
Full Text Available A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization, leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far.
Chen, Wei-Sheng; Cao, Zhiyi; Leffler, Hakon; Nilsson, Ulf J; Panjwani, Noorjahan
Corneal neovascularization and scarring commonly lead to significant vision loss. This study was designed to determine whether a small-molecule inhibitor of galectin-3 can inhibit both corneal angiogenesis and fibrosis in experimental mouse models. Animal models of silver nitrate cautery and alkaline burn were used to induce mouse corneal angiogenesis and fibrosis, respectively. Corneas were treated with the galectin-3 inhibitor, 33DFTG, or vehicle alone and were processed for whole-mount immunofluorescence staining and Western blot analysis to quantify the density of blood vessels and markers of fibrosis. In addition, human umbilical vein endothelial cells (HUVECs) and primary human corneal fibroblasts were used to analyze the role of galectin-3 in the process of angiogenesis and fibrosis in vitro. Robust angiogenesis was observed in silver nitrate-cauterized corneas on day 5 post injury, and markedly increased corneal opacification was demonstrated in alkaline burn-injured corneas on days 7 and 14 post injury. Treatment with the inhibitor substantially reduced corneal angiogenesis and opacification with a concomitant decrease in α-smooth muscle actin (α-SMA) expression and distribution. In vitro studies revealed that 33DFTG inhibited VEGF-A-induced HUVEC migration and sprouting without cytotoxic effects. The addition of exogenous galectin-3 to corneal fibroblasts in culture induced the expression of fibrosis-related proteins, including α-SMA and connective tissue growth factor. Our data provide proof of concept that targeting galectin-3 by the novel, small-molecule inhibitor, 33DFTG, ameliorates pathological corneal angiogenesis as well as fibrosis. These findings suggest a potential new therapeutic strategy for treating ocular disorders related to pathological angiogenesis and fibrosis.
Taimi Cárdenas Díaz
Full Text Available La neovascularización corneal es causa de pérdida de su transparencia y también es un factor de riesgo para el rechazo secundario de trasplantes en esa estructura. El bevacizumab es un anticuerpo monoclonal humanizado que bloquea selectivamente la cascada de formación del VEGF y con esto disminuye la formación de vasos sanguíneos. Se presentan tres casos con neovascularización corneal por diferentes causas, a los cuales se le administró tres dosis subconjuntival de 2,5 mg de bevacizumab, con una frecuencia mensual. En los ojos tratados se observó una regresión parcial de la neovascularización corneal y fue más visible en el paciente con antecedente de quemadura corneal.Neovascularization of the cornea is a cause of loss of transparency of the same and is also a risk factor for secondary rejection corneal transplants. Bevacizumab is a humanized monoclonal antibody that selectively blocks the formation of the VEGF cascade and, with this, decreases the formation of blood vessels. Three cases with corneal neovascularization from different causes were presented, which were given three doses of 2.5 mg subconjunctival bevacizumab once a month. A partial regression of corneal neovascularization was observed in the treated eyes, being more visible in the patient with a history of corneal burn.
Sella, Ruti; Gal-Or, Orly; Livny, Eitan; Dachbash, Mor; Nisgav, Yael; Weinberger, Dov; Livnat, Tami; Bahar, Irit
The aim of this experimental study was to compare the efficacy of topical aflibercept and topical bevacizumab in preventing corneal neovascularization. A chemical burn was created in the right central cornea of male Sprague-Dawley rats, followed immediately by instillation of one drop (25 mg/ml, 20 μl volume) of aflibercept (15 eyes), bevacizumab (14 eyes), or saline (15 eyes). Treatment was repeated twice daily for 7 days. Corneal neovascularization was determined using corneal photographs (ImageJ) on days 1, 4, 7, 10, and histological and immunofluorescence studies, on day 10. Stromal immunoreactivity was evaluated 2 days after injury in 6 rats treated singly with bevacizumab or aflibercept. Corneal neovascularization was observed clinically on day 4 in all groups. In the aflibercept group, the area of neovascularization increased from 7.38 ± 2.23% on day 4 to 21.73 ± 14.59% on day 7 and 31.0 ± 23.61% on day 10. Corresponding values in the bevacizumab group were 6.04% ± 1.81%, 51.27 ± 15.50%, and 54.4 ± 11.33%, and in the control group, 8.99 ± 1.93%, 42.6 ± 19.59%, and 55.15 ± 11.54%. The area of neovascularization was significantly smaller on days 7 and 10 in the aflibercept group than in the control and bevacizumab groups (P < 0.001, all analyses), with no significant differences between the latter two groups (day 7, P = 0.868; day 10, P = 0.213). Clinical findings were compatible with the histological data and supported by immunofluorescence and corneal flat-mount staining. Both drugs demonstrated variable penetration into the corneal stroma. Topical aflibercept effectively inhibits corneal neovascularization in a rat model of chemical burn. These findings may have important therapeutic implications for humans. Copyright © 2016 Elsevier Ltd. All rights reserved.
Glauco Reggiani Mello
Full Text Available PURPOSE: To evaluate the use of subconjunctival bevacizumab on corneal neovascularization in an experimental rabbit model for its effect on vessel extension, inflammation, and corneal epithelialization. METHODS: In this prospective, randomized, blinded, experimental study, 20 rabbits were submitted to a chemical trauma with sodium hydroxide and subsequently divided into two groups. The experimental group received a subconjunctival injection of bevacizumab (0.15 m; 3.75 mg, and the control group received an injection of 0.15 ml saline solution. After 14 days, two blinded digital photograph analyses were conducted to evaluate the inflammation/diameter of the vessels according to pre-established criteria. A histopathological analysis of the cornea evaluated the state of the epithelium and the number of polymorphonuclear cells. RESULTS: A concordance analysis using Kappa's statistic showed a satisfactory level of agreement between the two blinded digital photography analyses. The neovascular vessel length was greater in the control group (p<0.01 than in the study group. However, the histopathological examination revealed no statistically significant differences between the groups in terms of the state of the epithelium and the number of polymorphonuclear cells. CONCLUSIONS: Subconjunctival bevacizumab inhibited neovascularization in the rabbit cornea. However, this drug was not effective at reducing inflammation. The drug did not induce persistent corneal epithelial defects.
Bellner, Lars; Vitto, Marco; Patil, Kiran A; Dunn, Michael W; Regan, Raymond; Laniado-Schwartzman, Michal
Heme oxygenase (HO-1 and HO-2) represents an intrinsic cytoprotective and anti-inflammatory system based on its ability to modulate leukocyte migration and to inhibit expression of inflammatory cytokines and proteins. HO-2 deletion leads to unresolved corneal inflammation and chronic inflammatory complications including ulceration, perforation and neovascularization. We examined the consequences of HO-2 deletion on hemangiogenesis and lymphangiogenesis in the model of suture-induced inflammatory neovascularization. An 8.0 silk suture was placed at the corneal apex of wild type and HO-2 null mice. Neovascularization was assessed by vital microscopy and quantified by image analysis. Hemangiogenesis and lymphangiogenesis were determined by immunofluorescence staining using anti-CD31 and anti-LYVE-1 antibodies, respectively. Inflammation was quantified by histology and myeloperoxidase activity. The levels of HO-1 expression and inflammatory cytokines were determined by real time PCR and ELISA, respectively. Corneal sutures produced a consistent inflammatory response and a time-dependent neovascularization. The response in HO-2 null mice was associated with a greater increase compared to the wild type in the number of leukocytes (827,600+/-129,000 vs. 294,500+/-57,510; pbiliverdin diminished the exaggerated inflammatory and neovascular response in HO-2 null mice. The demonstration that the inflammatory responses, including expression of proinflammatory proteins, inflammatory cell influx and hemangiogenesis are exaggerated in HO-2 knockout mice strongly supports the notion that the HO system is critical for controlling the inflammatory and neovascular response in the cornea. Hence, pharmacological amplification of this system may constitute a novel therapeutic strategy for the treatment of corneal disorders associated with excessive inflammation and neovascularization.
Full Text Available AIM: To describe the expression of hypoxia-inducible factor-1α(HIF-1αand erythropoietin(EPOin rats' corneal and evaluate its potential effect on corneal neovascularization(CNVgrowth. METHODS: The young SD rats(3mowas chosen and randomly divided into 2 groups, which were experimental group and normal control group. CNV model was established by alkali burn, and the length and area of CNV was observed everyday after operation by slit lamp. After that, the expression of HIF-1α and EPO was measured by SABC and RT-PCR methods at 1, 3, 5, 7, and 14d after alkali burn. The data was analyzed by SPSS 20.0. RESULTS: The area of CNV was increasing at 1, 3, 5, 7, and 14d after alkali burn, and the peak point appear at 7d. The growth speed was decreased after 14d. SABC method told us that no HIF-1α and very tiny amount EPO was detected at normal rats' corneal. The expression of the two factors increased at 1d after alkali burn in corneal epithelium and endoderm. The results of RT-PCR showed that a few amounts of HIF-1α and EPO mRNA were detected at normal group. The expression of the two factors was increased at 3d after alkali burn, and the peak value was found at 7d, however, it was decreased at 14d. Statistical difference was found at different time(PCONCLUSION: HIF-1α and EPO is closely related to CNV.
Gal-Or, Orly; Livny, Eitan; Sella, Ruti; Nisgav, Yael; Weinberger, Dov; Livnat, Tami; Bahar, Irit
We aimed to evaluate the efficacy of subconjunctival aflibercept, a vascular endothelial growth factor trap compound, for the treatment of corneal neovascularization in a rat model. Chemical burn was produced in the central cornea of 31 male Sprague-Dawley rats. Animals were randomized to receive treatment with subconjunctival injection of 0.08 mL aflibercept (25 mg/mL), 0.05 mL bevacizumab (25 mg/mL), or 0.05 mL physiologic saline. Corneal neovascularization was evaluated on postinjury days 1, 3, 7, 9, and 13 by corneal photographs. The rats were killed on day 21 and samples were collected for histological and flat-mount immunofluorescence analyses. In all rats, vascular sprouting began on day 3, reached maximum density on days 7-9, and spontaneously regressed thereafter. Mean burn area in the central cornea comprised ∼15% of the total corneal area. The aflibercept group had a significantly smaller relative area of neovascularization than both control group (P < 0.05, 12.27 ± 9.91, 29.66 ± 9.96 days 7) and bevacizumab group (P < 0.05, 12.27 ± 9.91, 21.27 ± 8.19 days 7 and 15.5 ± 10.25, 32.38 ± 9.44 days 9; Mann-Whitney test). On histological study, hematoxylin and eosin staining revealed blood vessels extending to the central cornea in the control and bevacizumab groups and limited to the periphery in the aflibercept group. Immunofluorescence study with an endothelial marker revealed a smaller area of staining in the aflibercept group. Aflibercept effectively inhibits corneal neovascularization in a rat model of chemical burn-induced neovascularization and warrants further study for potential use in humans.
Inhibition of Corneal Neovascularization with the Combination of Bevacizumab and Plasmid Pigment Epithelium-Derived Factor-Synthetic Amphiphile INTeraction-18 (p-PEDF-SAINT-18 Vector in a Rat Corneal Experimental Angiogenesis Model
Full Text Available Bevacizumab, a 149-kDa protein, is a recombinant humanized monoclonal antibody to VEGF. PEDF, a 50-kDa glycoprotein, has demonstrated anti-vasopermeability properties. In this study, we demonstrated that the combination of bevacizumab and plasmid pigment epithelium-derived factor-synthetic amphiphile INTeraction-18 (p-PEDF-SAINT-18 has a favorable antiangiogenic effect on corneal NV. Four groups (Group A: 0 μg + 0 μg, B: 0.1 μg + 0.1 μg, C: 1 μg + 1 μg, and D: 10 μg + 10 μg of bevacizumab + p-PEDF-SAINT-18 were prepared and implanted into the rat subconjunctival substantia propria 1.5 mm from the limbus on the temporal side. Then, 1 μg of p-bFGF-SAINT-18 was prepared and implanted into the rat corneal stroma 1.5 mm from the limbus on the same side. The inhibition of NV was observed and quantified from days 1 to 60. Biomicroscopic examination, western blot analysis and immunohistochemistry were used to analyze the 18-kDa bFGF, 50-kDa PEDF and VEGF protein expression. No inhibition activity for normal limbal vessels was noted. Subconjunctival injection with the combination of bevacizumab and p-PEDF-SAINT-18 successfully inhibited corneal NV. The bFGF and PEDF genes were successfully expressed as shown by western blot analysis, and a mild immune response to HLA-DR was shown by immunohistochemistry. We concluded that the combination of bevacizumab and p-PEDF-SAINT-18 may have more potent and prolonged antiangiogenic effects, making it possible to reduce the frequency of subconjunctival.Bevacizumab, a 149-kDa protein, is a recombinant humanized monoclonalantibody to VEGF. PEDF, a 50-kDa glycoprotein, has demonstrated anti-vasopermeabilityproperties. In this study, we demonstrated that the combination of bevacizumaband plasmid pigment epithelium-derived factor-synthetic amphiphile INTeraction-18(p-PEDF-SAINT-18 has a favorable antiangiogenic effect on corneal NV. Four groups(Group A: 0 μg + 0 μg, B: 0.1 μg + 0.1 μg, C: 1 μg + 1 μg, and
Yin, Lan; Pi, Yu-Li
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 g...
Full Text Available AIM:To explore the suitable conditions in rapid model of corneal neovascularization(CNVafter thermal burn under different constant temperature in rabbit. METHODS: Total 45 New Zealand white rabbits were divided randomly into five groups(A, B, C, D, E. A groups: 100℃(n=10, B groups: 200℃(n=10, C groups: 300℃(n=10, D groups: 400℃(n=10, and E groups: control group(n=5. All left eyes of rabbits in A,B,C,D groups were induced corneal neovascularization by constant temperature burning device. The growth of CNV was observed by slit lamp microscope and the area of CNV were recorded on 4 th, 7 th, 14th, 30th days postoperatively. SPSS 19.0 statistical package was used for data analysis, and the data was recorded by mean±standard deviation. Comparison by analysis of variance was made by repeated measures in the area of neovascularization at each time point in groups. Statistical tests were considered significantly when P values were less than 0.05. RESULTS: On postoperative 4th, 7th, 14th, 30th days: no neovascularization was found after corneal thermal burn in A group, but only a few nebula left(n=2; the area of CNV were(9.16±1.45mm2,(37.73±5.49mm2,(62.44±7.54mm2,(40.28±7.39mm2 in B group respectively; and(11.45±1.04mm2,(44.51±4.64mm2,(66.13±4.13mm2,(43.04±2.33mm2 in C group respectively; and(13.23±0.86mm2,(47.26±4.59mm2,(67.57±4.56mm2,(45.59±4.44mm2 in D group respectively, and part corneal carbide(n=4was observed as well as corneal perforation(n=6were found on 3d in D group. No neovascularization was found in normal control group. Comparison of the areas of CNV at each time point between groups was statistically different, PPCOCLUSION: In 4 to 7d, the higher the temperature is, the more the neovascularization area of CNV are. It has no significant difference in 14 to 30d. But corneal carbide and corneal perforation are often found in 400℃ group, so its modeling failure rate is high. It is between 200℃ and 300℃ that
Yoon, Hyeon Jeong; Kim, Mee Kum; Seo, Kyung Yul; Ueta, Mayumi; Yoon, Kyung Chul
To investigate the effectiveness of combined photodynamic therapy with verteporfin and intrastromal injection of bevacizumab for the treatment of corneal neovascularization in patients with Stevens-Johnson syndrome (SJS). Eight eyes of eight patients with SJS having corneal neovascularization who were refractory to 1% prednisolone instillation received photodynamic therapy with verteporfin (6 mg/m 2 ) combined with intrastromal bevacizumab injection (2.5 mg/0.1 mL). Best-corrected visual acuity and intraocular pressure were assessed, and slit-lamp biomicroscopic examination was performed before treatment and at 1 week and every month. A chronic ocular manifestation score was assigned based on the involvement area or the severity before treatment. The cumulative length of corneal blood vessels and area of corneal neovascularization were measured by anterior segment photographs before and after treatment. At 3 and 6 months after treatment, all eyes showed regression of corneal neovascularization. Complete regression was achieved in five eyes (62.5%) and partial regression in three eyes (37.5%). Among five patients who were followed up for more than 1 year, two eyes maintained complete regression and one eye maintained partial regression at 1 year. However, two eyes with severe chronic ocular manifestation showed revascularization. Combined photodynamic therapy with intrastromal bevacizumab injection can effectively inhibit corneal neovascularization in patients with SJS. However, patients with severe chronic ocular manifestation may exhibit revascularization.
Full Text Available AIM: To compare the inhibitory effect of curcunmin and Avastin on the rat corneal neovascularization(CNV, and approach the mechanism of the curcunmin's inhibition. METHODS: CNV was established in thirty SD rats by alkaline burning. Rats were divided equally to group A and group B at random. In group A, right eyes were experimental group A1, treated by 40μmol/L curcunmin solution, and left eyes were control group A2, treated by 0.09% sodium chloride. In group B, right eyes were experimental group group B1, treated by 5g/L avastin, and left eyes were control group B2, treated by 0.09% sodium chloride. Cornea and aqueous humor were collected by time spot. The capillary vessels were study, and the expressions of VEGF were detected by Enzyme-Linked immunosorbnent Assay(ELISA. RESULTS: No toxic effects of the drugs were found. The capillary vessels in experimental group were less than those of control group(P<0.01. No statistical different of the capillary vessels between two drugs were found. The expressions of VEGF in experimental group were less than those in control group(P<0.01. The expressions of VEGF in B1 group were less than in group A1. CONCLUSION: The inhibitory effect to CNV of curcunmin and avastin have no statistical different in the experiment, but curcunmin has the less inhibitory effect to the expressions of VEGF than avastin. Curcunmin may have other mechanism in the inhibitory action on CNV.
Agarwal, Shweta; Angayarkanni, Narayanasamy; Iyer, Geetha; Srinivasan, Bhaskar; Natarajan, Radhika; Charola, Sanket; Arumugam, Sumathi; Padmanabhan, Prema
The aim of this study was to evaluate the effect of clinical and biochemical effects of subconjunctival bevacizumab injection in eyes with corneal neovascularization (CNV) due to varied etiologies. This prospective interventional case series included 12 eyes of 12 patients with CNV after failed therapeutic penetrating keratoplasty (4 eyes), viral keratitis (4 eyes), adherent leucoma (2 eyes), and pseudophakic bullous keratopathy (2 eyes). Each eye received 3 doses of 1.25 mg (0.05 mL) of bevacizumab at 1-month intervals. Morphological changes in neovascularization were evaluated at each visit by slit-lamp examination and corneal digital photography. Corneal buttons of 4 eyes that underwent optical penetrating keratoplasty after bevacizumab injections were analyzed for vascular endothelial growth factor (VEGF) expression and were compared with untreated vascularized and normal cadaveric donor corneas. Of the 12 patients, 10 were males and 2 were females. Four eyes received injections in the early phase of vascularization (12 weeks) of which 5 showed regression. The follow-up ranged from 1 to 16 months. Five eyes underwent optical penetrating keratoplasty after receiving the last dose of bevacizumab and maintained graft clarity with no episodes of rejection over a mean follow-up of 9.8 months. Four of these 5 corneal buttons analyzed for VEGF expression revealed clinically significant lower levels of expression as compared with the vascular untreated corneas. No local or systemic adverse effects were noted in any patient. Subconjunctival bevacizumab helps to regress CNV due to a decrease in corneal VEGF levels and might prove beneficial for use in clinical conditions leading to CNV.
Cano, Marisol del Valle; Karagiannis, Emmanouil D; Soliman, Mohamed; Bakir, Belal; Zhuang, Wenjuan; Popel, Aleksander S; Gehlbach, Peter L
Ocular neovascularization is the primary cause of blindness in a wide range of prevalent ocular diseases including proliferative diabetic retinopathy, exudative age-related macular degeneration, and retinopathy of prematurity, among others. Antiangiogenic therapies are starting to give promising results in these diseases. In the present study the antiangiogenic potential of an 18-mer peptide derived from type 1 thrombospondin repeat-containing protein WISP-1 (wispostatin-1) was analyzed in vitro with human retinal endothelial cell proliferation and migration assays. The peptide was also tested in vivo in the corneal micropocket and the laser-induced choroidal neovascularization (CNV) mouse models. Human retinal endothelial cells were treated with the WISP-1 peptide and in vitro migration and proliferation assays were performed. Also evaluated was the antiangiogenic effect of this peptide in vivo using the corneal micropocket assay and the laser-induced CNV model. Wispostatin-1 derived peptide demonstrated antimigratory and antiproliferative activity in vitro. Wispostatin-1 completely abolished bFGF-induced neovascularization in the corneal micropocket assay. The peptide also demonstrated significant inhibition of laser-induced CNV. An inhibitory effect of Wispostatin-1 on ocular neovascularization was found in vitro and in vivo. The identification of novel and potent endogenous peptide inhibitors provides insight into the pathogenesis of corneal and choroidal neovascularization. The results demonstrate potential for therapeutic application in prevalent ocular disease.
Full Text Available AIM: To investigate anti-angiogenic effects of polysulfated heparin endostatin (PSH-ES on alkali burn induced corneal neovascularization (NV in rabbits. METHODS: An alkali burn was made on rabbit corneas to induce corneal NV in the right eye of 24 rabbits. One day after burn creation, a 0.2 mL subconjunctival injection of 50 μg/mL PSH-ES, 50 μg/mL recombinant endostatin (ES, or normal saline was administered every other day for a total of 14d (7 injections. Histology and immunohistochemisty were used to examine corneas. Corneal NV growth was evaluated as microvessel quantity and corneal vascular endothelial growth factor (VEGF expression was measured by immunohistochemical assay. RESULTS: Subconjunctival injection of ES and PSH-ES resulted in significant corneal NV suppression, but PSH-ES had a more powerful anti-angiogenic effect than ES. Mean VEGF concentration in PSH-ES treated corneas was significantly lower than in ES treated and saline treated corneas. Histological examination showed that corneas treated with either PSH-ES or ES had significantly fewer microvessels than eyes treated with saline. Additionally corneas treated with PSH-ES had significantly fewer microvessels than corneas treated with ES. CONCLUSION: Both PSH-ES and recombinant ES effectively inhibit corneal NV induced by alkali burn. However, PSH-ES is a more powerful anti-angiogenic agent than ES. This research has the potential to provide a new treatment option for preventing and treating corneal NV.
Paranthan, Riya R; Bargagna-Mohan, Paola; Lau, Daniel L; Mohan, Royce
To develop an animal model for simultaneously eliciting corneal angiogenesis and retinal gliosis that will enable the assessment of inhibitor efficacy on these two pathological processes in separate anatomic sites of the ocular globe. Four to six week-old mice in a C57BL/6J background were anesthetized and 0.15 N NaOH was applied to the cornea, followed by mechanical scraping of the epithelium from limbus and central cornea. After this injury, mice were treated with vehicle or with an inhibitor (withaferin A [WFA]), which were delivered by intraperitoneal injection, to assess the pharmacological effects on angiogenesis and/or gliosis. Mice were sacrificed after 14 days and tissues (corneas and retinas) were prepared for analysis of corneal neovascularization and retinal gliosis by immunohistochemistry and western blotting, respectively. This protocol was also suited for studying earlier disease end points, for assessment of drug dose efficacy or genetic influences and the entire procedure and this analysis was completed in 16-17 days. Both corneal angiogenesis and retinal gliosis were maximally sustained at fourteen days following chemical and mechanical injury of the cornea. 1) Injured corneas showed abundant CD31+ staining, with new blood vessels branching out from the limbus to the central cornea. WFA treatment potently inhibited corneal neovascularization. 2) Retinal gliosis in injured mice was associated with upregulated expression of glial fibrillary acidic protein (GFAP) that appeared as polymeric filaments and soluble forms expressed in reactive Müller glial cells. WFA treatment potently downregulated the expression of soluble and filamentous GFAP; the latter protein was fragmented. We have developed a mouse model for investigating retinal gliosis and corneal neovascularization. We used this model to demonstrate the simultaneous inhibitory effects of WFA on both of these disease processes. Retinal gliosis occurs in several major degenerative conditions of
Zhang, Yun; Zhang, Ting; Ma, Xiaoyun; Zou, Jun
Corneal neovascularization may result in loss of corneal transparency and blindness. However, developing successful and inexpensive medical treatments for corneal neovascularization remains an unresolved issue. Recently, several studies have implicated miRNA functions in the regulation of cornea homeostasis. This study aimed to identify the miRNA expression profile in the neovascularized cornea after an alkali burn and to investigate the related underlying mechanisms. Here, alkali-burned corneas and matched normal tissues were pooled to perform miRNA sequencing. MiR-21 in alkali-burned cornea showed the greatest increment of abundance at 4 and 7 d after injury compared to the healthy cornea. The miR-21 expression was positively correlated with both the mRNA and protein level of key angiogenic factors including vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor-1α (HIF-1α). At 2 and 8 d after alkali burn, the mice received subconjunctival injections of antagomir-21 (1 or 5 nmol per injection). The injection of antagomir-21 (5 nmol) inactivated miR-21 and attenuated neovascularization progression by inhibiting the expression of VEGF-A and HIF-1α. Western blot analysis of the corneas demonstrated that antagomir-21 restored Sprouty 2/4 expression and silenced p-ERK activation. Therefore, these data reveal that antagomir-21 ameliorates the progression of corneal neovascularization likely via Sprouty 2/4-mediated inactivation of p-ERK. Delivery of antagomir-21 might be a potential therapeutic approach to prevent or treat visual loss caused by corneal neovascularization.
Yeung, Karen K; Yang, Helen J; Nguyen, Andrew L; Weissman, Barry A
The purpose of this study is to determine the peripheral oxygen transmissibility (pDk/t) and respective central oxygen transmissibility (cDk/t) in soft contact lenses (SCLs) which might preclude SCL-driven corneal neovascularization (NV) in healthy myopic SCL users. Twenty subjectively successful SCL-wearing patients who presented with asymptomatic but active peripheral corneal NV (not ghost vessels) were recruited as study patients. Twenty-one patients who did not have NV were similarly recruited as controls. Demographic data were collected. Corneal NV was documented and photographed. Current habitual SCLs were collected and thicknesses measured to allow for the calculation of both pDk/t and cDk/t and estimation of local tear oxygen tensions. No statistical differences between study and control groups in patient age, refraction, or the numbers of years, days per week, or hours per day patients reported SCL wear were identified. Statistically significant differences were found between the two groups for both pDk/t (P=0.006) and cDk/t (P=0.004): mean (±SD) pDk/t was 38.0±23.5 and 19.2±17.7 Fatt units for control and study corneas, respectively. Mean cDk/t were 80.0±54.4 and 36.8±33.1 Fatt units for control and study corneas, respectively. Peripheral tear oxygen tension that "protected" corneas from vascular filling was over 84 mm Hg. Maintaining a pDk/t above 30 to 40 Fatt units with daily wear SCLs should protect most normal corneas from NV as a complication of SCL wear.
Rajiv R Mohan
Full Text Available Decorin, small leucine-rich proteoglycan, has been shown to modulate angiogenesis in nonocular tissues. This study tested a hypothesis that tissue-selective targeted decorin gene therapy delivered to the rabbit stroma with adeno-associated virus serotype 5 (AAV5 impedes corneal neovascularization (CNV in vivo without significant side effects. An established rabbit CNV model was used. Targeted decorin gene therapy in the rabbit stroma was delivered with a single topical AAV5 titer (100 µl; 5×10(12 vg/ml application onto the stroma for two minutes after removing corneal epithelium. The levels of CNV were examined with stereomicroscopy, H&E staining, lectin, collagen type IV, CD31 immunocytochemistry and CD31 immunoblotting. Real-time PCR quantified mRNA expression of pro- and anti-angiogenic genes. Corneal health in live animals was monitored with clinical, slit-lamp and optical coherence tomography biomicroscopic examinations. Selective decorin delivery into stroma showed significant 52% (p<0.05, 66% (p<0.001, and 63% (p<0.01 reduction at early (day 5, mid (day 10, and late (day 14 stages of CNV in decorin-delivered rabbit corneas compared to control (no decorin delivered corneas in morphometric analysis. The H&E staining, lectin, collagen type IV, CD31 immunostaining (57-65, p<0.5, and CD31 immunoblotting (62-67%, p<0.05 supported morphometric findings. Quantitative PCR studies demonstrated decorin gene therapy down-regulated expression of VEGF, MCP1 and angiopoietin (pro-angiogenic and up-regulated PEDF (anti-angiogenic genes. The clinical, biomicroscopy and transmission electron microscopy studies revealed that AAV5-mediated decorin gene therapy is safe for the cornea. Tissue-targeted AAV5-mediated decorin gene therapy decreases CNV with no major side effects, and could potentially be used for treating patients.
Full Text Available Purpose: The aim of this study was to evaluate the inhibitory effect of different concentrations of KH902 eye drops on rabbit corneal neovascularization (CNV induced by alkali burn. Methods: Forty-eight adult rabbits were randomized into four groups after alkali burning: Group A (2.5 mg/ml, Group B (5 mg/ml, and Group C (10 mg/ml by different concentrations of KH902 eye drops and Group D by saline solution as control with three times a day for 2 weeks. At days 7, 14, and 28, the anterior segment photographs, confocal microscopy, and histopathology were performed to evaluate corneal opacity, neovascularization, inflammatory cell density, vessel size, and edema. Immunohistochemistry was applied to analyze the vascular endothelial growth factor (VEGF level. Results: (1 The CNV in the medicine-treated groups showed a reduction without obvious corneal side effects histologically. (2 Compared to the control group, the three medicine-treated groups showed a reduction in the VEGF levels and CNV areas on days 7, 14, and 28 and in the inflammatory cell density on days 14 and 28 (P 0.05. Conclusion: KH902 eye drops in lower concentration showed an obvious reduction of the CNV growing for rabbit corneal alkali burn without side effects.
Li, Zhanrong; Li, Jingguo; Zhu, Lei; Zhang, Ying; Zhang, Junjie; Yao, Lin; Liang, Dan; Wang, Liya
The aim of the present study was to investigate the inhibitory effects of celastrol-loaded nanomicelles (CNMs) on activated macrophage-induced corneal neovascularization (CNV) in rats and cytokine secretion in macrophages. Using an angiogenesis assay in vitro, we detected the effects of CNMs on human umbilical vein endothelial cell (HUVEC) migration and invasion. In addition, the expression levels of cytokines secreted from hypoxia-induced macrophages were assessed through cytokine array analysis. The expression of hypoxia-inducible factors-1α (HIF-1α), nuclear factor-kappa B p65 (NF-κB p65), phospho-nuclear factor-kappa B p65 (phospho-NF-κB p65), p38 mitogen-activated protein kinase (p38 MAPK), phospho-p38 MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2), and phospho-ERK1/2 was analyzed by western blotting. Activated macrophages were elicited through mineral oil lumbar injection, labeled with 1,19-dioctadecyl-3-3-39,39-tetramethylindocarbocyanine (DiI) and implanted into the corneal micro-pocket to induce CNV and to assess the antiangiogenic effect in rats. CNV was morphometrically analyzed using ImageJ software. Histopathological features were evaluated by immunofluorescence immunostaining for vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) on day 2 after surgery. In the present study, the results indicated that CNMs significantly inhibited the migration and invasion of HUVECs; remarkably attenuated the expression of VEGF, tumor necrosis factor-α, interleukin-1α, monocyte chemoattractant protein 1, cytokine-induced neutrophil chemoattractant 3, and MMP-9 protein; and downregulated ERK1/2, p38 MAPK, NF-κB activation, and HIF-1α expression in macrophages. The peritoneal cells elicited using mineral oil were highly purified macrophages, and the length and area of CNV were significantly decreased in the CNMs group compared with the control group. There was a significant reduction in the expression of VEGF and MMP-9 in
Elsheikh, Ahmed; Brown, Michael; Alhasso, Daad; Rama, Paolo; Campanelli, Marino; Garway-Heath, David
To determine the variation of corneal biomechanical properties with anatomical orientation. Strip specimens extracted from fresh porcine corneas were tested under uniaxial tension with strain rates representing static and dynamic loading conditions. The specimens were extracted from the vertical, horizontal, and 45 degrees diagonal directions. The load elongation results were used to derive the stress-strain behavior of each specimen. The average behavior for specimens taken in each anatomical direction was determined along with the effect of strain rate. Specimens from a small number of human corneas were included in the study to verify the findings. Specimens extracted from the vertical direction of porcine and human corneas demonstrated the highest strength (fracture stress) followed by horizontal then diagonal specimens. Vertical specimens were 10% to 20% stronger than horizontal specimens in porcine and human corneas. At low strain rates (1%/min), vertical specimens displayed similar stiffness (resistance to deformation) to horizontal specimens but greater stiffness than diagonal specimens. On increasing the strain rate to 500%/min, the stiffness behavior matched that of strength with vertical specimens being 10% to 20% stiffer than horizontal specimens in porcine and human corneas. The corneal anisotropic behavior is compatible with the preferential orientation of stromal fibrils in the vertical and horizontal directions. Quantifying the effect of this nonuniform fibril organization on corneal anisotropic behavior will be useful in developing numerical models of the cornea for applications where its integrity is compromised such as in simulating refractive surgery procedures.
Ogata, N; Otsuji, T; Matsushima, M; Kimoto, T; Yamanaka, R; Takahashi, K; Wada, M; Uyama, M; Kaneda, Y
The purpose of this study was to determine whether the inactivated hemagglutinating virus of Japan (HVJ)-liposome method can induce phosphorothioate oligonucleotides effectively into an experimentally-induced choroidal neovascularization of rats. We also examined whether antisense phosphorothioate oligonucleotides against VEGF could be induced into choroidal neovascularization as a therapeutic agent by the HVJ-liposome method. The experiments were conducted on a rat model of choroidal neovascularization. FITC-labeled phosphorothioate oligonucleotides were coencapsulated in liposomes. The liposomes were coated with the envelope of inactivated HVJ and injected into the vitreous cavity following photocoagulation of pigmented rat eyes. The eyes were removed following injection, fixed, frozen and cut into thin sections. Induction of oligonucleotides was observed under a laser confocal scanning microscope for fluorescence and the development of choroidal neovascularization was evaluated histopathologically. Phosphorothioate oligonucleotides were effectively induced into ganglion cells and into the cells of the choroidal neovascularization induced by laser photocoagulation. Highly effective induction of oligos was observed 3 to 14 days after intravitreal injection of HVJ-liposomes after which the level decreased. Antisense oligonucleotides against VEGF were induced specifically into cells in the choroidal neovascularization, however neovascularization was still observed. Phosphorothioate oligonucleotides can be effectively induced into ganglion cells, and specifically into cells in choroidal neovascularization. Although antisense oligonucleotides against VEGF failed to prevent choroidal neovascularization, the HVJ-liposome method provided a highly effective means of inducing antisense oligos for in vivo antisense therapy.
Elsheikh, Ahmed; Wang, Defu; Rama, Paolo; Campanelli, Marino; Garway-Heath, David
Hysteresis is a viscoelastic property characterized by the difference in behavior under loading and unloading. The aim of the study was to determine corneal hysteresis using experimental means. Twenty-nine human corneas with 50-95 year age were subjected to cycles of pressure loading and unloading. Two pressure application rates were adopted to approximate static and dynamic loading conditions. The behavior under both loading and unloading was found to stiffen with increased age. The unloading behavior appeared to be largely independent of the pressure level at which unloading started. The difference between the behavior patterns under loading and unloading was quantified and used as a measure of corneal hysteresis. The hysteresis area was significantly larger with faster loading and with decreased age. The trend for hysteresis to decrease with age is in agreement with previous clinical observations. Hysteresis was also found to increase with faster pressure application.
Preparation of arginine-glycine-aspartic acid-modified biopolymeric nanoparticles containing epigalloccatechin-3-gallate for targeting vascular endothelial cells to inhibit corneal neovascularization.
Chang, Che-Yi; Wang, Ming-Chen; Miyagawa, Takuya; Chen, Zhi-Yu; Lin, Feng-Huei; Chen, Ko-Hua; Liu, Guei-Sheung; Tseng, Ching-Li
Neovascularization (NV) of the cornea can disrupt visual function, causing ocular diseases, including blindness. Therefore, treatment of corneal NV has a high public health impact. Epigalloccatechin-3-gallate (EGCG), presenting antiangiogenesis effects, was chosen as an inhibitor to treat human vascular endothelial cells for corneal NV treatment. An arginine-glycine-aspartic acid (RGD) peptide-hyaluronic acid (HA)-conjugated complex coating on the gelatin/EGCG self-assembly nanoparticles (GEH-RGD NPs) was synthesized for targeting the α v β 3 integrin on human umbilical vein endothelial cells (HUVECs) in this study, and a corneal NV mouse model was used to evaluate the therapeutic effect of this nanomedicine used as eyedrops. HA-RGD conjugation via COOH and amine groups was confirmed by 1 H-nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The average diameter of GEH-RGD NPs was 168.87±22.5 nm with positive charge (19.7±2 mV), with an EGCG-loading efficiency up to 95%. Images of GEH-RGD NPs acquired from transmission electron microscopy showed a spherical shape and shell structure of about 200 nm. A slow-release pattern was observed in the nanoformulation at about 30% after 30 hours. Surface plasmon resonance confirmed that GEH-RGD NPs specifically bound to the integrin α v β 3 . In vitro cell-viability assay showed that GEH-RGD efficiently inhibited HUVEC proliferation at low EGCG concentrations (20 μg/mL) when compared with EGCG or non-RGD-modified NPs. Furthermore, GEH-RGD NPs significantly inhibited HUVEC migration down to 58%, lasting for 24 hours. In the corneal NV mouse model, fewer and thinner vessels were observed in the alkali-burned cornea after treatment with GEH-RGD NP eyedrops. Overall, this study indicates that GEH-RGD NPs were successfully developed and synthesized as an inhibitor of vascular endothelial cells with specific targeting capacity. Moreover, they can be used in eyedrops to inhibit angiogenesis in corneal NV
Scott W Cousins
Full Text Available The neovascular (wet form of age-related macular degeneration (AMD leads to vision loss due to choroidal neovascularization (CNV. Since macrophages are important in CNV development, and cytomegalovirus (CMV-specific IgG serum titers in patients with wet AMD are elevated, we hypothesized that chronic CMV infection contributes to wet AMD, possibly by pro-angiogenic macrophage activation. This hypothesis was tested using an established mouse model of experimental CNV. At 6 days, 6 weeks, or 12 weeks after infection with murine CMV (MCMV, laser-induced CNV was performed, and CNV severity was determined 4 weeks later by analysis of choroidal flatmounts. Although all MCMV-infected mice exhibited more severe CNV when compared with control mice, the most severe CNV developed in mice with chronic infection, a time when MCMV-specific gene sequences could not be detected within choroidal tissues. Splenic macrophages collected from mice with chronic MCMV infection, however, expressed significantly greater levels of TNF-α, COX-2, MMP-9, and, most significantly, VEGF transcripts by quantitative RT-PCR assay when compared to splenic macrophages from control mice. Direct MCMV infection of monolayers of IC-21 mouse macrophages confirmed significant stimulation of VEGF mRNA and VEGF protein as determined by quantitative RT-PCR assay, ELISA, and immunostaining. Stimulation of VEGF production in vivo and in vitro was sensitive to the antiviral ganciclovir. These studies suggest that chronic CMV infection may serve as a heretofore unrecognized risk factor in the pathogenesis of wet AMD. One mechanism by which chronic CMV infection might promote increased CNV severity is via stimulation of macrophages to make pro-angiogenic factors (VEGF, an outcome that requires active virus replication.
Diedrichs-Möhring, Maria; Leban, Johann; Strobl, Stefan; Obermayr, Franz; Wildner, Gerhild
We investigated the effect of PP-001, a new small molecule inhibitor of dihydro-orotate dehydrogenase in two experimental rat experimental autoimmune uveitis (EAU) models: a spontaneously relapsing-remitting model and a monophasic/chronic disease model that results in late chorioretinal neovascularization. Both of the diseases are induced by immunization with autoantigen peptides. Prevention was tested using daily oral applications of PP-001 after immunization with the retinal S-antigen peptide PDSAg (for induction of monophasic uveitis and neovascularization) or the interphotoreceptor retinoid-binding protein peptide R14 (for induction of spontaneously relapsing-remitting EAU). Treatment to inhibit relapses and neovascularization was tested using PP-001 daily after the first attack of R14-induced or after onset of PDSAg-induced EAU. Uveitis was graded clinically and histologically. The effect of PP-001 on cytokine secretion and proliferation was evaluated using rat T-cell lines. Preventive feeding of PP-001 abrogated both types of EAU. Starting treatment after the resolution of the first attack led to a significant reduction of the number and intensity of relapses in R14-induced EAU. PP-001-treatment initiated after onset or after peak of PDSAg-induced EAU significantly reduced neovascularization (as determined by histology). Proliferation of antigen-specific T-cell lines and secretion of IFN-γ, IL-17, IL-10, IP-10, and VEGF were efficiently suppressed by PP-001. We investigated a new dihydroorotate dehydrogenase inhibitor as treatment for primary and recurrent disease in relapsing-remitting and chronic rat models of experimental autoimmune uveitis. The small molecule compound PP-001 suppressed proliferation and cytokine secretion of autoreactive T cells (i.e., IFN-g, IL-17, and VEGF) and chorioretinal neovascularization in chronic EAU. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
Hirose, Tokihito; Nakajima, Masami; Kyou, Tetsuhiro; Yuzawa, Mitsuko
To evaluate an appropriate irradiative condition for selective occlusion of experimental choroidal neovascularization(CNV) with photodynamic therapy (PDT) using ATX-S 10 (Na). Experimental CNV was induced in monkey eyes by laser photocoagulation. PDT(dose of irradiative energy 40 to 80J/cm2) was performed after 3.5 mg/kg of body weight intravenous injections of ATX-S 10(Na). CNV and retinal vessel occlusion induced by PDT was evaluated by fluorescein angiography (FA) at 1 and 7 days after irradiation. If FA showed no fluorescein dye leakage from CNV at 1 and 7 days after irradiation, CNV was evaluated by histopathological analysis at 7 days after irradiation. Within 30 to 33 minutes after ATX-S 10(Na) injection and irradiation with 50 to 60 J/ cm2, FA showed no fluorescein dye leakage from CNV and no closure of retinal vessels at 1 and 7 days after irradiation. Light micrographs showed occluded CNV, and retinal vessels remained patent and there was no apparent change in the inner layer of the retina. Irradiative condition of ATX-S10 (Na) 3.5 mg/kg was appropriate 30 to 33 minutes after ATX-S 10(Na) injection and irradiation with 50 to 60 J/cm2.
Full Text Available AIM: To investigate the inhibition of the recombinant human endostatin adenavirus(Ad-Eson the experimental choroidal neovascularization(CNVmodels by intravitreous injection. METHODS: Experimental CNV models were induced by semiconductor laser in 30 male Brown Norway(BNrats and randomly divided into 3 groups with 10 rats in each group. At 21d after photocoagulation, the single administration group were given intravitreous injection with Ad-Es 0.01mL; the repeated administration group were given intravitreous injection with Ad-Es 0.01mL and a repeated injection 7d later; the saline control group were given intravitreous injection with saline 0.01mL. At 7d after final administration, the leakage of fundus fluorescein angiography(FFAwas observed. Various CNV areas were measured by using laser confocal microscopy of choroidal flatmount method. Pathology and ultrastructure were observed with light microscopy, the expressions of CD105 were measured by immunohistochemistry. RESULTS: The leakage of CNV of the administration group abviously decreased as compared with those in the saline group, the leakage of repeated administration group decreased compared with that of single administration group(PPCONCLUSION: Ad-Es can effectively inhibit semiconductor laser induced CNV in BN rats, and the inhibition effect of repeated administration group is better than that of single administration group. It may be a useful new method in the treatment of CNV.
Zheng, R; Jin, X; Yang, B; Li, B; Li, L; Xu, Z; Zhu, H
To investigate the effects of recombinant human epidermal growth factor (rhEGF) eye drops on corneal wound healing. Twenty-four white rabbits were randomly divided into 4 groups, 6 rabbits 12 eyes each. Anterior keratectomy of 8 mm in diameter and 1/3 cornea in thickness was performed on each eye. Each of the following concentrations of rhEGF: 1, 10, 100 microg/ml eye drops or normal saline (control) was applied four times daily for a week respectively for one group. The wound area was determined by computer imaging analysis. The mean epithelial healing rate of rhEGF 1, 10, 100 microg/ml groups was 9.31, 9.96, 9.31 mm(2)/day respectively, significantly greater than 8.11 mm(2)/day of the control group. The action of rhEGF of 10 microg/ml was somewhat better than that of 1 or 100 microg/ml, and no significant difference was noticed among the three rhEGF groups. Moderate inflammation and corneal neovascularization were induced in the rhEGF 100 microg/ml treated group. rhEGF 1 - 10 microg/ml can accelerate corneal wound healing in the rabbit with no adverse side-effects. It may be used to treat serious corneal trauma and ulcer clinically.
Torres, P. F.; de Vos, A. F.; van der Gaag, R.; Martins, B.; Kijlstra, A.
Allograft rejection is the main cause of corneal graft failure. T lymphocytes and macrophages have been implied to be involved in corneal rejection, but little is known about the molecular mechanism in this process. In this study, cytokine mRNA expression in the cornea was analysed during
Galindo, Sara; Herreras, José M; López-Paniagua, Marina; Rey, Esther; de la Mata, Ana; Plata-Cordero, María; Calonge, Margarita; Nieto-Miguel, Teresa
Limbal stem cells are responsible for the continuous renewal of the corneal epithelium. The destruction or dysfunction of these stem cells or their niche induces limbal stem cell deficiency (LSCD) leading to visual loss, chronic pain, and inflammation of the ocular surface. To restore the ocular surface in cases of bilateral LSCD, an extraocular source of stem cells is needed to avoid dependence on allogeneic limbal stem cells that are difficult to obtain, isolate, and culture. The aim of this work was to test the tolerance and the efficacy of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) to regenerate the ocular surface in two experimental models of LSCD that closely resemble different severity grades of the human pathology. hAT-MSCs transplanted to the ocular surface of the partial and total LSCD models developed in rabbits were well tolerated, migrated to inflamed tissues, reduced inflammation, and restrained the evolution of corneal neovascularization and corneal opacity. The expression profile of the corneal epithelial cell markers CK3 and E-cadherin, and the limbal epithelial cell markers CK15 and p63 was lost in the LSCD models, but was partially recovered after hAT-MSC transplantation. For the first time, we demonstrated that hAT-MSCs improve corneal and limbal epithelial phenotypes in animal LSCD models. These results support the potential use of hAT-MSCs as a novel treatment of ocular surface failure due to LSCD. hAT-MSCs represent an available, non-immunogenic source of stem cells that may provide therapeutic benefits in addition to reduce health care expenses. Stem Cells 2017;35:2160-2174. © 2017 AlphaMed Press.
Full Text Available Malignant hypertension develops in some cases of hypertension but not in others. We hypothesized that an impaired neovascularization and a reduced capillary supply characterizes the malignant course of experimental hypertension. Two-kidney, one-clip renovascular hypertension was induced in rats; controls (sham were sham operated. To distinguish malignant hypertension from non-malignant hypertension, we considered two factors: weight loss, and the number of typical vascular lesions (onion skin lesions and fibrinoid necroses per kidney section of the nonclipped kidney. Animals in the upper half for both criteria were defined as malignant hypertensives. After 5 weeks, mean arterial blood pressure was elevated to the same degree in malignant hypertension and non-malignant hypertension whereas plasma renin and aldosterone were significantly higher in malignant hypertensives. The expression of plasminogen activator inhibitor-1 was elevated (up to 14-fold in non-malignant but significantly more increased (up to 36-fold in malignant hypertensive rats, compared to sham. As a bioassay for neovascularization, the area of granulation tissue ingrowth in polyvinyl discs (implanted subcutaneously was reduced in malignant hypertension compared to non-malignant hypertension and sham, while there was no difference between non-malignant hypertension and sham. The number of renal and left ventricular capillaries was significantly lower in malignant hypertension compared to non-malignant hypertension, as was the number of proliferating endothelial cells. We conclude that an impaired neovascularization and capillarization occurs in malignant renovascular hypertension but not in the non-malignant course of the disease despite comparable blood pressure levels. This might contribute to the unique vascular lesions and progressive target organ damage observed in malignant hypertension.
Huang, Hu; Vasilakis, Panagiotis; Zhong, Xiufeng; Shen, Ji-Kui; Geronatsiou, Katerina; Papadaki, Helen; Maragoudakis, Michael E.; Gartaganis, Sotirios P.; Vinores, Stanley A.
Purpose. Parstatin is a 41-mer peptide formed by proteolytic cleavage on activation of the PAR1 receptor. The authors recently showed that parstatin is a potent inhibitor of angiogenesis. The purpose of the present study was to evaluate the therapeutic effect of parstatin on ocular neovascularization. Methods. Choroidal neovascularization was generated in mice using laser-induced rupture of Bruch's membrane and was assessed after 14 days after perfusion of FITC-dextran. Oxygen-induced retinal neovascularization was established in neonatal mice by exposing them to 75% O2 at postnatal day (P)7 for 5 days and then placing them in room air for 5 days. Evaluation was performed on P17 after staining with anti-mouse PECAM-1. The effect of parstatin was tested after intravitreal administration. The effects of subconjunctival-injected parstatin on corneal neovascularization and inflammation in rats were assessed 7 days after chemical burn-induced corneal neovascularization. Retinal leukostasis in mice was assessed after perfusion with FITC-conjugated concanavalin A. Results. Parstatin potently inhibited choroidal neovascularization with an IC50 of approximately 3 μg and a maximum inhibition of 59% at 10 μg. Parstatin suppressed retinal neovascularization with maximum inhibition of 60% at 3 μg. Ten-microgram and 30-μg doses appeared to be toxic to the neonatal retina. Subconjunctival parstatin inhibited corneal neovascularization, with 200 μg the most effective dose (59% inhibition). In addition, parstatin significantly inhibited corneal inflammation and VEGF-induced retinal leukostasis. In all models tested, scrambled parstatin was without any significant effect. Conclusions. Parstatin is a potent antiangiogenic agent of ocular neovascularization and may have clinical potential in the treatment of angiogenesis-related ocular disorders. PMID:20538980
Wijdh, RH; van Rij, G
PURPOSE: To investigate the effect of circular keratotomy depth and diameter on corneal astigmatism. METHODS: High astigmatism was induced in 25 human donor eyes by an anterior radial 7-0 silk suture across the corneoscleral limbus. With a 6.0, 6.5, 7.0, or 7.5 mm trephine, a 0.3 mm deep circular
Full Text Available We established a sustained vasohibin-1 (a 42-kDa protein, delivery device by a novel method using photopolymerization of a mixture of polyethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and collagen microparticles. We evaluated its effects in a model of rat laser-induced choroidal neovascularization (CNV using a transscleral approach. We used variable concentrations of vasohibin-1 in the devices, and used an enzyme-linked immunosorbent assay and Western blotting to measure the released vasohibin-1 (0.31 nM/day when using the 10 μM vasohibin-1 delivery device [10VDD]. The released vasohibin-1 showed suppression activity comparable to native effects when evaluated using endothelial tube formation. We also used pelletized vasohibin-1 and fluorescein isothiocyanate-labeled 40 kDa dextran as controls. Strong fluorescein staining was observed on the sclera when the device was used for drug delivery, whereas pellet use produced strong staining in the conjunctiva and surrounding tissue, but not on the sclera. Vasohibin-1 was found in the sclera, choroid, retinal pigment epithelium (RPE, and neural retina after device implantation. Stronger immunoreactivity at the RPE and ganglion cell layers was observed than in other retinal regions. Significantly lower fluorescein angiography (FA scores and smaller CNV areas in the flat mounts of RPE-choroid-sclera were observed for the 10VDD, VDD (1 μM vasohibin-1 delivery device, and vasohibin-1 intravitreal direct injection (0.24 μM groups when compared to the pellet, non-vasohibin-1 delivery device, and intravitreal vehicle injection groups. Choroidal neovascularization can be treated with transscleral sustained protein delivery using our novel device. We offer a safer sustained protein release for treatment of retinal disease using the transscleral approach.
Szaflik, J; Fryczkowski, A W; Liberek, I; Czubak, M; Brix, M; Broniek, G; Fryczkowski, P
To check post penetrating keratoplasty (PK) corneal wound healing characteristics after epidermal growth factor (EGF) application and to compare it with controls. The PK was performed in the group of 72 young, healthy New Zealand rabbits (36 females and 36 males). Slit-lamp examination, tonometry and corneal topography by Tomey's corneal modeling system (TMS-1) were carried out before and after surgery. The PK was performed in both eyes. Half of animals were used as a bilateral donor for the other half, with a rule: right eye cornea to the right eye and left eye cornea to the left eye. As a result, after completed surgery 36 rabbits had bilateral grafts. The animals were divided into 3 equal groups (12 in each). Two drops of the human recombined EGF dissolved in the saline solution with concentration varied from 500 to 1500 ng in each drop were applied to the right eye according to schedule. The left eye was used as a control and did not receive EGF. Time of observation varied from 24 hours to 6 months. The tensinometry and the histopathologic study--light and electron microscopy were performed to determine corneal scarring. The wound healing pattern after PK was characteristic and constant in each group. The corneal wound healing significantly accelerated in the EGF treated group of rabbits compared with the controls (p times/day, after two weeks of application we noted increase of the wound strength up to 600 folds, comparing with controls. Well-organized scar was histologically seen on the 21st post-surgery day. The post-operative corneal astigmatism was less expressed in the eyes treated with EGF comparing to controls. These preliminary results of our experimental study indicated accelerated effect on the corneal wound healing after PK with topical, low dose hrEGF application. Clinical observation of utilization of similar low doses of the hrEGF after PK--is in progress.
Effects of topical 0.2% Cyclosporine A on corneal neovascularization induced by xenologous amniotic membrane implantation into a corneal stroma micropocket of rats Efeitos do uso tópico da Ciclosporina A (CsA 0,2% na neovascularização corneal induzida pelo implante de membrana amniótica xenógena em microbolsa no estroma da córnea de ratos
Juliana F. Milani
Full Text Available The objective of the study was to evaluate the topical effects of 0.2% Cyclosporine A (CsA on corneal neovascularization of rats following surgical implantation of equine amniotic membrane into a corneal stroma micropocket. The implantation of xenologous amniotic membrane was performed bilaterally in 90 rats. In the same day of the surgery each right eye started receiving topical CsA twice a day. The left eye received no medication and served as a control. The evaluation of corneal neovascularization was performed by computerized image analysis and histopathological evaluation at 1, 3, 7, 15, 30 and 60 days postoperatively. For the image analysis 10 animals were used per time period, and for the histopathological examination, five animals were used per time period. Image analysis found that corneal neovascularization began on the 3rd postoperative day, reached its peak on the 7th day, and then progressively and rapidly decreased. Statistic analysis indicated that neovascularization of the CsA treated eye on the 7th day was significantly higher than that observed in untreated eyes. On the 30th day, however, this pattern was reversed with the neovascularization observed in the CsA treated eyes declining to the low levels observed on the 3rd day. The degree of neovascularization in the untreated eyes on the 30th day declined to the baseline levels found on day 3 at the 60th day. Histopathological analysis indicated that deposition of collagen in the implanted tissue was completed by the 15th day. Therefore, we concluded that (1 equine amniotic membrane in rat corneal stroma produced an intense neovascularization until the 15th day postoperatively and then regressed, (2 deposition of collagen of the implanted tissue was completed on the 15th day postoperatively, and (3 use of CsA was associated with increase in the corneal neovascularization initially, followed by a quick and intense regression.Este estudo teve como objetivo a avaliação dos
Kumagai, Yuta; Kurokawa, Manae S; Ueno, Hiroki; Kayama, Maki; Tsubota, Kazuo; Nakatsuji, Norio; Kondo, Yasushi; Ueno, Satoki; Suzuki, Noboru
We previously reported the successful transplantation of corneal epithelium-like cells derived from mouse embryonic stem (ES) cells onto injured mouse cornea. Here, we tested whether nonhuman primate ES cells have ability to differentiate into corneal epithelial cells and whether monkey ES cell-derived corneal epithelium-like cells were applicable for the experimental transplantation to damaged cornea. Monkey ES cells were cultivated on type IV collagen-coated dishes for various days to induce differentiation into corneal epithelium-like cells. The differentiation was evaluated by reverse transcription-polymerase chain reaction and immunostaining. The corneal epithelium-like cells were transplanted to the injured mouse cornea. Reconstitution of the corneal epithelium was evaluated by immunostaining. The cells cultured on type IV collagen showed cobblestone-like appearance resembling epithelial cells. They expressed messenger RNA of pax6, p63, E-cadherin, CD44, proliferating cell nuclear antigen, keratin 3, and keratin 12. Protein expressions of pax6, keratin 3/12, p63, proliferating cell nuclear antigen, E-cadherin, and CD44 were confirmed by immunostaining. When the corneal epithelium-like cells were transplanted, they adhered to the corneal stroma, leading to formation of multiple cell layers. The grafted cells were stained with anti-human nuclear protein antibody, which cross-reacted with nuclei of monkey cells but not with those of mouse cells. They retained the expressions of keratin 3/12, E-cadherin, and CD44. We induced corneal epithelium-like cells from monkey ES cells with moderate efficiency. The cells were successfully transplanted onto the injured mouse cornea. This is the first demonstration that nonhuman primate ES cells were induced to differentiate into corneal epithelium-like cells, which were applicable for transplantation to an animal model of corneal injury.
Alcalde, I; Íñigo-Portugués, A; Carreño, N; Riestra, A C; Merayo-Lloves, J M
The purpose of this study is to assess the effectiveness of the topical application of cacicol regenerating agent (RGTA) in an experimental model of corneal ulcer after photorefractive keratectomy (PRK) in mice. Mice were subjected to PRK surgery with a 2.0mm ablation zone on the central cornea and 45mm of depth on a VISX Star S2 excimer laser. Corneas were treated topically with cacicol drops 1hour and 48hours after injury. Control groups received balanced salt solution (BSS) in the same dosage. Clinical and histopathological events were evaluated at 1, 2, 3 and 7 days after surgery. Sections obtained through the central region of the corneas were used to analyze the histopathological events of injured and healed corneas. αSMA (myofibroblast transformation), E cadherin (assembly of epithelial cells) and neuronal class III β-tubulin (innervation) were performed. Corneas treated topically with cacicol for 7 days showed a greater degree of transparency compared to controls. cacicol treated corneas showed improved epithelial cytoarchitecture. Analysis of αSMA profiles in the stroma showed that cacicol reduced or delayed the presence of myofibroblasts in the stroma compared to BSS (P<0.001). Finally, a putative neuroregenerative effect of cacicol was found in corneas subjected to an experimental PRK lesion. In some cases some interindividual variability could be observed due to the design of the experimental model. This is a limitation to consider, despite the statistical significance of the data. In a model of laser induced surgical lesions in the cornea, topical application of an RGTA (i.e. cacicol) could be involved in avoiding myofibroblast scarring formation and promoting nerve regeneration. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.
Full Text Available Abstract Introduction Keratoconus and choroidal neovascularization can occur as a result of dysfunction of the epithelium and its basement membrane. Case presentation A 17-year-old Asian man, who was diagnosed with myopic choroidal neovascularization in both eyes and who subsequently underwent intravitreal injection of ranibizumab (Lucentis® five times over six months, presented with further vision decrease and pain in his right eye. Examination showed corneal steepening and stromal edema in the inferocentral cornea of his right eye, both of which were indicative of advanced keratoconus with acute hydrops. Corneal topography also showed features consistent with keratoconus in his left eye. Fluorescein angiography and optical coherence tomography revealed choroidal neovascularization-associated subretinal hemorrhages and lacquer cracks in both eyes. Conclusion Keratoconus and choroidal neovascularization, possibly resulting from dysfunction of the epithelium and its basement membrane, can occur together in the same individual. This would suggest a possible connection in pathogenesis between these two conditions.
Full Text Available ... What Is Corneal Laceration? Corneal Laceration Symptoms What Causes Corneal Laceration? Corneal Laceration Diagnosis Corneal Laceration Treatment ... the corneal laceration is deep enough it can cause a full thickness laceration. This is when the ...
Full Text Available ... What Is Corneal Laceration? Corneal Laceration Symptoms What Causes Corneal Laceration? Corneal Laceration Diagnosis Corneal Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué ...
Deb-Joardar, Nilanjana; Thuret, Gilles; Dumollard, Jean-Marc; Absi, Lena; Campos-Guyotat, Lydia; Peoc'h, Michel; Garraud, Olivier; Gain, Philippe
Transmission of donor malignancy to the recipient could be one of the most disastrous complications of corneal grafting. Because of the scarcity of donor tissue and the lack of sufficient scientific evidence, the harvest of donor tissues from deaths due to systemic malignancy is permitted. This study was conducted to investigate the possible transmission of donor metastatic disease via corneal tissue preserved in organ culture (OC) conditions. The viability of four frequent human cancer cell lines (lung, breast, skin, and colon) was studied in OC. Various inoculums of cancer cells labeled with the membrane marker PKH67 were seeded on donor corneas and preserved in OC, followed by cell-tracking studies, histopathology, and immunohistochemistry. HLA matching of the dissected Descemet's membrane (DM) of preserved corneas was conducted, to demonstrate cell adherence. Primary cell culture was performed to confirm the viability of adherent tumor cells. Viability tests showed a poor but persistent survival of cancer cells after 2 weeks in OC. Cell tracking, histopathology, and immunohistochemistry demonstrated cancer cell adherence to donor endothelium. HLA typing of the DM of preserved corneas revealed the presence of cancer cell alleles. Primary culture of the DM showed cell proliferation that was identical with the original cancer cell line, according to HLA studies. The findings demonstrate that under laboratory conditions, metastatic cancer cells adhere to donor corneal tissue, survive, and retain proliferative capacity during storage in OC. Cell lines differ in their viability potential, as well as the pattern of adherence to donor endothelium. Further in vivo experimentation in laboratory animals is need to determine the safety of such harvests.
Wong, Yin-zhi; Lam, Andrew K C
This study investigated the influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis (CH) and the corneal resistance factor (CRF) in a group of normal Chinese persons. Ninety-five participants were recruited and data from the eye with higher corneal astigmatism were analysed. The anterior corneal curvature was measured by corneal topography. The Goldmann-correlated intraocular pressure (IOPg), corneal-compensated intraocular pressure (IOPcc), CH and CRF at different meridians (default horizontal position, 10°, 20° and 30° along the superotemporal and inferonasal meridians) were obtained from an ocular response analyser. The corneal powers at these specific meridians also were calculated. At the default position, the IOPg and CRF had weak correlations with corneal astigmatism, while the IOPcc and CH were not significantly correlated with corneal astigmatism. Both the IOPg and IOPcc were measured significantly higher at the default position. The CH and CRF were lower at the default position but the difference in the CRF from obliquity could not reach statistical significance. The CH was not significantly correlated with the corneal power at all meridians. The CRF correlated with the corneal power only at 30° superotemporal. Corneal astigmatism and head tilt did not have much effect on the measurement of CH and the CRF, both of which were lowest along the horizontal meridian. Clinically, the difference was small. The influence of corneal power on CH and the CRF was minimal. © 2011 The Authors. Clinical and Experimental Optometry © 2011 Optometrists Association Australia.
Laborante, A; Buzzonetti, L; Longo, C
Massive corneal edema disrupts the fine architecture of corneal stroma that guarantees its transparency, causing opacities that seriously impair clear vision and are usually solved by corneal transplant. Corneal cross-linking, a treatment developed to halt keratoconus progression, results in a loss of water and a compaction of corneal stroma. It might therefore be useful to improve the pathologic edematous condition of some corneas, ameliorating visual acuity and allowing more time for a surgical procedure of keratoplasty. Six patients with visual impairing corneal edemas further to lens phacoemulsification, penetrating keratoplasty, or post-infective neovascularization were treated with corneal cross-linking alone, or in combination with amniotic membrane apposition with or without anti-angiogenic therapy. All patients partly resolved the edematous condition, improving both corneal transparency and visual acuity. Corneal cross-linking appears to be a useful method to treat massive corneal edemas, so that keratoplasty can be at least delayed, and need not to be an emergency treatment in these cases.
Yang, Min; Du, Gai-ping; Wang, Li-qiang; Wang, Xiao-ping; Cui, Fu-zhai; Lu, Yu-jie; Huang, Yi-fei
To investigate the expression level of metalloproteinases-2(MMP-2) and Collagen in a hydroxyapatite surfaced-modified of three Pan type titanium keratoprosthesis after that implanted into the corneal stroma of rabbits, further evaluate its biological compatibility. Experimental study. Twenty-four New Zealand white rabbits, 2.0-2.5 kg, were respectively divided into three groups. Surgery was performed in right eye of all animals. skirt of HA-Ti and Ti were respectively inserted into the corneal stroma of rabbit of experimental group A and group B; only a sack was made without implantation in control group C . Cornea edema and corneal neovascularization were observed at scheduled times after operation; animals were sacrificed 2, 4 and 16 weeks after operation and their cornea was removed and examined under light microscopy; the surface of skirt was observed under scanning electron microscope. During the study period, all skirts were stable without infected, dissolved and excluded. Different degree of cornea edema and neovascularization was revealed after surgery. MMP-2 were absent in the normal corneal matrix. The expression level of MMP-2 in group A was higher than group C at all time points (F = 6.083, P collagen and yellow red type I collagen, 16 weeks corneal mainly for bright red when within the collagen type I, still have a small amount of collagen type III. Rabbit cornea implanted HA-Ti skirts cause MMP-2 activation, continuous high expression didn't cause the cornea to dissolve; Collagen -III turned into collagen-I gradually in the extracellular matrix around the skirts. Hydroxyapatite modified titanium for Keratoprosthesis promoted the corneal neovascularization and improve the interfacial bio integration of skirt and host cornea.
Cosar, C Banu; Kucuk, Mutlu; Celik, Ekrem; Gonen, Tansu; Akyar, Isin; Serteser, Mustafa; Tokat, Fatma; Ince, Umit
To determine the effects of corneal collagen cross-linking (CXL) on the penetration of topical 0.5% moxifloxacin, on the number of colony-forming units (CFUs) in the cornea, and on the clinical course in a rabbit eye model of experimentally induced Pseudomonas aeruginosa keratitis. In this prospective animal study, experimental Pseudomonas corneal ulcers were induced in 56 corneas of 28 albino New Zealand rabbits. The corneas were randomly divided into the following 4 groups: the control group (14 eyes), the MOX group (moxifloxacin) (14 eyes), the MOX + CXL group (14 eyes), and the CXL group (14 eyes). On day 4 of the experiment, the eyes in the control group were enucleated and CFU counting was performed. On day 10 of the experiment, all eyes were enucleated and CFU counting was performed. In the MOX and MOX + CXL groups, the moxifloxacin level in the cornea, aqueous humor, iris, plasma, and serum was measured by reverse-phase high-performance liquid chromatography. The difference in the corneal CFU count between the MOX group and the MOX + CXL group was not significant (P = 0.317). Clinical improvement was greatest in the MOX + CXL group (P < 0.001). The mean corneal moxifloxacin level was 0.391 ± 0.09 μg·mg in the MOX group versus 0.291 ± 0.09 μg·mg in the MOX + CXL group; as such, CXL did not have a significant effect on antibiotic penetrance (P = 0.386). Clinical improvement was greatest in the MOX + CXL group. The synergistic effect of CXL on corneal ulcer treatment is not through antibiotic penetrance.
Maruyama, Yuko; Ikeda, Yoko; Yokoi, Norihiko; Mori, Kazuhiko; Kato, Hiroaki; Ueno, Morio; Kinoshita, Shigeru; Sotozono, Chie
The primary side effects associated with 0.1% brimonidine tartrate (BT) ophthalmic solution with sodium chlorite are allergic conjunctivitis, blepharitis, and conjunctival hyperemia. However, cornea-related side effects are rare. In this study, we report 2 similar cases in which corneal neovascularization, corneal infiltration, and corneal opacity developed after BT eye-drop use. Retrospective report of 2 cases of corneal infiltration after BT eye-drop use. Case 1 involved a 78-year-old woman with follicular conjunctivitis, corneal neovascularization, and infiltration in her left eye after unilateral instillation of BT eye drops in that eye. Case 2 involved a 75-year-old woman with bilateral corneal neovascularization and infiltration after instillation of BT eye drops. In both cases, the corneal complications were deemed to be side effects of BT, so those eye drops were replaced with 0.1% fluorometholone eye drops. After replacement, blepharitis and corneal neovascularization successfully resolved; however, a layer of opacity remained across the transparent layer of the cornea in both cases. We encountered 2 cases of corneal and conjunctival complications that developed as side effects after BT eye-drop use, thus indicating that strict attention should be paid to the possibility of side effects after initiation of antiglaucoma eye-drop use.
Full Text Available ... Corneal Laceration? Corneal Laceration Diagnosis Corneal Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué Es una Laceración de la Córnea? Written By: Daniel ...
Ariza-Gracia, M Á; Ortillés, Á; Cristóbal, J Á; Rodríguez Matas, J F; Calvo, B
Tonometers are intended to determine the intraocular pressure (IOP) and the quality of corneal tissue. In contrast to the physiological state of stress of the cornea, tonometers induce non-physiological bending stress. Recently, the use of a single experiment to calibrate a set of corneal mechanical properties was suggested to be an ill-posed problem. Thus, we propose a numerical-experimental protocol that uses inflation and indentation experiments simultaneously, restricting the optimization space to circumvent the ambiguity of the fitting. For the first time, both corneal behaviors, i.e., biaxial tension (physiological) and bending (non-physiological), are taken into account. The experimental protocol was performed using an animal model (New Zealand rabbit's cornea). The patient-specific geometry and IOP were registered using a MODI topographer (CSO, Italy) and an applanation tonometer, respectively. The mechanical response was evaluated using inflation and indentation experiments. Subsequently, the optimal set of material properties is identified via an inverse finite element method. To validate the methodology, an in vivo incisional refractive surgery (astigmatic keratotomy, AK) is performed on four animals. The optical outcomes showed a good agreement between the real and simulated surgeries, indicating that the protocol can provide a reliable set of mechanical properties that enables further applications and simulations. After a reliable ex vivo database of inflation experiments is built, our protocol could be extended to humans. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available AIM:To investigate the appropriate methods to establish corneal alkali chemical injury on rats. METHODS:The rats(n=87were randomly divided into three groups. Corneal alkali injury was induced by placing 1mol/L NaOH soaked filter paper on the limbus of right cornea for 20 seconds(group A, n=34or 40 seconds(group B, n=23, and on the central axis of the right cornea for 40 seconds(group C, n=30respectively. Corneal transparency, corneal ulceration, and corneal neovascularization were observed and recorded under slit- lamp biomicroscope on day 7 post-operation. RESULTS: Incidence of corneal ulceration, corneal perforation and positive rate of corneal fluorescein staining in limbal corneal injury groups(group A and Bwere significantly higher than that of central corneal injury group(group C(P<0.05. Incidence of corneal ulceration and corneal perforation in group B was significantly higher than group A(P<0.05. Corneal neovascularization was observed in all three groups. CONCLUSION: Corneal alkali burns induced by 3mm diameter central cornea injury are fit for the study of corneal neovascularization, while those induced by limbus injury for 20 seconds are fit for the study on limbal stem cells deficiency.
Alió del Barrio, Jorge L; Chiesa, Massimo; Gallego Ferrer, Gloria; Garagorri, Nerea; Briz, Nerea; Fernandez-Delgado, Jorge; Sancho-Tello Valls, Maria; Botella, Carmen Carda; García-Tuñón, Ignacio; Bataille, Laurent; Rodriguez, Alejandra; Arnalich-Montiel, Francisco; Gómez Ribelles, Jose L; Antolinos-Turpín, Carmen M; Gómez-Tejedor, Jose A; Alió, Jorge L; De Miguel, Maria P
Currently available keratoprosthesis models (nonbiological corneal substitutes) have a less than 75% graft survival rate at 2 years. We aimed at developing a model for keratoprosthesis based on the use of poly(ethyl acrylate) (PEA)-based copolymers, extracellular matrix-protein coating and colonization with adipose-derived mesenchymal stem cells. Human adipose tissue derived mesenchymal stem cells (h-ADASC) colonization efficiency of seven PEA-based copolymers in combination with four extracellular matrix coatings were evaluated in vitro. Then, macroporous membranes composed of the optimal PEA subtypes and coating proteins were implanted inside rabbit cornea. After a 3-month follow-up, the animals were euthanized, and the clinical and histological biointegration of the implanted material were assessed. h-ADASC adhered and survived when cultured in all PEA-based macroporous membranes. The addition of high hydrophilicity to PEA membranes decreased h-ADASC colonization in vitro. PEA-based copolymer containing 10% hydroxyethyl acrylate (PEA-HEA10) or 10% acrylic acid (PEA-AAc10) monomeric units showed the best cellular colonization rates. Collagen plus keratan sulfate-coated polymers demonstrated enhanced cellular colonization respect to fibronectin, collagen, or uncoated PEAs. In vivo implantation of membranes resulted in an extrusion rate of 72% for PEA, 50% for PEA-AAc10, but remarkably of 0% for PEA-HEA10. h-ADASC survival was demonstrated in all the membranes after 3 months follow-up. A slight reduction in the extrusion rate of h-ADASC colonized materials was observed. No significant differences between the groups with and without h-ADASC were detected respect to transparency or neovascularization. We propose PEA with low hydroxylation as a scaffold for the anchoring ring of future keratoprosthesis. © 2014 Wiley Periodicals, Inc.
Pinsard, L; Malet, F; Colin, J; Touboul, D
The endothelio-descemetic interface (EDI) of a deep anterior lamellar keratoplasty (DALK) may become the locus of a neovascular proliferation. Bevacizumab (Avastin) is an antiangiogenic alternative available for curative treatment in deep corneal neovascularization. We report the case of a 49-year-old woman who had received two arcuate relaxing incisions for high astigmatism after DALK. She developed graft rejection associated with significant neovascular stromal invasion in the EDI of the graft-host interface. Two subconjunctival injections of bevacizumab 1 month apart as well as thermocauterization of the feeding vessel were necessary and effective. No recurrence has been observed after 2 years of follow-up. Corneal neovascularization can be a cause of DALK rejection. A combination of anti-antiangiogenic and physical methods may abort graft rejection and permanently restore graft function. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
... Español Eye Health / Eye Health A-Z Corneal Ulcer Sections What Is a Corneal Ulcer? Corneal Ulcer ... Diagnosis Corneal Ulcer Treatment What Is a Corneal Ulcer? Leer en Español: ¿Qué es una Úlcera de ...
Kiilgaard, J.F.; Andersen, Mads V. Nis; Wiencke, A.K.
ophthalmology, age-related macular degeneration, Bruch's membrane, retinal pigment epithelium, choroidal neovascularization, subretinal neovascularization......ophthalmology, age-related macular degeneration, Bruch's membrane, retinal pigment epithelium, choroidal neovascularization, subretinal neovascularization...
Touboul, D; Salin, F; Mortemousque, B; Courjaud, A; Chabassier, P; Mottay, E; Léger, F; Colin, J
Despite progress in mechanical microkeratomes used in refractive surgery, mechanical complications during cutting of the cornea still occur. Cutting by laser could reduce these complications and to date, the femtosecond laser is the only potential candidate for this purpose. Our study reports preliminary results with a femtosecond microkeratome for cutting porcine corneas ex vivo. We first examined the fundamental principles of the interaction between the femtosecond laser and the corneal stroma, including the volume of tissue lesions, the laser breakdown threshold of the stroma and the laser ablation selectivity. We then analyzed the quality of cutting corneal flaps with the laser, focusing on collateral tissue effects and the roughness of the interfaces observed both histologically and with scanning electron microscopy. The photoablative and photodisruptive effects were very similar with the femtosecond laser. This characteristic is specific to ultrashort impulsion photodisruptor lasers and allows for a very precise surgical procedure. The laser-induced breakdown threshold of porcine corneal stroma was found to be 0.55 J/cm2. Collateral tissue lesions were on the submicrometer level. The roughness of the stromal bed was optimal for postage stamp cutting, providing very many contiguous points of impact which were as spherical as possible. Corneal photodisruption with a femtosecond laser is reproducible and extremely accurate. The optomechanical parameters involved with this technique require great technological skill and should be placed in experienced hands.
Kim, Jong Won; Lim, Chae Woong; Kim, Bumseok
Epidemiological studies have indicated that smoking is a pivotal risk factor for the progression of several chronic diseases. Nicotine, the addictive component of cigarettes, has powerful pathophysiological properties in the body. Although the effects of cigarette smoking on corneal re-epithelialization have been studied, the effects of nicotine on corneal wound healing-related neovascularization and fibrosis have not been fully demonstrated. The aim of this study was to evaluate the effects of chronic administration of nicotine on corneal wound healing following acute insult induced by an alkali burn. BALB/C female mice randomly received either vehicle (2% saccharin) or nicotine (100 or 200 μg/ml in 2% saccharin) in drinking water ad libitum. After 1 week, animals were re-randomized and the experimental group was subjected to a corneal alkali burn, and then nicotine was administered until day 14 after the alkali burn. A corneal alkali burn model was generated by placing a piece of 2 mm-diameter filter paper soaked in 1N NaOH on the right eye. Histopathological analysis and the expression level of the pro-angiogenic genes vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP9) revealed that chronic nicotine administration enhanced alkali burn-induced corneal neovascularization. Furthermore, the mRNA expression of the pro-fibrogenic factors α-smooth muscle actin (αSMA), transforming growth factor-β (TGF-β), and collagen α1 (Col1) was enhanced in the high-concentration nicotine-treated group compared with the vehicle group after corneal injury. Immunohistochemical analysis also showed that the αSMA-positive area was increased in chronic nicotine-treated mice after corneal alkali burn. An in vitro assay found that expression of the α3, α7, and β1 nicotinic acetylcholine receptor (nAChR) subunits was significantly increased by chemical injury in human corneal fibroblast cells. Moreover, alkali-induced fibrogenic gene expression and
Topical 1% Nalbuphine on corneal sensivity and epitheilization after experimental lamellar keratectomy in rabbits Nalbufina 1% tópica sobre a sensibilidade e a epitelização corneal após ceratectomia lamelar experimental
Miguel Ladino Silva
Full Text Available The present study was aimed to evaluate the effects of topical 1% nalbuphine on corneal sensitivity and re-epithelialization, after lamellar keratectomy in rabbits. All protocols were approved by the Animal Care Comission of São Paulo State University (Protocol 028793-08 and were conducted in accordance with the Institutional Animal Committee and the Association for Research in Vision and Ophthalmology (ARVO statement for the use of animals in research. Surgeries were performed on the left eye (Nalbuphine Group and on the right eye (Control Group. Two groups were formed (n=10 and corneas received either 30µl of 1% nalbuphine (NG or 30µl of 0,9% saline (CG. Treatments occurred at 7, 11, 15 and 19 hours. After the surgery, the corneas were stained with fluorescein and photographed daily; corneal touch threshold (CTT was assessed with Cochet-Bonnet aesthesiometer, at 7 and 19 hours, 20 minutes after treatments. Data were statistically compared with repeated measures ANOVA and Bonferroni post-hoc test, and T test (P0.05; however, a higher area under the curve for both parameters was observed in the NG (2771, in comparison to CG (2164. Topical 1% nalbuphine did not change significantly corneal sensitivity and re-epithelialization, after experimental lamellar keratectomy in rabbits.Avaliaram-se os efeitos da nalbufina 1% sobre o limiar de sensibilidade corneal (LSC e a epitelização corneal em coelhos submetidos à ceratectomia lamelar unilateral. Os procedimentos foram aprovados pela Comissão de Ética no Uso de Animais da Faculdade de Ciências Agrarias e Veterinárias da Universidade Estadual Paulista (Protocolo no 028793-08, de acordo com as normas do Institutional Animal Committee and the Association for Research in Vision and Ophthalmology (ARVO. Conceberam-se dois grupos (n=10 e os olhos foram tratados com 30µl de Nalbufina 1% (Olho esquerdo - GN ou com 30µl de solução salina (Olho direito - GC, às 7, 11, 15 e 19 horas das
Full Text Available Following laser vision correction, corneal keratocytes must repopulate areas of cell loss by migrating through the intact corneal stroma, and this can impact corneal shape and transparency. In this study, we evaluate 3D culture models for simulating this process in vitro. Buttons (8 mm diameter were first punched out of keratocyte populated compressed collagen matrices, exposed to a 3 mm diameter freeze injury, and cultured in serum-free media (basal media or media supplemented with 10% FBS, TGFb1 or PDGF BB. Following freeze injury, a region of cell death was observed in the center of the constructs. Although cells readily migrated on top of the matrices to cover the wound area, a limited amount of cell migration was observed within the constructs. We next developed a novel “sandwich” model, which better mimics the native lamellar architecture of the cornea. Using this model, significant migration was observed under all conditions studied. In both models, cells in TGFb and 10% FBS developed stress fibers; whereas cells in PDGF were more dendritic. PDGF stimulated the most inter-lamellar migration in the sandwich construct. Overall, these models provide insights into the complex interplay between growth factors, cell mechanical phenotypes and the structural properties of the ECM.
Full Text Available Pathological neovascularization is a hallmark of late stage neovascular (wet age-related macular degeneration (AMD and the leading cause of blindness in people over the age of 50 in the western world. The treatments focus on suppression of choroidal neovascularization (CNV, while current approved therapies are limited to inhibiting vascular endothelial growth factor (VEGF exclusively. However, this treatment does not address the underlying cause of AMD, and the loss of VEGF's neuroprotective can be a potential side effect. Therapy which targets the key processes in AMD, the pathological neovascularization, vessel leakage and inflammation could bring a major shift in the approach to disease treatment and prevention. In this study we have demonstrated the efficacy of such broad spectrum antiangiogenic therapy on mouse model of AMD.Lodamin, a polymeric formulation of TNP-470, is a potent broad-spectrum antiangiogenic drug. Lodamin significantly reduced key processes involved in AMD progression as demonstrated in mice and rats. Its suppressive effects on angiogenesis, vascular leakage and inflammation were studied in a wide array of assays including; a Matrigel, delayed-type hypersensitivity (DTH, Miles assay, laser-induced CNV and corneal micropocket assay. Lodamin significantly suppressed the secretion of various pro-inflammatory cytokines in the CNV lesion including monocyte chemotactic protein-1 (MCP-1/Ccl2. Importantly, Lodamin was found to regress established CNV lesions, unlike soluble fms-like tyrosine kinase-1 (sFlk-1. The drug was found to be safe in mice and have little toxicity as demonstrated by electroretinography (ERG assessing retinal and by histology.Lodamin, a polymer formulation of TNP-470, was identified as a first in its class, broad-spectrum antiangiogenic drug that can be administered orally or locally to treat corneal and retinal neovascularization. Several unique properties make Lodamin especially beneficial for ophthalmic
Full Text Available Purpose: The present experimental study aimed to investigate the effects of intracameral trypan blue (TB on oxidative stress parameters and apoptosis in corneal tissue. Methods: Thirty rats were randomly assigned to three groups of 10 rats each: the sham group (Group 1; control group (Group 2; and treatment group (Group 3. The control group was administered 0.01 cc of balanced salt solution. The treatment group was administered 0.006 mg/0.01 cc of TB. The total antioxidant status (TAS and total oxidant status (TOS in corneal tissue and blood were measured and the oxidative stress index (OSI was calculated. Finally, corneal tissue histopathology was evaluated using staining for caspase-3 and -8, and apoptotic activity was examined. Results: The TAS, TOS and OSI levels in the blood samples were not significantly different (p>0.05 for all. Compared with the sham and control groups, the TOS and OSI levels in corneal tissue were significantly different in the treatment group (p0.05. Immunohistochemical staining for caspase-3 and caspase-8 demonstrated higher apoptotic activity in the TB group than in the sham and control groups. Conclusion: The present study showed that intracameral TB injection is safe systematically but may be toxic to corneal tissue, as demonstrated using oxidative stress parameters and histopathological evaluation.
Full Text Available Annie Chan, Douglas R Fredrick, Theodore Leng Department of Ophthalmology, Byers Eye Institute at Stanford University, Stanford University School of Medicine, Stanford, CA, USA Abstract: We report a case of neovascularization secondary to Purtscher's retinopathy that showed minimal improvement with photocoagulation treatment. A 14-year-old boy with a history of cerebellar medulloblastoma presented with blurry vision and floaters after being struck by a motor vehicle while riding his bike. At presentation, visual acuity was 20/400 in his right eye and counting fingers in his left eye. Fundus examination showed disk edema, retinal whitening, and retinal hemorrhages in both eyes. Optical coherence tomography demonstrated thinning of the temporal retina and disruption of the inner segment–outer segment junction of the photoreceptor layer in the right eye and thickening and edema of the nasal macula, as well as a central foveal hyper-reflectivity, in the left eye. At the initial visit, there was no ischemia or neovascularization (NV. One month later, the patient developed NV of the disk and ischemia in the mid-periphery of the left eye. The patient underwent treatment with pan-retinal photocoagulation. The NV regressed, but visual outcome remained poor at his 5-month follow-up visit. Keywords: Purtscher's retinopathy, neovascularization, laser photocoagulation, disk edema
Full Text Available ... or apply pressure to eye avoid giving aspirin, ibuprofen or other non-steroidal, anti-inflammatory drugs. These ... lost sight from a corneal scar as a child. Now that I’m older, will a corneal ...
Full Text Available ... rub or apply pressure to eye avoid giving aspirin, ibuprofen or other non-steroidal, anti-inflammatory drugs. ... lost sight from a corneal scar as a child. Now that I’m older, will a corneal ...
Full Text Available ... Now that I’m older, will a corneal transplant help me? May 15, 2015 Why Do My ... May Have A Future Alternative to Full Corneal Transplantation Nov 29, 2016 Combating Eye Injuries from Air ...
Mooren, Pepijn; Gobin, Laure; Bostan, Nezahat; Wouters, Kristien; Zakaria, Nadia; Mathysen, Danny G P; Koppen, Carina
To evaluate endothelial cytotoxicity after exposure of human corneas to ultraviolet-A (UVA) (λ = 365 nm; 5.4 J/cm(2)) in an experimental ex vivo corneal cross-linking setting. Sixteen pairs of human donor corneas were cut into two pieces. One piece of each cornea was treated with 0.025% riboflavin solution prior to UVA irradiation (5 minutes; 18 mW/cm(2)), whereas the other piece was not irradiated but treated with riboflavin (right eye) or preservation medium (left eye). By irradiating from the endothelial side, the UVA dosage applied to endothelial cells exceeded at least eight times the cytotoxic threshold established in animal models (0.65 J/cm(2)). Endothelial cell counts were performed by two independent investigators after storage (4 to 5 days at 31 °C) and staining (trypan blue, alizarin red). Normality (Q-Q plot; Shapiro-Wilk test) and equivalence (mixed-effects modeling with a 10% equivalence threshold) of the endothelial cell counts of the different groups were evaluated. Equivalence of mean endothelial cell density between both groups was observed: 2,237 ± 208 cells/mm(2) in UVA-irradiated pieces and 2,290 ± 281 cells/mm(2) in control pieces (mean difference of 53 ± 240 cells/mm(2) between both groups). Despite direct irradiation of human donor endothelium using the clinical dosage for cross-linking, equivalence in endothelial cell counts was observed between irradiated tissues and controls. Ex vivo human corneal endothelial cells seem to be far more resistant to riboflavin-enhanced UVA irradiation than previously estimated by animal experiments. Copyright 2016, SLACK Incorporated.
Full Text Available The purpose of this study is to demonstrate the feasibility of DALK using a decellularized corneal matrix obtained by HHP methodology. Porcine corneas were hydrostatically pressurized at 980 MPa at 10°C for 10 minutes to destroy the cells, followed by washing with EGM-2 medium to remove the cell debris. The HHP-treated corneas were stained with H-E to assess the efficacy of decellularization. The decellularized corneal matrix of 300 μm thickness and 6.0 mm diameter was transplanted onto a 6.0 mm diameter keratectomy wound. The time course of regeneration on the decellularized corneal matrix was evaluated by haze grading score, fluorescein staining, and immunohistochemistry. H-E staining revealed that no cell nuclei were observed in the decellularized corneal matrix. The decellularized corneal matrices were opaque immediately after transplantation, but became completely transparent after 4 months. Fluorescein staining revealed that initial migration of epithelial cells over the grafts was slow, taking 3 months to completely cover the implant. Histological sections revealed that the implanted decellularized corneal matrix was completely integrated with the receptive rabbit cornea, and keratocytes infiltrated into the decellularized corneal matrix 6 months after transplantation. No inflammatory cells such as macrophages, or neovascularization, were observed during the implantation period. The decellularized corneal matrix improved corneal transparency, and remodelled the graft after being transplanted, demonstrating that the matrix obtained by HHP was a useful graft for corneal tissue regeneration.
Klintworth Gordon K
Full Text Available Abstract The term corneal dystrophy embraces a heterogenous group of bilateral genetically determined non-inflammatory corneal diseases that are restricted to the cornea. The designation is imprecise but remains in vogue because of its clinical value. Clinically, the corneal dystrophies can be divided into three groups based on the sole or predominant anatomical location of the abnormalities. Some affect primarily the corneal epithelium and its basement membrane or Bowman layer and the superficial corneal stroma (anterior corneal dystrophies, the corneal stroma (stromal corneal dystrophies, or Descemet membrane and the corneal endothelium (posterior corneal dystrophies. Most corneal dystrophies have no systemic manifestations and present with variable shaped corneal opacities in a clear or cloudy cornea and they affect visual acuity to different degrees. Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or X-linked recessive Mendelian mode of inheritance. Different corneal dystrophies are caused by mutations in the CHST6, KRT3, KRT12, PIP5K3, SLC4A11, TACSTD2, TGFBI, and UBIAD1 genes. Knowledge about the responsible genetic mutations responsible for these disorders has led to a better understanding of their basic defect and to molecular tests for their precise diagnosis. Genes for other corneal dystrophies have been mapped to specific chromosomal loci, but have not yet been identified. As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. Main differential diagnoses include various causes of monoclonal gammopathy, lecithin-cholesterol-acyltransferase deficiency, Fabry disease, cystinosis, tyrosine transaminase deficiency, systemic lysosomal storage
Huang, Qiong; Hu, Yanhua; Jiang, Fagang; Chen, Hong
To investigate whether the TGF-beta 1 plasmid DNA carried by lipofectamine could be introduced into cultured rabbit corneal epithelial cells, specific expression of the plasmid pMAM TGF-beta 1 in the cultured corneal epithelial cells was studied. Two days after 12 h of transfection of pMAMT-GF-beta 1 mediated by lipofectamine into the cultured corneal epithelial cells, the TGF-beta 1 protein expression specific for pMAMTGF-beta 1 in the cells was detected by means of immunohistochemical staining and the positive rate was 23.37%. The results suggested that foreign plasmid DNA could be effectively delivered into cultured rabbit corneal epithelial cells by means of lipofectamine, and this will provide a promising method of studying TGF-beta 1 on the mechanism of physiology and pathology concerned with corneal epithelial cells.
Wang, Liqiang; Ma, Ruijue; Du, Gaiping; Guo, Huiling; Huang, Yifei
Silk proteins represent a unique choice in the selection of biomaterials that can be used for corneal tissue engineering and regenerative medical applications. We implanted helicoidal multilamellar arginine-glycine-aspartic acid-functionalized silk biomaterials into the corneal stroma of rabbits, and evaluated its biocompatibility. The corneal tissue was examined after routine hematoxylin-eosin staining, immunofluorescence for collagen I and III, and fibronectin, and scanning electron microscopy. The silk films maintained their integrity and transparency over the 180-day experimental period without causing immunogenic and neovascular responses or degradation of the rabbit corneal stroma. Collagen I increased, whereas Collagen III and fibronectin initially increased and then gradually decreased. The extracellular matrix deposited on the surface of the silk films, tightly adhered to the biomaterial. We have shown this kind of silk film graft has suitable biocompatibility with the corneal stroma and is an initial step for clinical trials to evaluate this material as a transplant biomaterial for keratoplasty tissue constructs. © 2014 Wiley Periodicals, Inc.
Junko Yoshida; Thomas Heflin; Andrea Zambrano; Qing Pan; Huan Meng; Jiangxia Wang; Stark, Walter J.; Daoud, Yassine J.
Purpose: Gamma irradiated corneas in which the donor keratocytes and endothelial cells are eliminated are effective as corneal lamellar and glaucoma patch grafts. In addition, gamma irradiation causes collagen cross inking, which stiffens collagen fibrils. This study evaluated gamma irradiated corneas for use in corneal transplantations in a rabbit model comparing graft clarity, corneal neovascularization, and edema. Methods: Penetrating keratoplasty was performed on rabbits using four ty...
José Luiz Laus
Full Text Available A comparative study of conjunctival pedicle and corneal autografts, for experimental healing of superficial keratectomies in dogs (Canis familiaris was performed. It was carried out by using 24 animals, and the technical procedures were analysed according to clinical, histologic and scanning electron microscopy parameters, in early and late postoperative periods. The obtained results are believed to represent feasible methods of proteresis, applied to the healing ophthalmic surgery. There were few, irrelevant differences between the two tested techniques.
R. L. Sampaio
Full Text Available Fibrin glue has been researched as an alternative method for tissue synthesis and is known for its capability to promote hemostasis at the application site, good approximation of wound edges and fast healing. The current study consisted in the application of fibrin glue derived from snake venom as treatment for experimental corneal ulcers. Twenty-one dogs had their corneas experimentally prepared through lamellar keratectomy (of standardized diameter and depth. Animals were divided into seven groups of three animals each. Six experimental groups were periodically evaluated and collection was carried out on the 1st, 3rd, 7th, 15th, 30th and 60th post-operative days, whereas one control group was evaluated throughout the experiment. Analyses consisted in the clinical evolution and in the histopathological study of all operated on eyes. Results indicated that fibrin glue was efficient in repairing keratectomy wounds in dogs and contributed to an earlier healing phenomenon, avoiding edema formation and keeping corneal clearness. The use of fibrin glue derived from snake venom showed to be easy to apply, feasible with animal models and of low cost, avoiding the lesion progress and allowing fast and appropriate corneal healing.
Marcos, Susana; Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos
The combination of air-puff systems with real-time corneal imaging (i.e. Optical Coherence Tomography (OCT), or Scheimpflug) is a promising approach to assess the dynamic biomechanical properties of the corneal tissue in vivo. In this study we present an experimental system which, together with finite element modeling, allows measurements of corneal biomechanical properties from corneal deformation imaging, both ex vivo and in vivo. A spectral OCT instrument combined with an air puff from a non-contact tonometer in a non-collinear configuration was used to image the corneal deformation over full corneal cross-sections, as well as to obtain high speed measurements of the temporal deformation of the corneal apex. Quantitative analysis allows direct extraction of several deformation parameters, such as apex indentation across time, maximal indentation depth, temporal symmetry and peak distance at maximal deformation. The potential of the technique is demonstrated and compared to air-puff imaging with Scheimpflug. Measurements ex vivo were performed on 14 freshly enucleated porcine eyes and five human donor eyes. Measurements in vivo were performed on nine human eyes. Corneal deformation was studied as a function of Intraocular Pressure (IOP, 15-45 mmHg), dehydration, changes in corneal rigidity (produced by UV corneal cross-linking, CXL), and different boundary conditions (sclera, ocular muscles). Geometrical deformation parameters were used as input for inverse finite element simulation to retrieve the corneal dynamic elastic and viscoelastic parameters. Temporal and spatial deformation profiles were very sensitive to the IOP. CXL produced a significant reduction of the cornea indentation (1.41x), and a change in the temporal symmetry of the corneal deformation profile (1.65x), indicating a change in the viscoelastic properties with treatment. Combining air-puff with dynamic imaging and finite element modeling allows characterizing the corneal biomechanics in-vivo.
Torres, R M; Merayo-Lloves, J; Jaramillo, M A; Galvis, V
To review the corneal biomechanic concepts and to analyse, clarify and understand their relevance in refractive surgery. A literature review has been done using different databases. Corneal biomechanic concepts are not new and are applied implicitly in numerous surgical procedures. Their origin is related to tonometry studies, but they gained in popularity when they were linked to the treatment of keratoconus, a pathology in which the mechanical properties of the cornea are altered. Factors determining corneal stability were thus defined. Corneal biomechanics have also been used following refractive surgery to study post-operative keratectasia and to improve ablation patterns, which ignores the corneal response. The new ablation systems need to include the biomechanical factors, which motivate research conducted in physical-mathematical models and in corneal wound healing, improving our knowledge about the corneal biomechanical response. The corneal biomechanic concepts have gained in popularity with the advent of refractive surgery, although they did exist previously. Their relevance is linked to improvements in the ablation systems used in an attempt to obtain more accurate and reliable results.
Full Text Available ... Answers How often and for how long should I use a hair dryer to treat my Fuchs’ dystrophy? May 06, 2017 I lost sight from a corneal scar as a child. Now that I’m older, will a corneal transplant help me? ...
Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué Es una Laceración de la Córnea? Written ...
Full Text Available ... Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask ... Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration Sections What Is Corneal Laceration? ...
Full Text Available PURPOSE: To investigate the protective effects of interleukin-1 receptor antagonist (IL-1ra gene transfer in a rat model of corneal graft rejection. METHODS: We constructed a recombinant plasmid (pcDNA3.1-hIL-1ra with high IL-1ra expression in eukaryotic cells. Using a Wistar-SD rat model of corneal graft rejection, we examined the effects of IL-1ra in vivo after cationic polymer jetPEI-mediated nonviral gene delivery. Four groups were included: negative controls (group I, n = 20, pcDNA3.1-hIL-1ra corneal stromal injection (group II, n = 34, pcDNA3.1-hIL-1ra anterior chamber injection (group III, n = 34, and 500 µg/ml IL-1ra protein subconjunctiva injection (group IV, n = 20. IL-1ra expression after transfection was evaluated by real-time polymerase chain reaction (RT-PCR and western blotting. The rejection indices of corneal grafts were analysed in the different groups. The expression levels of transforming growth factor β1 (TGF-β1, inflammatory chemokines including RANTES, interleukin-1 (IL-1 and the numbers of CD4+ and CD8+ T cells in the grafts were determined by biochemical assays at different time points after corneal transplantation. RESULTS: Various degrees of inflammatory cell infiltration and graft neovascularisation were observed by histopathology. After injecting the pcDNA3.1-hIL-1ra plasmid into the cornea, IL-1ra mRNA and protein expression was detected in the corneal stroma and reached a peak on day 3. The graft survival curves indicated that the corneal transparency rates of grafts in the IL-1ra gene-treated group and the IL-1ra protein-treated group were higher compared with the untreated group (P<0.05. During the period of acute rejection, TGF-β1, RANTES, IL-1α and IL-1β levels in the grafts in the IL-1ra treatment groups were lower than the control group (P<0.05. CD4+ and CD8+ T cell counts were reduced significantly in the corneal grafts of groups II, III and IV compared with group I (P<0.05. CONCLUSION
Ruban, Vasanthakumar V; Archana, Philip T; Sundararajan, Mahalingam; Geraldine, Pitchairaj; Thomas, Philip A
Combined antifungal and antioxidant therapy may help to reduce oxidative stress in fungal keratitis. Experimental Fusarium solani keratitis was induced by application of F. solani conidia to scarified cornea (right eye) of 16 rabbits (another four rabbits were negative controls [Group I]). Five days later, F. solani-infected animals began receiving hourly topical saline alone (Group II), voriconazole (10 mg/mL) alone (Group III), epigallocatechin gallate (EGCG, 10 mg/mL) alone (Group IV) or voriconazole and EGCG (Group V). Twenty days post-inoculation, corneal lesions were graded. After animal sacrifice, excised corneas underwent histopathological and microbiological investigations. Corneal tissue levels/activities of interleukin 1 beta (IL-1β) and tumour necrosis factor alpha (TNF-α) gene mRNA transcripts, matrix metalloproteinase (MMP) 2 and 9 proteins, malondialdehyde (MDA) and reduced glutathione (GSH), and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were also measured. Clinical and histopathological scores (severity of corneal lesions; [P Groups IV and III > Groups V and I. Mean SOD, CAT, GPx and GSH levels (P solani keratitis, as manifested by improved clinical, histological, microbiological and molecular parameters. © 2017 Blackwell Verlag GmbH.
Seitz, B; Behrens, A; Langenbucher, A
In the review period, limitations of individual Placido disk-based topography systems have been studied and new principles, such as raster photogrammetry, pancorneal slit topography, laser holographic interferometry, and confocal laser scanning topography, have been introduced for laboratory or clinical work. Both Fourier analysis and Zernike decomposition of topographic height data seem to be powerful new tools for cross-sectional analysis of complex topographic corneal images, such as after cataract surgery, penetrating keratoplasty, and refractive surgery, as well as for longitudinal studies of corneal changes, such as in schoolchildren. Subdividing into rational optical components may improve consistency and standardization of topography data from different systems. Topography-based flying-spot-mode excimer laser photoablation after Zernike decomposition of topography height data has been proposed for correction of irregular corneal astigmatism. Topography-based central power measurements are of increasing value for intraocular lens power calculation before cataract surgery in eyes with irregular corneal surfaces, such as in keratoconus or after refractive surgery procedures. Quantitative and qualitative classification of corneal topography maps after corneal transplantation following conventional mechanical and nonmechanical trephination or after refractive surgery may lead to a better understanding of impaired visual acuity despite a clear graft or despite significantly reduced ametropia or corneal astigmatism.
A new image processing strategy is detailed for the simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. A technique for locally mapping tumor perfusion parameters using skeletonized neovascular data is also introduced. Simulated images were used to test the neovascular skeletonization technique and variance (error) of relevant parametric estimates. Preliminary DCE-US image datasets were collected in 6 female patients diagnosed with invasive breast cancer and using a Philips iU22 ultrasound system equipped with a L9-3 MHz transducer and Definity contrast agent. Simulation data demonstrates that neovascular morphology parametric estimation is reproducible albeit measurement error can occur at a lower signal-to-noise ratio (SNR). Experimental results indicate the feasibility of our approach to performing both tumor perfusion and neovascular morphology measurements from DCE-US images. Future work will expand on our initial clinical findings and also extent our image processing strategy to 3-dimensional space to allow whole tumor characterization.
Full Text Available BIGH3 gene plays an important role in ocular diseases. On the one hand, it is closely related to the occurrence of corneal diseases. BIGH3 gene can inhibit corneal neovascularization, lead to corneal dystrophy, participate in keratoconus formation. On the other hand, it can lead to the formation of neovascularization in diabetic retinopathy. The latest experiments show that TGF beta secreted by macrophages can promote the expression of BIGH3 mRNA and BIGH3 protein, and promote apoptosis of retinal endothelial cells and pericytes, which leads to the formation of neovascularization in diabetic retinopathy. This article will describe the new progress of BIGH3 gene in ocular diseases from several aspects as mentioned above.
Ferreira, A E R; Castro, B F M; Vieira, L C; Cassali, G D; Souza, C M; Fulgêncio, G O; Ayres, E; Oréfice, R L; Jorge, R; Silva-Cunha, A; Fialho, S L
To evaluate the antiangiogenic activity of bevacizumab-loaded polyurethane using two animal models of neovascularization. The percentage of blood vessels was evaluated in a chicken chorioallantoic membrane model (n=42) and in the rabbit cornea (n=24) with neovascularization induced by alkali injury. In each model, the animals were randomly divided into the groups treated with the bevacizumab-loaded polyurethane device, phosphate-buffered-saline (negative control) and bevacizumab commercial solution (positive control). Clinical examination, as well as histopathological and immunohistochemical evaluation, were performed in the rabbit eyes. Microvascular density in hot spot areas was determined in semi-thin sections of corneal tissue by hematoxylin-eosin staining and factor VIII immunohistochemistry. Immunohistochemical analysis was also performed to evaluate VEGF expression. In the evaluated models, the use of bevacizumab (Avastin®) and the bevacizumab-loaded polyurethane device led to similar results with regard to inhibition of neovascularization. In the chorioallantoic membrane model, the bevacizumab-loaded polyurethane device reduced angiogenesis by 50.27% when compared to the negative control group. In the rabbit model of corneal neovascularization, the mean density of vessels/field was reduced by 46.87% on analysis of factor VIII immunohistochemistry photos in the bevacizumab-loaded polyurethane device group as compared to the negative control (PBS) sections. In both models, no significant difference could be identified between the bevacizumab-loaded polyurethane device and the positive control group, leading to similar results with regard to inhibition of neovascularization. The present study shows that the bevacizumab-loaded polyurethane device may release bevacizumab and inhibit neovascularization similarly to commercial bevacizumab solution in the short-term. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Full Text Available ... by something sharp flying into the eye. It can also be caused by something striking the eye ... If the corneal laceration is deep enough it can cause a full thickness laceration. This is when ...
Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... 27, 2015 Dark Spot in Vision After Blunt Trauma Dec 21, 2014 Pain a Year After Eyelid ...
Full Text Available ... the blood and may increase bleeding after you have finished protecting the eye, see a physician immediately ... Jun 30, 2017 People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation Nov ...
Full Text Available ... People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation Nov 29, 2016 Combating Eye Injuries from ... of Service For Advertisers For Media Ophthalmology Job Center © American Academy of Ophthalmology 2017 ...
Full Text Available ... inflammatory drugs. These drugs thin the blood and may increase bleeding after you have finished protecting the ... a hair dryer to treat my Fuchs’ dystrophy? May 06, 2017 I lost sight from a corneal ...
Full Text Available ... By: Devin A Harrison MD Sep. 01, 2017 The cornea is the clear front window of the eye . A corneal laceration is a cut on the cornea. It is usually caused by something sharp ...
Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... Ask an Ophthalmologist Answers Did my traumatic brain injury cause early cataracts? Jan 21, 2018 Did I ...
Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... Dangerous for Your Eyes Sep 20, 2017 Eye Injuries from Laundry Packets On the Rise Jun 30, ...
de Farias, Charles C; Allemann, Norma; Gomes, José Á P
There are few studies comparing different surgical procedures for the treatment of corneal thinning. Lamellar corneal transplantation (LCT) has been reported to be efficient, but its results can be jeopardized by allograft rejection, opacification, or high astigmatism. Amniotic membrane transplantation (AMT) has been considered a good alternative, but it is not as resistant as LCT and the tissue can be reabsorbed after surgery. A prospective, randomized, interventional, and comparative study of consecutive patients with corneal thinning over 6 months was performed. Ophthalmological examination was performed before transplant surgery and then repeated 1, 7, 15, 30, 90, and 180 days after surgery and ultrasound biomicroscopy was performed before and then 30, 90, and 180 days after surgery to assess corneal thinning. Herpes simplex infection was the main cause of corneal thinning (9 eyes), followed by surgery (cataract, glaucoma, 5 cases), rheumatoid arthritis (1), chemical burn (1), perforating trauma (1), previous band keratopathy treatment (1), and Stevens-Johnson syndrome (1). Although all patients showed significant increase in final thickness in the area of thinning, it was higher in those submitted to LCT at 180 days postoperatively. Regardless of the surgical technique, all patients showed epithelialization. Patients undergoing AMT showed an 89% decrease in neovascularization. Final corrected distance visual acuity was better in patients submitted to AMT. LCT proved to be the best option for treating corneal thinning. AMT represents an alternative that allows good visual recovery but does not restore corneal thickness as efficiently as LCT.
Robert, L; Legeais, J M; Robert, A M; Renard, G
Cornea is a highly differentiated tissue rich in extracellular matrix (ECM) specifically distributed in space in order to insure its dual role--transparency and protection of inner eye-tissues. Corneal ECM is especially rich in collagens. Since the characterisation of a number of distinct collagen types it appeared that most of them are present in the cornea. Their synthesis follows a specific program of sequential expression of the different collagen types to be synthesised during the development and maturation of the cornea. The precise regulation of the diameter and orientation of fibers, and of the interfibrillar spaces is partially at least attributed to interactions between glycosaminoglycans and collagens. The 'program' of vectorial collagen synthesis and GAG-collagen interactions changes also with age and in several pathological conditions as corneal dystrophies and wound healing. The Maillard reaction, especially in diabetes, is one of these important factors involved in age-dependent modifications of corneal structure and function. Far from being inert, corneal collagens were shown to have relatively short half-lives. The biosynthesis of corneal collagens was studied also during wound healing. The refibrillation of wounded corneas does not follow the original 'program' of ECM-synthesis as shown by the comparative study of wound healing using biochemical and morphometric methods. This review recapitulates briefly previous and recent studies on corneal collagens in order to present to clinicians and scientists an overview of the state of the art of this important field at the intersection of eye research and matrix biology.
N. S. Egorova
Full Text Available The research objective was to study the reparative effects of the collagen type I bio-construct loaded with buccal epithelial cells, on the rabbit cornea after experimental keratectomy at various stages of treatment (on the 3rd, 7th, 14th, 3 0th days.Material and methods. The experiments were conducted on 20 rabbits of the Chinchilla breed that were operated on cornea of both eyes aiming to inflict epithelial and stromal cornea defects. The collagen-based bio-construct bearing buccal epithelial cells was placed over the cornea of the experimental eyes. The cornea of the control eyes was covered with smooth contact lens. After the surgery, a temporal blepharorrhaphy was performed and kept for 3 days. We studied macroand microscopic pattern of corneal regeneration at 3, 7, 14, and 30 days of experiment.Results. When using the collaged-based bio-construct containing buccal epithelial cells, the complete epithelialization of the corneal defect occurred at mean 7 days earlier compared to that in the control eyes. Thus, the offered bio-construct stimulated the cell migration and proliferation at early stages of treatment (3–7 days reducing the inflammation activity.Conclusion. The bio-construct comprising a collagen type I matrix loaded with buccal epithelial cells can provide an effective treatment option for corneal defects.
Hjortdal, Jesper Østergaard
Corneal transplantation has been performed for more than 100 years. Until 15 years ago the state-of-the art type of transplantation was penetrating keratoplasty, but since the start of this millennium, newly designed surgical techniques have developed considerably. Today, the vast majority...... with less risk of rejection episodes. Besides covering updated chapters on penetrating keratoplasty, and anterior and posterior lamellar procedures, this textbook also gives a thorough overview of the history of corneal transplantation and a detailed presentation of the microstructural components....... Economic considerations on cost and benefi t of medical treatment and surgical procedures are today an integrated part of the health system in many countries, and a chapter covers these aspects of corneal transplantation. This textbook is aimed at presenting an updated review of the new techniques...
Espinosa-Heidmann, Diego G.; Malek, Goldis; Mettu, Priyatham S.; Caicedo, Alejandro; Saloupis, Peter; Gach, Sarah; Dunnon, Askia K.; Hu, Peng; Spiga, Maria-Grazia; Cousins, Scott W.
Purpose. Neovascular remodeling (NVR), the progression of small capillaries into large-caliber arterioles with perivascular fibrosis, represents a major therapeutic challenge in neovascular age-related macular degeneration (AMD). Neovascular remodeling occurs after laser-induced choroidal neovascularization (CNV) in aged but not young mice. Additionally, bone marrow–derived cells, including macrophages, endothelial precursor cells, and mesenchymal precursor cells, contribute to CNV severity. In this study, we investigated the impact of aged bone marrow transplantation (BMT) on the degree of fibrosis, size, and vascular morphology of CNV lesions in a mouse model of laser-induced CNV. Methods. Young (2 months) and old (16 months) mice were transplanted with green fluorescent protein (GFP)-labeled bone marrow isolated from either young or old donors. Laser CNV was induced 1 month following transplant, and eyes were analyzed via choroidal flat mounts and immunohistochemistry 1 month postlaser. The identity of cells infiltrating CNV lesions was determined using specific markers for the labeled transplanted cells (GFP+), macrophages (F4/80+), perivascular mesenchymal-derived cells (smooth muscle actin, SMA+), and endothelial cells (CD31+). Results. Bone marrow transplantation from aged mice transferred susceptibility to NVR into young recipients. Inversely, transplantation of young marrow into old mice prevented NVR, preserving small size and minimal fibrosis. Mice with NVR demonstrated a greater relative contribution of marrow-derived SMA+ perivascular mesenchymal cells as compared to other cells. Conclusions. Our findings indicate that the status of bone marrow is an important determining factor of neovascular severity. Furthermore, we find that perivascular mesenchymal cells, rather than endothelial cells, derived from aged bone marrow may contribute to increased CNV severity in this murine model of experimental neovascularization. PMID:24135751
Avadhanam, Venkata S; Smith, Helen E; Liu, Christopher
According to the World Health Organization, globally 4.9 million are blind due to corneal pathology. Corneal transplantation is successful and curative of the blindness for a majority of these cases. However, it is less successful in a number of diseases that produce corneal neovascularization, dry ocular surface and recurrent inflammation, or infections. A keratoprosthesis or KPro is the only alternative to restore vision when corneal graft is a doomed failure. Although a number of KPros have been proposed, only two devices, Boston type-1 KPro and osteo-odonto-KPro, have came to the fore. The former is totally synthetic and the latter is semi-biological in constitution. These two KPros have different surgical techniques and indications. Keratoprosthetic surgery is complex and should only be undertaken in specialized centers, where expertise, multidisciplinary teams, and resources are available. In this article, we briefly discuss some of the prominent historical KPros and contemporary devices. PMID:25945031
Full Text Available AIM: To observe the clinical curative effect of intravitreal Bevacizumab injection combined duplex technique in treatment of neovascular glaucoma(NVG.METHODS:Totally 25 eyes of 25 patients with NVG who underwent intravitreal Bevacizumab injection of 1.0mg(0.05mL, after the regression of iris neovascularization, 5 eyes with anterior chamber paracentesis fluid auxiliary controlled intraocular pressure. After 2wk, patients were treated by trabeculectomy and phacomulsification(9 eyes were implanted intraocular lens. The changes and complications of intraocular pressure, visual acuity, corneas and neovessels were observed after surgery, and followed up 12mo.RESULTS:After injection Bevacizumab in 25 eyes, iris neovascularization of 20 eyes subsided in 3～5d, and 5 eyes subsided in 7d. After controlling intraocular pressure, count of the corneal endothelial cell were 1 629±226mm2, and none suffered decompensation of corneal endothelium after two-surgery of trabeculectomy and phacomulsification. After followed up 12mo, intraocular pressure of 20 eyes were controlled in normal range; 2 eyes could control in normal range after treated by a kind of anti-glaucoma medicine and 3 eyes was 34～38mmHg after treated by anti-glaucoma medicine. 9 eyes had improved vision after implanted intraocular lens.CONCLUSION:Intravitreal Bevacizumab injection can subside iris and anterior chamber angle neovascularization effectively in a short time and reduce intraocular pressure. It can also reduce the risk of bleeding during operation or after operation. Intravitreal Bevacizumab injection combined with two-surgery of trabeculectomy and phacomulsification can treat neovascular glaucoma effectively.
the damping effect of the tissue to an applied force) or corneal compliance being the major risk factor. Figure 1. The percentage of participants in the observation group who developed primary open-angle glaucoma (median follow-up, 72 months) ...
visual acuity chart. • fluorescein strips. • topical anaesthetic eye drops. • direct ophthalmoscope. Examination. Assessing vision with a Snellen visual acuity chart gives a clue as to the extent of the problem (e.g. a corneal abrasion with good vision is unlikely to require specialist intervention). Each eye should be tested ...
Corneal Intelligence. Ian Murdoch. Institute of Ophthalmology, Bath Street, London. In 2002, the ocular hypertension treatment study (OHTS) published their results. This study had taken 1636 ocular hypertensives. 1, 2. (IOP 24-32mmHg) and randomized them to receive therapy or no therapy. The primary outcome of the ...
Chang, Ki Cheol; Kwon, Ji-Won; Han, Young Keun; Wee, Won Ryang; Lee, Jin Hak
To describe etiologies and clinical characteristics of corneal opacities leading patients to seek cosmetic treatments. The medical records of 401 patients who presented for cosmetic improvement in corneal opacities between May 2004 and July 2007 were retrospectively reviewed. The following parameters were analyzed: age, gender, cause of corneal opacity, time course of the corneal disease, associated diseases, prior and current cosmetic treatments, visual acuity, location and depth of the corneal opacity, and the presence of either corneal neovascularization or band keratopathy. A single practitioner examined all patients. The most common causes of corneal opacity were ocular trauma (203 eyes, 50.6%), retinal disease (62 eyes, 15.5%), measles (38 eyes, 9.5%), and congenital etiologies (22 eyes, 5.5%). Prior treatments included iris colored contact lenses (125 eyes, 31.1%) and corneal tattooing (34 eyes, 8.46%). A total of 321 of 401 eyes underwent cosmetic treatment for corneal opacities. The most common treatment performed after the primary visit was corneal tattooing (261 eyes, 64.92%). This is the first study to investigate the causes and clinical characteristics of patients presenting for cosmetic treatment of corneal opacities rather than for functional improvement. Various cosmetic interventions are available for patients with corneal opacities, and these should be individualized for the needs of each patient.
He, Jiucheng; Eastlack, Jason P; Bazan, Haydee E P
Although the exact mechanisms underlying corneal neovascularization remain unclear, cytokines and growth factors play an important role in their development. We have shown previously that the inflammatory mediator platelet-activating factor (PAF) is a potent inducer of corneal neovascularization in vivo. In this study, we investigate the role of stromal myofibroblasts in neovascularization and the effect of PAF on this process. Myofibroblasts were obtained from rabbit corneal keratocytes and identified with anti-α-SMA antibody. Cells were treated with PAF (100 nM) for 24 hr. In some experiments, cells were pre-treated with the PAF antagonist LAU-0901 (150 nM). Expression of vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) was examined by immunofluorescence and immunoblotting. To study the effect of myofibroblasts on vessel formation in vitro, Vybrant(®) CM-DiI labeled human umbilical vein endothelial cells (HUVECs) were cultured on myofibroblasts in a thin layer of collagen gel. CD31 was used as the cell marker of HUVEC. VEGF and TSP-1 were not detectable in keratocytes, but they were positively stained in myofibroblasts. PAF induced a significant increase in VEGF expression and a decrease in TSP-1 expression. These changes were inhibited in the presence of LAU-0901. HUVECs co-cultured with corneal myofibroblasts formed a typical structure of vessel-like tubes within 1 week. The addition of PAF to the medium increased HUVEC-induced vessel-like tube formation, which was abolished by LAU-0901. Addition of anti-VEGF antibody to the medium completely prevented the formation of vessel-like tubes. We provide evidence for the role of stromal myofibroblasts in the corneal neovascularization process. By enhancing VEGF production and decreasing TSP-1 production in myofibroblasts, PAF augments the angiogenic response. The PAF antagonist LAU-0901 could represent a new therapeutic venue for inhibiting corneal neovascularization.
Hackett, Joanne M; Lagali, Neil; Merrett, Kimberley; Edelhauser, Henry; Sun, Yifei; Gan, Lisha; Griffith, May; Fagerholm, Per
To evaluate the performance of structurally reinforced, stabilized recombinant human collagen-phosphorylcholine (RHCIII-MPC) hydrogels as corneal substitutes in a rabbit model of severe corneal damage. One eye each of 12 rabbits received a deep corneal alkali wound. Four corneas were implanted with RHCIII-MPC hydrogels. The other eight control corneas were implanted with either allografts or a simple cross-linked RHCIII hydrogel. In all cases, 6.25 mm diameter, 350 μm thick buttons were implanted by anterior lamellar keratoplasty to replace damaged corneal tissue. Implants were followed for nine months by clinical examination and in vivo confocal microscopy, after which implanted corneas were removed and processed for histopathological and ultrastructural examination. Alkali exposure induced extensive central corneal scarring, ocular surface irregularity, and neovascularization in one case. All implants showed complete epithelial coverage by four weeks postoperative, but with accompanying suture-induced vascularization in 6 out of 12 cases. A stable, stratified epithelium with hemidesmosomal adhesion complexes regenerated over all implants, and subbasal nerve regeneration was observed in allograft and RHCIII-MPC implants. Initially acellular biosynthetic implants were populated with host-derived keratocytes as stromal haze subsided and stromal collagen was remodeled. Notably, RHCIII-MPC implants exhibited resistance to vascular ingrowth while supporting endogenous cell and nerve repopulation. Biosynthetic implants based on RHC promoted cell and nerve repopulation in alkali burned rabbit eyes. In RHCIII-MPC implants, evidence of an enhanced resistance to neovascularization was additionally noted.
generally performed by either corneal specialists or refractive surgeons. It involves creating tunnels in the corneal stroma to secure the implants either by a diamond knife or laser calibrated to an approximate depth of 70% of the cornea. Variable approaches have been employed by surgeons in selecting ring segment size, number and position. Generally, two segments of equal thickness are placed superiorly and inferiorly to manage symmetrical patterns of corneal thinning whereas one segment may be placed to manage asymmetric thinning patterns. Following implantation, the major safety concerns are for potential adverse events including corneal perforation, infection, corneal infiltrates, corneal neovascularization, ring migration and extrusion and corneal thinning. Technical results can be unsatisfactory for several reasons. Treatment may result in an over or under-correction of refraction and may induce astigmatism or asymmetry of the cornea. Progression of the corneal cone with corneal opacities is also invariably an indication for progression to corneal transplant. Other reasons for treatment failure or patient dissatisfaction include foreign body sensation, unsatisfactory visual quality with symptoms such as double vision, fluctuating vision, poor night vision or visual side effects related to ring edge or induced or unresolved astigmatism. The literature search strategy employed keywords and subject headings to capture the concepts of 1) intrastromal corneal rings and 2) corneal diseases, with a focus on keratoconus, astigmatism, and corneal ectasia. The initial search was run on April 17, 2008, and a final search was run on March 6, 2009 in the following databases: Ovid MEDLINE (1996 to February Week 4 2009), OVID MEDLINE In-Process and Other Non-Indexed Citations, EMBASE (1980 to 2009 Week 10), OVID Cochrane Library, and the Centre for Reviews and Dissemination/International Agency for Health Technology Assessment. Parallel search strategies were developed for the
Geraldine R. Slean
Conclusions and importance: Chronic bullous retinoschisis can be associated with anterior segment neovascularization such as rubeosis iridis, presumably due to non-perfusion within the retinoschisis cavity.
Full Text Available AIM: To evaluate the outcomes and safety of lamellar keratoplasty (LK assisted by fibrin glue in corneal perforations.METHODS: Six eyes of 6 patients affected by different corneal pathologies (2 posttraumatic corneal scar and 3 bacterial keratitis underwent LK procedures by using fibrin glue. The mean corneal perforation diameter was 1.35±0.64mm (range, 0.7-2.5mm, and the greatest diameter of the ulcerative stromal defect was 2.47±0.77mm in average (range, 1.5-3.5mm. The donor corneal lamella diameters were 0.20-mm larger and thicker than the recipient to restore a physiologic corneal thickness and shape:mean donor diameter was 8.34±0.28mm (range, 8.2-8.7mm and mean thickness was 352±40.27mm (range, 220-400mm. Mean follow-up was 7.33±1.97 months (range, 6-11 months. Postoperatively, the graft status, graft clarity, anterior chamber response, the visual prognosis, intraocular pressures, and postoperative complications were recorded.RESULTS: All the corneal perforations were successfully healed after the procedure. The best-corrected visual acuity (BCVA ranged from 20/1 000 to 20/50 in their initial presentation, and from 20/100 to 20/20 in their last visit, showed increase in all the patients. No major complications such as graft dislocation and graft failure were noted. Neovascularization developed in the superficial stroma of donor graft in 1 case. High intraocular pressure developed on day 2 after surgery, while was remained in normal range after application of anti-glaucomatous eyedrops for 1 week in 1 case.CONCLUSION: Fibrin glue-assisted sutureless LK is valuable for maintaining the ocular integrity in the treatment of corneal perforations.
Full Text Available Roberto Gallego-Pinazo1, Ruth López-Lizcano1, José María Millán2,3, J Fernando Arevalo5, J Luis Mullor6, Manuel Díaz-Llopis1,3,41Department of Ophthalmology, 2Department of Genetics, Unit of Experimental Opthalmology, Hospital Universitario La Fe, Valencia, Spain; 3Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER, Valencia, Spain; 4Faculty of Medicine, University of Valencia, Valencia, Spain; 5Retina and Vitreous Service, Clínica Oftalmológica Centro Caracas, Caracas, Venezuela; 6Unit of Experimental Opthalmology, Fundación Parala Investigación del Hospital La Fe, Valencia, SpainPurpose: To describe a case of choroidal neovascularization (CNV in a female diagnosed with Beals–Hecht syndrome.Methods: A retrospective, interventional case is described in a 26-year-old female complaining of metamorphopsia and visual loss in her left eye (counting fingers. The fluorescein angiogram and the optical coherence tomography supported the diagnosis of CNV. Intravitreal ranibizumab was administered.Results: After the third intravitreal ranibizumab, her visual acuity improved to 0.8 and the morphology of the macular area was restored.Conclusions: To our knowledge this is the first report of CNV in Beals–Hecht syndrome treated with ranibizumab. Self-monitoring by periodically performing Amsler grid test is strongly recommended in these patients in order to achieve an early diagnosis of eventual CNV and avoid visual acuity loss.Keywords: Beals–Hecht syndrome, connective tissue disease, choroidal neovascularization, ranibizumab
Kim, Young L; Walsh, Joseph T Jr.; Goldstick, Thomas K; Glucksberg, Matthew R [Biomedical Engineering Department, Northwestern University, Evanston, IL 60208 (United States)
We report the effect of changes in the corneal hydration on the refractive index of the cornea. Using optical coherence tomography (OCT), the geometrical thickness and the group refractive index of the bovine cornea were derived simultaneously as the corneal hydration was varied. The corneal hydration was then calculated from the corneal thickness. The group refractive index of the cornea increased non-linearly as the cornea dehydrated. In addition, a simple mathematical model was developed, based on the assumption that changes in corneal hydration occur only in the interfibrilar space with constant water content within the collagen fibrils. Good agreement between the experimental results and the mathematical model supports the assumption. The results also demonstrate that the measurement of refractive index is a quantitative indicator of corneal hydration.
Li, Qing; Wang, Hongmei; Dai, Zhenye; Cao, Yichen; Jin, Chuanyu
To construct an acellular porcine corneal stroma (aPCS) as a human corneal stroma alternative and to further explore its biomechanical properties. A combination of DNA-RNA enzymes and ultrasound technology was used to strip the native porcine corneal cells. The microstructure of aPCS was observed by H&E staining, DAPI staining, and α-Gal tests. The mechanical properties were detected by a tension machine. Cytotoxicity of aPCS was measured by the MTT assay. The subcutaneous embedding experiment in rats was also used to detect immunity and degradation. The aPCS was transplanted into the rabbit cornea by lamellar keratoplasty, general observations were made at 3 days, 1 week, 1 month, and 3 months after implantation, respectively. The microstructure and mechanical properties of aPCS were not damaged during the decellularization process. The aPCS extracts had no significant cytotoxicity on human corneal stroma cells. Moreover, the subcutaneous embedding experiment in rats demonstrated that aPCS could not be degraded and induced no immune reaction in and around the transplanted discs. More important is that the aPCS reconstructed normal corneal stroma and maintained corneal transparency and thickness, with almost no neovascularization and inflammation at 3 months after surgery. The aPCS prepared in this study had good biocompatibility, safety, and low antigenicity, which has great potential for corneal disease treatment.
Full Text Available AIM:To examine the efficacy and safety of cryotherapy in the management of Fusarium corneal ulcer. METHODS: Retrospective contract analysis of the clinical data of 41 patients(41 eyeswho infected with Fusarium corneal ulcer. All of them underwent focal lesion keratectomy combined with amniotic membrane transplantation between January 2010 and May 2013. The cryotherapy treatment group of 22 cases(22 eyes, non-cryotherapy group of 19 cases(19 eyes. All the cases were followed up for 3～12mo. We analyzed the healing of corneal ulcer, corneal neovascularization, postoperative visual acuity, complications and ulcer recurrences. RESULTS: There were no significant difference for the two groups at the cure rate and the recovery rate, the corneal neovascularization and postoperative visual acuity(P>0.05. The total effective rate and corneal healing time in cryotherapy group was significantly higher than that in non-cryotherapy group(PPCONCLUSION: Cryotherapy is an effective and safe method for the treatment of Fusarium corneal ulcer.
Gabrić, N.; Dekaris, I.; Vojniković, B.; Karaman, Ž.; Mravičić, I.; Katušić, J.
The main purpose of the study was to describe the surgical success rate and visual results of penetrating keratoplasty in children. This retrospective study included children that underwent corneal transplantation at the Department of Ophthalmology, General Hospital »Sveti Duh«, in the period 1994–1999. Patients’ age ranged from 6 to 16 years. Twenty-five corneal transplants were performed in 24 eyes. Corneal pathologies were corneal leucoma, congenital dystrophy, corneal combu...
Arif, Abdus Salam; Aaqil, Bushra; Siddiqui, Afsheen; Nazneen, Zainab; Farooq, Umer
Vernal kerato-conjunctivitis (VKC) is an infrequent but serious form of allergic conjunctivitis common in warm and humid areas where air is rich in allergens. It affects both eyes asymmetrically. Although VKC is a self-limiting disease but visions affecting corneal complications influence the quality of life in school children. The aim of this study was to list the corneal complications due to this condition and to find out the extent of visual impairment among VKC patients. This cross-sectional study was conducted in the department of Ophthalmology, Benazir Bhutto Shaheed Hospital on 290 eyes of diagnosed cases of VKC. The diagnosis of VKC was made on the basis of history and examination. Visual acuity was recorded using Snellen's notation and visual impairment was classified according to World Health Organization classification for visual disabilities. The mean age of presentation was 10.83±6.13 years. There were 207 (71.4%) males and 83 (28.6%) females. Corneal scarring was observed in 59 (20.3%) eyes. Keratoconus was found to be in 17 (5.9%) eyes. Shield ulcer was detected in 09 (3.1%) eyes while 07 (2.4%) eyes had corneal neovascularization. Majority of the patients with visual loss had corneal scarring and the complication that led to severe visual loss in most of the eyes was Keratoconus. Vernal kerato-conjunctivitis in the presence of corneal complications is a sight threatening disease and can lead to severe visual impairment.
Alexandra X Crawford
Full Text Available This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD. Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17 th and 18 th centuries, true scientific and surgical experimentation in this field did not begin until the 19 th century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of
Full Text Available AIM:To understand the clinical effect of trabeculectomy with mitomycin and interferon therapy on neovascular glaucoma.METHODS:Neovascular glaucoma patients in our hospital from January 2011 to January 2013 were sampled, from them, 57 cases(57 eyeswere randomly divided into two groups, control group received routine trabeculectomy for treatment, the experimental group accepted combination therapy of trabeculectomy + mitomycin + interferon. The clinical efficacy of two groups were observed. RESULTS:The total effective rate(96%in experimental group was significantly better than that in the control group(76%, and the visual acuity, filtering bleb and postoperative 1wk, 1a of intraocular pressure changes were better than those of the control group, there was a statistically significant difference(PP>0.05.CONCLUSION:Trabeculectomy combined mitomycin and interferon treatment of neovascular glaucoma has exact clinical effect, and is worthy of clinical popularization and application.
Kanyukov, V N; Stadnikov, A A; Trubina, O M; Yakhina, O M
To substantiate the use of nanostructured bioplastic material for the treatment of traumatic eye injuries. The study enrolled 96 eyes of 48 rabbits and was carried out in 3 series of experiments, different in the type of induced corneal trauma: mechanical erosion, alkaline or acid burn. The animals were clinically monitored and sacrificed for morphological investigation at days 3, 7, 14, 30, and 90. The size of mechanical corneal erosions was repeatedly evaluated with fluorescein eye stain test. In the experimental group, Hyamatrix biomaterial was topically administered according to an original technique. In the controls, soft contact lenses were inserted and sutured. Complete closure of the epithelial defect with no impact on corneal properties was achieved in 3 days in the experimental group and in4 days in the control group. As for alkaline and acid corneal burns, experimental and control groups received Hyamatrix biomaterial and Solcoseryl eye gel correspondingly. In the experimental group of alkaline burn the defect closed by day 7, in the controls--by day 10-11. Acid-induced corneal edema also resolved by day 7 in the experimental group and by day 14 in the control group. 1. The results of this experimental and morphological study prove the hyaluronic acid-derived nanostructured bioplastic material effective in accelerating corneal re-epithelialization after mechanical erosions as compared with the controls. 2. Topical application of the hyaluronic acid-derived nanostructured bioplastic material shortens the exudative phase of inflammation, promotes corneal defect closure with formation of a more subtle opacification, and stimulates corneal restoration after chemical burns.
Ljubimov, Alexander V.; Saghizadeh, Mehrnoosh
Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal epithelium, and
Full Text Available The effect of local and systemic injections of mesenchymal stem cells derived from adipose tissue (AD-MSC into rabbit models of corneal allograft rejection with either normal-risk or high-risk vascularized corneal beds was investigated. The models we present in this study are more similar to human corneal transplants than previously reported murine models. Our aim was to prevent transplant rejection and increase the length of graft survival. In the normal-risk transplant model, in contrast to our expectations, the injection of AD-MSC into the graft junction during surgery resulted in the induction of increased signs of inflammation such as corneal edema with increased thickness, and a higher level of infiltration of leukocytes. This process led to a lower survival of the graft compared with the sham-treated corneal transplants. In the high-risk transplant model, in which immune ocular privilege was undermined by the induction of neovascularization prior to graft surgery, we found the use of systemic rabbit AD-MSCs prior to surgery, during surgery, and at various time points after surgery resulted in a shorter survival of the graft compared with the non-treated corneal grafts. Based on our results, local or systemic treatment with AD-MSCs to prevent corneal rejection in rabbit corneal models at normal or high risk of rejection does not increase survival but rather can increase inflammation and neovascularization and break the innate ocular immune privilege. This result can be partially explained by the immunomarkers, lack of immunosuppressive ability and immunophenotypical secretion molecules characterization of AD-MSC used in this study. Parameters including the risk of rejection, the inflammatory/vascularization environment, the cell source, the time of injection, the immunosuppression, the number of cells, and the mode of delivery must be established before translating the possible benefits of the use of MSCs in corneal transplants to clinical
Horstmann, Jens; Schulz-Hildebrandt, Hinnerk; Bock, Felix; Siebelmann, Sebastian; Lankenau, Eva; Hüttmann, Gereon; Steven, Philipp; Cursiefen, Claus
Corneal neovascularization, in particular lymphangiogenesis, is a limiting factor in corneal transplant survival. Novel treatment approaches focus on (selective) inhibition and regression of lymphatic vessels. Imaging clinically invisible corneal lymphatic vessels is a prerequisite for these strategies. Using a murine model, this study investigates whether corneal lymphatic vessels can be imaged using microscopic optical coherence tomography (mOCT). Corneal neovascularization was induced by intrastromal placement of 11.0 nylon sutures in one eye of BALB/c mice. After 2 weeks, cross-sectional images and volumes of the corneas with a 0.5 mm lateral and axial field of view were acquired using a custom-built mOCT system enabling a resolution of 1 μm at a B-scan rate of 165/s. Three of the six animals received an additional intrastromal injection of India ink 24 hours before the measurement to stain the corneal lymphatic system in vivo. Immunohistochemistry using CD31 and LYVE-1 was used to validate the mOCT findings. Using mOCT, lymphatic vessels were visible as dark vessel-like structures with the lumen lacking a hyperreflective wall and mostly lacking cells. However, individual, slowly moving particles, which most likely are immune cells, occasionally could be observed inside the lumen. In lymphatic vessels of ink-stained corneas, hyperreflection and shadowing underneath was observed. Ink-filled lymphatic vessels were colocalized in consecutive corneal flat mounts of the same specimen. Corneal lymphatic vessels can be imaged using mOCT. This novel approach opens new options for noninvasive clinical imaging of corneal lymphatic vessels for diagnostic and therapeutic indications.
Hos, Deniz; Saban, Daniel R; Bock, Felix; Regenfuss, Birgit; Onderka, Jasmine; Masli, Sharmila; Cursiefen, Claus
To analyze whether topical application of corticosteroids inhibits inflammatory corneal lymphangiogenesis and to study the potential underlying antilymphangiogenic mechanisms. Inflammatory corneal neovascularization was induced by suture placement, and the corneas were then treated with topical fluorometholone, prednisolone acetate, or dexamethasone sodium phosphate. After 1 week, the corneas were stained with lymphatic vessel endothelial hyaluronan receptor 1 for detection of pathological corneal lymphangiogenesis. The effect of these corticosteroids on macrophage recruitment was assessed via fluorescence-activated cell sorting analysis. The effect of these corticosteroids on proinflammatory cytokine expression by peritoneal exudate cells was tested via real-time polymerase chain reaction. Furthermore, the effect of steroid treatment on the proliferation of lymphatic endothelial cells was assessed via enzyme-linked immunosorbent assay. Treatment with corticosteroids resulted in a significant reduction of inflammatory corneal lymphangiogenesis. The antilymphangiogenic effect of fluorometholone was significantly weaker than that of prednisolone and dexamethasone. Corneal macrophage recruitment was also significantly inhibited by the application of topical steroids. Treatment of peritoneal exudate cells with corticosteroids led to a significant downregulation of the RNA expression levels of tumor necrosis factor and interleukin 1β. Additionally, proliferation of lymphatic endothelial cells was also inhibited. Corticosteroids are strong inhibitors of inflammatory corneal lymphangiogenesis, with significant differences between various corticosteroids in terms of their antilymphangiogenic potency. The main mechanism of the antilymphangiogenic effect seems to be through the suppression of macrophage infiltration, proinflammatory cytokine expression, and direct inhibition of proliferation of lymphatic endothelial cells. Steroids block corneal lymphangiogenesis, the main
Jhanji, Vishal; Mehta, Jod S; Sharma, Namrata; Sharma, Bhavana; Vajpayee, Rasik B
Corneal transplantation surgery has moved from an era of conventional penetrating keratoplasty to selective replacement of the diseased corneal layer with complementary healthy donor corneal tissue. Anterior lamellar transplantation surgeries do not involve replacement of corneal endothelium, consequently eliminating the occurrence of endothelial rejection. Similarly, in diseases affecting the corneal endothelium, selective replacement with a lamellar lenticule bearing healthy endothelium provides better outcomes in terms of ocular surface, lesser astigmatism and quick visual recovery. In addition to the advantages of enhanced surgical outcomes, targeted corneal transplantation allows the use of one donor cornea for more than one recipient, thereby offering a viable solution to the problem of paucity of donor corneas. Evolving techniques of corneal transplantation have enabled better utilization of donor corneal tissue. Anterior lamellar as well as endothelial keratoplasty surgeries have become first-choice surgeries in appropriately selected cases. This review briefly discusses some of these novel surgical techniques. A better understanding of targeted corneal transplantation would lead to adaptation of the concept of component corneal surgery. This would further enable the corneal surgeons to circumvent the problem of donor corneal shortage especially in the developing world.
Lee, Hyo Seok; Choi, Joo-Hee; Cui, Lian; Li, Ying; Yang, Jee Myung; Yun, Je-Jung; Jung, Ji Eun; Choi, Won; Yoon, Kyung Chul
To analyze the anti-inflammatory and antioxidative effects of Camellia japonica (CJ) on human corneal epithelial (HCE) cells and its therapeutic effects in a mouse model of experimental dry eye (EDE). Camellia japonica extracts of varying concentrations (0.001%, 0.01%, and 0.1%) were used to treat HCE cells. Dichlorofluorescein diacetate (DCF-DA) and dihydroethidium (DHE) assays were performed. The production of peroxiredoxin (PRX) 1-6 and manganese-dependent superoxide dismutase (MnSOD) in HCE cells was assessed using Western blot analysis. Furthermore, eye drops containing 0.001%, 0.01%, or 0.1% CJ extract or a balanced salt solution (BSS) were applied to the EDE. Clinical parameters were measured 7 days after treatment. The levels of inflammatory markers and intracellular reactive oxygen species (ROS) were measured. Treatment with 0.01% and 0.1% CJ extracts decreased apoptosis in HCE cells. In addition, band intensities of PRX 1, 4, and 5, as well as MnSOD, after hydrogen peroxide (H2O2) treatment showed a significant improvement after pretreatment with 0.01% and 0.1% CJ extracts. Mice treated with 0.1% CJ extract showed significantly improved clinical parameters when compared to those of the EDE control and BSS groups. A significant decrease in the levels of inflammatory markers and intracellular ROS was observed in the 0.01% and 0.1% CJ extract groups. Camellia japonica extracts promoted antioxidative protein expression and suppressed apoptosis in HCE cells. Furthermore, CJ extracts improved clinical signs of dry eye and reduced oxidative stress and the expression of inflammatory markers, suggesting that eye drops containing CJ extract could be used as an adjunctive treatment for dry eye.
Full Text Available AIM: To evaluate the clinical effect of two different surgical treatments for neovascular glaucoma(NVG.METHODS: A total of 30 NVG inpatients(30 eyesat our hospital from April 2008 to December 2011 were reviewed. Patients were divided into two groups according to the different surgical treatments. In group A, 12 cases(12 eyeswere treated with Ahmed glaucoma valve(AGVimplantation and in group B, 18 cases(18 eyeswere treated with semiconductor diode laser photocoagulation transscleral cyclophotocoagulation(TSCPC. Intraocular pressure, visual acuity and complications were compared between two groups postoperatively.RESULTS: The postoperative IOP was significantly lower in each group(PPP>0.05in IOP 1 month after surgery. Visual acuity: in group A, the visual acuity was improved in 3 eyes, unchanged in 7 eyes and worsened in 2 eyes.; in group B, the visual acuity was improved in 3 eyes, unchanged in 12 eyes and worsened in 3 eyes. Postoperative complications: in group A, eyeball pain and corneal edema were found in 5 cases(41.7%, shallow anterior chamber in 3 cases(25%, anterior chamber fibroid exudation in 2 cases(16.7%, hyphema in 3 cases(25%; in group B, eyeball pain atearly stage after surgery were found in 10 cases(55.6% , corneal edema in 11 cases(61.1%, anterior chamber fibroid exudation in 5 cases(27.8%, hyphema in 6 cases(33.3%.CONCLUSION: AGV implantation and TSCPC are both effective surgical treatment methods for NVG. AGV implantation is a filtration surgery, which is relatively safe. TSCPC is more economical and suitable for glaucoma of advanced or absolute stage.
Nuhoglu, Fadime; Altiparmak, Ugur E; Hazirolan, Dicle O; Kasim, Remzi; Duman, Sunay
The aim of the present study was to evaluate the cicatricial repair of a corneal artificial perforation in rats with 10-0 nylon suture, N-butyl-2-cyanoacrylate (NBCA) adhesive, or NBCA + methacryloxysulfolane (NBCA-MS) adhesive through microscopic and histological assays. Twenty Wistar rats were randomly divided into 4 groups each containing 5 rats: (1) control group (corneal trauma without suturing and tissue adhesives), (2) suture group, (3) NBCA group and (4) NBCA-MS group. A central full-thickness 2-mm laceration was performed in the left eyes of the studied rats in all 4 groups. The presence of corneal edema, corneal neovascularization and tissue adhesive/suture were evaluated. On the 21st day, the rats were sacrificed and histological examination was performed to determine irregularity of corneal layers, superficial epithelization, polymorphonuclear leucocytes and neovascularization. Tissue adhesives were as effective as suturing in closing full-thickness corneal wounds and no difference in postoperative healing was observed clinically. As for the histological results, suture-treated eyes had persistent corneal irregularity that can limit visual acuity and may also lead to astigmatism. The use of tissue adhesives constitutes a viable alternative clinical procedure to conventional sutures. Possible influences on astigmatism are hypothetical, as no objective measure of astigmatism was performed in the test animals. Copyright © 2013 S. Karger AG, Basel.
Otsuji, T; Ogata, N; Takahashi, K; Matsushima, M; Uyama, M; Kaneda, Y
To evaluate the efficacy of the HVJ liposome method for gene transfer in rats with experimentally induced choroidal neovascularization. Plasmid DNA containing the LacZ reporter gene, or fluorescein isothiocyanate (FITC)-labeled double-stranded phosphorothioate oligodeoxynucleotides (S-ODNs), was encapsulated in liposomes. The liposomes were coated with the envelope of inactivated hemagglutinating virus of Japan (HVJ). Intense laser burns were applied to the posterior pole of the retina of pigmented rats to induce choroidal neovascularization. Following photocoagulation, HVJ liposome suspension was injected into the vitreous. On days 3, 7, 14, and 28 after injection, the eyes were removed and fixed. The eyes injected with LacZ gene were reacted with X-gal, frozen, and cut into thin sections. The sections were examined for the expression of the LacZ gene by light microscopy. The enucleated eyes injected with double-stranded S-ODNs were frozen, cut into thin sections, and examined a confocal scanning laser microscope for FITC labeling. Eyes without injection of HVJ liposomes served as controls. Expression of LacZ genes (beta-galactosidase activity), or localization of FITC labeling, was observed mainly in the laser-induced choroidal neovascular tissue from 3 to 28 days after the intravitreal injection of HVJ liposome. We conclude that the HVJ liposome method achieved effective gene transfer into choroidal neovascular tissue. Thus, this method can be used as a nonviral gene therapy system for the treatment of choroidal neovascularization in vivo.
Zito, E; Borderie, V; Touzeau, O; Bourcier, T; Allouch, C; Laroche, L
To evaluate amniotic membrane transplantation (AMT) in severe corneal epithelial diseases. Amniotic membrane transplantation was performed in 14 eyes of 14 patients from four groups: A, five severe ocular burns; B, four cases of cicatricial keratoconjunctivitis; C, three persistent epithelial defects after penetrating keratoplasty; D, two cases of pseudophakic bullous keratopathy. Five patients underwent AMT alone; two patients underwent AMT combined with limbal transplantation; the other three patients had limbal transplantation performed before AMT. Eight patients required combined penetrating keratoplasty. Patients with corneal stable reepithelialization, no corneal neovascularization, and no recurrence of the initial pathology were considered successful. The mean follow-up was 7+/-3 months. All but three patients underwent corneal reepithelialization within 6 weeks of AMT, with a mean healing time of 31+/-23 days. The success rate was 75% at 6 months (Kaplan-Meier method). Three of four procedures in group B failed. In eight patients, visual acuity improved, in one it worsened, and in the last five patients it remained unchanged. Visual acuity increased by an average of 7+/-9 lines. AMT is a useful technique for ocular surface reconstruction, especially in association with limbal transplantation. It could also improve the prognosis of penetrating keratoplasty in patients with severe corneal conditions.
Mirshahi, Ahmad; Azimi, Pourya; Abdolahi, Ali; Mirshahi, Romina; Abdollahian, Mahnaz
Tetracyclines, especially doxycycline, play a role in the regulation of inflammation, immunomodulation, cell proliferation, and angiogenesis. Treatment of corneal angiogenesis or choroidal neovascularization with tetracyclines has been shown to be effective in animal models. The aim of this study was to evaluate the efficacy of oral doxycycline in reducing the total number of intraocular injections needed for controlling neovascular age-related macular degeneration in human patients. In this interventional case series, 28 random consecutive patients with neovascular age-related macular degeneration from Farabi Eye Hospital, Tehran, Iran were treated for 4 months with 200 mg doxycycline once a day after the first intravitreal bevacizumab injection in addition to standard therapy in agreement with as-needed regimen. After 12 months of follow-up, total number of injections, foveal thickness and visual acuity were compared to those at baseline and of similar studies. Similar to standard treatment, co-treatment with doxycycline was able to control active disease (intraretinal or subretinal fluid or leakage, new-onset of macular hemorrhage, and reduction of visual acuity more than 5 letters based on Early Treatment Diabetic Retinopathy Study [ETDRS] charts) yet with fewer injections (for current study and standard treatment, respectively 3.14 vs. 5.92, P 0.05). If confirmed in larger studies, the findings of this interventional case series could provide a strategy to control neovascular age-related macular degeneration with fewer intraocular bevacizumab injections by co-administering a well-known oral agent-doxycycline.
Henriksen, M. D. L.; Andersen, P. H.; Plummer, C. E.
The last 30 years have seen many changes in the understanding of the pathogenesis and treatment of equine corneal stromal abscesses (SAs). Stromal abscesses were previously considered an eye problem related to corneal bacterial infection, equine recurrent uveitis, corneal microtrauma and corneal...... foreign bodies in horses. They were more commonly diagnosed in horses living in subtropical climatic areas of the world. Therapeutic recommendations to treat equine SAs were historically nearly always a medical approach directed at bacteria and the often associated severe iridocyclitis. Today...... the pathogenesis of most equine SAs appears to be more often related to fungal inoculation of the anterior corneal stroma followed by posterior migration of the fungi deeper into the corneal stroma. There is also now an increased incidence of diagnosis of corneal SAs in horses living in more temperate climates...
Gabrić, N; Dekaris, I; Vojniković, B; Karaman, Z; Mravicić, I; Katusić, J
The main purpose of the study was to describe the surgical success rate and visual results of penetrating keratoplasty in children. This retrospective study included children that underwent corneal transplantation at the Department of Ophthalmology, General Hospital "Sveti Duh", in the period 1994-1999. Patients' age ranged from 6 to 16 years. Twenty-five corneal transplants were performed in 24 eyes. Corneal pathologies were corneal leucoma, congenital dystrophy, corneal combustion, corneal scar after perforating injury, keratoconus, corneal melting, hematocornea and rekeratoplasty. The follow-up period was at least 6 months. The rate of graft survival was 1 year in 75% of eyes with congenital dystrophy and keratoconus. Hematocornea and rekeratoplasty ended with graft failure. Postoperative visual acuity improvement was recorded in 14 out of 25 eyes. Penetrating keratoplasty in children showed very good surgical success. The final visual outcome was affected by irreversible amblyopia.
Full Text Available Saidin Nor-Masniwati, Ismail Shatriah, Embong ZunainaDepartment of Ophthalmology, Universiti Sains Malaysia, Kelantan, MalaysiaAbstract: We report a case of myopic choroidal neovascularization that showed improvement after a single injection of ranibizumab. A 45-year-old Chinese man with high myopia presented with sudden onset painless central scotoma of his right eye of 2 weeks’ duration. There was no history of trauma. His right eye vision on presentation was 6/30 which showed no improvement with pinhole. The right fundus showed myopic maculopathy at the posterior pole with subretinal hemorrhage at the inferotemporal fovea. The optic disc was tilted with inferotemporal peripapillary atrophy. There was a myopic maculopathy appearance in the macula of the left eye. Fundus fluorescein angiography revealed choroidal neovascularization at the fovea of the right eye. A diagnosis of right eye choroidal neovascularization secondary to myopic maculopathy was made. A single intravitreal injection of ranibizumab 0.05 mL was given. Ten weeks following intravitreal injection, vision had improved to 6/7.5, and repeated fundus fluorescein angiography showed absence of choroidal neovascularization. Follow-up at 6 months showed visual acuity had normalized to 6/6 with glasses, which was maintained up to 12 months following treatment. The right fundus showed no further subretinal hemorrhage with no new lesions.Keywords: myopia, choroidal neovascularization, antivascular endothelial growth factor
M.C. Bartels (Marjolijn)
textabstractThe normally transparent cornea can lose its ability to refract light regularly from various conditions. Among these conditions are corneal opacities and corneal diseases leading to a distortion of the corneal contour. Vision might be restored by a corneal transplantation. Corneal
Liu, Xun; Yu, Min; Yang, Chunbo; Li, Xiaorong
Corneal chemical burns are common ophthalmic injuries that may result in permanent visual impairment. Although significant advances have been achieved on the treatment of such cases, the structural and functional restoration of a chemical burn-injured cornea remains challenging. The applications of polysaccharide hydrogel and subconjunctival injection of mesenchymal stem cells (MSCs) have been reported to promote the healing of corneal wounds. In this study, polysaccharide was extracted from Hardy Orchid and mesenchymal stem cells (MSCs) were derived from Sprague-Dawley rats. Supplementation of the polysaccharide significantly enhanced the migration rate of primarily cultured rat corneal epithelial cells. We examined the therapeutic effects of polysaccharide in conjunction with MSCs application on the healing of corneal alkali burns in rats. Compared with either treatment alone, the combination strategy resulted in significantly better recovery of corneal epithelium and reduction in inflammation, neovascularization and opacity of healed cornea. Polysaccharide and MSCs acted additively to increase the expression of anti-inflammatory cytokine (TGF-β), antiangiogenic cytokine (TSP-1) and decrease those promoting inflammation (TNF-α), chemotaxis (MIP-1α and MCP-1) and angiogenesis (VEGF and MMP-2). This study provided evidence that Hardy Orchid derived polysaccharide and MSCs are safe and effective treatments for corneal alkali burns and that their benefits are additive when used in combination. We concluded that combination therapy with polysaccharide and MSCs is a promising clinical treatment for corneal alkali burns and may be applicable for other types of corneal disorder. PMID:25789487
Full Text Available Corneal chemical burns are common ophthalmic injuries that may result in permanent visual impairment. Although significant advances have been achieved on the treatment of such cases, the structural and functional restoration of a chemical burn-injured cornea remains challenging. The applications of polysaccharide hydrogel and subconjunctival injection of mesenchymal stem cells (MSCs have been reported to promote the healing of corneal wounds. In this study, polysaccharide was extracted from Hardy Orchid and mesenchymal stem cells (MSCs were derived from Sprague-Dawley rats. Supplementation of the polysaccharide significantly enhanced the migration rate of primarily cultured rat corneal epithelial cells. We examined the therapeutic effects of polysaccharide in conjunction with MSCs application on the healing of corneal alkali burns in rats. Compared with either treatment alone, the combination strategy resulted in significantly better recovery of corneal epithelium and reduction in inflammation, neovascularization and opacity of healed cornea. Polysaccharide and MSCs acted additively to increase the expression of anti-inflammatory cytokine (TGF-β, antiangiogenic cytokine (TSP-1 and decrease those promoting inflammation (TNF-α, chemotaxis (MIP-1α and MCP-1 and angiogenesis (VEGF and MMP-2. This study provided evidence that Hardy Orchid derived polysaccharide and MSCs are safe and effective treatments for corneal alkali burns and that their benefits are additive when used in combination. We concluded that combination therapy with polysaccharide and MSCs is a promising clinical treatment for corneal alkali burns and may be applicable for other types of corneal disorder.
Ma, Xiao Yun; Zhang, Yun; Zhu, Dan; Lu, Yang; Zhou, Guangdong; Liu, Wei; Cao, Yilin; Zhang, Wen Jie
Acellular corneal stroma matrix has been used for corneal stroma engineering. However, because of its compact tissue structure, regrowth of keratocytes into the scaffold is difficult. Previously, we developed a sandwich model for cartilage engineering using acellular cartilage sheets. In the present study, we tested this model for corneal stroma regeneration using acellular porcine corneal stroma (APCS) sheets and keratocytes. Porcine corneas were decellularized by NaCl treatment, and the APCS was cut into 20-μm-thick sheets. A rabbit corneal stroma defect model was created by lamellar keratoplasty and repaired by transplantation of five pieces of APCS sheets with keratocytes. Six months after transplantation, transparent corneas were present in the experimental group, which were confirmed by anterior segment optical coherence tomography examination and transmittance examination. The biomechanical properties in the experimental group were similar to those of normal cornea. Histological analyses showed an even distribution of keratocytes and well-oriented matrix in the stroma layer in the experimental group. Together, these results demonstrated that the sandwich model using acellular corneal stroma sheets and keratocytes could be potentially useful for corneal stroma regeneration.
Xiao Yun Ma
Full Text Available Acellular corneal stroma matrix has been used for corneal stroma engineering. However, because of its compact tissue structure, regrowth of keratocytes into the scaffold is difficult. Previously, we developed a sandwich model for cartilage engineering using acellular cartilage sheets. In the present study, we tested this model for corneal stroma regeneration using acellular porcine corneal stroma (APCS sheets and keratocytes. Porcine corneas were decellularized by NaCl treatment, and the APCS was cut into 20-μm-thick sheets. A rabbit corneal stroma defect model was created by lamellar keratoplasty and repaired by transplantation of five pieces of APCS sheets with keratocytes. Six months after transplantation, transparent corneas were present in the experimental group, which were confirmed by anterior segment optical coherence tomography examination and transmittance examination. The biomechanical properties in the experimental group were similar to those of normal cornea. Histological analyses showed an even distribution of keratocytes and well-oriented matrix in the stroma layer in the experimental group. Together, these results demonstrated that the sandwich model using acellular corneal stroma sheets and keratocytes could be potentially useful for corneal stroma regeneration.
Tian, Xiao-Feng; Xia, Xiao-Bo; Xu, Hui-Zhuo; Xiong, Si-Qi; Jiang, Jian
Caveolin-1 expression correlates with the permeability of endothelial barriers and angiogenesis. However, the role of caveolin-1 in retinal neovascularization remains unknown. We evaluated the effect of caveolin-1 on the blood-retina barrier and retinal neovascularization in a murine model of oxygen-induced retinopathy. Starting at postnatal day 7, mice were exposed to 75 ± 5% oxygen for 5 days and then returned to room air conditions to induce retinal neovascularization. Effects on blood-retina barrier were evaluated by Western blot analysis of extravasated albumin in the retina. Retinal neovascularization morphology was studied by fluorescence angiography and was quantified by counts of the endothelial nuclei that protruded into the vitreous cavity. Reverse transcription-polymerase chain reaction and Western blot analysis was used to examine retinal expression levels of caveolin-1. siRNA against caveolin-1 was injected intravitreally in the oxygen-induced retinopathy models. Effects on caveolin-1 mRNA and protein, and retinal neovascularization were assessed as described above. Caveolin-1 expression was found to increase during hypoxia and overexpression of caveolin-1 correlated with the appearance of extravascular albumin. Caveolin-1 siRNA reduced caveolin-1 mRNA and protein levels by 47.94% and 54.76%, respectively. Furthermore, caveolin-1 siRNA inhibition reduced retinal neovascularization by 51.3% and reduced albumin leakage by 56.32%. Caveolin-1 may play an important role in induction of retinal neovascularization. SiRNA against caveolin-1 can inhibit experimental retinal hyperpermeability and neovascularization. Therefore, the inhibition of caveolin-1 may be a powerful and novel therapeutic tool for the treatment of ischaemia-induced retinal diseases. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.
Slean, Geraldine R; Fu, Arthur D; Chen, Judy; Kalevar, Ananda
To report the association of rubeosis iridis with chronic bullous degenerative peripheral retinoschisis. A 63-year-old female presented with acute hyphema and neovascularization of the iris in association with elevated intraocular pressure. Posterior segment examination including imaging revealed no vascular occlusion as a potential cause. However, large, peripheral bullous retinoschisis was noted in the right eye. No nonperfusion aside from that seen within the schism detachment, or neovascularization of the retina on wide-field fundus photography or fluorescein angiography was noted. Bullous retinoschisis was also found in the left eye. The patient was treated conservatively with prednisolone acetate and timolol eye drops. Chronic bullous retinoschisis can be associated with anterior segment neovascularization such as rubeosis iridis, presumably due to non-perfusion within the retinoschisis cavity.
Carstocea, Benone D.; Gafencu, Otilia L.; Apostol, Silvia; Ionita, Marcel A.; Pascu, Mihail-Lucian; Moise, N.; Popescu, Gheorghe; Roman, Miruna; Hogiu, S.
A new method for corneal structure investigation is reported. The light reflected form rabbit cornea is recorded by a video-camera so that the images of epithelium and endothelium are obtained. Because of the great magnification factor due to the corneal curvature, the characteristics of the cells can be directly visualized. The theoretical evaluation of the optical magnification fits reasonably well the experimental results for collimated laser beams; therefore in the future it will be possible to determine with a good accuracy the corneal cell dimensions. Corneal diagnosis based on this method is discussed.
Nicholson, Luke; Chana, Rupinder
We wish to highlight the importance of acknowledging the accompanying effects of topical phenylephrine drops on the eye other than its intended mydriasis. We reported a case of a 92-year-old woman with a corneal graft who was noted to have superficial corneal vascularisation which was not documented previously. After the instillation of topical tropicamide 1% and phenylephrine 2.5%, for funduscopy, the corneal vascularisation was not visible. When reassessed on another visit, tropicamide had no effect on the vessels and only phenylephrine did. We wish to highlight that when reviewing patients in cornea clinics, instilling phenylephrine prior to being seen may mask important corneal vascularisation. PMID:24121816
Full Text Available Pathological neovascularization, a leading cause of blindness, is seen in retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration. Using a mouse model of hypoxia-driven retinal neovascularization, we find that fibroblast growth factor 21 (FGF21 administration suppresses, and FGF21 deficiency worsens, retinal neovessel growth. The protective effect of FGF21 against neovessel growth was abolished in adiponectin (APN-deficient mice. FGF21 administration also decreased neovascular lesions in two models of neovascular age-related macular degeneration: very-low-density lipoprotein-receptor-deficient mice with retinal angiomatous proliferation and laser-induced choroidal neovascularization. FGF21 inhibited tumor necrosis α (TNF-α expression but did not alter Vegfa expression in neovascular eyes. These data suggest that FGF21 may be a therapeutic target for pathologic vessel growth in patients with neovascular eye diseases, including retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration.
Inoue, Tomoyuki; Hara, Yuko; Kobayashi, Takeshi; Zheng, Xiaodong; Suzuki, Takashi; Shiraishi, Atsushi; Ohashi, Yuichi
To describe a characteristic form of the corona sign and its clinical relevance to the degree of corneal endothelial decompensation and investigate the underlying mechanism using a rabbit model. These observational cases include 31 patients undergoing penetrating keratoplasty (PKP) and 15 patients undergoing Descemet stripping automated endothelial keratoplasty (DSAEK) with special attention to the circumferentially developed corneal epithelial edema. We also conducted a laboratory observation of horizontal water flow in the rabbit cornea. We consistently observed the corona sign at the superior periphery during the initial stage of corneal endothelial decompensation after PKP. With progressive corneal endothelial cellular loss, the epithelial edema gradually expanded circumferentially in the periphery. The endothelial cellular density associated with the corona sign significantly (P corona sign compared with a superior corona sign. After DSAEK, however, the corneal epithelial edema subsided from the center but persisted peripherally as a corona sign in all cases. By 3 months postoperatively, the epithelial edema was confined to the superior periphery along with uneventful corneal endothelial healing. Rabbit experiments showed that total corneal endothelial decompensation decreased the horizontal intracorneal water migration (Inoue-Ohashi phenomenon) in the corneal periphery and induced peripheral corneal edema. The slit-lamp microscopic findings of the corona-like epithelial edema in the peripheral cornea are associated with the stage of corneal endothelial function. To support this, the developmental mechanism of the corona sign was demonstrated experimentally.
Aim: To find out the short-term outcome of ciliary ablation with diode laser contact cyclophotocoagulation in Nigerians with neovascular glaucoma. Methods: The study is a retrospective, non-comparative, interventional case series. Demographic data, ocular and systemic history were obtained. Clinical examination included ...
Nor-Masniwati, Saidin; Shatriah, Ismail; Zunaina, Embong
We report a case of myopic choroidal neovascularization that showed improvement after a single injection of ranibizumab. A 45-year-old Chinese man with high myopia presented with sudden onset painless central scotoma of his right eye of 2 weeks' duration. There was no history of trauma. His right eye vision on presentation was 6/30 which showed no improvement with pinhole. The right fundus showed myopic maculopathy at the posterior pole with subretinal hemorrhage at the inferotemporal fovea. The optic disc was tilted with inferotemporal peripapillary atrophy. There was a myopic maculopathy appearance in the macula of the left eye. Fundus fluorescein angiography revealed choroidal neovascularization at the fovea of the right eye. A diagnosis of right eye choroidal neovascularization secondary to myopic maculopathy was made. A single intravitreal injection of ranibizumab 0.05 mL was given. Ten weeks following intravitreal injection, vision had improved to 6/7.5, and repeated fundus fluorescein angiography showed absence of choroidal neovascularization. Follow-up at 6 months showed visual acuity had normalized to 6/6 with glasses, which was maintained up to 12 months following treatment. The right fundus showed no further subretinal hemorrhage with no new lesions.
Full Text Available BACKGROUND: Peripheral nerve damage of the cornea is a complication following surgery or infection which may lead to decreased visual function. We examined the efficacy of the semaphorin 3A inhibitor, SM-345431, in promoting regeneration of peripheral nerves in a mouse corneal transplantation model. METHODOLOGY/PRINCIPAL FINDINGS: P0-Cre/Floxed-EGFP mice which express EGFP in peripheral nerves cells were used as recipients of corneal transplantation with syngeneic wild-type mouse cornea donors. SM-345431 was administered subconjunctivally every 2 days while control mice received vehicle only. Mice were followed for 3 weeks and the length of regenerating nerves was measured by EGFP fluorescence and immunohistochemistry against βIII tubulin. Cornea sensitivity was also measured by the Cochet-Bonnet esthesiometer. CD31 staining was used to determine corneal neovascularization as a possible side effect of SM-345431. Regeneration of βIII tubulin positive peripheral nerves was significantly higher in SM-345431 treated mice compared to control. Furthermore, corneal sensitivity significantly improved in the SM-345431 group by 3 weeks after transplantation. Neovascularization was limited to the peripheral cornea with no difference between SM-345431 group and control. CONCLUSIONS/SIGNIFICANCE: Subconjunctival injections of SM-345431 promoted a robust network of regenerating nerves as well as functional recovery of corneal sensation in a mouse keratoplasty model, suggesting a novel therapeutic strategy for treating neurotrophic corneal disease.
Liu, Yang; Ren, Li; Long, Kai; Wang, Lin; Wang, Yingjun
Corneal disease is a major cause of blindness and keratoplasty is an effective treatment method. However, clinical treatment is limited due to a severe shortage of high-quality allogeneic corneal tissues and the bacterial infection after corneal transplantation. In this study, we develop a novel artificial and antibacterial collagen film (called Col-Tob) for corneal repair. In the Col-Tob film, the tobramycin, which is an aminoglycoside antibiotic to treat various types of bacterial infections, was cross-linked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide and N-hydroxysuccinimide onto the collagen. Physical properties, antibacterial property and biocompatibility of the films were characterized. The results indicate that the film is basically transparent and has appropriate mechanical properties. Cell experiments show that human corneal epithelial cells could adhere to and proliferate well on the film. Most importantly, the film exhibits excellent antibacterial effect in vitro. Lamellar keratoplasty shows that the Col-Tob film can be sutured in rabbit eyes and are epithelialized completely in 15 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization and keratoconus are not observed within 3 months. This film, which can be prepared in large quantities and at low cost,should have potential application in corneal repair. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Ko, Match W L; Dongming Wei; Leung, Christopher K S
Corneal indentation is adapted for the design and development of a characterization method for corneal hysteresis behavior - Corneal Indentation Hysteresis (CIH). Fourteen porcine eyes were tested using the corneal indentation method. The CIH measured in enucleated porcine eyes showed indentation rate and intraocular pressure (IOP) dependences. The CIH increased with indentation rate at lower IOP ( 25 mmHg). The CIH was linear proportional to the IOP within an individual eye. The CIH was positively correlated with the IOP, corneal in-plane tensile stress and corneal tangent modulus (E). A new method based on corneal indentation for the measurement of Corneal Indentation Hysteresis in vivo is developed. To our knowledge, this is the first study to introduce the corneal indentation hysteresis and correlate the corneal indentation hysteresis and corneal tangent modulus.
Full Text Available Venkata S Avadhanam,1,2 Helen E Smith,2 Christopher Liu1–3 1Sussex Eye Hospital, 2Brighton and Sussex Medical School, Brighton, 3Tongdean Eye Clinic, Hove, UK Abstract: According to the World Health Organization, globally 4.9 million are blind due to corneal pathology. Corneal transplantation is successful and curative of the blindness for a majority of these cases. However, it is less successful in a number of diseases that produce corneal neovascularization, dry ocular surface and recurrent inflammation, or infections. A keratoprosthesis or KPro is the only alternative to restore vision when corneal graft is a doomed failure. Although a number of KPros have been proposed, only two devices, Boston type-1 KPro and osteo-odonto-KPro, have came to the fore. The former is totally synthetic and the latter is semi-biological in constitution. These two KPros have different surgical techniques and indications. Keratoprosthetic surgery is complex and should only be undertaken in specialized centers, where expertise, multidisciplinary teams, and resources are available. In this article, we briefly discuss some of the prominent historical KPros and contemporary devices. Keywords: keratoprosthesis, OOKP, KPro, Boston KPro, cornea, ocular surface
Sep 14, 2012 ... Figure 3: A child with pyogenic cornea granuloma intra operatively. After excision of the mass, central corneal stromal defect developed. The patient was followed up for more than a month with topical antibiotic and cycloplegic. Subsequently, the defect healed and leucoma corneal opacity (figure.
Kling, Sabine; Hafezi, Farhad
In recent years, the interest in corneal biomechanics has strongly increased. The material properties of the cornea determine its shape and therefore play an important role in corneal ectasia and related pathologies. This review addresses the molecular origin of biomechanical properties, models for their description, methods for their characterisation, techniques for their modification, and computational simulation approaches. Recent research has focused on developing non-contact techniques to measure the biomechanical properties in vivo, on determining structural and molecular abnormalities in pathological corneas, on developing and optimising techniques to reinforce the corneal tissue and on the computational simulation of surgical interventions. A better understanding of corneal biomechanics will help to improve current refractive surgeries, allow an earlier diagnosis of ectatic disorders and a better quantification of treatments aiming at reinforcing the corneal tissue. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.
Xu, Haifeng; Zeng, Fanxing; Shi, Depeng; Sun, Xiaolei; Chen, Xiuli; Bai, Yao
To evaluate the clinical findings of focal choroidal excavation (FCE) complicated by choroidal neovascularization (CNV). Retrospective, observational case series. Twelve patients (15 eyes) with FCE and CNV. The medical records of the patients were reviewed. Clinical findings including age, sex, refraction, color photography, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and spectral-domain optical coherence tomography (OCT) were analyzed. Fundus fluorescein angiography, ICGA, and OCT findings. The 12 patients included 6 women and 6 men. The mean age was 46.8±13.4 years (range, 26-64 years). One half of the patients were emmetropic, and the others were myopic (-0.5 to -3.0 diopters). All subjects were Chinese. Before CNV development, normal appearance or nonspecific pigment disturbance could be seen around the choroidal excavation. Corresponding to the excavation, window defects were observed by FFA, whereas hypofluorescence was found on ICGA images. Choroidal neovascularization in all eyes was classic as revealed by FFA. The OCT images showed that all eyes had a single choroidal excavation. In 7 of the 15 eyes, the choroidal excavation was located subfoveally, and in the other 8 eyes, it was eccentric. All CNV lesions grew from the bottom or slope of the excavation. Three patients had bilateral involvement. Choroidal neovascularization occurred in both conforming and nonconforming type FCEs, regardless of whether the excavation was shallow or deep, subfoveal or eccentric. All CNV lesions responded well to intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents. After a single injection, CNV regressed in 13 of 15 eyes. Two eyes received an additional injection. Nonconforming FCE changed to the conforming type after successful treatment of CNV. Focal choroidal excavation is not always stable. Choroidal neovascularization commonly can be seen in patients with FCE and responds well to intravitreal anti-VEGF agents
Nor-Masniwati, Saidin; Shatriah, Ismail; Zunaina, Embong
Saidin Nor-Masniwati, Ismail Shatriah, Embong ZunainaDepartment of Ophthalmology, Universiti Sains Malaysia, Kelantan, MalaysiaAbstract: We report a case of myopic choroidal neovascularization that showed improvement after a single injection of ranibizumab. A 45-year-old Chinese man with high myopia presented with sudden onset painless central scotoma of his right eye of 2 weeks’ duration. There was no history of trauma. His right eye vision on presentation was 6/30 which showed no ...
Jurjevic, D; Böni, C; Barthelmes, D; Fasler, K; Becker, M; Michels, S; Stemmle, J; Herbort, C; Zweifel, S A
Background Torpedo maculopathy is a very rare, congenital, usually unilateral hypopigmented lesion in the temporal macula. Material and Methods This retrospective case series describes three patients with torpedo maculopathy. Results The first two cases demonstrate typical clinical and imaging findings of torpedo maculopathy in asymptomatic patients. The third case relates to a symptomatic young patient with a torpedo lesion, a smaller satellite lesion, and evidence of choroidal neovascularization confirmed by fluorescence angiography. In the area of the clinically visible torpedo lesion, spectral domain optical coherence tomography showed atrophy of the outer retina with increased choroidal signalling and a hyperreflective lesion above the retinal pigment epithelium suggestive of choroidal neovascularization. Fundus autofluorescence imaging revealed a hyperautofluorescent rim along the margin of the hypoautofluorescent torpedo lesion. Conclusion In the literature, torpedo lesions are usually regarded as benign lesions with no tendency for progression. The third case demonstrates that torpedo lesions may be associated with choroidal neovascularization, which has been successfully treated with anti-VEGF therapy. Georg Thieme Verlag KG Stuttgart · New York.
Full Text Available Masasko Kuroda,1 Akihiro Nishida,1 Masashi Kikuchi,2 Yasuo Kurimoto11Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Hyogo, Japan; 2Kikuchi Eye Clinic, Kobe, Hyogo, JapanAbstract: We report the case of a 66-year-old Japanese man who developed neovascular glaucoma secondary to Purtscher's retinopathy following a head injury. The patient presented at our hospital with blurred vision and a visual field abnormality in his left eye 1 month after suffering from a head injury. Upon initial presentation, his best-corrected visual acuity on a decimal chart was 1.5 oculus dexter and 0.6 oculus sinister. The intraocular pressure (IOP was 12 mmHg in both eyes. Fundus examination of the left eye revealed multiple white lesions in the posterior pole. Optical coherence tomography demonstrated retinal edema, particularly in the inner retina. On the basis of these findings, a diagnosis of Purtscher's retinopathy was made. One month after the initial examination, the visual acuity in the left eye deteriorated to 0.01 in decimal chart, and the IOP increased to 37 mmHg. Gonioscopy showed angle neovascularization. The patient received an intravitreal bevacizumab injection and panretinal photocoagulation. Subsequently, the IOP normalized and the angle neovascularization regressed.Keywords: blurred vision, visual field, retinal edema, head injury, head trauma
Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K.C.
Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world’s blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies among parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty (ALK), and endothelial keratoplasty (EK). Indications for corneal transplantation vary among countries, with Fuchs’ dystrophy being the leading indication in the U.S. and keratoconus in Australia. With the exception of the US, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, e.g., stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically-engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future. PMID:25268248
Ghadiali, Quraish; Dansingani, Kunal K; Freund, K Bailey
To report a case of focal choroidal excavation and choroidal neovascularization in the setting of pachychoroid disease. Multimodal imaging, including fundus photography, fundus autofluorescence, enhanced depth imaging optical coherence tomography, indocyanine green angiography, and en face structural and angiographic optical coherence tomography. The authors describe a 39-year-old female with moderately high myopia presenting with focal choroidal excavation and associated choroidal neovascularization. Multimodal imaging demonstrated pachychoroid features with dilated choroidal vessels surrounding the lesion. Optical coherence tomography angiography showed Type 2 neovascularization. Some cases of focal choroidal excavation and associated neovascularization may be related to structural abnormalities of the associated choroidal vasculature.
Piñero, David P; Alcón, Natividad
Biomechanics is often defined as 'mechanics applied to biology'. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that are currently commercially available (Ocular Response Analyzer and CorVis ST). The clinical applicability of the parameters provided by these devices are discussed, especially in the fields of glaucoma, detection of ectatic disorders and orthokeratology. Likewise, other methods are also reviewed, such as Brillouin microscopy or dynamic optical coherence tomography and others with potential application to clinical practice but not validated for in vivo measurements, such as ultrasonic elastography. Advantages and disadvantages of all these techniques are described. Finally, the concept of biomechanical modelling is revised as well as the requirements for developing biomechanical models, with special emphasis on finite element modelling. © 2014 The Authors. Clinical and Experimental Optometry © 2014 Optometry Australia.
Wei, Shufang; Zhang, Cuiying; Zhang, Shaoru; Xu, Yanyun; Mu, Guoying
To study the treatment effect of corneal collagen cross-linking (CXL) combined with 440 nm blue light and riboflavin on bacterial corneal ulcer using animal experiments. A total of 21 New Zealand white rabbits that developed Staphylococcus aureus corneal ulcer were randomly divided into three groups. Seven rabbits were used as blank control groups; seven rabbits were treated with CXL combined with riboflavin and 440 nm blue light; and seven rabbits were treated with CXL combined with riboflavin and 370 nm ultraviolet A light. Necrotic tissues or secretions from the ulcer surface, eye secretions, conjunctival hyperemia, hypopyon, corneal infiltration, and pathological changes of the cornea were all observed. The 1st, 3th, and 7th day after CXL treatment, a statistically significant difference was found among the inflammation scores of the three groups. The scores of 440 and 370 groups decreased gradually, significantly lower than that of the control group. Bacterial cultures of 440 and 370 groups turned to be negative while that of the control group remained positive. After 1 day of CXL treatment, pathology pictures of the three groups all showed loss of corneal epithelia with many inflammatory cells in deep stroma. After 7 days of CXL treatment, abscess formed in almost all corneal area in the control group, while in 440 and 370 groups, multilayer healing of corneal epithelia, neovascularization, and many inflammatory cells within ulcers and proliferation of a small amount of fibroblast were seen. CXL combined with riboflavin and 440 nm blue light is effective in treating S. aureus corneal ulcer.
Le, Viet Nhat Hung; Hou, Yanhong; Horstmann, Jens; Bock, Felix; Cursiefen, Claus
Corneal lymphatic vessels are clinically invisible because of their thin walls and clear lymph fluid. There is no easy and established method for in vivo imaging of corneal lymphatic vessels so far. In this study, we present a novel approach to visualize corneal lymphatic vessels in vivo by injecting intrastromal fluorescein sodium. Six- to eight-week-old female BALB/c mice were used in the mouse model of suture-induced corneal neovascularization. Two weeks after the suture placement, fluorescein sodium was injected intrastromally. The fluorescein, taken up by the presumed lymphatic vessels, was then tracked using a clinically used Spectralis HRA + OCT device. Immunohistochemistry staining with specific lymphatic marker LYVE-1 and pan-endothelial marker CD31 was used to confirm the indirect lymphangiography findings. By injecting fluorescein intrastromally, both corneal blood and lymphatic vessels were detected. While the lymphatic vessels were visible as bright vessel-like structures using HRA, the blood vessels appeared as dark networks. Fluorescein-labeled lymphatic vessels were colocalized with LYVE-1 in immunohistochemically stained sections of the same specimen. Corneal lymphatic vessels can be easily imaged in vivo in the murine model using intrastromal fluorescein injection.
... ency/presentations/100082.htm Corneal transplant - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...
Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos; Pascual, Daniel; Marcos, Susana
Biomechanical properties are an excellent health marker of biological tissues, however they are challenging to be measured in-vivo. Non-invasive approaches to assess tissue biomechanics have been suggested, but there is a clear need for more accurate techniques for diagnosis, surgical guidance and treatment evaluation. Recently air-puff systems have been developed to study the dynamic tissue response, nevertheless the experimental geometrical observations lack from an analysis that addresses specifically the inherent dynamic properties. In this study a viscoelastic finite element model was built that predicts the experimental corneal deformation response to an air-puff for different conditions. A sensitivity analysis reveals significant contributions to corneal deformation of intraocular pressure and corneal thickness, besides corneal biomechanical properties. The results show the capability of dynamic imaging to reveal inherent biomechanical properties in vivo. Estimates of corneal biomechanical parameters will contribute to the basic understanding of corneal structure, shape and integrity and increase the predictability of corneal surgery. PMID:25121496
Zahir-Jouzdani, Forouhe; Mahbod, Mirgholamreza; Soleimani, Masoud; Vakhshiteh, Faezeh; Arefian, Ehsan; Shahosseini, Saeed; Dinarvand, Rasoul; Atyabi, Fatemeh
Corneal haze, commonly caused by deep physical and chemical injuries, can greatly impair vision. Growth factors facilitate fibroblast proliferation and differentiation, which leads to haze intensity. In this study, the potential effect of chitosan (CS) and thiolated-chitosan (TCS) nanoparticles and solutions on inhibition of fibroblast proliferation, fibroblast to myofibroblast differentiation, neovascularization, extracellular matrix (ECM) deposition, and pro-fibrotic cytokine expression was examined. Transforming growth factor beta-1 (TGFβ1) was induced by interleukin-6 (IL6) in human corneal fibroblasts and expression levels of TGFβ1, Platelet-derived growth factor (PDGF), α-smooth muscle actins (α-SMA), collagen type I (Col I), fibronectin (Fn) and vascular endothelial growth factor (VEGF) were quantified using qRT-PCR. To assess wound-healing capacity, TCS-treated mice were examined for α-SMA positive cells, collagen deposition, inflammatory cells and neovascularization through pathological immunohistochemistry. The results revealed that CS and TCS could down-regulate the expression levels of TGFβ1 and PDGF comparable to that of TGFβ1 knockdown experiment. However, down-regulation of TGFβ1 was not regulated through miR29b induction. Neovascularization along with α-SMA and ECM deposition were significantly diminished. According to these findings, CS and TCS can be considered as potential anti-fibrotic and anti-angiogenic therapeutics. Furthermore, TCS, thiolated derivative of CS, will increase mucoadhesion of the polymer at the corneal surface which makes the polymer efficient and non-toxic therapeutic approach for corneal injuries. Copyright © 2017 Elsevier Ltd. All rights reserved.
Di Zazzo, Antonio; Tahvildari, Maryam; Subbarayal, Brinda; Yin, Jia; Dohlman, Thomas H; Inomata, Takenori; Mashaghi, Alireza; Chauhan, Sunil K; Dana, Reza
Corneal neovascularization increases the risk of T cell-mediated allograft rejection. Here, we investigate whether T cells promote angiogenesis in transplantation. Conventional effector T cells were collected from draining lymph nodes of allogeneic or syngeneic corneal transplanted BALB/c mice. T cells were either cocultured with vascular endothelial cells (VECs) to assess VEC proliferation or used in a mixed lymphocyte reaction assay. Messenger RNA (mRNA) expression of vascular endothelial growth factor (VEGF)-A, -C, and VEGF receptor 2 (VEGF-R2) in VECs was assessed by real-time PCR. VEGF-A protein expression was determined by enzyme-linked immunosorbent assay. Flow cytometry was used to analyze VEGF-R2 expression in corneal CD31 cells, and VEGF-A and IFNγ expression in corneal CD4 T cells. Allogeneic T cells from high-risk (HR) grafted mice induced more VEC proliferation than those from syngeneic transplant recipients (P = 0.03). Vascular endothelial growth factor-A mRNA and protein expression were higher in T cells from draining lymph nodes (P = 0.03 and P = 0.04, respectively) and cornea (protein; P = 0.04) of HR compared with low-risk (LR) grafted hosts. Vascular endothelial growth factor-A, VEGF-C, and VEGF-R2 mRNA expression were increased in VECs when cocultured with T cells from HR transplants compared with LR transplants and naive mice. In addition, IFNγ blockade in T cell/VEC coculture increased VEC proliferation and VEGF-A protein expression, whereas blocking VEGF-A significantly reduced VEC proliferation (P = 0.04). Allogeneic T cells from corneal transplant hosts promote VEC proliferation, probably via VEGF-A signaling, whereas IFNγ shows an antiangiogenic effect. Our data suggest that T cells are critical mediators of angiogenesis in transplantation.
Bellner, Lars; Wolstein, Jesse; Patil, Kiran A; Dunn, Michael W; Laniado-Schwartzman, Michal
PURPOSE. The heme oxygenase system (HO-1 and HO-2) represents an intrinsic cytoprotective and anti-inflammatory pathway based on its ability to modulate leukocyte migration and to inhibit the expression of inflammatory cytokines and proteins by its products biliverdin/bilirubin and carbon monoxide. Corneal injury in HO-2 null mice leads to impaired healing and chronic inflammatory complications, including ulceration and neovascularization. The authors examined whether topically administered biliverdin can counteract the effects of HO deficiency in a corneal epithelial injury model. METHODS. HO-2 null mice were treated with biliverdin 1 hour before epithelial injury and twice a day thereafter. Reepithelialization and neovascularization were assessed by fluorescein staining and vital microscopy, respectively, and were quantified by image analysis. Inflammation was quantified by histology and Gr-1-specific immunofluorescence, and oxidative stress was assessed by DHE fluorescence. RESULTS. Treatment with biliverdin accelerated wound closure, inhibited neovascularization and reduced epithelial defects. It also reduced inflammation, as evidenced by a reduction in the appearance of inflammatory cells and the expression levels of inflammatory and oxidant proteins, including KC and NOXs. CONCLUSIONS. The results clearly show that biliverdin, directly or through its metabolism to bilirubin by biliverdin reductase-the expression of which is increased after injury-rescues the aberrant inflammatory phenotype, further underscoring the importance of the HO system in the cornea for the execution of an ordered inflammatory and reparative response.
Full Text Available Choroidal nevi are the most common benign pigmented lesions of the fundus. Choroidal neovascularization is a rare complication of choroidal nevi. We report herein a young patient managed successfully with intravitreal bevacizumab injections for juxtapapillary choroidal neovascularization secondary to choroidal nevus simulating an inflammatory lesion.
Sharma, Ajay; Bettis, Daniel I; Cowden, John W; Mohan, Rajiv R
of corneal neovascularization was 1.8, 2.8, and 3.2 mm(2) on days 4, 9, and 14, respectively. Enalapril treatment caused a notable decrease in corneal neovascularization of 44% (1 mm(2)), 28% (2.1 mm(2)), and 31% (2.2 mm(2)) on the three tested time points, respectively. The immunostaining of corneal tissue sections with collagen type IV and lectin confirmed the presence of blood vessels, with enalapril-treated rabbit corneas showing a lesser degree of blood vessel staining. Corneal cells show expression of tissue RAS components, such as ACE, AT(1), and AT(2). Treatment with ACE inhibitor enalapril markedly decreased corneal angiogenesis in a rabbit model of VEGF-induced corneal neovascularization, suggesting that ACE inhibitors may represent a novel therapeutic strategy to treat corneal angiogenesis.
Full Text Available AIM: To investigate the clinical effect for treating bullous keratopathy(BKby anterior corneal stromal acupuncture combined with amniotic membrane transplantation.METHODS: Totally 35 patients(35 eyeswith bullous keratopathy were treated by corneal stromal acupuncture combined with amniotic membrane transplantation. All patients preoperative and postoperative underwent anterior segment OCT, corneal topography, corneal sensitivity and confocal microscopy. To observe postoperative ocular symptoms in patients with BK, recurrence of bulla, changes in corneal thickness, corneal sensitivity and changes in the organizational structure of the layers of the cornea.RESULTS: Thirty-five were followed up for 6-18mo. The symptom of pain disappeared in 32 cases(91%in the first day after operation and did not recur during follow-up. The symptom of pain relieved in 3 cases(9%in the first day after operation and disappeared in 3 days. Corneal epithelium of 9 cases(26%were all healed within 1wk, 21 cases(60%were all healed within 2wk, and 5 cases(14%were all healed within 3wk. Following up for 6-18mo, there was no recurrence of symptoms or bulla. A small amount of tiny bubbles in the surrounding area appeared in 2 cases after 3 and 4wk. All patients had no neovascularization, and had smooth corneal surface. The amnions of 30 cases(86%were thinning after 2mo, partially dissolved and absorped, not seen with the naked eye after 3mo. Thirty-four cases(97%had no changes in vision, one case(3%was from the light to front of the manual. After 2mo, corneal sensation decreased in 30 cases(86%, corneal thickness increased from preoperative 788±35μm to 940±43μm. After 12mo, corneal thickness increased to 1060±27μm. Results of confocal microscopy: after 3mo, the number density of the trigeminal nerve fibers under corneal basement membrane reduced, shallow stromal cells became into fibrotic stroma, deep stroma was more loose, and cells swelled significantly. The number of
Avetisov, Sergey E.; Budzinskaja, Maria V.; Kiseleva, Tatyana N.; Balatskaya, Natalia V.; Gurova, Irina V.; Loschenov, Viktor B.; Shevchik, Sergey A.; Kuzmin, Sergey G.; Vorozhtsov, Georgy N.
This work are devoted our experience with photodynamic therapy (PDT) with > for patients with choroidal neovascularization (CNV). 18 patients with subfoveal CNV in age-related macular degeneration (AMD), 24 patients with subfoveal CNV in pathological myopia (PM) and 4 patients with subfoveal CNV associated with toxoplasmic retinochoroiditis were observed. CNV was 100% classic in all study patients. Standardized protocol refraction, visual acuity testing, ophthalmologic examinations, biomicroscopy, fluorescein angiography, and ultrasonography were performed before treatment and 1 month, 3 months, 6 months, and 1 year after treatment; were used to evaluate the results of photodynamic therapy with > (0.02% solution of mixture sulfonated aluminium phtalocyanine 0.05 mg/kg, intravenously). A diode laser (>, Inc, Moscow) was used operating in the range of 675 nm. Need for retreatment was based on fluorescein angiographic evidence of leakage at 3-month follow-up intervals. At 3, 6, 9 month 26 (56.5%) patients had significant improvement in the mean visual acuity. At the end of the 12-month minimal fluorescein leakage from choroidal neovascularization was seen in 12 (26.1%) patients and the mean visual acuity was slightly worse than 0.2 which was not statistically significant as compared with the baseline visual acuity. Patients with fluorescein leakage from CNV underwent repeated PDT with >. 3D-mode ultrasound shown the decreasing thickness of chorioretinal complex in CNV area. Photodynamic therapy with > can safely reduce the risk of severe vision loss in patients with predominantly classic subfoveal choroidal neovascularization secondary to AMD, PM and toxoplasmic retinochoroiditis.
Full Text Available Lattice corneal dystrophy gelsolin type was first described in 1969 by Jouko Meretoja, a Finnish ophthalmologist. It is caused by an autosomal dominant mutation in gelsolin gene resulting in unstable protein fragments and amyloid deposition in various organs. The age of onset is usually after the third decade of life and typical diagnostic triad includes progressive bilateral facial paralysis, loose skin, and lattice corneal dystrophy. We report a case of a 53-year-old female patient referred to our Department of Ophthalmology by severe dry eye and incomplete eyelid closure. She had severe bilateral facial paresis, significant orbicularis, and perioral sagging as well as hypoesthesia of extremities and was diagnosed with Meretoja’s syndrome at the age of 50, confirmed by the presence of gelsolin mutation. At our observation she had bilateral diminished tear film break-up time and Schirmer test, diffuse keratitis, corneal opacification, and neovascularization in the left eye. She was treated with preservative-free lubricants and topical cyclosporine, associated with nocturnal complete occlusion of both eyes, and underwent placement of lacrimal punctal plugs. Ocular symptoms are the first to appear and our role as ophthalmologists is essential for the diagnosis, treatment, and monitoring of ocular alterations in these patients.
Insler, M S; Lopez, J G
To investigate the ability of extended incubation times to improve the success of endothelial cell transplantation, eight human donor corneas were denuded of their native endothelium, seeded twice during a 1-hr interval with a suspension of cultured infant human corneal endothelial cells, and then incubated for 144 hr under standard conditions. Subsequently the corneas were transplanted into African green monkeys using routine penetrating keratoplasty techniques. Rotational autografts and corneas devoid of endothelial cells served as controls. The seeded corneas appeared hazy at the time of surgery (mean pachymetry 48 hr postoperatively, 0.794 mm). Six corneas (75%) subsequently cleared, yielding a mean corneal thickness of 0.541 +/- 0.040 and 0.554 +/- 0.040 at 6 and 12 postoperative months, respectively. All control eyes showed advanced edema (thickness, greater than 1.0 mm) and developed extensive neovascularization. Clinically, the extended postseeding incubation corneas were observed to clear more rapidly and stabilize their thickness earlier than corneas incubated for only 24-48 hr. Scanning electron microscopy of extended postseeding incubation corneas revealed an intact monolayer of contact-inhibited cells with the hexagonal mosaic typical of corneal endothelium in vivo and improved intercellular contact compared with corneas incubated for only 24-48 hr.
Toffoli, Daniela; Allaire, Guy S; Barkat, Fayrouz; Sebag, Mikaël
We report on a patient with Terson syndrome in the left eye complicated by a neovascularized epiretinal membrane likely secondary to cocaine use. Case report and literature review using the Medline database (1966-2007). A woman known for cocaine use was seen in the ophthalmology clinic for Terson syndrome in the left eye after subarachnoid hemorrhage. Ten months later, a neovascularized epiretinal membrane was noted in the left eye and confirmed with retinal angiography and optical coherence tomography. After vitrectomy, the neovascular membrane was sent for histopathological examination, revealing neovascular capillaries. Neovascularized epiretinal membranes have never been reported in Terson syndrome and in our patient this likely occurred due to an ischemic retinal environment created by cocaine use and decreased retinal perfusion after subarachnoid hemorrhage.
Michel Guerra Almaguer
Full Text Available La principal entidad hereditaria con depósitos de lípidos en el estroma corneal es la distrofia cristalina central, conocida como distrofia de Schnyder, quien la describió en Suiza en 1927. Se caracteriza por depósitos blanco-amarillentos en el estroma corneal central y superficial. Se presenta un paciente de 28 años, del sexo masculino y piel negra, con antecedente de salud anterior. Acudió a consulta y refirió una disminución de la visión y cambio de coloración progresiva de ambos ojos, de años de evolución. En la exploración oftalmológica de ambos ojos se apreciaron lesiones blanquecinas anulares a nivel del estroma corneal, con ligera turbidez corneal central. Los estudios refractivos realizados constataron un astigmatismo hipermetrópico simple. El resto del examen oftalmológico fue negativo. Para el diagnóstico de certeza se empleó el microscopio confocal. Se concluye que el caso presenta una distrofia corneal estromal de tipo cristalina, de Schnyder.
Bing-Jie Zhang; Heng Sun; Yuan-Ping Zhang; Lin-Kun Ma
Corneal transplantation is an ophthalmology treatment technique for corneal disease to help restore vision or control the development of corneal diseases by removing a scarred or damaged host cornea and replacing it with a clear and healthy donor cornea. Traditional corneal transplantation includes penetrating keratoplasty and lamellar keratoplasty. In recent ten years, deep lamellar keratoplasty and endothelial keratoplasty have gradually developed. At present, the development of keratoprost...
Full Text Available Atherosclerosis is a common cardiovascular disease that involves the build-up of plaque on the inner walls of the arteries. Intraplaque neovacularization has been shown to be essential in the pathogenesis of atherosclerosis. Previous studies showed that small-molecule compounds targeting farnesyl transferase have the ability to prevent atherosclerosis in apolipoprotein E-deficient mice, but the underlying mechanism remains to be elucidated. In this study, we found that lonafarnib, a specific inhibitor of farnesyl transferase, elicits inhibitory effect on vascular endothelial capillary assembly in vitro in a dose-dependent manner. In addition, we showed that lonafarnib treatment led to a dose-dependent decrease in scratch wound closure in vitro, whereas it had little effect on endothelial cell proliferation. These data indicate that lonafarnib inhibits neovascularization via directly targeting endothelial cells and disturbing their motility. Moreover, we demonstrated that pharmacological inhibition of farnesyl transferase by lonafarnib significantly impaired centrosome reorientation toward the leading edge of endothelial cells. Mechanistically, we found that the catalytic β subunit of farnesyl transferase associated with a cytoskeletal protein important for the establishment and maintenance of cell polarity. Additionally, we showed that lonafarnib remarkably inhibited the expression of the cytoskeletal protein and interrupted its interaction with farnesyl transferase. Our findings thus offer novel mechanistic insight into the protective effect of farnesyl transferase inhibitors on atherosclerosis and provide encouraging evidence for the potential use of this group of agents in inhibiting plaque neovascularization.
Roy, Abhijit Sinha; Dupps, William J
To investigate the impact of corneal elasticity on corneal shape changes before and after simulated LASIK with and without consideration of whole-eye biomechanics. A finite element whole-eye model of a human eye was constructed. The cornea was modeled as hyperelastic and incompressible using experimental data representing a range of corneal stiffness. The corneal response to intraocular pressure loading and LASIK for 2.00, 4.00, and 6.00 diopters of spherical myopia was analyzed as a function of corneal stiffness and limbal boundary conditions. Myopic LASIK produced different degrees of central flattening and postoperative ametropia in low-stiffness and high-stiffness corneas. Although a cornea-only model demonstrated maximum stresses and displacements in the central cornea and predicted residual myopia, a whole-eye model with equivalent corneal stiffness predicted greater paracentral displacements and less myopic undercorrection. In a whole-eye model with a stiffer cornea, maximum displacements shifted further toward the limbus, favoring additional mechanically mediated central flattening and refractive overcorrection (hyperopia). In postoperative LASIK models thinned by high myopic corrections, corneal stiffening caused central cornea flattening. Differences in the corneoscleral stiffness relationship affect simulated refractive outcomes after LASIK and may be a source of individual variation in refractive surgery outcomes. A whole-eye model allowing limbal motion illustrates a stiffness-dependent biomechanical balance between central corneal flattening and pre-ectatic weakening of the corneal apex not demonstrated in previous computational models and provides insight into under- and overcorrection in myopic LASIK and the previously unexplained phenomenon of corneal flattening after therapeutic collagen cross-linking for keratoconus. Copyright 2009, SLACK Incorporated.
Mearza, Ali A; Koufaki, Fedra N; Aslanides, Ioannis M
To report a case of airbag induced corneal ectasia. Case report. A patient 3 years post-LASIK developed bilateral corneal ectasia worse in the right eye following airbag deployment in a road traffic accident. At last follow up, best corrected vision was 20/40 with -4.00/-4.00 x 25 in the right eye and 20/25 with -1.25/-0.50 x 135 in the left eye. This is a rare presentation of trauma induced ectasia in a patient post-LASIK. It is possible that reduction in biomechanical integrity of the cornea from prior refractive surgery contributed to this presentation.
Nguyen-Khoa, Bao-Anh; Goehring, Earl L; Werther, Winifred; Gower, Emily W; Do, Diana V; Jones, Judith K
To compare the incidence rate of hospitalized myocardial infarctions (MIs) and cerebrovascular accidents (CVAs) in subjects with and without neovascular age-related macular degeneration (AMD). A retrospective database cohort study was performed in subjects with neovascular AMD and controls matched for age, sex, geography, and enrollment duration. Healthcare claims for the study period from January 1, 2002, to June 30, 2005, were used to identify subjects and outcomes. Incidence of hospitalized MI and CVA events and rate ratios adjusted for 11 risk factors were calculated. In 7203 subjects with neovascular AMD and 20,208 controls, the rate of MI was 16.2 events per 1000 subjects with neovascular AMD and 23.1 events per 1000 controls. The adjusted rate ratio for MI was 0.58 (95% confidence interval, 0.48-0.72; P < .001) for subjects with neovascular AMD vs controls. The rate of CVA was 14.3 events per 1000 subjects with neovascular AMD and 22.1 events per 1000 controls. The adjusted rate ratio for CVA was 0.56 (95% confidence interval, 0.45-0.70; P < .001). Rates of MI or CVA were significantly lower in subjects with neovascular AMD than in controls. These findings could not be explained by systematic differences in case selection, health care use, or comorbidities, although other possible biases cannot be ruled out.
Full Text Available O objetivo deste trabalho é relatar e discutir os aspectos de um caso clínico em que foi observada a formação de neovascularização no túnel do anel intra-estromal corneano. Trata-se de paciente com ectasia corneana 4 anos após LASIK, comprovada pela paquimetria e topografia, e submetido ao implante de anel intra-estromal corneano. No terceiro ano de acompanhamento após implante do anel intraestromal, com o paciente em uso de lente de contato gelatinosa, verificou-se extrusão de um segmento e neovascularização no túnel. Removeu-se o segmento afetado, realizou-se fotocoagulação vascular, observando-se regressão completa do quadro neovascular.The purpose of this paper is to describe the clinical aspects of one case with deep corneal vascularization after corneal ring implantation to treat corneal ectasia due to LASIK 4 years before. The corneal ectasia diagnostic was performed by corneal pachimetry and topography. Intrastromal corneal ring segment was implanted. On the third year of follow-up, extrusion of one segment was noted and deep corneal neovascularization was found. The segment was removed, laser photocoagulation was applied and complete vascular regression was observed.
Full Text Available Corneal transplantation is an ophthalmology treatment technique for corneal disease to help restore vision or control the development of corneal diseases by removing a scarred or damaged host cornea and replacing it with a clear and healthy donor cornea. Traditional corneal transplantation includes penetrating keratoplasty and lamellar keratoplasty. In recent ten years, deep lamellar keratoplasty and endothelial keratoplasty have gradually developed. At present, the development of keratoprosthesis provides a new choice for the patients no suitable for traditional. The review describes current surgical techniques in the field of corneal transplantation about indications, postoperative complications, and so on.
Yoshida, Junko; Heflin, Thomas; Zambrano, Andrea; Pan, Qing; Meng, Huan; Wang, Jiangxia; Stark, Walter J; Daoud, Yassine J
Gamma irradiated corneas in which the donor keratocytes and endothelial cells are eliminated are effective as corneal lamellar and glaucoma patch grafts. In addition, gamma irradiation causes collagen cross inking, which stiffens collagen fibrils. This study evaluated gamma irradiated corneas for use in corneal transplantations in a rabbit model comparing graft clarity, corneal neovascularization, and edema. Penetrating keratoplasty was performed on rabbits using four types of corneal grafts: Fresh cornea with endothelium, gamma irradiated cornea, cryopreserved cornea, and fresh cornea without endothelium. Slit lamp examination was performed at postoperative week (POW) one, two, and four. Corneal clarity, edema, and vascularization were graded. Confocal microscopy and histopathological evaluation were performed. A P cornea with endothelium compared to the other three groups (P cornea scored better than the cryopreserved and fresh cornea without endothelium groups in clarity (0.9 vs. 1.5 and 2.6, respectively), and edema (0.6 vs. 0.8 and 2.0, respectively). The gamma irradiated corneas, cryopreserved corneas and the fresh corneas without endothelium, developed haze and edema after POW 2. Gamma irradiated cornea remained statistically significantly clearer than cryopreserved and fresh cornea without endothelium during the observation period (P cornea. Gamma irradiated corneas remained clearer and thinner than the cryopreserved cornea and fresh cornea without endothelium. However, this outcome is transient. Gamma irradiated corneas are useful for lamellar and patch grafts, but cannot be used for penetrating keratoplasty.
Joanna S. Saade
Full Text Available Purpose. To discuss two rare presentations of ocular rosacea in a Hispanic patient and an African American patient with unusual ocular manifestations. Case Report. Case 1: a 43-year-old Hispanic woman presented with right eye corneal perforation. Her prior medical history was significant for rosacea only, diagnosed clinically by a dermatologist. Her eye exam showed signs of bilateral ocular rosacea. An emergent full thickness tectonic corneal patch graft was done. The patient’s bilateral eye symptoms improved one month after initiating rosacea treatment. Case 2: a 51-year-old African American man with long standing history of untreated rosacea presented with bilateral peripheral corneal thinning with neovascularization that led to right eye corneal perforation. Glue and bandage contact lens were applied. The patient did well 4 weeks after starting antibacterial, oral steroids, and rosacea treatment. Discussion. Ocular rosacea can present in Hispanic and African American patients with severe manifestations such as corneal perforation.
Jhanji, Vishal; Sharma, Namrata; Agarwal, Tushar; Vajpayee, Rasik B
Corneal transplantation is the most commonly performed solid organ transplantation in the world. Despite a glorious history of more than a 100 years, the success of conventional corneal transplantation surgery is marred by problems like graft rejection,graft infection and associated glaucoma due to long-term use of topical corticosteroids.In addition there is a dearth of donor corneal tissue in some parts of the world which subsequently adds on to the existing burden on the eye banks every year. We propose alternatives to the conventional corneal transplantation surgery for the management of corneal scarring. The potential use of alternatives to allograft corneal transplantation surgery has been described by corneal surgeons around the world. These techniques consist of nonsurgical interventions like contact lens fitting. Surgical alternatives include excimer laser phototherapeutic keratectomy, optical iridectomy, rotational autokeratoplasty and contralateral autokeratoplasty. Although these techniques are not practiced routinely, however, their appropriate utilization would clearly help the corneal surgeons to get rid of certain problems associated with allograft corneal transplantation. Careful selection of patients can yield encouraging results with the use of these alternative techniques. Visual outcomes may not be as good as after a routine keratoplasty; nevertheless, this setback is outweighed by advantages such as absence of corneal graft rejection. We also believe that the use of these techniques would at least partially resolve the issue of scarcity of donor corneal tissue in the developing world.
Full Text Available Purpose: We report the case of a 77-year-old man with no history of keratoconus or other ectatic disorders who presented with corneal hydrops in the setting of a corneal ulcer. The risk factors, pathogenesis and treatment options of corneal hydrops are discussed. Method: This is an observational case report study. Results: A 77-year-old man presented with a 1-day history of severe pain, redness, mucous discharge and photophobia in the right eye. A slit-lamp examination of the right eye showed an area of focal corneal edema and protrusion. Within the area of edema and protrusion, there was an infiltrate with an overlying epithelial defect consistent with an infectious corneal ulcer. The Seidel test showed no leakage, so a clinical diagnosis of corneal hydrops associated with nonperforated corneal ulcer was made. With appropriate antibiotic treatment, the corneal ulcer and hydrops both resolved over a 1-month period. Conclusion: Corneal hydrops can occur in the setting of corneal infections.
Lee, Jae Hyung; Lee, Won Ki
To describe the clinical and imaging characteristics of choroidal neovascularization (CNV) accompanied by focal choroidal excavation. Retrospective, interventional case series. The medical records of 16 patients (16 eyes) were reviewed. Imaging findings including fluorescein angiography (FA), indocyanine green angiography, and spectral-domain optical coherence tomography (SD OCT) were analyzed. CNV complexes were primarily located beneath the retinal pigment epithelium (type 1 CNV) in 9 eyes and in the subneurosensory retinal space (type 2 CNV) in 7 eyes, as assessed by SD OCT. Seven of 8 patients over 50 years old had type 1 CNV, and 6 of 8 patients under 50 had type 2 lesions. All 7 eyes with type 2 CNV exhibited classic CNV on FA. Additionally, 7 of 9 eyes with type 1 CNV had the classic pattern, and in these eyes, the CNV complexes were confined to the concavity of choroidal excavation. In 15 patients treated by anti-vascular endothelial growth factor (anti-VEGF) injections, the mean best-corrected visual acuity improved from 20/44 to 20/26 with a mean of 3.7 injections during a mean follow-up period of 14.5 months. The CNV growth pattern and extent seem to be determined by the degree of damage to the retinal pigment epithelium/Bruch membrane complex resulting from choroidal excavation, as well as age. Neovascular complexes tend to be located within the boundary of choroidal excavation and are revealed as classic patterns on FA, even in type 1 CNV. Anti-VEGF was notably effective for treating these lesions, with a low rate of recurrence. Copyright © 2014 Elsevier Inc. All rights reserved.
Jia, Changkai; Zhang, Feng; Zhu, Ying; Qi, Xia; Wang, Yiqiang
Matrix-remodeling associated 7 (MXRA7) gene was first reported in 2002 and named so for its co-expression with several genes known to relate with matrix-remodeling. However, not any studies had been intentionally performed to characterize this gene. We started defining the functions of MXRA7 by integrating bioinformatics analysis and experimental study. Data mining of MXRA7 expression in BioGPS, Gene Expression Omnibus and EurExpress platforms highlighted high level expression of Mxra7 in murine ocular tissues. Real-time PCR was employed to measure Mxra7 mRNA in tissues of adult C57BL/6 mice and demonstrated that Mxra7 was preferentially expressed at higher level in retina, corneas and lens than in other tissues. Then the inflammatory corneal neovascularization (CorNV) model and fungal corneal infections were induced in Balb/c mice, and mRNA levels of Mxra7 as well as several matrix-remodeling related genes (Mmp3, Mmp13, Ecm1, Timp1) were monitored with RT-PCR. The results demonstrated a time-dependent Mxra7 under-expression pattern (U-shape curve along timeline), while all other matrix-remodeling related genes manifested an opposite changes pattern (dome-shape curve). When limited data from BioGPS concerning human MXRA7 gene expression in human tissues were looked at, it was found that ocular tissue was also the one expressing highest level of MXRA7. To conclude, integrative assay of MXRA7 gene expression in public databank as well as domestic animal models revealed a selective high expression MXRA7 in murine and human ocular tissues, and its change patterns in two corneal disease models implied that MXRA7 might play a role in pathological processes or diseases involving injury, neovascularization and would healing. Copyright © 2017 Elsevier B.V. All rights reserved.
Lassota, Nathan; Kiilgaard, Jens Folke; Prause, Jan Ulrik
PURPOSE: To develop a reproducible surgical technique for the induction of choroidal neovascularization (CNV) in the subretinal space of porcine eyes and to analyse the resulting CNV clinically and histologically. METHODS: Two different modifications of a surgical technique previously described...
Conclusion: Distinct choroidal neovascular patterns were visualized in these two cases of pediatric CNV when compared to adult subtypes. OCTA is a noninvasive imaging modality capable of evaluating and characterizing pediatric CNV and their associated vascular patterns.
Dhrami-Gavazi, Elona; Balaratnasingam, Chandrakumar; Lee, Winston; Freund, K Bailey
To report a series of age-related macular degeneration (AMD) patients in whom progression to geographic atrophy (GA) in one eye receiving frequent intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) therapy for type 1 neovascularization (NV) was slower than that of the fellow eye with non-neovascular AMD. Retrospective, observational case series examining the clinical course and GA progression rate in four consecutive patients in which one eye harbored type 1 neovascular AMD and was receiving anti-VEGF therapy, while the fellow eye manifested signs of non-neovascular AMD only. Eligibility criteria included anti-VEGF therapy duration of over 4 years and over 50 injections. Lesion evolution was documented via multimodal imaging. GA at baseline and final visits was quantified and GA progression rate for each eye was determined. Four consecutive patients were followed for a mean interval of 94 months (range 62-120). One eye harbored type 1 NV while the fellow eye remained non-neovascular. The former received a mean of 65.5 ± 15.2 anti-VEGF injections. Mean rate of GA progression in non-neovascular eyes was 0.076 ± 0.024 mm2/month and in type 1 NV eyes was 0.004 ± 0.005 mm2/month. Difference in GA progression rate between type 1 and non-neovascular eyes was found to be statistically significant (P = 0.001). These findings support previous hypotheses that, unlike type 2 and 3 lesions, type 1 NV may represent a neovascular AMD subtype more resilient to GA formation. This may have implications for anti-VEGF regimens in the management of type 1 NV.
We evaluated the refractive consequences of corneal transplants using a biomechanical model with homogeneous and inhomogeneous Young's modulus distributions within the cornea, taking into account ablation of some stromal tissue. A FEM model was used to simulate corneal transplants in diseased cornea. The diseased cornea was modeled as an axisymmetric structure taking into account a nonlinearly elastic, isotropic formulation. The model simulating the penetrating keratoplasty procedure gives more change in the postoperative corneal curvature when compared to the models simulating the anterior and posterior lamellar graft procedures. When a lenticle shaped tissue was ablated in the graft during the anterior and posterior keratoplasty, the models provided an additional correction of about -3.85 and -4.45 diopters, respectively. Despite the controversy around the corneal thinning disorders treatment with volume removal procedures, results indicate that significant changes in corneal refractive power could be introduced by a corneal transplantation combined with myopic laser ablation.
Søndergaard, Chris Bath
subpopulations in human corneal epithelium using a combination of laser capture microdissection and RNA sequencing for global transcriptomic profiling. We compared dissociation cultures, using either expansion on γ-irradiated NIH/3T3 feeder cells in serum-rich medium or expansion directly on plastic in serum......-free EpiLife medium, using a range of physiologically relevant oxygen concentrations (2%, 5%, 10%, 15% and 20%). Using immunocytochemistry and advanced fluorescence microscopy, cells were characterized regarding growth, cell cycle distribution, colony-forming efficiency (CFE), phenotypes...... was not dependent on the system used for propagation (Bath et al. 2013a). Laser capture microdissection was used to isolate cellular subpopulations in situ from the spatially defined differentiation pathway in human corneal epithelium according to an optimized protocol for maintenance of expression profiles...
Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant de...
Piñero Llorens, David Pablo; Alcón, Natividad
Biomechanics is often defined as ‘mechanics applied to biology’. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that a...
Liyanage, Sidath E; Mearza, Ali A
To describe a case of airbag-induced corneal flap in a previously normal cornea. Case report. A 27-year-old woman presented with complete loss of vision in her left eye following a road traffic accident which involved airbag deployment. There was no previous ocular history. Examination revealed a large corneal flap of 6mm in diameter, extending to the depth of anterior stroma. This was accompanied by a traumatic optic neuropathy. One month follow-up revealed complete reattachment of the corneal flap. This is the first reported case of a corneal flap induced by airbag deployment in a cornea with previously normal architecture.
Mort, Richard L; Douvaras, Panagiotis; Morley, Steven D; Dorà, Natalie; Hill, Robert E; Collinson, J Martin; West, John D
Maintenance of the corneal epithelium is essential for vision and is a dynamic process incorporating constant cell production, movement and loss. Although cell-based therapies involving the transplantation of putative stem cells are well advanced for the treatment of human corneal defects, the scientific understanding of these interventions is poor. No definitive marker that discriminates stem cells that maintain the corneal epithelium from the surrounding tissue has been discovered and the identity of these elusive cells is, therefore, hotly debated. The key elements of corneal epithelial maintenance have long been recognised but it is still not known how this dynamic balance is co-ordinated during normal homeostasis to ensure the corneal epithelium is maintained at a uniform thickness. Most indirect experimental evidence supports the limbal epithelial stem cell (LESC) hypothesis, which proposes that the adult corneal epithelium is maintained by stem cells located in the limbus at the corneal periphery. However, this has been challenged recently by the corneal epithelial stem cell (CESC) hypothesis, which proposes that during normal homeostasis the mouse corneal epithelium is maintained by stem cells located throughout the basal corneal epithelium with LESCs only contributing during wound healing. In this chapter we review experimental studies, mostly based on animal work, that provide insights into how stem cells maintain the normal corneal epithelium and consider the merits of the alternative LESC and CESC hypotheses. Finally, we highlight some recent research on other stem cell systems and consider how this could influence future research directions for identifying the stem cells that maintain the corneal epithelium.
Corrales, Rosa M; Stern, Michael E; De Paiva, Cintia S; Welch, Jonathan; Li, De-Quan; Pflugfelder, Stephen C
To determine the effects of experimental dryness on production of matrix metalloproteinases (MMPs) and their physiological inhibitors (TIMPs) by the corneal epithelium. Experimental dry eye (EDE) was created in two strains of mice: BALB/c and C57BL/6. Real-time PCR was performed with MMP and TIMP probes, and the results were analyzed by the comparative C(T) method, selecting the relative mRNA levels in untreated control samples as calibrator. Immunofluorescent staining with specific antibodies immunolocalized MMP proteins in situ. MMP enzymatic activity was evaluated in tears and corneal lysates. Corneal permeability to Oregon green dextran (OGD) and sodium fluorescein was measured. Corneal smoothness was evaluated by graded regularity of a ring reflected off the corneal surface. Desiccating stress significantly increased levels of MMP-1, -3, -9, and -10 transcripts in the corneal epithelium in C57BL/6 mice, but had no effect on levels of MMP transcripts in the corneal epithelium of BALB/c mice. There was no change in levels of TIMP transcripts except for TIMP-4 which significantly increased on day 10 in C57BL/6 mice. The MMP-1, -3, and -9 concentration in tears significantly increased compared with control levels after EDE for 4 and 6 days, respectively, in C57BL/6 and BALB/c. Changes in MMP protein expression detected by immunofluorescent staining were similar to changes in gene transcripts for most MMPs. EDE increased corneal permeability to OGD and fluorescein and corneal surface irregularity. Corneal dryness stimulates production of certain MMPs in a strain-dependent fashion and causes the disruption of the corneal barrier, thus increasing permeability and corneal irregularity.
Full Text Available AIM: To compare the effect of two surgical methods on neovascular glaucoma(NVG. METHODS: The clinical date of 46 cases(57 eyeswith NVG underwent surgical treatment were retrospectively analyzed and followed-up. Patients were divided into Ahmed glaucoma valve(AGVimplantation group(group A, 24 cases, 31 eyesand semiconductor diode laser transscleral ciliary body photocoagulation(TSCPCgroup(group B, 22cases, 26 eyesaccording to the surgical approach. The intraocular pressure, visual acuity and postoperative complications were compared before and after operation. RESULTS: The intraocular pressure postoperative in two groups were significantly lower than those preoperative(P P>0.05. The changes of visual acuity postoperative showed no statistical difference between the two groups(P>0.05. The postoperative complications of group A was significantly lower than that in group B, in which the incidence of eye pain, anterior chamber bleeding were significant differences between two groups(P CONCLUSION: AGV implantation treatment and TSCPC for NVG are both valid, but AGV implantation is filtration surgery, and TSCPC isciliary body destructive surgery, and the latter has higher rate of postoperative complications.
Touboul, David; Roberts, Cynthia; Kérautret, Julien; Garra, Caroline; Maurice-Tison, Sylvie; Saubusse, Elodie; Colin, Joseph
To analyze the correlation between corneal hysteresis (CH) measured with the Ocular Response Analyzer (ORA, Reichert) and ultrasonic corneal central thickness (CCT US) and intraocular pressure measured with Goldmann applanation tonometry (IOP GA). Bordeaux 2 University, Ophthalmology Department, Bordeaux, France. This study comprised 498 eyes of 258 patients. Corneal hysteresis, corneal resistance factor (CRF), and IOP corneal-compensated (IOPcc) were provided by the ORA device; CCT US and IOP GA were also measured in each eye. The study population was divided into 5 groups: normal (n = 122), glaucoma (n = 159), keratoconus (n = 88), laser in situ keratomileusis (LASIK) (n = 78), and photorefractive keratectomy (n = 39). The Pearson correlation was used for statistical analysis. Corneal hysteresis was not strongly correlated with IOP or CCT US. The mean CH in the LASIK (8.87 mm Hg) and keratoconus (8.34 mm Hg) groups was lower than in the glaucoma (9.48 mm Hg) and normal (10.26 mm Hg) groups. The lower the CH, the lower its correlation with IOPcc and IOP GA. A CH higher than the CRF was significantly associated with the keratoconus and post-LASIK groups. Corneal hysteresis, a new corneal parameter, had a moderate dependence on IOP and CCT US. Weaker corneas could be screened with ORA parameters, and low CH could be considered a risk factor for underestimation of IOP. The CCT US should continue to be considered a useful parameter.
Hager, Annette; Loge, Kristina; Füllhas, Marc-Oliver; Schroeder, Bernd; Grossherr, Martin; Wiegand, Wolfgang
To assess the changes in corneal hysteresis (CH) as measured by the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, New York, USA) to describe the influence of clear corneal cataract surgery on corneal viscoelastic properties and intraocular pressure (IOP) measured by noncontact tonometry (NCT) and Goldmann applanation tonometry (GAT). Retrospective, interventional, comparative study. One hundred and one eyes of 101 consecutive patients who underwent routine clear corneal cataract surgery were evaluated. CH, NCT, and central corneal thickness (CCT) were measured by ORA before surgery and at postoperative day 1. A control group of 48 pseudophakic eyes (surgery >3 months previously) was included. CCT increased from 556.82 +/- 32.5 microm before surgery to 580.26 +/- 45.5 microm after surgery (P corneal cataract surgery, CH is diminished, whereas CCT is increased significantly. Postoperative corneal edema leads to a change of corneal viscoelastic properties, resulting in a lower damping capacity of the cornea. It is supposed that GAT and NCT measurements are significantly different because of postoperative changes in viscoelastic properties of the cornea.
Ali, Maryam; Raghunathan, VijayKrishna; Li, Jennifer Y; Murphy, Christopher J; Thomasy, Sara M
The posterior face of the cornea consists of the corneal endothelium, a monolayer of cuboidal cells that secrete and attach to Descemet's membrane, an exaggerated basement membrane. Dysfunction of the endothelium compromises the barrier and pump functions of this layer that maintain corneal deturgesence. A large number of corneal endothelial dystrophies feature irregularities in Descemet's membrane, suggesting that cells create and respond to the biophysical signals offered by their underlying matrix. This review provides an overview of the bidirectional relationship between Descemet's membrane and the corneal endothelium. Several experimental methods have characterized a richly topographic and compliant biophysical microenvironment presented by the posterior surface of Descemet's membrane, as well as the ultrastructure and composition of the membrane as it builds during a lifetime. We highlight the signaling pathways involved in the mechanotransduction of biophysical cues that influence cell behavior. We present the specific example of Fuchs' corneal endothelial dystrophy as a condition in which a dysregulated Descemet's membrane may influence the progression of disease. Finally, we discuss some disease models and regenerative strategies that may facilitate improved treatments for corneal dystrophies. Copyright © 2016 Elsevier Ltd. All rights reserved.
Seiler, Theo G; Fischinger, Isaak; Senfft, Tim; Schmidinger, Gerald; Seiler, Theo
To experimentally evaluate the efficacy of corneal crosslinking (CXL) by injecting the photomediator riboflavin into the corneal stroma via intrastromal channels. Five groups of pig corneas, nine each, were compared regarding stress-strain relationship and UV-absorption. Group 1 had intrastromal channels floated with riboflavin 0.5%-solution followed by UVA-irradiation (3 mW/cm(2) for 30 minutes); group 2 was handled like group 1, but were irradiated with 9 mW/cm(2) for 10 minutes; group 3 was treated according to the Dresden protocol (epi-off, 9 mW/cm(2) for 10 minutes); group 4 had the identical channel system, no riboflavin but identical irradiation; group 5 with native corneas served as a control group. The intrastromal channels were created with a femtosecond laser. The stress-strain relations were measured in corneal strips using a uniaxial material tester at strains up to 12%. The UV-transmission of the corneas was measured in groups 1, 3, and 5. The stress needed for a 10% strain was significantly increased by 82% in the corneas treated with the Dresden protocol compared with native cornea (P = 0.0005). With intrastromal application of riboflavin the significant increase was 87% (P = 0.0005) in group 1 and 64% (P = 0.007) in group 2. The channel formation alone did not alter biomechanics (P = 0.923). The corneal UVA-transmission was 2.4% after intrastromal riboflavin application, 8.9% after the treatment according to the Dresden protocol, and 57.9% in native corneas. The experiments demonstrate the intrastromal application of riboflavin by means of intrastromal channels a feasible "epi-on" approach for CXL. More experimental data are needed before clinical testing. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Long, Kai; Liu, Yang; Li, Weichang; Wang, Lin; Liu, Sa; Wang, Yingjun; Wang, Zhichong; Ren, Li
Although collagen with outstanding biocompatibility has promising application in corneal tissue engineering, the mechanical properties of collagen-based scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This article describes a toughness reinforced collagen-based membrane using silk fibroin. The collagen-silk fibroin membranes based on collagen [silk fibroin (w/w) ratios of 100:5, 100:10, and 100:20] were prepared by using silk fibroin and cross-linking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These membranes were analyzed by scanning electron microscopy and their optical property, and NaCl and tryptophan diffusivity had been tested. The water content was found to be dependent on the content of silk fibroin, and CS10 membrane (loading 10 wt % of silk fibroin) performed the optimal mechanical properties. Also the suture experiments have proved CS10 has high suture retention strength, which can be sutured in rabbit eyes integrally. Moreover, the composite membrane proved good biocompatibility for the proliferation of human corneal epithelial cells in vitro. Lamellar keratoplasty shows that CS10 membrane promoted complete epithelialization in 35 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization, and keratoconus are not observed. The composite films show potential for use in the field of corneal tissue engineering. © 2014 Wiley Periodicals, Inc.
Ambati, Balamurali K; Nozaki, Miho; Singh, Nirbhai; Takeda, Atsunobu; Jani, Pooja D; Suthar, Tushar; Albuquerque, Romulo J C; Richter, Elizabeth; Sakurai, Eiji; Newcomb, Michael T; Kleinman, Mark E; Caldwell, Ruth B; Lin, Qing; Ogura, Yuichiro; Orecchia, Angela; Samuelson, Don A; Agnew, Dalen W; St Leger, Judy; Green, W Richard; Mahasreshti, Parameshwar J; Curiel, David T; Kwan, Donna; Marsh, Helene; Ikeda, Sakae; Leiper, Lucy J; Collinson, J Martin; Bogdanovich, Sasha; Khurana, Tejvir S; Shibuya, Masabumi; Baldwin, Megan E; Ferrara, Napoleone; Gerber, Hans-Peter; De Falco, Sandro; Witta, Jassir; Baffi, Judit Z; Raisler, Brian J; Ambati, Jayakrishna
Corneal avascularity-the absence of blood vessels in the cornea-is required for optical clarity and optimal vision, and has led to the cornea being widely used for validating pro- and anti-angiogenic therapeutic strategies for many disorders. But the molecular underpinnings of the avascular phenotype have until now remained obscure and are all the more remarkable given the presence in the cornea of vascular endothelial growth factor (VEGF)-A, a potent stimulator of angiogenesis, and the proximity of the cornea to vascularized tissues. Here we show that the cornea expresses soluble VEGF receptor-1 (sVEGFR-1; also known as sflt-1) and that suppression of this endogenous VEGF-A trap by neutralizing antibodies, RNA interference or Cre-lox-mediated gene disruption abolishes corneal avascularity in mice. The spontaneously vascularized corneas of corn1 and Pax6+/- mice and Pax6+/- patients with aniridia are deficient in sflt-1, and recombinant sflt-1 administration restores corneal avascularity in corn1 and Pax6+/- mice. Manatees, the only known creatures uniformly to have vascularized corneas, do not express sflt-1, whereas the avascular corneas of dugongs, also members of the order Sirenia, elephants, the closest extant terrestrial phylogenetic relatives of manatees, and other marine mammals (dolphins and whales) contain sflt-1, indicating that it has a crucial, evolutionarily conserved role. The recognition that sflt-1 is essential for preserving the avascular ambit of the cornea can rationally guide its use as a platform for angiogenic modulators, supports its use in treating neovascular diseases, and might provide insight into the immunological privilege of the cornea.
Full Text Available AIM: To observe the postoperative intraocular pressure(IOPand operation safety in the eyes of the neovascular glaucoma pateints treated by intraocular cyclophotocoagulation which needed vitrectomy at the same time. METHODS: A total of 12 neovascular glaucoma cases(14 eyessecondary to diabetic retinopathy, retinal detachment surgery and trauma were reviewed in our study. This procedure mainly used intraocular photocoagulation catheter to highlight the ciliary processes until the ciliary became white atrophy or plosion after vitreous surgery treatment. The intraocular photocoagulation catheter was performed at a power of 300-500mW, for a duration of 0.1-0.2ms. Postoperative follow-up was at least for 6mo. The observation of 14 postoperative neovascular glaucoma was performed at 1wk, 1, 6mo observing the IOP and complications. RESULTS: IOP of the 11 eyes was significantly declined and controlled in normal. After cyclophotocoagulation, average IOP at 1wk was 16.7±14.4mmHg, 15.7±8.8mmHg at 1mo and 12.9±4.5mmHg at 6mo, which compared with untreatment(39.6 ±10.0mmHgwas statistically significant different(PCONCLUSION: The intraocular cyclophotocoagulation and vitrectomy simultaneously can deal with the primary disease and secondary neovascular glaucoma. The operation can be accurately performed under direct cyclophotocoagulation and it is a safe and effective way for neovascular glaucoma which needs vitreous surgery.
van Hinsbergh, Victor W. M.; Eringa, Etto C.; Daemen, Mat J. A. P.
Neovascularization is a prominent feature in advanced human atherosclerotic plaques. This review surveys recent evidence for and remaining uncertainties regarding a role of neovascularization in atherosclerotic plaque progression. Specific emphasis is given to hypoxia, angiogenesis inhibition, and
Full Text Available The cornea is a soft tissue located at the front of the eye with the principal function of transmitting and refracting light rays to precisely sense visual information. Corneal shape, refraction, and stromal stiffness are to a large part determined by corneal fibrils, the arrangements of which define the corneal cells and their functional behaviour. However, the modality and alignment of native corneal collagen lamellae are altered in various corneal pathological states such as infection, injury, keratoconus, corneal scar formation, and keratoprosthesis. Furthermore, corneal recuperation after corneal pathological change is dependent on the balance of corneal collagen degradation and contraction. A thorough understanding of the characteristics of corneal collagen is thus necessary to develop viable therapies using the outcome of strategies using engineered corneas. In this review, we discuss the composition and distribution of corneal collagens as well as their degradation and contraction, and address the current status of corneal tissue engineering and the progress of corneal cross-linking.
Kusari, Jyotirmoy; Padillo, Edwin; Zhou, Sheila X.; Bai, Yanyan; Wang, Juanjuan; Song, Zhiming; Zhu, Meili; Le, Yun-Zheng; Gil, Daniel W.
Purpose. To determine whether chronic treatment with brimonidine (BRI) attenuates retinal vascular leakage and neovascularization in neonatal mice after exposure to high oxygen in a mouse model of retinopathy of prematurity (ROP), and choroidal neovascularization (CNV) in rats after laser treatment. Methods. Experimental CNV was induced by laser treatment in Brown Norway (BN) rats. BRI or vehicle (VEH) was administered by osmotic minipumps, and CNV formation was measured 11 days after laser treatment. Oxygen-induced retinopathy was generated in neonatal mice by exposure to 75% oxygen from postnatal day (P)7 to P12. BRI or VEH was administered by gavage, and vitreoretinal vascular endothelial growth factor (VEGF) concentrations and retinal vascular leakage, neovascularization, and vaso-obliteration were measured on P17. Experimental CNV was induced in rabbits by subretinal lipopolysaccharide/fibroblast growth factor-2 injection. Results. Systemic BRI treatment significantly attenuated laser-induced CNV formation in BN rats when initiated 3 days before or within 1 hour after laser treatment. BRI treatment initiated during exposure to high oxygen significantly attenuated vitreoretinal VEGF concentrations, retinal vascular leakage, and retinal neovascularization in P17 mice subjected to oxygen-induced retinopathy. Intravitreal treatment with BRI had no effect on CNV formation in a rabbit model of nonischemic angiogenesis. Conclusions. BRI treatment significantly attenuated vitreoretinal VEGF concentrations, retinal vascular leakage, and retinal and choroidal neovascularization in animal models of ROP and CNV. BRI may inhibit underlying event(s) of ischemia responsible for upregulation of vitreoretinal VEGF and thus reduce vascular leakage and retinal-choroidal neovascularization. PMID:21482645
Full Text Available AIM:To study the clinical effect of trabeculectomy combined with mitomycin and retinal condensation on neovascular glaucoma and their influence on ocular hemodynamics. METHODS:A total of 45 patients(45 eyeswith neovascular glaucoma treated with trabeculectomy, mitomycin and retinal condensation were selected, and the postoperative clinical effect, visual acuity, intraocular pressure(IOPand complications were observed. The color Doppler imaging technique was used to detect hemodynamics index of contralateral and ipsilateral eye before and 2wk after surgeries. RESULTS:All the patients were followed up for 3～6mo. The successful rate was 84%, the rate of forming functional filtering bleb was 82%, and the complication rate was 27%. The IOP at 1, 3 and 6mo after surgeries decreased significantly compared with pre-operation(PPPCONCLUSION:Trabeculectomy combined with mitomycin and retinal condensation has high success rate on treating neovascular glaucoma, which can effectively control IOP, improve vision and ocular hemodynamics.
Yamaguchi, Takefumi; Hamrah, Pedram; Shimazaki, Jun
This review summarizes recent literature regarding corneal imaging in human subjects using in vivo confocal microscopy and corneal immune cells, nerves, and tear cytokine levels in ocular surface diseases as well as corneal immune privilege. The significance of interactions between corneal immune cells and nerves in health, neurotrophic keratopathy, and infectious keratitis are discussed. Furthermore, bilateral alterations of immune cells and nerves in clinically unilateral corneal diseases and the link to changes of tear cytokines or neuropeptide levels in contralateral eyes are described. Recent studies reported increased density and morphologic changes of corneal dendritic cells in ocular surface disease that correlated with a decrease in sub-basal nerve corneal nerves, suggesting potential interactions between the immune and nervous systems in the cornea. Although the relevance of tear cytokines is poorly understood, tear cytokines might have an important role in the pathogenesis of ocular surface diseases. In humans and experimental animal models, alterations in immune cells, cytokines and immunomodulatory neuropeptide levels in contralateral eyes might mediate the incidence of bilateral infectious keratitis and loss of immune privilege of the cornea in bilateral corneal transplantation or neurotrophic keratopathy cases. The discovery of bilateral alterations of immune cells and nerves in ocular surface diseases is considered the missing link between the immune and nervous systems in the cornea, and demonstrates how studies of animal models and human patients aid our understanding of human corneal disease phenomena. PMID:27617877
Kling, Sabine; Akca, Imran B; Chang, Ernest W; Scarcelli, Giuliano; Bekesi, Nandor; Yun, Seok-Hyun; Marcos, Susana
Most techniques measuring corneal biomechanics in vivo are biased by side factors. We demonstrate the ability of optical coherence tomographic (OCT) vibrography to determine corneal material parameters, while reducing current prevalent restrictions of other techniques (such as intraocular pressure (IOP) and thickness dependency). Modal analysis was performed in a finite-element (FE) model to study the oscillation response in isolated thin corneal flaps/eye globes and to analyse the dependency of the frequency response function on: corneal elasticity, viscoelasticity, geometry (thickness and curvature), IOP and density. The model was verified experimentally in flaps from three bovine corneas and in two enucleated porcine eyes using sound excitation (100-110 dB) together with a phase-sensitive OCT to measure the frequency response function (range 50-510 Hz). Simulations showed that corneal vibration in flaps is sensitive to both, geometrical and biomechanical parameters, whereas in whole globes it is primarily sensitive to corneal biomechanical parameters only. Calculations based on the natural frequency shift revealed that flaps of the posterior cornea were 0.8 times less stiff than flaps from the anterior cornea and cross-linked corneas were 1.6 times stiffer than virgin corneas. Sensitivity analysis showed that natural vibration frequencies of whole globes were nearly independent from corneal thickness and IOP within the physiological range. OCT vibrography is a promising non-invasive technique to measure corneal elasticity without biases from corneal thickness and IOP.
Kling, Sabine; Akca, Imran B.; Chang, Ernest W.; Scarcelli, Giuliano; Bekesi, Nandor; Yun, Seok-Hyun; Marcos, Susana
Most techniques measuring corneal biomechanics in vivo are biased by side factors. We demonstrate the ability of optical coherence tomographic (OCT) vibrography to determine corneal material parameters, while reducing current prevalent restrictions of other techniques (such as intraocular pressure (IOP) and thickness dependency). Modal analysis was performed in a finite-element (FE) model to study the oscillation response in isolated thin corneal flaps/eye globes and to analyse the dependency of the frequency response function on: corneal elasticity, viscoelasticity, geometry (thickness and curvature), IOP and density. The model was verified experimentally in flaps from three bovine corneas and in two enucleated porcine eyes using sound excitation (100–110 dB) together with a phase-sensitive OCT to measure the frequency response function (range 50–510 Hz). Simulations showed that corneal vibration in flaps is sensitive to both, geometrical and biomechanical parameters, whereas in whole globes it is primarily sensitive to corneal biomechanical parameters only. Calculations based on the natural frequency shift revealed that flaps of the posterior cornea were 0.8 times less stiff than flaps from the anterior cornea and cross-linked corneas were 1.6 times stiffer than virgin corneas. Sensitivity analysis showed that natural vibration frequencies of whole globes were nearly independent from corneal thickness and IOP within the physiological range. OCT vibrography is a promising non-invasive technique to measure corneal elasticity without biases from corneal thickness and IOP. PMID:25320067
Jiang, Wei; Sun, Hui-Min; Li, Xiao-Rong; Yuan, Xu-Bo; Wang, Yu-Qing; Zhang, Shu-Xian; Tian, En-Jiang; Yuan, Jia-Qin
To evaluate the combined effect of topical rapamycin (RAPA) eye drop in nanometer vector and poly (lactic acid) (PLA) wafers of cyclosporine A (CsA) in the prevention of acute allograft rejection after rabbit corneal transplantation. Methods It was an experimental study. RAPA was incorporated into the nanometer particles and CsA was incorporated into PLA wafers. A was syngeneic control whose both donor and recipient are New Zealand rabbit. Gray donor corneas were implanted into the 102 recipients of New Zealand albino rabbits with corneal neovascularization who were randomly divided into B, C, D, E, F, G 6 groups to receive the different types of therapy: B was no therapy control; C was eye drop of nanometer vector but no RAPA twice a day, 28 days; D was PLA wafers in the anterior chamber of rabbit eyes but no drugs; E was 0.5% RAPA eye drop of nanometer vector twice a day, 28 days; F was PLA wafers of CsA in the anterior chamber of rabbit eyes; G was PLA wafers of CsA in the anterior chamber of rabbit eyes and 0.5% RAPA eye drop of nanometer vector eye drop twice a day for 28 days together. Postoperative evaluation included slit-lamp biomicroscopy, histopathology and immunohistology, Cytokines related with neovascularization and immunosuppression in the corneal tissue by RT-PCR. The graft survival was assessed by One-Way ANOVA and q test. Corneal allograft survival time: A (100.00 +/- 0.00), B (8.44 +/- 1.24), C (8.89 +/- 2.57), D (8.56 +/- 2.30), E (43.11 +/- 5.58), F (43.67 +/- 9.54), G (72.00 +/- 15.34) d. Group G led to a statistically significant prolongation of transplant survival and was superior than group E and F which was a statistical prolongation compared with group B, C and D (qGE = 11.42, qGF = 11.24, qEB = 13.64, qEC = 13.38, qED = 13.46, qFB = 13.82, qFC = 13.56, qFD = 13.64; P < 0.01). Immunohistopathologically, the grafts were subjected to an immune response contained a dense infiltrate of neutrophils, CD4+ and CD8+ T lymphocytes in the group B
Meek, Keith M.; Knupp, Carlo
The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225
Full Text Available AIM: To explore the feasibility of culturing human umbilical vein endothelial cells(HUVECon acellular corneal stroma and performing the posterior lamellar endothelial keratoplasty(PLEKtreating corneal endothelial decompensation.METHODS: Thirty New-Zealand rabbits were divided into three groups randomly, 10 rabbits for experimental group, 10 for stroma group and 10 for control group. Corneal endothelial cells were removed to establish animal model of corneal endothelial failure. PLEK was performed on the rabbits of experimental group and stroma group, and nothing was transplantated onto the rabbits of control group with the deep layer excised only. Postoperative observation was taken for 3mo. The degree of corneal edema and central corneal thickness were recorded for statistical analysis.RESULTS: Corneas in experimental group were relieved in edema obviously compared with that in stroma group and the control group, and showed increased transparency 7d after the operation. The average density of endothelial cells was 2 026.4±129.3cells/mm2, and average central corneal thickness was 505.2±25.4μm in experimental group, while 1 535.6±114.5μm in stroma group and 1 493.5±70.2μm in control group 3mo after operation.CONCLUSION:We achieved preliminary success in our study that culturing HUVEC on acellular corneal stroma and performing PLEK for corneal endothelial decompensation. HUVEC transplanted could survive in vivo, and have normal biological function of keeping cornea transparent. This study provides a new idea and a new way clinically for the treatment of corneal endothelial diseases.
Full Text Available Human corneal endothelial cells (HCECs do not replicate after wounding. Therefore, corneal endothelial deficiency can result in irreversible corneal edema. Descemet stripping automated endothelial keratoplasty (DSAEK allows selective replacement of the diseased corneal endothelium. However, DSAEK requires a donor cornea and the worldwide shortage of corneas limits its application. This review presents current knowledge on the tissue engineering of corneal endothelium using cultured HCECs. We also provide our recent work on tissue engineering for DSAEK grafts using cultured HCECs. We reconstructed DSAEK grafts by seeding cultured DiI-labelled HCECs on collagen sheets. Then HCEC sheets were transplanted onto the posterior stroma after descemetorhexis in the DSAEK group. Severe stromal edema was detected in the control group, but not in the DSAEK group throughout the observation period. Fluorescein microscopy one month after surgery showed numerous DiI-labelled cells on the posterior corneal surface in the DSAEK group. Frozen sections showed a monolayer of DiI-labelled cells on Descemet’s membrane. These findings indicate that cultured adult HCECs, transplanted with DSAEK surgery, maintain corneal transparency after transplantation and suggest the feasibility of performing DSAEK with HCECs to treat endothelial dysfunction.
Khan, Adnan; Akhtar, Naveed; Kamran, Saadat; Ponirakis, Georgios; Petropoulos, Ioannis N; Tunio, Nahel A; Dargham, Soha R; Imam, Yahia; Sartaj, Faheem; Parray, Aijaz; Bourke, Paula; Khan, Rabia; Santos, Mark; Joseph, Sujatha; Shuaib, Ashfaq; Malik, Rayaz A
Corneal confocal microscopy can identify corneal nerve damage in patients with peripheral and central neurodegeneration. However, the use of corneal confocal microscopy in patients presenting with acute ischemic stroke is unknown. One hundred thirty patients (57 without diabetes mellitus [normal glucose tolerance], 32 with impaired glucose tolerance, and 41 with type 2 diabetes mellitus) admitted with acute ischemic stroke, and 28 age-matched healthy control participants underwent corneal confocal microscopy to quantify corneal nerve fiber density, corneal nerve branch density, and corneal nerve fiber length. There was a significant reduction in corneal nerve fiber density, corneal nerve branch density, and corneal nerve fiber length in stroke patients with normal glucose tolerance ( P stroke. Corneal confocal microscopy is a rapid noninvasive ophthalmic imaging technique that identifies corneal nerve fiber loss in patients with acute ischemic stroke. © 2017 American Heart Association, Inc.
Full Text Available Corneal keratoplasty (penetrating or lamellar using cadaveric human tissue, is nowadays the main treatment for corneal endotelial dysfunctions. However, there is a worldwide shortage of donor corneas available for transplantation and about 53% of the world's population have no access to corneal transplantation. Generating a complete cornea by tissue engineering is still a tough goal, but an endothelial lamellar graft might be an easier task. In this study, we developed a tissue engineered corneal endothelium by culturing human corneal endothelial cells on a human purified type I collagen membrane. Human corneal endothelial cells were cultured from corneal rims after corneal penetrating keratoplasty and type I collagen was isolated from remnant cancellous bone chips. Isolated type I collagen was analyzed by western blot, liquid chromatography -mass spectrometry and quantified using the exponentially modified protein abundance index. Later on, collagen solution was casted at room temperature obtaining an optically transparent and mechanically manageable membrane that supports the growth of human and rabbit corneal endothelial cells which expressed characteristic markers of corneal endothelium: zonula ocluddens-1 and Na+/K+ ATPase. To evaluate the therapeutic efficiency of our artificial endothelial grafts, human purified type I collagen membranes cultured with rabbit corneal endothelial cells were transplanted in New Zealand white rabbits that were kept under a minimal immunosuppression regimen. Transplanted corneas maintained transparency for as long as 6 weeks without obvious edema or immune rejection and maintaining the same endothelial markers that in a healthy cornea. In conclusion, it is possible to develop an artificial human corneal endothelial graft using remnant tissues that are not employed in transplant procedures. This artificial endothelial graft can restore the integrality of corneal endothelium in an experimental model of
Fateme Alipour; Mojgan Letafatnejad; Amir Hooshang Beheshtnejad; Seyed-Farzad Mohammadi; Seyed Reza Ghaffary; Narges Hassanpoor; Mehdi Yaseri
Purpose. To evaluate the difference in biomechanical properties between contact lens induced corneal warpage and normal and keratoconic eyes. Method. Prospective observational case control study, where 94 eyes of 47 warpage suspicious and 46 eyes of 23 keratoconic patients were included. Warpage suspected cases were followed until a definite diagnosis was made (warpage, normal, or keratoconus). Results. 44 eyes of 22 patients had contact lens related corneal warpage. 46 eyes of 23 people were...
Hodge, Christopher; Chan, Colin; Bali, Shveta Jindal; Sutton, Gerard
Corneal melting is a rare complication that may occur following a number of different types of surgery. Keratolysis may lead to scarring, irregular astigmatism, photophobia and decreased vision. This article reviews the incidence, pathophysiology and treatment of this condition in kerato-refractive surgery. © 2012 The Authors; Clinical and Experimental Optometry © 2012 Optometrists Association Australia.
Full Text Available BACKGROUND: The role of lymphatic vessels in tissue and organ transplantation as well as in tumor growth and metastasis has drawn great attention in recent years. METHODOLOGY/PRINCIPAL FINDINGS: We now developed a novel method using non-invasive two-photon microscopy to simultaneously visualize and track specifically stained lymphatic vessels and autofluorescent adjacent tissues such as collagen fibrils, blood vessels and immune cells in the mouse model of corneal neovascularization in vivo. The mouse cornea serves as an ideal tissue for this technique due to its easy accessibility and its inducible and modifiable state of pathological hem- and lymphvascularization. Neovascularization was induced by suture placement in corneas of Balb/C mice. Two weeks after treatment, lymphatic vessels were stained intravital by intrastromal injection of a fluorescently labeled LYVE-1 antibody and the corneas were evaluated in vivo by two-photon microscopy (TPM. Intravital TPM was performed at 710 nm and 826 nm excitation wavelengths to detect immunofluorescence and tissue autofluorescence using a custom made animal holder. Corneas were then harvested, fixed and analyzed by histology. Time lapse imaging demonstrated the first in vivo evidence of immune cell migration into lymphatic vessels and luminal transport of individual cells. Cells immigrated within 1-5.5 min into the vessel lumen. Mean velocities of intrastromal corneal immune cells were around 9 µm/min and therefore comparable to those of T-cells and macrophages in other mucosal surfaces. CONCLUSIONS: To our knowledge we here demonstrate for the first time the intravital real-time transmigration of immune cells into lymphatic vessels. Overall this study demonstrates the valuable use of intravital autofluorescence two-photon microscopy in the model of suture-induced corneal vascularizations to study interactions of immune and subsequently tumor cells with lymphatic vessels under close as possible
Executive Summary Objective The purpose of this project was to determine the role of corneal implants in the management of corneal thinning disease conditions. An evidence-based review was conducted to determine the safety, effectiveness and durability of corneal implants for the management of corneal thinning disorders. The evolving directions of research in this area were also reviewed. Subject of the Evidence-Based Analysis The primary treatment objectives for corneal implants are to normalize corneal surface topography, improve contact lens tolerability, and restore visual acuity in order to delay or defer the need for corneal transplant. Implant placement is a minimally invasive procedure that is purported to be safe and effective. The procedure is also claimed to be adjustable, reversible, and both eyes can be treated at the same time. Further, implants do not limit the performance of subsequent surgical approaches or interfere with corneal transplant. The evidence for these claims is the focus of this review. The specific research questions for the evidence review were as follows: Safety Corneal Surface Topographic Effects: Effects on corneal surface remodelling Impact of these changes on subsequent interventions, particularly corneal transplantation (penetrating keratoplasty [PKP]) Visual Acuity Refractive Outcomes Visual Quality (Symptoms): such as contrast vision or decreased visual symptoms (halos, fluctuating vision) Contact lens tolerance Functional visual rehabilitation and quality of life Patient satisfaction: Disease Process: Impact on corneal thinning process Effect on delaying or deferring the need for corneal transplantation Clinical Need: Target Population and Condition Corneal ectasia (thinning) comprises a range of disorders involving either primary disease conditions such as keratoconus and pellucid marginal corneal degeneration or secondary iatrogenic conditions such as corneal thinning occurring after LASIK refractive surgery. The condition
A retrospective study was carried out to determine the results of laser treatment for choroidal neovascular membranes in age-related macular degeneration in 92 patients in whom fluorescein angiography was performed for this condition over a 7-year period. Twenty-nine of these patients, treated with the argon laser, were ...
Sep 1, 1990 ... A retrospective study was carried out to determine the results of laser treatment for choroidal neovascular membranes in age-related macular degeneration in 92 patients in whom fluorescein angiography was performed for this condition over a 7-year period. Twenty-nine of these patients, treated with the ...
Young, S.; Kretlow, J.D.; Nguyen, C.; Bashoura, A.G.; Baggett, L.S.; Jansen, J.A.; Wong, M.; Mikos, A.G.
Vasculogenesis and angiogenesis have been studied for decades using numerous in vitro and in vivo systems, fulfilling the need to elucidate the mechanisms involved in these processes and to test potential therapeutic agents that inhibit or promote neovascularization. Bone tissue engineering in
Though conventional corneal transplantation has achieved great success, it still has several drawbacks including limited availability of donor corneas, recurrent allograft rejection, and subsequent graft failure in certain cases. Reconstructing clinically usable corneas by applying the technology of regenerative medicine can offer a solution to these problems, as well as making corneal transplantation a non-emergency surgery and enabling the usage of banked corneal cells. In the present study, we focused on corneal endothelium that is critical for corneal transparency and investigated the reconstruction of cornea utilizing cultured human corneal endothelial cells (HCECs). We succeeded in steadily culturing HCECs by using culture dishes pre-coated with extracellular matrix produced by calf corneal endothelial cells and culture media that contained basic fibroblast growth factor and fetal bovine serum. We performed the following analysis utilizing these cultured HCECs. The older the donor was, the more frequently large senescent cells appeared in the passaged HCECs. The telomeres of HCECs were measured as terminal restriction fragments (TRF) by Southern blotting. HCECs, in vivo from donors in their seventies had a long TRFs of over 12 kilobases. Passaging shortened the TRFs but there was no difference in TRFs among donors of various ages. These results indicated that shortening of telomere length is not related to senescence of HCECs. We investigated the role of advanced glycation end products (AGEs) in the senescence of in vivo HCECs. The results indicated that AGE-protein in the aqueous humor is endocytosed into HCECs via AGE receptors expressed on the surface of HCECs and damages HCECs by producing reactive oxygen species and inducing apoptosis, suggesting that AGEs, at least partly, cause the senescence of HECEs. HCECs were cultured using adult human serum instead of bovine serum to get rid of bovine material that can be infected with prions. Primary and passage
Tsubota, K; Mashima, Y; Murata, H; Yamada, M.; Sato, N.
AIMS--This study was designed to observe any changes to the corneal epithelium after penetrating keratoplasty. METHODS--The corneal epithelia of 26 patients were observed by specular microscopy 1 week, 1 month, 3 months, and 6 months following penetrating keratoplasty. RESULTS--After re-epithelialisation was confirmed by biomicroscopy 1 week after surgery, specular microscopy revealed many abnormal cells, including spindle shaped cells, nucleated cells, large cells, as well as irregular cell ...
Sanyal, Shalini; Law, Atrayo; Law, Sujata
Ocular toxicity as a consequence of chronic pesticide exposure is one of the health hazards caused due to extended exposure to pesticides. The cornea, due to its position as the outer ocular layer and its role in protecting the internal layers of the eye; is gravely affected by this xenobiotic insult to the eye, leading to ocular irritation and damage to normal vision. The deleterious effects of chronic pesticide exposure on the various corneal layers and the ocular risks involved therein, were explored by mimicking the on-field scenario. Cytological, histological and flowcytometric parameters were taken into consideration to determine the enhanced risk of corneal neovascularisation and keratectasia, specifically, keratoconus. Chronic exposure to pesticides leads to heightened ocular morbidity wherein there were visible pathophysiological changes to the ocular surface. The cornea was found to be adversely affected with visible protuberance in a cone-like shape, characteristic of keratoconus in a majority of the experimental animals. Further analyses revealed a detrimental impact on all the corneal layers and an amplified expression of inflammation markers such as TNF-α, VCAM-1 and ICAM-1. Additionally, it was found that post pesticide exposure, the corneal surface developed hypoxia, leading to a significant increase of angiogenesis promoting factors and consequential neovascularisation. Apart from ocular toxicity, chronic exposure to pesticides significantly increases the risks of keratectasia and corneal neovascularisation; disorders which lead to diminished vision and if untreated, blindness. Copyright © 2017 Elsevier Ltd. All rights reserved.
Savino, Gustavo; Battendieri, Remo; Riso, Monica; Traina, Salvatore; Poscia, Andrea; DʼAmico, Giovanni; Caporossi, Aldo
To evaluate the corneal topography and the topographic changes after ptosis surgery on patients affected by congenital and acquired blepharoptosis. Twenty eyes of 17 patients affected by acquired and congenital ptosis underwent surgical correction through anterior levator complex tightening. Computerized tomography (Syrius Sistem; CSO) was used to analyze any change in corneal astigmatism (CYL), simulated keratometry, anterior corneal symmetry index front, apical keratometry front, and central corneal thickness. Visual acuity, margin reflex distance, and levator function were also measured. After surgical ptosis repair, corneal topography demonstrated a reduction in average keratometry of 0.15 ± 0.47 diopters (D) and in corneal astigmatism of 0.26 ± 1.12 D. Significant differences were found in apical keratometry front (-1.84 ± 1.76 D) and in best-corrected visual acuity (-0.18 ± 0.06 logMAR) in the postoperative examinations. Central corneal thickness did not show significant differences between preoperative and postoperative examinations. Postoperative topographic maps showed a reduction of symmetry index front (0.10 ± 0.64 D). Eyelid ptosis modifies anterior corneal surface inducing refractive errors and modifying corneal astigmatism in patients, thus affecting the quality of vision. The surgical correction of blepharoptosis induces anterior corneal surface modification, restoring corneal symmetry and regular corneal astigmatism. Postoperative corneal topography showed normal corneal contours.
Lombardo, Marco; Serrao, Sebastiano; Rosati, Marianna; Ducoli, Pietro; Lombardo, Giuseppe
To evaluate the corneal response to variable intraocular pressure (IOP) in human eye globes after ultraviolet-A (UVA) transepithelial corneal crosslinking using iontophoresis. Fondazione G.B. Bietti IRCCS, Rome, Italy. Experimental study. Four human donor eye globes were treated with transepithelial crosslinking using iontophoresis and rapid UVA corneal irradiation, and 4 globes had standard crosslinking. Inflation experiments were performed on the globes before and after crosslinking. Topographic maps of the anterior and posterior cornea were acquired using Scheimpflug topography. Images were obtained using a mechanical regimen to analyze corneal strain in response to cyclic stress. Corneal shape changes were analyzed as a function of IOP, and corneal stress-strain curves were generated. Before crosslinking, instillation of hypotonic riboflavin-5-phosphate sodium 0.1% solution using iontophoresis increased corneal thickness by 5% and instillation of dextran-enriched riboflavin 0.1% solution decreased corneal thickness by 13%. Five minutes after treatment, both crosslinking procedures reduced corneal thickness by 2%. Young's modulus (E) of the anterior cornea increased by a mean of 1.8 times (from 1.6 to 2.9 MPa) and 1.9 times (from 1.3 to 2.5 MPa) after transepithelial crosslinking using iontophoresis and standard crosslinking, respectively. The E value of the posterior cornea also increased after both procedures (mean 1.7 times versus 3.1 times). Transepithelial crosslinking using iontophoresis increased the biomechanical strength of human corneal tissue in inflation testing of donor eye globes. The effect on corneal stiffness was almost comparable to that of standard crosslinking. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
This paper presents a novel digital interferometric method to demodulate Placido fringe patterns. This is a synchronous method which uses a computer-stored conic-wavefront as demodulating reference. Here we focuses on the experimental aspects to phase-demodulate Placido mires applied to corneal topography. This synchronous method is applied to two topographic Placido images and their de-modulated corneal-slope deformation is estimated. This conic-interferometric method is highly robust against typical "noisy" signals in Placido topography such as: reflected eyelashes and iris structures. That is because the eyelashes and the iris structure are high frequency "noisy" signals corrupting the reflected Placido mire, so they are filtered-out by this method. Digital synchronous interferometry is here applied for the first time to demodulate corneal topographic concentric-rings images (Patent pending at the USPTO).
Cabrera Fernández, D; Niazy, A M; Kurtz, R M; Djotyan, G P; Juhasz, T
Refractive consequences of corneal transplants are analyzed using corneal biomechanical models assuming homogeneous and inhomogeneous stiffness distributions across the cornea. Additionally, refractive effects of grafts combined with volume removal procedures are also evaluated to develop methods to reduce postoperative refractive management of patients. Refinements of a two-dimensional finite element model are applied to simulate the biomechanical and refractive effects of different corneal transplant procedures: anterior lamellar keratoplasty, posterior lamellar keratoplasty, and penetrating keratoplasty. The models are based on a nonlinearly elastic, isotropic formulation. Predictions are compared with published clinical data. The model simulating the penetrating keratoplasty procedure predicts more change in the postoperative corneal curvature than models simulating anterior lamellar keratoplasty or posterior lamellar keratoplasty procedures. When a lenticle-shaped tissue with a central thickness of 50 microns and a diameter of 4 mm is removed from the anterior corneal surface along with the anterior lamellar keratoplasty or posterior lamellar keratoplasty, the models predict a refractive correction of -8.6 and -8.9 diopters, respectively. Simulations indicate that a posterior lamellar keratoplasty procedure is preferable for obtaining a better corneal curvature profile, eliminating the need for specific secondary treatments.
Tan, Donald T H; Anshu, Arundhati; Mehta, Jodhbir S
Conventional corneal transplantation, in the form of penetrating keratoplasty (PK), involves full-thickness replacement of the cornea, and is a highly successful procedure. However, the cornea is anatomically a multi-layered structure. Pathology may only affect individual layers of the cornea, hence selective lamellar surgical replacement of only the diseased corneal layers whilst retaining unaffected layers represents a new paradigm shift in the field. Recent advancements in surgical techniques and instrumentation have resulted in several forms of manual, microkeratome and femto-second laser-assisted lamellar transplantation procedures. Anterior lamellar keratoplasty (ALK) aims at replacing only diseased or scarred corneal stroma, whilst retaining the unaffected corneal endothelial layer, thus obviating the risk of endothelial allograft rejection. Posterior lamellar keratoplasty/endothelial keratoplasty (PLK/EK) involves the replacement of the dysfunctional endothelial cell layer only. Whilst significant technical and surgical challenges are involved in performing lamellar micro-dissection of a tissue which is only 0.5 mm thick, the benefits of a more controlled surgical procedure and improved graft survival rates have resulted in a shift away from conventional PK. This review details the current advances in emerging lamellar corneal surgical procedures and highlights the main advantages and disadvantages of these new lamellar corneal procedures.
Martinez, C E; Klyce, S D
Keratometry and corneal topography remain the most important means of evaluating induced corneal changes after surgery and have comparable sensitivities in the paracentral region of the cornea. However, keratometry gives no information about the peripheral cornea or about asymmetry of the cornea. Videokeratography should be performed after cataract surgery in cases in which best-corrected visual acuity is not adequate and there are no other obvious causes for poor vision to determine whether corneal irregularities are present. The recent literature on corneal topographic evaluation of induced astigmatism after cataract surgery suggests that in general, smaller, temporal incisions result in less astigmatism. Preoperatively, corneal topography can be used in the calculation of intraocular lens power as well as incision planning. Postoperatively, it can be used to detect tight sutures, torsion of the wound, internal wound gape, and irregular astigmatism, as well as to guide suture removal. In the future, corneal topography will become increasingly important in the determination of intraocular lens power in difficult cases such as patients undergoing combined cataract extraction and penetrating keratoplasty as well as patients with a history of radial keratotomy or photorefractive surgery.
Full Text Available A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are:overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.
Petroll, W M; Roy, P; Chuong, C J; Hall, B; Cavanagh, H D; Jester, J V
The goal of this study was to develop and apply a new set of experimental techniques for measuring the local deformations induced by partial-thickness corneal incisions in situ. Eight adult cat eyes were enucleated and cannulated, with corneal viability maintained as close to in vivo conditions as possible and intraocular pressure (IOP) carefully controlled. Experimental measurements were made pre/post radial keratotomy (RK) surgery in situ at IOPs of 15, 30, and 45 mm Hg. Incision depth and cross-sectional profiles were measured at the midpoint of selected incisions using three-dimensional (3-D) tandem scanning confocal microscopy (TSCM); central corneal curvature was estimated using a commercial corneal topographical analysis system, and corneal thickness was assessed by both 3-D TSCM and ultrasonic pachymetry. Corneas were then processed for light microscopy and incision depth was measured histologically. Finite element models were developed for comparison with the experimental measurements. There was no significant change in central corneal thickness (-5.3 +/- 3.9%, n = 8) over the course of the experiments, demonstrating that normal endothelial cell function and normal stromal hydration was maintained. The in situ TSCM incision depth measurements were significantly correlated with the histological measurements (slope = 0.95, R = 0.854, p mechanical behavior of the cornea after refractive surgery. These data should provide the foundation for future studies into the relationships between local tissue mechanics and corneal wound healing.
Kaji, Yuichi; Yamashita, Hidetoshi; Oshika, Tetsuro
Excimer laser keratectomy is widely used to correct refractive errors. Several complications of excimer laser keratectomy are reported including corneal infection, regression, corneal haze formation, glare and halo. Most of the complications are closely related to the corneal stromal wound healing process. In order to perform the excimer laser keratectomy with minimum complications, we should understand the mechanism of the corneal stroma wound healing process. In addition, such knowledge will help us to regulate the corneal stromal wound healing process in the future. In the present article, we discuss the molecular mechanism of the corneal stromal wound healing process after excimer laser keratectomy and its regulation by anti-inflammatory agents.
Greenstein, Steven A; Shah, Vinnie P; Fry, Kristen L; Hersh, Peter S
To determine the changes in corneal thickness over time after corneal collagen crosslinking (CXL) for keratoconus and corneal ectasia. Cornea and refractive surgery subspecialty practice. Prospective randomized controlled clinical trial. Corneal thickness at the apex, thinnest point, and pupil center were measured using Scheimpflug imaging (Pentacam) at baseline and 1, 3, 6, and 12 months after CXL. The treatment group was compared with both a sham-procedure control group and a fellow-eye control group. Associations with clinical outcomes (uncorrected and corrected distance visual acuities and maximum keratometry) were analyzed. The study comprised 82 eyes, 54 with keratoconus and 28 with ectasia after laser in situ keratomileusis. The mean preoperative thinnest pachymetry was 440.7 μm ± 52.9 (SD). After CXL, the cornea thinned at 1 month (mean change -23.8 ± 28.7 μm; Pdegree of corneal thinning at 3 months and clinical outcomes after CXL. After CXL, the cornea thins and then recovers toward baseline thickness. The cause and implications of corneal thickness changes after CXL remain to be elucidated. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
Elvira Barbosa Abreu
Full Text Available INTRODUCTION: Corneal dystrophy is defined as bilateral and symmetric primary corneal disease, without previous associated ocular inflammation. Corneal dystrophies are classified according to the involved corneal layer in superficial, stromal, and posterior dystrophy. Incidence of each dystrophy varies according to the geographic region studied. PURPOSE: To evaluate the prevalence of stromal corneal dystrophies among corneal buttons specimens obtained by penetrating keratoplasty (PK in an ocular pathology laboratory and to correlate the diagnosis with patient age and gender. METHODS: Corneal button cases of penetrating keratoplasty from January-1996 to May-2009 were retrieved from the archives of The Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, Montreal, Canada. The cases with histopathological diagnosis of stromal corneal dystrophies were stained with special stains (Peroxid acid Schiff, Masson trichrome, Congo red analyzed under polarized light, and alcian blue for classification and correlated with epidemiological information (age at time of PK and gender from patients' file. RESULTS: 1,300 corneal buttons cases with clinical diagnose of corneal dystrophy were retrieved. Stromal corneal dystrophy was found in 40 (3.1% cases. Lattice corneal dystrophy was the most prevalent with 26 cases (65%. Nineteen were female (73.07% and the PK was performed at average age of 59.3 years old. Combined corneal dystrophy was found in 8 (20% cases, 5 (62.5% of them were female and the average age of the penetrating keratoplasty was 54.8 years old. Granular corneal dystrophy was represented by 5 (12.5% cases, and 2 (40% of them were female. Penetrating keratoplasty was performed at average age of 39.5 years old in granular corneal dystrophy cases. Macular corneal dystrophy was present in only 1 (2.5% case, in a 36 years old female. CONCLUSION: Systematic histopathological approach and evaluation, including special stains in all stromal
Full Text Available History of present illness: A 15-year-old male was transported to the emergency department via ambulance as a trauma activation after being struck by an automobile while jogging. Patient was alert and oriented, with no focal neurological deficits and no loss of consciousness. The patient complained of right eye foreign body sensation. Significant findings: Physical exam was significant for multiple broken teeth, multiple minor abrasions on the face, and fine shards of shattered glass on his face and hair. His right eye had conjunctival injection, with no signs of subconjunctival hemorrhage or ocular penetration. Vision, extraocular movement, and pupillary exam were grossly intact. Fluorescein staining with slit lamp exam with cobalt blue filter examination of the right eye revealed superficial bulbar conjunctival uptake of fluorescein dye staining an area of the conjunctiva inferior to the limbus 5 mm vertical by 2 mm horizontal (estimation by photo provided. No foreign bodies were visualized in the inferior fornix. These findings were consistent with superficial conjunctival abrasion. The exam noted sparing of the corneal epithelium. Discussion: The conjunctiva is a thin, transparent membrane covering the ocular surface from the corneal limbus to the posterior eyelid margin.1 When damaged, the patient will classically have a “foreign body” sensation. It is important to identify the extent of the injury as not extending over the cornea, and also to search for lodged foreign bodies that damage the conjunctiva further with each blink. Classically retained foreign bodies will form a linear and vertical pattern of staining with fluorescein.2,3 Fluorescein stains expose basement membrane and fluoresces bright green under ultraviolet light, thus indicating areas of damage in contrast to its surrounding tissue.4,5 In the setting of acute trauma, urgent Ophthalmologic consultation is indicated if there is anterior chamber hemorrhage, a ruptured or
Congdon, Nathan G; Broman, Aimee T; Bandeen-Roche, Karen; Grover, Davinder; Quigley, Harry A
We sought to measure the impact of central corneal thickness (CCT), a possible risk factor for glaucoma damage, and corneal hysteresis, a proposed measure of corneal resistance to deformation, on various indicators of glaucoma damage. Observational study. Adult patients of the Wilmer Glaucoma Service underwent measurement of hysteresis on the Reichert Ocular Response Analyzer and measurement of CCT by ultrasonic pachymetry. Two glaucoma specialists (H.A.Q., N.G.C.) reviewed the chart to determine highest known intraocular pressure (IOP), target IOP, diagnosis, years with glaucoma, cup-to-disk ratio (CDR), mean defect (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), and presence or absence of visual field progression. Among 230 subjects, the mean age was 65 +/- 14 years, 127 (55%) were female, 161 (70%) were white, and 194 (85%) had a diagnosis of primary open-angle glaucoma (POAG) or suspected POAG. In multivariate generalized estimating equation models, lower corneal hysteresis value (P = .03), but not CCT, was associated with visual field progression. When axial length was included in the model, hysteresis was not a significant risk factor (P = .09). A thinner CCT (P = .02), but not hysteresis, was associated with a higher CDR at the most recent examination. Neither CCT nor hysteresis was associated with MD, PSD, or GHT "outside normal limits." Thinner CCT was associated with the state of glaucoma damage as indicated by CDR. Axial length and corneal hysteresis were associated with progressive field worsening.
Cabrera Fernandez, Delia; Niazy, Abdel-Salam M.; Kurtz, Ronald M.; Djotyan, Gagik P.; Juhasz, Tibor
A finite element method was used to study the biomechanical behavior of the cornea and its response to refractive surgery when stiffness inhomogeneities varying with depth are considered. Side-by-side comparisons of different constitutive laws that have been commonly used to model refractive surgery were also performed. To facilitate the comparison, the material property constants were identified from the same experimental data, which were obtained from mechanical tests on corneal strips and membrane inflation experiments. We then validated the resulting model by comparing computed refractive power changes with clinical results. The model developed provides a much more predictable refractive outcome when the stiffness inhomogeneities of the cornea and nonlinearities of the deformations are included in the finite element simulations. Thus, it can be stated that the inhomogeneous model is a more accurate representation of the corneal material properties in order to model the biomechanical effects of refractive surgery. The simulations also revealed that the para-central and peripheral parts of the cornea deformed less in response to pressure loading compared to the central cornea and the limbus. Furthermore, the deformations in response to pressure loading predicted by the non-homogeneous and nonlinear model, showed that the para-central region is mechanically enhanced in the meridional direction. This result is in agreement with the experimentally documented regional differences reported in the literature by other investigators.
Full Text Available Abstract Background The polyherbal eye drop (Itone™ is a mixture of aqueous distillates of nineteen traditionally used ingredients that sum up to impart potency to the formulation and make it a useful adjunct in various ocular pathologies. However, as there have been no controlled experimental studies accounting to the above claim, therefore, the present study was designed to evaluate the polyherbal formulation (PHF for antiangiogenic, anti-inflammatory, anticataract, antioxidant and cytotoxicity in addition to the evaluation of intraocular penetration of PHF in rabbit eyes using LC-MS/MS. Materials and methods Antiangiogenic activity of the PHF was evaluated using in ovo chick chorio-allantoic membrane (CAM assay and in vivo cautery induced corneal neovascularization assay in rats. Anticataract potential was evaluated using steroid induced cataract in developing chick embryos, sodium selenite induced cataract in rat pups and galactose induced cataract in rats. The antioxidant activity was evaluated using di-phenyl picryl hydrazyl (DPPH radical scavenging assay. Anti-inflammatory activity was evaluated in vitro using inhibition of LTB4 formation in human WBCs and in vivo using carrageenan induced paw edema assay in rats. The cytotoxicity was evaluated against HeLa cancer cell lines using (3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Furthermore evaluation of the intraocular penetration of the PHF was carried out in rabbit eyes via aqueous humor paracentesis and further analysis using LC-MS/MS. Results PHF significantly inhibited VEGF induced proliferation of new blood vessels in CAM assay and inhibited the cautery induced corneal neovascularization in rats. Additionally, PHF showed noticeable delay in the progression of cataract in the selenite and galactose induced cataract models whereby the PHF treated lenses were graded for stages II and III respectively. However, the PHF did not show any anticataract activity in
Ichiyama, Yusuke; Sawada, Tomoko; Ito, Yuka; Kakinoki, Masashi; Ohji, Masahito
The aim of the study was to investigate blood flow in choroidal neovascular membrane in remission phase of neovascular age-related macular degeneration using optical coherence tomography (OCT) angiography. OCT angiography was obtained in eyes with remission phase of neovascular age-related macular degeneration after treatments, defined as no exudative change (such as macular edema, subretinal fluid, and subretinal hemorrhage) observed in eyes without any treatment for neovascular age-related macular degeneration within the previous 6 months. Irregular blood flows shown in the segmentation of outer retina detected by OCT angiography were considered as blood flows in choroidal neovascular membrane. The vascular area and vessel density were obtained from OCT angiography images. Twenty eyes of 20 patients were included in this analysis. The blood flows in choroidal neovascular membrane were observed in all eyes (100%) using OCT angiography. The mean vascular area was 3.81 ± 3.41 mm and the mean vessel density of lesion was 28.9 ± 8.2%. The vessel density was significantly correlated with best-corrected visual acuity and duration of remission (best-corrected visual acuity: P = 0.008, r = -0.576; duration of remission: P = 0.017, r = -0.525, respectively). Optical coherence tomography angiography revealed that blood flows in choroidal neovascular membrane remained in eyes with clinically inactive neovascular age-related macular degeneration.
Full Text Available Corneal endothelium is a single layer of specialized cells that lines the posterior surface of cornea and maintains corneal hydration and corneal transparency essential for vision. Currently, transplantation is the only therapeutic option for diseases affecting the corneal endothelium. Transplantation of corneal endothelium, called endothelial keratoplasty, is widely used for corneal endothelial diseases. However, corneal transplantation is limited by global donor shortage. Therefore, there is a need to overcome the deficiency of sufficient donor corneal tissue. New approaches are being explored to engineer corneal tissues such that sufficient amount of corneal endothelium becomes available to offset the present shortage of functional cornea. Although human corneal endothelial cells have limited proliferative capacity in vivo, several laboratories have been successful in in vitro expansion of human corneal endothelial cells. Here we provide a comprehensive analysis of different substrates employed for in vitro cultivation of human corneal endothelial cells. Advances and emerging challenges with ex vivo cultured corneal endothelial layer for the ultimate goal of therapeutic replacement of dysfunctional corneal endothelium in humans with functional corneal endothelium are also presented.
Michel Guerra Almaguer
Full Text Available El dermoide es un tipo de coristoma (tejido embrionario normal en una localización anormal que afecta con frecuencia la córnea. Aparece como una masa sólida, blanca, redonda y elevada. Suele localizarse en el limbo inferotemporal, aunque puede hacerlo en cualquier lugar del globo ocular o de la órbita. Se presenta un paciente masculino, de 8 años de edad, quien desde su nacimiento muestra una mancha blanca en ambos ojos, agudeza visual sin corrección de movimiento de mano a 33 centímetros en el ojo derecho y percepción luminosa en el ojo izquierdo. En la exploración oftalmológica de ambos ojos se apreciaron lesiones blanquecinas sobre la córnea. Se le realizó exéresis del quiste y queratoplastia lamelar de ambos ojos, con resultados visuales satisfactorios. Se concluye que el caso presenta un quiste dermoide corneal bilateral.
Wu, Kuan-I; Chu, Hsiao-Sang; Pai, Amy Shih-I; Hou, Yu-Chih; Lin, Szu-Yuan; Chen, Wei-Li; Hu, Fung-Rong
To assess the surgical and clinical outcomes of anterior lamellar keratoplasty using anterior corneal buttons from Descemet stripping automated endothelial keratoplasty (DSAEK) donor tissue. Retrospective data from 8 patients with unilateral limbal dermoids, treated between February 2011 and January 2016 at National Taiwan University Hospital, were analyzed. Donor corneas for DSAEK were divided into anterior and posterior lamellae using a 350-μm microkeratome. Anterior corneal buttons were stored for up to 4 weeks in storage media before being used as patch grafts for anterior lamellar keratoplasty. Corneoscleral integrity was preserved in all cases. Three of the 8 patients showed improved best-corrected visual acuity after surgery. Three patients' astigmatism reduced by more than 0.75 diopters. All 8 patients had satisfactory cosmesis after surgery. Neovascularization at the graft-host junction and graft edema was noted in 1 patient and was treated using bevacizumab injection and topical steroid. Anterior corneal buttons obtained from DSAEK can be used as patch grafts for surgical management of limbal dermoids. This procedure achieved satisfactory cosmetic and visual outcomes in our study. This procedure may potentially allow one corneal tissue to be received by multiple patients.
Gao, T T; Li, Y; Liu, J; Long, Q
Objective: To describe corneal alterations visible on in vivo confocal microscopy in patients with debilitating ocular sequelae caused by Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Methods: Twenty-two eyes of 11 consecutive patients suffering from chronic SJS or TEN were studied using slit lamp and in vivo confocal microscopy in the Ophthalmology Outpatient Department of Peking Union Medical College Hospital from March 2014 to April 2015. Results: Dry eye with meibomian gland dysfunction (19 eyes of 10 patients, 86.4%) was the most frequent clinical sequelae. Two patients (3 eyes, 13.6%) had severe vison loss with corneal neovascularization and conjunctivization. One patient had asymmetric binocular disease. Corneal epithelial cells were observed at an active state in 10 patients (19 eyes, 86.4%) and corneal stromal cells at an active state in all patients (22 eyes, 100%). Twenty eyes (10 patients, 91%) were noted with abnormal nerve layout and 10 eyes (5 patients, 45.5%) with dendritic cell infiltration around pathological nerve damages. Numerous inflammory cells were observed in 6 eyes (3 patients, 27.3%). Conclusions: The corneas of patients with chronic ocular sequelae associated with SJS or TEN present a number of abnormalities. In vivo confocal microscopy is a potetial useful tool for therapeutic indications and for follow-up of the debilitating chronic ocular problems linked to SJS and TEN. (Chin J Ophthalmol, 2017, 53:177-181) .
Kurtz, Ron M.; Spooner, Greg J. R.; Sletten, Karin R.; Yen, Kimberly G.; Sayegh, Samir I.; Loesel, Frieder H.; Horvath, Christopher; Liu, HsiaoHua; Elner, Victor; Cabrera, Delia; Muenier, Marie-Helene; Sacks, Zachary S.; Juhasz, Tibor
We evaluated the efficacy, safety, and stability of femtosecond laser intrastromal refractive procedures in ex vivo and in vivo models. When compared with longer pulsewidth nanosecond or picosecond laser pulses, femtosecond laser-tissue interactions are characterized by significantly smaller and more deterministic photodisruptive energy thresholds, as well as reduced shock waves and smaller cavitation bubbles. We utilized a highly reliable, all-solid-state femtosecond laser system for all studies to demonstrate clinical practicality. Contiguous tissue effects were achieved by scanning a 5 μm focused laser spot below the corneal surface at pulse energies of approximately 2 - 4 microjoules. A variety of scanning patterns was used to perform three prototype procedures in animal eyes; corneal flap cutting, keratomileusis, and intrastromal vision correction. Superior dissection and surface quality results were obtained for lamellar procedures (corneal flap cutting and keratomileusis). Preliminary in vivo evaluation of intrastromal vision correction in a rabbit model revealed consistent and stable pachymetry changes, without significant inflammation or loss of corneal transparency. We conclude that femtosecond laser technology may be able to perform a variety of corneal refractive procedures with high precision, offering advantages over current mechanical and laser devices and techniques.
Vernal keratoconjunctivitis (VKC) is a severe bilateral chronic allergic inflammatory disease of the ocular surface. In most of the cases, the disease is limited to the tarsal conjunctiva and to the limbus. However, in the more severe cases, the cornea may be involved, leading to potentially sight threatening complications. Prompt recognition of these complications is crucial in the management of VKC, which is one of the most severe ocular allergic diseases. A vicious cycle of inflammation occurs as a result of a set of reciprocal interactions between the conjunctiva and the cornea, which results in damage to the corneal epithelium and corneal stoma, and to the formation of shield ulcers and plaques, infectious keratitis, keratoconus, scarring, and limbal stem cell deficiency. These corneal complications can cause permanent decrease or loss of vision in children suffering from VKC. Corneal complications in VKC are the result of an on-going process of uncontrolled inflammation. Proper recognition of the corneal complications in VKC is crucial, as most of these can be managed or prevented by a combination of medical and surgical measures.
André Luís Beling da Rosa
Corneal topography consists of measuring the corneal shape, which is a key factor for visual acuity. The exam is used, for instance, in keratoconus detection, personalized contact lens fitting, in pre- and post-procedures associated with refractive surgery and corneal transplants. This thesis presents an accessible, inexpensive and portable approach to perform corneal topographies. The results obtained with our prototype show a mean difference of about 0.02 millimeters, equivalent to 0.5% of ...
Full Text Available Corneal collagen cross-linking(CXLcould increase the mechanical strength, biological stability and halt ectasia progression due to covalent bond formed by photochemical reaction between ultraviolet-A and emulsion of riboflavin between collagen fibers in corneal stroma. Corneal melting is an autoimmune related noninfectious corneal ulcer. The mechanism of corneal melting, major treatment, the basic fundamental of ultraviolet-A riboflavin induced CXL and the clinical researches status and experiment in CXL were summarized in the study.
El Matri L
Full Text Available Leila El Matri, Ahmed Chebil, Fedra Kort Department B of Ophthalmology, Hedi Rais Institute of Ophthalmology, Faculty of Medicine of Tunis, University of El Manar, Tunis, Tunisia Abstract: Choroidal neovascularization (CNV is the main cause of visual impairment in highly myopic patients younger than 50 years of age. There are different treatments for myopic CNV (mCNV, with 5- to 10-year outcomes currently. Chorioretinal atrophy is still the most important determinant factor for visual outcome. The purpose of this study is to provide an overview of the current treatments for mCNV, including laser, surgical management, verteporfin photodynamic therapy, and mainly anti-vascular endothelial growth factor therapy. Emerging treatment options are also discussed. Keywords: myopia, choroidal neovascularization, current treatment, emerging treatment
Full Text Available [english] A healthy 12 month old infant without significant medical history presented with left eye redness for one week. Ophthalmic examination showed elevated intraocular pressure with iris neovascularization in the affected eye with increased optic nerve cupping. Scleral depression revealed a ciliary body mass in the supratemporal quadrant. A large, non-pigmented, vascular mass was noted; biopsy results showed multilayered cords, tubules, and sheets resembling primitive medullary epithelium arising from the ciliary body. The patient was diagnosed with medulloepithelioma. The patient underwent enucleation of the affected eye. Medulloepithelioma is a rare but important cause of neovascular glaucoma in the pediatric population. This case will focus on the characteristics of medulloepthelioma and the differential diagnosis for a non-pigmented ciliary body mass in a child.
Velazquez-Villoria, D; Macià Badia, C; Rigo Quera, J; Velez-Escola, L; Arcos-Algaba, G; Martínez-Castillo, V; García-Arumí, J
A 27-year old woman presented with loss of vision in the right eye (20/200). Ophthalmoscopic examination showed intrarretinal hemorrhage in the macular region with neurosensory detachment in the right eye, and viteliform deposit on the left eye. Fluorescein angiography and the electrooculogram confirmed the diagnosis of choroidal neovascularization associated with Best's disease. Four weeks after a single bevacizumab intravitreal injection, visual acuity was restored (20/25) and remained stable after a 12 month follow-up. Intravitreal bevacizumab appears to be an effective treatment for choroidal neovascularization associated to Best's disease. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.
Luo, Hailang; Lu, Yongbo; Wu, Tiantian; Zhang, Mi; Zhang, Yongjie; Jin, Yan
Although acellular corneas have been reported to be a potential substitute for allogeneic cornea transplantation to treat corneal injury, severe corneal injury is hard to repair due to inflammation and neovascularization. The use of the amniotic membrane as a graft in ocular surface reconstruction has become widespread because of the anti-inflammatory and anti-angiogenic properties of amniotic epithelial cells (AECs). Our objective was to construct a tissue-engineered cornea (TEC) composed of an acellular porcine cornea (APC) and AECs to repair severe corneal injury. Corneal cells were completely removed from the prepared APC, and the microstructure, mechanical properties, and stability of a natural porcine cornea (NPC) was maintained. In vitro, MTT and flow cytometry analyses showed that the APC did not negatively affect cell viability and apoptosis. In vivo, corneal pocket and subcutaneous transplantation demonstrated that the APC was incapable of trigging accepted immune response. AECs isolated from the human amniotic membrane have proliferation potential and present healthy morphology before 6 passages. After 7 days of culture on the surface of the APC, the AECs were stratified into 5-6 layers. We found that the AECs reconstituted the basement membrane that had been disrupted by the decellularization process. ELISA results showed that after culturing the TEC, the culture medium contained anti-inflammatory and anti-angiogenic growth factors, such as MIF, IL6, Fas-L, and PDEF. Finally, the results of lamellar keratoplasty to treat an alkali burn showed that the transplanted TEC was transparent and completely inoculated into the host cornea. However, the transplanted APC was degraded due to host rejection. Therefore, we conclude that a TEC composed of AECs and an APC holds great potential for the repair of severe corneal injury. Copyright © 2013 Elsevier Ltd. All rights reserved.
Badial, Peres R; Cisneros-Àlvarez, Luis Emiliano; Brandão, Cláudia Valéria S; Ranzani, José Joaquim T; Tomaz, Mayana A R V; Machado, Vania M; Borges, Alexandre S
The aim of this study was to compare ocular dimensions, corneal curvature, and corneal thickness between horses affected with hereditary equine regional dermal asthenia (HERDA) and unaffected horses. Five HERDA-affected quarter horses and five healthy control quarter horses were used. Schirmer's tear test, tonometry, and corneal diameter measurements were performed in both eyes of all horses prior to ophthalmologic examinations. Ultrasonic pachymetry was performed to measure the central, temporal, nasal, dorsal, and ventral corneal thicknesses in all horses. B-mode ultrasound scanning was performed on both eyes of each horse to determine the dimensions of the ocular structures and to calculate the corneal curvature. Each corneal region examined in this study was thinner in the affected group compared with the healthy control group. However, significant differences in corneal thickness were only observed for the central and dorsal regions. HERDA-affected horses exhibited significant increases in corneal curvature and corneal diameter compared with unaffected animals. The ophthalmologic examinations revealed mild corneal opacity in one eye of one affected horse and in both eyes of three affected horses. No significant between-group differences were observed for Schirmer's tear test, intraocular pressure, or ocular dimensions. Hereditary equine regional dermal asthenia-affected horses exhibit decreased corneal thickness in several regions of the cornea, increased corneal curvature, increased corneal diameter, and mild corneal opacity. Additional research is required to determine whether the increased corneal curvature significantly impacts the visual accuracy of horses with HERDA. © 2014 American College of Veterinary Ophthalmologists.
Menon, I.A.; Basu, P.K.; Hasany, S.M.; Persad, S.D. (Univ. of Toronto, Ontario (Canada))
The phototoxic effects of 8-methoxypsoralen (8-MOP) were investigated using the rabbit corneal endothelium in organ culture. The corneas were divided into four groups: (a) irradiated with a mercury vapor lamp (emitting UVA and visible radiation) in the presence of 8-MOP (experimental), (b) irradiated without 8-MOP (control A), (c) incubated with 8-MOP (control B) and (d) incubated without 8-MOP (control C). Specular and light microscopic examination showed that the experimental corneas had greater cellular damage compared to the control corneas. The effects of 8-MOP were restricted to certain localized areas of the cornea. However there was no significant difference in the amounts of 51Cr released from the labelled experimental and control corneas. These results show phototoxic damage of the corneal endothelial cells.
Prafulla K Maharana
Full Text Available Acute corneal hydrops is a condition characterized by stromal edema due to leakage of aqueous through a tear in descemet membrane. The patient presents with sudden onset decrease in vision, photophobia, and pain. Corneal thinning and ectasias combined with trivial trauma to the eye mostly by eye rubbing is considered as the underlying cause. With conservative approach self-resolution takes around 2 to 3 months. Surgical intervention is required in cases of non-resolution of corneal edema to avoid complications and for early visual rehabilitation. Intracameral injection of air or gas such as perflouropropane is the most common surgical procedure done. Recent investigative modality such as anterior segment optical coherence tomography is an extremely useful tool for diagnosis, surgical planning, and postoperative follow up. Resolution of hydrops may improve the contact lens tolerance and visual acuity but most cases require keratoplasty for visual rehabilitation.
Avendaño-Cantos, E M; Celis-Sánchez, J; Mesa-Varona, D; Gálvez-Martínez, J; López-Arroquia, E; González Del Valle, F
A 64 year-old female with Parkinson disease treated with amantadine for two years who suddenly suffered bilateral corneal oedema. It was initially treated as herpetic endotheliitis without improvement as we lacked information on her chronic treatment. The corneal oedema finally resolved after withdrawing the drug. Amantadine hydrochloride may produce endothelial dysfunction. Once the amantadine treatment is stopped, the corneal oedema may be reversible but endothelial density remains low. An ophthalmologist examination should be performed before the initiation of amantadine treatment in order to establish a risk: benefit ratio, especially in those patients with low endothelial density or any endothelial anomaly. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.
Full Text Available AIM: To discuss the effect and safety of Ahmed valve implantation in late neovascular glaucoma. METHODS: The Ahmed glaucoma valve were implanted in 41 eyes(41 caseswith late neovascular glaucoma, the follow-up was 12 months on average, intraocular pressure was recorded at 1 day, 1 week, 1 month, 3, 6, 12 months respectively after operation and compared with that before operation, at the same time, the complications and treatment were analyzed.RESULTS: The mean intraocular pressure before operation, 1 day, 1 week, 1 month, 3, 6, 12 months after operation was 59.83±5.53, 19.27±8.19, 19.69±6.86, 20.67±6.73, 21.05±6.93, 21.49±7.42, 22.14±8.08mmHg, the mean intraocular pressure before operation was higher than that after operation and the difference was obvious in statistics. Major complications included hyphema, low intraocular pressure early postoperation, shallow anterior chamber, obstruction of the tube, the plate wrapped or exposed.CONCLUSION: Ahmed valve implantation is an effective method to treatlate neovascular glaucoma.
Full Text Available The purpose of this study was to evaluate posterior corneal surface variation after femtosecond laser-assisted keratomileusis in patients with myopia and myopic astigmatism. Patients were evaluated by corneal tomography preoperatively and at 1, 6, and 12 months. We analyzed changes in the posterior corneal curvature, posterior corneal elevation, and anterior chamber depth. Moreover, we explored correlation between corneal ablation depth, residual corneal thickness, percentage of ablated corneal tissue, and preoperative corneal thickness. During follow-up, the posterior corneal surface did not have a significant forward corneal shift: no significant linear relationships emerged between the anterior displacement of the posterior corneal surface and corneal ablation depth, residual corneal thickness, or percentage of ablated corneal tissue.
Full Text Available AIM:To investigate the role of heparanase-1 in laser-induced choroidal neovascularization (CNV.METHODS:Experimental CNV was induced by krypton laser photocoagulation in 15 male Brown Norway rats. Fundus fluorescein angiography and histopathological examination were performed in observing the CNV development. The expression and distribution of heparanase-1 protein in the laser lesions were determined by immunohistochemistry and western blotting analysis.RESULTS:The success rate of laser induced CNV was approximately 75% on 3-4 weeks after laser photocoagulation. The protein levels of heparanase-1 increased significantly in the retina-choroidal complex of CNV models when compared to normal rat eyes (P<0.01. Immunostaining confirmed strong heparanase-1 expressions in all laser lesions, and it displayed to be highest at the newly formed blood vessels within the fibrovascular complex in the subretinal space.CONCLUSION:Heparanase-1 is closely involved in the development of laser induced CNV.
Rätsep, Tõnu; Minajeva, Ave; Asser, Toomas
Lumbar disc degeneration may be associated with intensity of neovascularization in disc herniations. Our study was designed to evaluate how much the severity of histodegeneration is related to the development of neovascularization and to the level of pleiotrophin in the herniated lumbar discs. Surgically excised lumbar disc specimens were obtained from 29 patients with noncontained (i.e., extruding through the posterior longitudinal ligament) and 21 patients with contained disc herniations. The histodegeneration scores and levels of neovascularization were estimated according to semiquantitative analysis in lumbar disc and endplate samples. Immunohistochemical staining were performed to identify the newly formed blood vessels and to detect the presence of pleiotrophin in the specimens. Higher levels of disc and endplate neovascularity were registered in noncontained herniations. The level of neovascularization was significantly related to the score of histodegeneration in the herniated disc tissues but not in the endplate specimens. Both contained and noncontained herniations had the highest values of histodegeneration in conjunction with the highest level of neovascularization but the relations between neovascularity and degenerative changes remained to be significant only in the group of noncontained herniations. Registration or frequency of pleiotrophin positive cells did not correlate significantly with histodegeneration or level of neovascularization in the disc samples. Severe histodegeneration of the lumbar disc herniations is associated with enhanced neovascularization and potentially also spontaneous regression of the herniated tissue.
Full Text Available Choroidal neovascular membrane, a known complication of choroidal osteoma causing visual loss when located subfoveally, can be successfully treated with transpupillary thermo therapy.
Verdier, David D.; Sugar, Alan; Baratz, Keith; Beck, Roy; Dontchev, Mariya; Dunn, Steven; Gal, Robin L.; Holland, Edward J.; Kollman, Craig; Lass, Jonathan H.; Mannis, Mark J.; Penta, Jeffrey
Purpose Assess corneal thickness (CT) and correlation with graft outcome after penetrating keratoplasty in the Cornea Donor Study. Methods 887 subjects with a corneal transplant for a moderate risk condition (principally Fuchs or pseudophakic corneal edema) had post-operative CT measurements throughout a 5 year follow up time. Relationships between baseline (recipient, donor, and operative) factors and CT were explored. Proportional hazards models were used to assess association between CT and graft failure. Relationship between CT and cell density was assessed with a longitudinal repeated measures model and Spearman correlation estimates. Results Higher longitudinal CT measurements were associated with diagnosis of pseudophakic or aphakic corneal edema (P 25mmHg during the first post-operative month (P=0.003), white (non-Hispanic) donor race (P=0.002) and respiratory causes of donor death (P600μm. In multivariate analysis, both 1 year CT and cell density were associated with subsequent graft failure (P=0.002 and 0.009). CT increase was modestly associated with endothelial cell loss during follow up (r=-0.29). Conclusion During the first 5 years following penetrating keratoplasty, CT can serve as a predictor of graft survival. However, CT is not a substitute for cell density measurement as both measures were independently predictive of graft failure. PMID:23343949
Hoyt, Kenneth; Umphrey, Heidi; Lockhart, Mark; Robbin, Michelle; Forero-Torres, Andres
A novel image processing strategy is detailed for simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. After normalization and tumor segmentation, a global time-intensity curve describing contrast agent flow was analyzed to derive surrogate measures of tumor perfusion (i.e., peak intensity, time-to-peak intensity, area under the curve, wash-in rate, wash-out rate). A maximum intensity image was generated from these same segmented image sequences, and each vascular component was skeletonized via a thinning algorithm. This skeletonized data set and collection of vessel segments were then investigated to extract parameters related to the neovascular network and physical architecture (i.e., vessel-to-tissue ratio, number of bifurcations, vessel count, average vessel length and tortuosity). An efficient computation of local perfusion parameters was also introduced and operated by averaging time-intensity curve data over each individual neovascular segment. Each skeletonized neovascular segment was then color-coded by these local measures to produce a parametric map detailing spatial properties of tumor perfusion. Longitudinal DCE-US image data sets were collected in six patients diagnosed with invasive breast cancer using a Philips iU22 ultrasound system equipped with a L9-3 transducer and Definity contrast agent. Patients were imaged using US before and after contrast agent dosing at baseline and again at weeks 6, 12, 18 and 24 after treatment started. Preliminary clinical results suggested that breast tumor response to neoadjuvant chemotherapy may be associated with temporal and spatial changes in DCE-US-derived parametric measures of tumor perfusion. Moreover, changes in neovascular morphology parametric measures may also help identify any breast tumor response (or lack thereof) to systemic treatment. Breast cancer management from early detection to therapeutic
Jain, Harsh Vardhan
Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O(2)) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O(2)-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O(2) pressure (pO(2)) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO(2) to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases.
Sakimoto, Tohru; Sawa, Mitsuru
Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases with the potential to degrade all types of extracellular matrix. The ADAM (a disintegrin and metalloproteinase) family of peptidases was recently identified as cleaving the extracellular domain of transmembrane proteins. This was termed ectodomain shedding. We investigated the MMP expression in patients with corneal diseases and the potential role of ADAMs in corneal pathophysiology. We detected upregulation of the active form of MMP-2 and MMP-9 in the tear fluid from patients with corneal melting or recurrent corneal erosion. Using human corneal epithelial cells, we observed ADAM17-dependent ectodomain shedding of soluble tumor necrosis factor receptor 1 and soluble interleukin-6 (IL-6) receptor (sIL-6R). The production of sIL-6R was also induced by messenger RNA splicing in the human corneal epithelial cells. IL-6/sIL-6R-induced signal transducer and activator of transcription 3 phosphorylation was observed in cultured human corneal fibroblasts, suggesting that IL-6 trans-signaling induced inflammatory cellular signaling in the human corneal fibroblasts. We demonstrated that MMPs are significantly upregulated in collagen-destructive disorders of the cornea. Additionally, we observed that ectodomain shedding by ADAMs in corneal epithelial cells mediated the production of soluble cytokine receptors. Trans-signaling of IL-6 can induce an inflammatory response in corneal stroma, indicating the significance of IL-6 trans-signaling in ocular surface inflammation. Thus, MMPs and ADAMs play an important role in the pathophysiology of corneal diseases.
Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane; Hanneken, Ludger
Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain. PMID:25444646
Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane; Hanneken, Ludger
Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.
Coster, Douglas J
Corneal transplantation is a triumph of modern ophthalmology. The possibility of corneal transplantation was first raised in 1797 but a century passed before Zirm achieved the first successful penetrating graft in 1905. Gibson reported the first corneal graft in Australia from Brisbane in 1940 and English established the first eye bank there a few years later. Corneal transplantation evolved steadily over the twentieth century. In the second half of the century, developments in microsurgery, including surgical materials such as monofilament nylon and strong topical steroid drops, accounted for improvements in outcomes. In 2013, approximately 1500 corneal transplants were done in Australia. Eye banking has evolved to cope with the rising demands for donor corneas. Australian corneal surgeons collaborated to establish and support the Australian Corneal Graft Registry in 1985. It follows the outcomes of their surgery and has become an important international resource for surgeons seeking further improvement with the procedure. © 2014 Royal Australian and New Zealand College of Ophthalmologists.
Muniesa, MaJesús; Muniesa Royo, MaJesús; March, Ana; March de Ribot, Ana; Sánchez-de-la-Torre, Manuel; Huerva, Valetín; Huerva Escanilla, Valetín; Jurjo, Carmen; Jurjo Campo, Carmen; Barbé, Ferran; Barbé Illa, Ferran
To determine corneal biomechanical properties in patients with floppy eyelid syndrome (FES) and to compare them with eyes of controls. This case-control study included 208 eyes (72 eyes with FES and 136 without FES) of 107 patients (37 patients with FES and 70 without FES). Patients underwent a complete clinical eye examination that included corneal biomechanical evaluation carried out with the Reichert Ocular Response Analyzer. Corneal hysteresis (CH), corneal resistance factor (CRF), central corneal thickness (CCT), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) were evaluated. Mean CH was significantly lower in patients with FES than in those without FES (9.51 ± 1.56 vs. 11.66 ± 9.11; P corneal biomechanical properties could be changed in patients with FES, reflecting additional structural changes in FES.
Huang, Yi-Hsun; Tseng, Fan-Wei; Chang, Wen-Hsin; Peng, I-Chen; Hsieh, Dar-Jen; Wu, Shu-Wei; Yeh, Ming-Long
In this study, we developed a novel method using supercritical carbon dioxide (SCCO 2 ) to prepare acellular porcine cornea (APC). Under gentle extraction conditions using SCCO 2 technology, hematoxylin and eosin staining showed that cells were completely lysed, and cell debris, including nuclei, was efficiently removed from the porcine cornea. The SCCO 2 -treated corneas exhibited intact stromal structures and appropriate mechanical properties. Moreover, no immunological reactions and neovascularization were observed after lamellar keratoplasty in rabbits. All transplanted grafts and animals survived without complications. The transplanted APCs were opaque after the operation but became transparent within 2weeks. Complete re-epithelialization of the transplanted APCs was observed within 4weeks. In conclusion, APCs produced by SCCO 2 extraction technology could be an ideal and useful scaffold for corneal tissue engineering. We decellularized the porcine cornea using SCCO 2 extraction technology and investigated the characteristics, mechanical properties, and biocompatibility of the decellularized porcine cornea by lamellar keratoplasty in rabbits. To the best of our knowledge, this is the first report describing the use of SCCO 2 extraction technology for preparation of acellular corneal scaffold. We proved that the cellular components of porcine corneas had been efficiently removed, and the biomechanical properties of the scaffold were well preserved by SCCO 2 extraction technology. SCCO 2 -treated corneas maintained optical transparency and exhibited appropriate strength to withstand surgical procedures. In vivo, the transplanted corneas showed no evidence of immunological reactions and exhibited good biocompatibility and long-term stability. Our results suggested that the APCs developed by SCCO 2 extraction technology could be an ideal and useful scaffold for corneal replacement and corneal tissue engineering. Copyright © 2017 Acta Materialia Inc. Published by
Hanlon, Samuel D.
Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (~10nm diameter). Immunogold evidence clearly
Madhavan H N
. Cells or tissues can be embedded in a liquid Mebiol gel solution at lower than 20°C and cultured three dimensionally in a hydrogel state at 37°C. The sol-gel transition temperature can be controlled by altering chemical composition of thermo-reversible gelation polymer (TGP. Mebiol Gel prevents the growth of the fibroblasts and it is not toxic to cells. In our earlier study, continuous culture cell lines 18 and we demonstrated that Mebiol Gel supported the growth of corneal limbal epithelial cells and these cells expressed both limbal and corneal phenotype, suggesting that limbal epithelial cells cultivated in Mebiol Gel would be a promising material for corneal surface tissue engineering. With this in view, we developed a novel method of cultivation of human limbal cells in a synthetic scaffold made of a thermo reversible polymer, that allows the limbal epithelial cells to survive, proliferate and differentiate into corneal epithelial cells and demonstrated the effectiveness of this polymer for corneal tissue engineering using an experimentally induced limbal deficiency in a rabbit model. In this report, the detailed procedure of the animal model and the results are discussed. We evaluated the efficacy of autologous expanded corneal epithelial cell transplants derived from harvested limbal biopsy cultured on a thermo-reversible polymer (Mebiol Gel for the management of unilateral limbal stem cell disease (LSCD.Corneal limbal biopsies from 12 rabbits were cultured on Mebiol Gel at 37°C. Cells were harvested from the dishes after 3 weeks by reducing temperature to 4°C. Autologous transplantation was undertaken to reconstruct the experimentally induced limbal stem cell deficiency in the rabbit eyes. The corneas of both eyes of all rabbits were harvested later for histological and RT-PCR studies. Reparative surgery was a total success in 7 (58.3%; score, 8-10, partial success in 2 (16.7%; score, 6-7 and failure in 3 (25%; score, <5. Histological and RT-PCR study
Full Text Available The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV, and other nonfibrillar collagens (XIII and XVIII. FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.
Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619
report, Figs. 2-7. Rose Bengal (RB) photosensitization was tested because RB is FDA-allowed as a diagnostic for corneal abrasions...incisions. J Cataract Refract Surg, 30, 2420-4. Personnel supported by this grant All personnel are employed by the Massachusetts General Hospital
To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus.
Wisse, Robert P L; Soeters, Nienke; Godefrooij, Daniel A.; De Koning-Tahzib, Nayyirih G.
Keratoconus is a corneal disease with onset typically occurring during puberty or early adulthood. The cornea progressively thins and acquires a cone-like shape which negatively affects visual acuity. In the early stages, visual acuity can be corrected with glasses or contact lenses. In more
Sen, Emine; Onaran, Yüksel; Nalcacioglu-Yuksekkaya, Pinar; Elgin, Ufuk; Ozturk, Faruk
To evaluate the variation in biomechanical properties and central corneal thickness (CCT) for each trimester during pregnancy and to compare the values with those in nonpregnant women. We prospectively studied the eyes of 32 pregnant and 34 age-matched non-pregnant women. The parameters included corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOP), and corneal-compensated IOP measured by the Ocular Response Analyzer (ORA). The CCT was also measured with an ultrasonic pachymeter attached to the ORA. The mean age was 27.0 ± 3.8 years in the study group and 28.0 ± 4.1 years in the control group. The mean CH measurement was 10.6 ± 1.4 mmHg in the study group and 10.1 ± 1.3 mmHg in the control group. The mean CRF value was 9.6 ± 1.7 mmHg in the study group and 10.0 ± 1.4 mmHg in the control group. The mean CCT value was 541.1 ± 22.4 µm in the study group and 536.5 ± 27.1 µm in the control group. No statistically significant differences were found regarding CH, CRF, or CCT values between the 2 groups (independent t test, p = 0.160, p = 0.355, p = 0.450, respectively). Hormonal changes during pregnancy may not affect corneal biomechanics. This may be due to the balanced effect of the various hormones on the cornea during pregnancy.
Full Text Available Hassan Razmjoo1,2, Mohammad-Ali Abtahi1,2,4, Peyman Roomizadeh1,3, Zahra Mohammadi1,2, Seyed-Hossein Abtahi1,3,41Medical School, Isfahan University of Medical Sciences (IUMS; 2Ophthalmology Ward, Feiz Hospital, IUMS; 3Isfahan Medical Students Research Center (IMSRC, IUMS; 4Isfahan Ophthalmology Research Center (IORC, Feiz Hospital, IUMS, Isfahan, IranAbstract: Corneal bee sting is an uncommon environmental eye injury that can result in various ocular complications with an etiology of penetrating, immunologic, and toxic effects of the stinger and its injected venom. In this study we present our experience in the management of a middle-aged male with a right-sided deep corneal bee sting. On arrival, the patient was complaining of severe pain, blurry vision with acuity of 160/200, and tearing, which he had experienced soon after the injury. Firstly, we administered conventional drugs for eye injuries, including topical antibiotic, corticosteroid, and cycloplegic agents. After 2 days, corneal stromal infiltration and edema developed around the site of the sting, and visual acuity decreased to 100/200. These conditions led us to remove the stinger surgically. Within 25 days of follow-up, the corneal infiltration decreased gradually, and visual acuity improved to 180/200. We suggest a two-stage management approach for cases of corneal sting. For the first stage, if the stinger is readily accessible or primary dramatic reactions, including infiltration, especially on the visual axis, exist, manual or surgical removal would be indicated. Otherwise, we recommend conventional treatments for eye injuries. Given this situation, patients should be closely monitored for detection of any worsening. If the condition does not resolve or even deteriorates, for the second stage, surgical removal of the stinger under local or generalized anesthesia is indicated.Keywords: bee sting, stinger, cornea, removal, management, surgery
Zotov, V V; Pashtaev, N P; Pozdeeva, N A
Over the last decade, corneal collagen cross-linking (CXL) has become a conventional treatment method for progressive keratoconus. Laboratory studies have shown that CXL increases the diameter of collagen fibers and also the number of intra- and interfibrillar cross-links, thus, increasing biomechanical strength of the irradiated cornea. As confirmed by a series of clinical and randomized controlled trials, CXL is able to slow down and, perhaps, to stop the progression of keratoconus. In most post-CXL patients visual acuity improves, while keratometric readings, spherical equivalent, and higher order aberrations reduce. Although published results prove CXL effective in the treatment of progressive keratoconus, its late consequences are yet unknown. This article reviews the stages of CXL development and results of published experimental and clinical studies. Prospects for CXL modifications that do not require epithelial debridement are discussed.
Full Text Available AIM: To study the role of immature dendritic cells (imDCs on immune tolerance in rat penetrating keratoplasty (PKP in high-risk eyes and to investigate the mechanism of immune hyporesponsiveness induced by donor-derived imDCs. METHODS: Seventy-five SD rats (recipient and 39 Wistar rats (donor were randomly divided into 3 groups: control, imDC and mature dendritic cell (mDC group respectively. Using a model of orthotopic corneal transplantation in which allografts were placed in neovascularized high-risk eyes of recipient rat. Corneal neovascularization was induced by alkaline burn in the central cornea of recipient rat. Recipients in imDC group or mDC group were injected donor bone marrow-derived imDCs or mDCs of 1×106 respectively 1 week before corneal transplantation via tail vein. Control rat received the same volume of PBS. In each group, 16 recipients were kept for determination of survival time and other 9 recipients were executed on day 3, 7 and 14 after transplantation. Cornea was harvested for hematoxylin-eosin staining and acute rejection evaluation, Western blot was used to detect the expression level of Foxp3. RESULTS: The mean survival time of imDC group was significantly longer than that of control and mDC groups (all P<0.05. The expression level of Foxp3 on CD4+CD25+T cells of imDC group (2.24±0.18 was significantly higher than that in the control (1.68±0.09 and mDC groups (1.46±0.13 (all P<0.05. CONCLUSION: Donor-derived imDC is an effective treatment in inducing immune hyporesponsiveness in rat PKP. The mechanism of immune tolerance induced by imDC might be inhibit T lymphocytes responsiveness by regulatory T cells.
Moreno, Miguel; Pow, Poh Yih; Tabitha, Tan Su Teng; Nirmal, Sonali; Larsson, Andreas; Radhakrishnan, Krishna; Nirmal, Jayabalan; Quah, Soo Tng; Geifman Shochat, Susana; Agrawal, Rupesh; Venkatraman, Subbu
This paper describes the synthesis of thiolated chitosan-based hydrogels with varying degrees of crosslinking that has been utilized to modulate release kinetics of two clinically relevant FDA-approved anti-VEGF protein drugs, ranibizumab and aflibercept. These hydrogels have been fabricated into disc shaped structures for potential use as patches on ocular surface. Protein conformational changes and aggregation after loading and release was evaluated by circular dichroism (CD), steady-state tryptophan fluorescence spectroscopy, electrophoresis and size-exclusion chromatography (SEC). Finally, the capacity of both released proteins to bind to VEGF was tested by ELISA and surface plasmon resonance (SPR) technology. The study demonstrates the versatility of thiolated chitosan-based hydrogels for delivering proteins. The effect of various parameters of the hydrogel on protein release kinetics and mechanism of protein release was studied using the Korsmeyer-Peppas release model. Furthermore, we have studied the stability of released proteins in detail while comparing it with non-entrapped proteins under physiological conditions to understand the effect of formulation conditions on protein stability. The disc-shaped thiolated chitosan-based hydrogels provide a potentially useful platform to deliver ranibizumab and aflibercept for the treatments of ocular diseases such as wet AMD, DME and corneal neovascularization.
McClintic, S M; Srinivasan, M; Mascarenhas, J; Greninger, D A; Acharya, N R; Lietman, T M; Keenan, J D
Bacterial keratitis results in corneal scarring and subsequent visual impairment. The long-term evolution of corneal scars has not been well described. In this case series, we identified patients who had improvement in corneal scarring and visual acuity from a clinical trial for bacterial keratitis. We searched the records of the Steroids for Corneal Ulcers Trial (SCUT) for patients who had improvement in vision between the 3-month and 12-month visits and reviewed their clinical photographs. Of the 500 patients enrolled in SCUT, five patients with large central corneal scars due to bacterial keratitis are presented. All experienced improvement in rigid contact lens-corrected visual acuity from months 3 to 12. All patients also had marked improvement in corneal opacity during the same time period. None of the patients opted to have penetrating keratoplasty. Corneal scars may continue to improve even many months after a bacterial corneal ulcer has healed. The corneal remodeling can be accompanied by considerable improvement in visual acuity, such that corneal transplantation may not be necessary.
Klyce, Stephen D.; Wilson, Steven E.
The cornea is the major refractive element in the eye; even minor surface distortions can produce a significant reduction in visual acuity. Standard clinical methods used to evaluate corneal shape include keratometry, which assumes the cornea is ellipsoidal in shape, and photokeratoscopy, which images a series of concentric light rings on the corneal surface. These methods fail to document many of the corneal distortions that can degrade visual acuity. Algorithms have been developed to reconstruct the three dimensional shape of the cornea from keratoscope images, and to present these data in the clinically useful display of color-coded contour maps of corneal surface power. This approach has been implemented on a new generation video keratoscope system (Computed Anatomy, Inc.) with rapid automatic digitization of the image rings by a rule-based approach. The system has found clinical use in the early diagnosis of corneal shape anomalies such as keratoconus and contact lens-induced corneal warpage, in the evaluation of cataract and corneal transplant procedures, and in the assessment of corneal refractive surgical procedures. Currently, ray tracing techniques are being used to correlate corneal surface topography with potential visual acuity in an effort to more fully understand the tolerances of corneal shape consistent with good vision and to help determine the site of dysfunction in the visually impaired.
Karabulut, Gamze Ozturk; Kaynak, Pelin; Altan, Cıgdem; Ozturker, Can; Aksoy, Ebru Funda; Demirok, Ahmet; Yılmaz, Omer Faruk
The purpose of this study is to investigate the effect of thyroid eye disease (TED) on the measurement of corneal biomechanical properties and the relationship between these parameters and disease manifestations. A total of 54 eyes of 27 individuals with TED and 52 eyes of 30 healthy control participants were enrolled. Thyroid ophthalmopathy activity was defined using the VISA (vision, inflammation, strabismus, and appearance/exposure) classification for TED. The intraocular pressure (IOP) measurement with Goldmann applanation tonometer (GAT), axial length (AL), keratometry, and central corneal thickness (CCT) measurements were taken from each patient. Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF) and noncontact IOP measurements, Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc) were measured with the Ocular Response Analyzer (ORA) using the standard technique. Parameters such as best corrected visual acuity, axial length, central corneal thickness, and corneal curvature were not statistically significant between the two groups (p > 0.05). IOP measured with GAT was higher in participants with TED (p corneal resistance factor between groups. However, IOPg and IOPcc were significantly higher in TED patients. CH and VISA grading of TED patients showed a negative correlation (p = 0.007). In conclusion, TED affects the corneal biomechanical properties by decreasing CH. IOP with GAT and IOPg is found to be increased in these patients. As the severity of TED increases, CH decreases in these patients. Copyright © 2014. Published by Elsevier B.V.
Full Text Available Mitra Tavakoli1, Parwez Hossain2, Rayaz A Malik11Division of Cardiovascular Medicine, University of Manchester and Manchester Royal Infirmary, Manchester, UK; 2University of Southampton, Southampton Eye Unit, Southampton General Hospital, Southampton, UKAbstract: Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowman’s layer, stroma, Descemet’s membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious conditions, corneal dystrophies and ecstasies, monitoring contact lens induced corneal changes and for pre and post surgical evaluation (PRK, LASIK and LASEK, flap evaluations and Radial Keratotomy, and penetrating keratoplasty. Most recently it has been used as a surrogate for peripheral nerve damage in a variety of peripheral neuropathies and may have potential in acting as a surrogate marker for endothelial abnormalities.Keywords: corneal confocal microscopy, cornea, infective keratitis, corneal dystrophy, neuropathy
Matthew S Oliva
Full Text Available Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world′s largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.
A study protocol for a multicentre randomised clinical trial evaluating the safety and feasibility of a bioengineered human allogeneic nanostructured anterior cornea in patients with advanced corneal trophic ulcers refractory to conventional treatment
González-Andrades, Miguel; Mata, Rosario; González-Gallardo, María del Carmen; Medialdea, Santiago; Arias-Santiago, Salvador; Martínez-Atienza, Juliana; Ruiz-García, Antonio; Pérez-Fajardo, Lorena; Lizana-Moreno, Antonio; Garzón, Ingrid; Campos, Antonio; Alaminos, Miguel; Carmona, Gloria; Cuende, Natividad
Introduction There is a need to find alternatives to the use of human donor corneas in transplants because of the limited availability of donor organs, the incidence of graft complications, as well as the inability to successfully perform corneal transplant in patients presenting limbal deficiency, neo-vascularized or thin corneas, etc. We have designed a clinical trial to test a nanostructured fibrin-agarose corneal substitute combining allogeneic cells that mimics the anterior human native cornea in terms of optical, mechanical and biological behaviour. Methods and analysis This is a phase I-II, randomised, controlled, open-label clinical trial, currently ongoing in ten Spanish hospitals, to evaluate the safety and feasibility, as well as clinical efficacy evidence, of this bioengineered human corneal substitute in adults with severe trophic corneal ulcers refractory to conventional treatment, or with sequelae of previous ulcers. In the initial phase of the trial (n=5), patients were sequentially recruited, with a safety period of 45 days, receiving the bioengineered corneal graft. In the second phase of the trial (currently ongoing), subjects are block randomised (2:1) to receive either the corneal graft (n=10), or amniotic membrane (n=5), as the control treatment. Adverse events, implant status, infection signs and induced neovascularization are evaluated as determinants of safety and feasibility of the bioengineered graft (main outcomes). Study endpoints are measured along a follow-up period of 24 months, including 27 post-implant assessment visits according to a decreasing frequency. Intention to treat, and per protocol, and safety analysis will be performed. Ethics and dissemination The trial protocol received written approval by the corresponding Ethics Committee and the Spanish Regulatory Authority and is currently recruiting subjects. On completion of the trial, manuscripts with the results of phases I and II of the study will be published in a peer
Wolffsohn, James S; Safeen, Saima; Shah, Sunil; Laiquzzaman, Mohammad
To perform advanced analysis of the corneal deformation response to air pressure in keratoconics compared with age- and sex-matched controls. The ocular response analyzer was used to measure the air pressure-corneal deformation relationship of 37 patients with keratoconus and 37 age (mean 36 ± 10 years)- and sex-matched controls with healthy corneas. Four repeat air pressure-corneal deformation profiles were averaged, and 42 separate parameters relating to each element of the profiles were extracted. Corneal topography and pachymetry were performed with the Orbscan II. The severity of the keratoconus was graded based on a single metric derived from anterior corneal curvatures, difference in astigmatism in each meridian, anterior best-fit sphere, and posterior best-fit sphere. Most of the biomechanical characteristics of keratoconic eyes were significantly different from normal eyes (P corneal applanation. With increasing keratoconus severity, the cornea was thinner (r = -0.407, P corneal concave deformation past applanation was quicker (dive; r2 = -0.314, P = 0.01), and the tear film index was lower (r = -0.319, P = 0.01). The variance in keratoconus severity could be accounted for by the corneal curvature and central corneal thickness (r = 0.80) with biomechanical characteristics contributing an additional 4% (total r = 0.84). The area under the receiver operating characteristic curve was 0.919 ± 0.025 for keratometry alone, 0.965 ± 0.014 with the addition of pachymetry, and 0.972 ± 0.012 combined with ocular response analyzer biomechanical parameters. Characteristics of the air pressure-corneal deformation profile are more affected by keratoconus than the traditionally extracted corneal hysteresis and corneal resistance factors. These biomechanical metrics slightly improved the detection and severity prediction of keratoconus above traditional keratometric and pachymetric assessment of corneal shape.
van der Strate, B. W. A.; Popa, E. R.; Schipper, M.; Brouwer, L. A.; Hendriks, M.; Harmsen, M. C.; van Luyn, M. J. A.
CD34(+) progenitor cells hold promise for therapeutic neovascularization in various settings. In this study, the role of human peripheral blood CD34(+) cells in neovascularization and inflammatory cell recruitment was longitudinally studied in vivo. Human CD34(+) cells were incorporated in Matrigel,
Madelung, Christopher Fugl; Falk, Mads; Sørensen, Torben Lykke
PURPOSE: To investigate regulatory T cells (Tregs) and subsets of the Treg population in patients with neovascular age-related macular degeneration (AMD). PATIENTS AND METHODS: Twenty-one neovascular AMD cases and 12 age-matched controls without retinal pathology were selected. Patients were...
Objective: To determine the causes and the intraocular pressure (IOP) outcome of neo-vascular glaucoma at the Guinness. Eye Centre of the Lagos University Teaching Hospital, Lagos, Nigeria. Materials and Methods: The case records of all patients with the diagnosis of neo-vascular glaucoma who presented at Guinness ...
Bloch, Sara Brandi; Lund-Andersen, Henrik; Sander, Birgit
To assess baseline and follow-up characteristics of choroidal neovascularization (CNV) lesions in age-related macular degeneration in relation to the development of subfoveal subretinal fibrosis.......To assess baseline and follow-up characteristics of choroidal neovascularization (CNV) lesions in age-related macular degeneration in relation to the development of subfoveal subretinal fibrosis....
Lassota, Nathan; Kiilgaard, Jens Folke; Prause, Jan Ulrik
To analyse the histological changes in the retina and the choroid in a pig model of choroidal neovascularization (CNV) and to correlate these findings with fundus photographic and fluorescein angiographic features.......To analyse the histological changes in the retina and the choroid in a pig model of choroidal neovascularization (CNV) and to correlate these findings with fundus photographic and fluorescein angiographic features....
Wang, Jianghui; Jiang, Wei; Kang, Zefeng; Liang, Lina; Liu, Xiaoman; Tian, Nannan; Zhang, Qing
To investigate the association between high anisometropia and the area of choroidal neovascularization (CNV) induced by krypton laser in guinea pigs and better understand the pathogenesis and prevention of myopic CNV. Nine 3-week old male guinea pigs with anisometropia >6.00D were randomly assigned to three groups according to examination date after laser photocoagulation (7d, 14d and 28d). All animals underwent refraction. The eye with higher myopia was used as the experimental eye, and the other as the control eye. All eyes received repeated multi-wavelength krypton laser photocoagulation treatments (wavelength: 532nm; laser power: 400mW; spot diameter: 50μm; exposure time: 0.1s). Fundus photography and indocyanine green angiography (ICGA) were performed. Afterwards, the animals were sacrificed immediately, and the eyes were enucleated and processed for histopathologic examination and flat mounts. CNV appeared at 7d after laser treatment. The area of CNV peaked at 14d, and decrease in area and the presence of scarring was noted at 28 d. CNV was present in 66.7% of eyes by ICGA at 14 d. CNV could be observed under light microscopy at all three time points. At 14d, flat mount showed the neovascular plexus around the lesion. Semi-quantitative analysis revealed that the area of CNV in treated eyes was greater than that of control eyes. Since the mechanism of CNV in this study resembles that of CNV in pathological myopia, this model can be used to investigate the etiology, pathogenesis and treatment of CNV in pathological myopia.
Full Text Available PURPOSE: RAGE regulates pro-inflammatory responses in diverse cells and tissues. This study has investigated if RAGE plays a role in immune cell mobilization and choroidal neovascular pathology that is associated with the neovascular form of age-related macular degeneration (nvAMD. METHODS: RAGE null (RAGE-/- mice and age-matched wild type (WT control mice underwent laser photocoagulation to generate choroidal neovascularization (CNV lesions which were then analyzed for morphology, S100B immunoreactivity and inflammatory cell infiltration. The chemotactic ability of bone marrow derived macrophages (BMDMs towards S100B was investigated. RESULTS: RAGE expression was significantly increased in the retina during CNV of WT mice (p<0.001. RAGE-/- mice exhibited significantly reduced CNV lesion size when compared to WT controls (p<0.05. S100B mRNA was upregulated in the lasered WT retina but not RAGE-/- retina and S100B immunoreactivity was present within CNV lesions although levels were less when RAGE-/- mice were compared to WT controls. Activated microglia in lesions were considerably less abundant in RAGE-/- mice when compared to WT counterparts (p<0.001. A dose dependent chemotactic migration was observed in BMDMs from WT mice (p<0.05-0.01 but this was not apparent in cells isolated from RAGE-/- mice. CONCLUSIONS: RAGE-S100B interactions appear to play an important role in CNV lesion formation by regulating pro-inflammatory and angiogenic responses. This study highlights the role of RAGE in inflammation-mediated outer retinal pathology.
Mofty, Hanan; Alzahrani, Khaled; Carley, Fiona; Harper, Sophie; Brahma, Arun; Au, Leon; Morley, Debbie; Hillarby, M Chantal
The purpose of this study was to assess UV corneal crosslinking (CXL) treatment outcomes for keratoconus by evaluating the corneal regularity in patients through follow-up using the Oculus Pentacam. A total of 18 eyes from CXL patients with keratoconus were studied before and after CXL treatment, and six eyes from six patients who were not treated with CXL served as controls. Treated patients had Pentacam images taken before CXL treatment and regularly 3 months post treatment up to the 12th month. Controls were imaged during their first appointment and after 12 months. Symmetry and asphericity were evaluated and correlated with both best-corrected visual acuity (BCVA) and maximum K -readings. In the CXL-treated group, there was a significant improvement in the index of symmetrical variation (ISV) and keratoconus index (KI) at 3 months and in the index of height asymmetry (IHA) and minimum radius of curvature ( R min ) at 9 months post treatment. On the contrary, the untreated group's indices showed some significant worsening in ISV, KI, central keratoconus index (CKI), and R min . A novel finding in our study was a slight positive shift of anterior asphericity in the 6 mm, 7 mm, and 8 mm 3 months after treatment, which had a correlation with BCVA ( R 2 =0.390, p =0.053) and a strong correlation with maximum K -reading ( R 2 =0.690, p =0.005). However, the untreated group had no significant changes after 1 year. The corneal asymmetrical shape is associated with the spherical aberration alteration influenced by temporal evolution of surface ablation and increased corneal haze. However, insignificant changes in symmetry attest the stabilization effect on cornea postoperatively as compared with controls.
de Jong, Tim; Sheehan, Matthew T.; Koopmans, Steven A.; Jansonius, Nomdo M.
Purpose: To compare the ability of 3 clinical corneal topographers to describe the posterior corneal shape. Setting: University Medical Center Groningen, the Netherlands. Design: Prospective observational study. Methods: Corneas of healthy participants were measured twice with a dual Scheimpflug
AIM: To investigate the repair efficacy of recombinant human epidermal growth factor on corneal epithelium after corneal foreign body eliminating operation. METHODS: There were 102 patients with corneal foreign body(188 affected eyes)chosen for the study. All patients were divided into treatment group and control group according to the random number table. Both groups received corneal foreign body elimination by slit lamp. Postoperatively, the treatment group was given eye drops containing ep...
Mikkelsen, Lauge Hjorth; Hamoudi, Hassan; Gül, Cigdem Altuntas
PURPOSE: To present a case of corneal toxicity following exposure to milky plant latex from Asclepias tuberosa. METHODS: A 70-year-old female presented with blurred vision and pain in her left eye after handling an Ascepias tuberosa. Clinical examination revealed a corneal stromal oedema with small...... that inhibit the Na+/ K+-ATPase in the corneal endothelium. The oedema resolved after 96 hours. After nine months the best corrected visual acuity was 20/20. CONCLUSION: Corneal toxicity has previously been reported for plants of the Asclepias family. This is a rare case describing severe corneal toxicity...... caused by exposure to latex from Asclepias tuberosa. Handling of plants of the Asclepias family should be kept as a differential diagnosis in cases of acute corneal toxicity....
Møller, H U; Bojsen-Møller, M; Schrøder, H D
Three patients with granular corneal dystrophy Groenouw type I underwent corneal grafting, and cryostat sections of the corneal buttons were examined immunohistochemically for immunoglobulins. Positive results were obtained for IgG, Kappa-, and Lambda chains with immunofluorescence technique. The...
Meyer, R F; Bobb, K C
We studied corneal epithelium in 66 patients with bullous keratopathy treated with penetrating keratoplasty using McCarey-Kaufman stored donor corneas. Epithelium was evaluated at times of storage, surgery, and postoperative dressing changes. Epithelium was intact in 43 of the donor corneas at storage, and 23 had 5 to 100% (median, 50%) epithelium missing. At the end of the keratoplasty procedure, 16 grafts had epithelium intact, and 50 had 5 to 100% (median, 20%) epithelium missing. Postoperative epithelial healing time ranged from one to 12 days, with a median of two days. Postoperative healing was significantly prolonged when donor corneal epithelium was missing at keratoplasty. As the amount of epithelium intact at the end of surgery decreased, the number of days to heal postoperatively increased. We found that donor corneas could be stored as long as 79 hours, with 63 hours in McCarey-Kaufman medium, and still have epithelium intact at the end of the keratoplasty procedure.
Wishart, M S; Wishart, P K; Gregor, Z J
The changes in corneal curvature in the first six months after cataract extraction were studied by performing sequential keratometry on a group of 57 patients. 8/0 Virgin silk interrupted sutures were used for the closure of corneoscleral incisions, and 10/0 monofilament tied in double running (bootlace) or single running (continuous) fashion was used for corneal wound closure. A high degree of with-the-rule astigmatism was evident in all patients two weeks postoperatively, but thereafter the character of the astigmatism produced by 8/0 virgin silk and 10/0 monofilament closure was quite different: in the 8/0 virgin silk group there was an early and pronounced shift in the axis of astigmatism to against-the-rule, whereas in the 10/0 monofilament group there was little further change in the astigmatism unless the sutures were removed. Wound compression and wound gape as factors responsible for these changes are discussed. PMID:3539177
Ammar M. Al-Mahmood
Full Text Available Glaucoma after corneal transplantation is a leading cause of ocular morbidity after penetrating keratoplasty. The incidence reported is highly variable and a number of etiologic factors have been identified. A number of treatment options are available; surgical intervention for IOP control is associated with a high incidence of graft failure. IOP elevation is less frequently seen following deep anterior lamellar keratoplasty. Descemet's striping-automated endothelial keratoplasty is also associated with postprocedure intraocular pressure elevation and secondary glaucoma and presents unique surgical challenges in patients with preexisting glaucoma surgeries. Glaucoma exists in up to three-quarters of patients who undergo keratoprosthesis surgery and the management if often challenging. The aim of this paper is to highlight the incidence, etiology, and management of glaucoma following different corneal transplant procedures. It also focuses on the challenges in the diagnosis of glaucoma and intraocular pressure monitoring in this group of patients.
Cazalot, G; Regnier, A; Deviers, A; Serra, F; Lucas, M N; Etienne, C L; Letron, I Raymond
A 10 year-old castrated male Domestic Short-hair cat with a history of chronic bilateral keratitis was referred for assessment of a red, elevated mass involving the left cornea. The rapid growth of the mass, over a month period in combination with pronounced vascularization and invasion of the corneal surface suggested an aggressive inflammatory or neoplastic process. Following keratectomy, the lesion was diagnosed histopathologically as a hemangiosarcoma. The tumor recurred locally within 3 weeks and enucleation was performed. Histopathologic examination of the globe confirmed the diagnosis and did not reveal infiltration of the limbus and conjunctiva. No signs of local recurrence or metastatic disease have been observed 18 months following enucleation. To the authors' knowledge this is the first case of primary corneal hemangiosarcoma described in the feline species. © 2011 American College of Veterinary Ophthalmologists.
Full Text Available Hanan Mofty,1,2 Khaled Alzahrani,2 Fiona Carley,3 Sophie Harper,3 Arun Brahma,3 Leon Au,3 Debbie Morley,3 M Chantal Hillarby2 1Optometry Department, College of Applied Medical Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3Manchester Royal Eye Hospital, Manchester, UK Purpose: The purpose of this study was to assess UV corneal crosslinking (CXL treatment outcomes for keratoconus by evaluating the corneal regularity in patients through follow-up using the Oculus Pentacam.Patients and methods: A total of 18 eyes from CXL patients with keratoconus were studied before and after CXL treatment, and six eyes from six patients who were not treated with CXL served as controls. Treated patients had Pentacam images taken before CXL treatment and regularly 3 months post treatment up to the 12th month. Controls were imaged during their first appointment and after 12 months. Symmetry and asphericity were evaluated and correlated with both best-corrected visual acuity (BCVA and maximum K-readings.Results: In the CXL-treated group, there was a significant improvement in the index of symmetrical variation (ISV and keratoconus index (KI at 3 months and in the index of height asymmetry (IHA and minimum radius of curvature (Rmin at 9 months post treatment. On the contrary, the untreated group’s indices showed some significant worsening in ISV, KI, central keratoconus index (CKI, and Rmin. A novel finding in our study was a slight positive shift of anterior asphericity in the 6 mm, 7 mm, and 8 mm 3 months after treatment, which had a correlation with BCVA (R2=0.390, p=0.053 and a strong correlation with maximum K-reading (R2=0.690, p=0.005. However, the untreated group had no significant changes after 1 year.Conclusion: The corneal asymmetrical shape is associated with the spherical aberration alteration
Woodward, Maria A.; Titus, Michael; Mavin, Kyle; Shtein, Roni M.
Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes1,2. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK...
Kunliang Qiu; Xuehui Lu; Riping Zhang; Geng Wang; Mingzhi Zhang
Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer? and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH), corneal resistance factor (CRF), cornea-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure (IOPg) were determined with the ...
Alió, Jorge L; Abdou, Ahmed A; Abdelghany, Ahmed A; Zein, Ghassam
To review the different surgical procedures for management of postkeratoplasty refractive errors after total suture removal. There are different surgical options to address residual refractive errors that frequently occur after corneal transplantation. The correction can be done on the corneal surface or intraocular with intraocular lens (IOL) implantation which requires complete tectonic and refractive stability after suture removal. The most commonly used procedures are photorefractive keratectomy, laser in-situ keratomileusis and Phakic IOLs. Keratoplasty has been profited by recent advances in refractive surgery. Custom excimer laser ablation is an alternative way to treat irregular errors. New IOL modalities are good practical options for a wide range of errors. Femtosecond laser, as a new option in the toolbox, can modify corneal grafting refractive results and assist corrective refractive procedures. Although being the most successful organ transplantation, keratoplasty is usually followed by significant ametropia. Different corrective modalities exist and the choice should fit ocular conditions, patient requirements, surgeon skills and the available technologies. Recent advances in ophthalmic surgery have improved the outcomes.
Chang, Daniel H; Hardten, David R
Many patients who have undergone corneal transplantation are unable to achieve satisfactory visual acuity with spectacle and contact lens correction alone. For these patients, refractive surgery becomes a viable option to reduce the post-keratoplasty ametropia. With the many recent advances in refractive surgery for naturally occurring refractive error, new possibilities arise for application to this complicated set of patients. This review discusses key recent developments in refractive surgery after corneal transplantation. The biomechanical effects of incisional keratotomy on post-keratoplasty corneas continue to be studied, and these techniques remain a common and simple method of reducing astigmatism. Photorefractive keratectomy, previously problematic for regression and haze formation, is gaining new prominence as early experience with the adjunctive use of mitomycin C has demonstrated good results. Long-term studies with laser in-situ keratomileusis (LASIK) have continued to show good safety and efficacy. Modern developments in cataract surgery appear to have lower incidences of graft rejection and failure. Developments in lens implantation technology continue to offer expanding options for intraocular refractive surgery. Although visual rehabilitation after corneal transplantation remains a formidable challenge, developments in refractive surgery for naturally occurring ametropias directly translate into an improved ability to help these most challenging refractive cases. Continued research will bring about improved efficacy while maintaining a high level of safety.
Navarro Martínez-Cantullera, A; Calatayud Pinuaga, M
Cornea transplant is the most common tissue transplant in the world. In Spain, tissue donation activities depend upon transplant coordinator activities and the well-known Spanish model for organ and tissue donation. Tissue donor detection system and tissue donor evaluation is performed mainly by transplant coordinators using the Spanish model on donation. The evaluation of a potential tissue donor from detection until recovery is based on an exhaustive review of the medical and social history, physical examination, family interview to determine will of the deceased, and a laboratory screening test. Corneal acceptance criteria for transplantation have a wider spectrum than other tissues, as donors with active malignancies and infections are accepted for kearatoplasty in most tissue banks. Corneal evaluation during the whole process is performed to ensure the safety of the donor and the recipient, as well as an effective transplant. Last step before processing, corneal recovery, must be performed under standard operating procedures and in a correct environment. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.
Sng, Chelvin C A; Ang, Marcus; Barton, Keith
The purpose of this review is to summarize the role of central corneal thickness (CCT) in the clinical management of a glaucoma patient. The prognostic value of CCT is well recognized in patients with ocular hypertension. However, its predictive value in other glaucoma suspects and patients with established glaucoma is less certain. Tonometry artefacts can result from variations in CCT. However, an adequately validated correction algorithm for Goldmann applanation tonometry measurements does not exist. Newer methods of tonometry are potentially less influenced by CCT but are limited in their clinical use. There may also be biological and genetic associations between corneal thickness and glaucoma. Demographics, environmental factors, glaucoma treatment and the measurement device used have a significant influence on CCT, and should be considered when interpreting the effect of cornea thickness in patients with glaucoma. New measurements of the biomechanical properties of the cornea are likely to be better approximations of the globe biomechanics than CCT, but these require further evaluation. The clinical significance of CCT is well recognized in the context of glaucoma diagnosis and management, though the extent of its importance remains debatable. Corneal biomechanical properties may be more significantly associated with glaucoma than CCT.
Pierro, L; Marchese, A; Gagliardi, M; Introini, U; Battaglia Parodi, M; Casalino, G; Bandello, F
PurposeTo describe multimodal imaging features of choroidal osteoma (CO) complicated by choroidal neovascularization (CNV) and focal choroidal excavation (FCE).MethodsPatients presenting with CO and CNV between January and October 2016 were considered for this study. Diagnosis of CO was confirmed by ultrasound examination. All patients underwent multimodal imaging including optical coherence tomography (OCT), swept-source OCT angiography (DRI OCT Triton, Topcon, Inc., Tokyo, Japan) and fluorescein angiography (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany).ResultsTwo patients (one with bilateral CO) were included in the study. OCT showed a FCE in two eyes of two patients (one in correspondence of the CNV and the other adjacent to the CNV). OCT-A demonstrated presence of microvascular flow within neovascular network of the CNVs. Decalcification of the tumor was noted in correspondence of one eye with FCE.ConclusionsFCE may be found in eyes with choroidal osteoma and CNV. OCT-A was a valuable tool for detection of CNV complicating choroidal osteoma. Decalcification of choroidal osteoma may represent a common pathogenic pathway for development of FCE and CNV in choroidal osteoma.
Anmar M. Abdul-Rahman
Full Text Available Purpose: To report a case of conjunctival microangiopathy secondary to diabetes presenting as a red eye 5 years after glaucoma implant surgery for neovascular glaucoma. Materials and Methods: A 52-year-old Tongan male with a past history of neovascular glaucoma secondary to proliferative diabetic retinopathy underwent slitlamp examination and color photography of the anterior and posterior segment, in addition to anterior segment fluorescein angiography. Results: The conjunctival venules perilimbally demonstrated tortuosity and dilation (saccular, fusiform and tricornuate. Capillaries were tortuous, with sparse microaneurysm formation, and arterioles were attenuated. Anterior segment fluorescein angiography showed generalized iris ischemia, extensive perilimbal microvascular degenerative changes and leakage of fluorescein into the anterior chamber. We are unaware of previous reports in the literature on conjunctival microangiopathy secondary to diabetes presenting as a red eye. Conclusions: We hypothesized that the clinical features in our case may have been modified by a combination of postoperative wound healing and degenerative vascular remodeling, in addition to microvascular alterations secondary to both diabetes and consequent ocular ischemia, which may have played a role.
Full Text Available AIM: To investigate the effects of ginkgo biloba extract(EGb 761on laser-induced choroidal neovascularization(CNVin rats.METHODS: Totally 60 BN rats were randomly divided into 4 groups: normal control group, model group, experimental group, physiological saline group with 15 in each group. All CNV models were made by krypton laser. Rats in experimental group were intraperitoneally injected with 0.35% EGb761(100mg/kgevery day after laser exposure until they were sacrificed. Rats in physiological saline group were intraperitoneally injected physiological saline every day after laser exposure until they were sacrificed. Fundus fluorescein angiography(FFAwas performed on every rat on the 7th day, 14th day and the 21st day after laser exposure, then the rats were sacrificed immediately. The eyes were enucleated and processed for histopathologic examination.RESULTS: There was no choroidal fluorescein leakage staining in normal rats. There were obviously less choroidal fluorescein leakage points in experimental groups than that in the corresponding model groups(PCONCLUSION: EGb761 len inhibit the formation of laser-induced CNV in rats. The longer the time, the better curative effect.
Nosch, Daniela Sonja; Pult, Heiko; Albon, Julie; Purslow, Christine; Murphy, Paul John
PURPOSETo examine the possible role of corneal sensitivity and tear film quality in triggering a blink by investigating the relationship between blink rate, central corneal sensitivity threshold (CST...
Nischal, Ken K; Lathrop, Kira L
The purposes of this study are first, to determine if the palisades of Vogt (POV) are present or absent in cases of congenital corneal opacification (CCO) by using spectral domain ocular coherence tomography (SD-OCT), and second, in those cases already undergoing penetrating keratoplasty (PKP), to see whether the absence or presence of POV corresponds to re-epithelialization following transplant. This was a retrospective case review of 20 eyes (10 normal, 10 with CCO) evaluated with SD-OCT. The operator was masked to the clinician's assessment of the ocular surface. In those cases where the decision to perform PKP had already been made, the correlation between POV presence or absence and posttransplant graft epithelialization was determined. All cases were imaged without adverse event. Nine eyes showed some evidence of POV and corresponding vasculature. Eight of 10 affected eyes underwent PKP, and subsequently 7 eyes epithelialized and 2 showed some peripheral neovascularization. The one eye that showed no signs of POV was the one that failed to epithelialize. All control subjects had consistent and regular POV. Congenital corneal opacification is rare, and this study shows that at least some POV are present in the majority of cases of CCO. However, the palisades may not be entirely normal compared to age-matched controls. When there was absence of POV in a case of CCO, there was immediate and complete failure of epithelialization.
Effects of ethyl-cyanoacrylate and octyl-cyanoacrylate on experimental corneal lesions in rabbits Efeitos do etil-cianoacrilato ou do octil-cianoacrilato sobre lesões corneais experimentais em coelhos
Full Text Available The use of ethyl-cyanoacrylate and octyl-cyanoacrylate were clinically and histopathologically compared on the corneas of 36 rabbits after lamellar keratectomy (standardized diameter and depth. The animals were distributed into two groups, one for each type of adhesive. From each group, six subgroups were histopathologically evaluated on the 3rd, 7th, 14th, 21st, 30th, and 60th day post-operative. General (daily and ophthalmic (days 0, 1, 3, 5, 7, 14, 21, 30, 44, and 60 evaluations clinically indicated that there were significant differences for the variables water intake, attitude, blepharitis, corneal edema, and fluorescein test. The adhesive permanence time for octyl-cyanoacrylate (17.22 days was greater than that for ethyl-cyanoacrylate (7.66 days. With respect to the histopathological evaluation, corneal epithelization and collagen organization occurred without severe complications. However, treatment with ethyl-cyanoacrylate led to a moderate inflammatory reaction in the initial phases. With octyl-cyanoacrylate, re-epithelization and collagen organization proceeded more slowly with a discrete inflammatory reaction in the initial phases. From clinical and histopathologic points of view, octyl-cyanoacrylate showed advantages over ethyl-cyanoacrylate, whereas wound healing was achieved in both groups without major complications.Comparou-se o uso do etil-cianoacrilato e do octil-cianoacrilato em córneas de 36 coelhos após ceratectomia lamelar (diâmetro e profundidade padronizados. Os animais foram distribuídos em dois grupos, segundo o tipo de adesivo, e redistribuídos em seis subgrupos com três animais cada, para as avaliações histológicas aos 3, 7, 14, 21, 30 e 60 dias de pós-operatório. As avaliações clínicas gerais (diárias e as oftálmicas (dias 0, 1, 3, 5, 7, 14, 21, 30, 44 e 60, indicaram diferença entre os dois grupos, quanto ao consumo de água, atitude, blefarite, edema da córnea e teste da fluoresceína. O Tempo de
Full Text Available AIM: To compare the effect of compound electrolyte solution and lactated Ringer's solution on corneal function in cataract phacoemulsification, and to provide scientific basis for clinical selection of appropriate perfusion fluid. METHODS: The patients with senile cataract were randomly divided into control group with lactated Ringer's solution as anterior chamber perfusion and experimental group with compound electrolyte as anterior chamber perfusion. Surgical removal of cataract and phacoemulsification with intraocular lens implantation were taken. The corneal endothelial cell density, central corneal thickness, hexagonal cell ratio and endothelial cell coefficient of variation were measured at preoperative and postoperative points. RESULTS: Totally 60 patients successfully completed all follow-ups, the experimental group of 30 cases, the control group of 30 cases. The density of corneal endothelial cells in experimental group was significantly higher than those in the lactated Ringer's solution group at 1 and 3d after operations(P=0.030, 0.046. The coefficient of variation of corneal endothelial cells in lactated Ringer's solution group was higher than that in compound electrolyte group at 1 and 14d after operation(P=0.025, 0.014. The visual acuity of the compound electrolyte group was better than that of the lactated Ringer's solution on the first day after operation(P=0.04. CONCLUSION: In the phacoemulsification of senile cataract, the compound electrolyte perfusion has better histocompatibility, which can maintain the stability of corneal endothelial cell structure and reduce corneal endothelial cell injury. The compound electrolyte perfusion solution is more suitable for senile cataract phacoemulsification surgery.
Kandarakis, Artemios; Soumplis, Vasileios; Karampelas, Michalis; Koutroumanos, Ioannis; Panos, Christos; Kandarakis, Stylianos; Karagiannis, Dimitrios
To evaluate the effect of routine phacoemulsification in corneal viscoelastic properties determined by corneal hysteresis (CH) and central corneal thickness (CCT) and to explore the impact of phaco energy on the above parameters. Forty-one eyes of 41 patients undergoing cataract surgery were enrolled in this prospective study. CH and CCT were measured preoperatively, 1 day and 1 week postoperatively. CCT measurement was performed using a non-contact optical pachymeter followed by ocular response analyzer (ORA) examination. Intraoperatively ultrasound time, average phaco power and effective phaco time (EPT) were recorded. Mean CH was 10.05±1.86 mmHg preoperatively, 8.25±1.85 mmHg 1 day and 9.12±1.37 mmHg 1 week postoperatively (pcorneal alterations following cataract surgery resulted in a statistical change in CH and CCT. These two parameters responded in a different manner that clearly demarcates their different nature. On the first postoperative day, CCT increase was correlated at a statistically significant level with intraoperative EPT. This correlation was not found with CH reduction. Other factors, besides cornea oedema or phacoemulsification energy, could be responsible for this CH modification. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.
Xu, Huizhuo; Liu, Jiaolian; Xiong, Siqi; Le, Yun-zheng; Xia, Xiaobo
Objectives The function of netrin-1 in pathological angiogenesis and its role in retinal neovascularization were investigated in the retinas of oxygen-induced retinopathy (OIR) mice by inhibition of netrin-1. Methods Expression of netrin-1 mRNA and protein in the retinas of OIR mice was analyzed by quantitative RT-PCR and immunoblotting. Inhibition of retinal neovascularization was achieved by lentivirus-mediated netrin-1 small hairpin RNA (shRNA) infection. Retinal neovascularization was examined by fluorescein angiography and quantification of preretinal neovascular nuclei in retinal sections. Results Both mRNA and protein expression of netrin-1 were significantly upregulated in postnatal day 17 OIR mouse retinas. Treatment of OIR mice with specific lentivirus-mediated netrin-1 shRNA dramatically reduced neovascular outgrowth into the inner limiting membrane. Neovascular tufts and nonperfused areas were also reduced. Conclusions High expression of netrin-1 was detected in the retina under ischemic conditions and played a significant role in pathological retinal angiogenesis. Therefore, netrin-1 represents a potential therapeutic target for diabetic retinopathy, retinopathy of prematurity and other ocular neovascular diseases. PMID:22122983
Woodward, Maria A; Titus, Michael; Mavin, Kyle; Shtein, Roni M
Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection. Initially, cornea donor posterior lamellar dissection for DSEK was performed manually resulting in variable graft thickness and damage to the delicate corneal endothelial tissue during tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in tissue processing. Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference in
Timberlake, George T.; Patmore, Ann; Shallal, Assaad; McHugh, Dominic; Marshall, John
It has been suggested that laser welds of collagenous tissues form by interdigitation and chemical bonding of thermally 'unraveled' collagen fibrils. We investigated this proposal by attempting to weld highly collagenous, avascular corneal tissue with an infrared (IR) diode laser as follows. First, the temperature at which corneal collagen shrinks and collagen fibrils 'split' into subfibrillary components was determined. Second, since use of a near-IR laser wavelength necessitated addition of an absorbing dye (indocyanine green (ICG) to the cornea, we measured absorption spectra of ICG-treated tissue to ensure that peak ICG absorbance did not change markedly when ICG was present in the cornea. Third, using gel electrophoresis of thermally altered corneal collagen, we searched for covalently crosslinked compounds predicted by the proposed welding mechanism. Finally, we attempted to weld partial thickness corneal incisions infused with ICG. Principal experimental findings were as follows: (1) Human corneal (type I) collagen splits into subfibrillary components at approximately 63 degree(s)C, the same temperature that produces collagen shrinkage. (2) Peak ICG absorption does not change significantly in corneal stroma or with laser heating. (3) No evidence was found for the formation of novel compounds or the loss of proteins as a result of tissue heating. All tissue treated with ICG, however, exhibited a novel 244 kD protein band indicating chemical activity between collagen and corneal stromal components. (4) Laser welding corneal incisions was unsuccessful possibly due to shrinkage of the sides of the incision, lack of incision compression during heating, or a less than optimal combination of ICG concentration and radiant exposure. In summary, these experiments demonstrate the biochemical and morphological complexity of ICG-enhanced IR laser-tissue welding and the need for further investigation of laser welding mechanisms.
Kling, Sabine; Remon, Laura; Pérez-Escudero, Alfonso; Merayo-Lloves, Jesus; Marcos, Susana
Understanding corneal biomechanics is important to refractive or therapeutic corneal treatments. The authors studied the corneal response to variable intraocular pressure (IOP) in porcines eyes after UV collagen cross-linking (CXL), in comparison with untreated eyes. Twenty-three enucleated eyes were treated with standard CXL conditions (365 nm, 3 mW, 30 minutes), and 15 contralateral eyes served as control. Eyes (within a humidity- and temperature-monitored wet chamber) were measured by Scheimpflug corneal three-dimensional topographer. Images were obtained automatically while IOP either remained constant (14 eyes) or increased (24 eyes) by 40 mm Hg and then decreased (4-mm Hg steps). Measurements were performed immediately after treatment and 24 hours later. Corneal geometry was analyzed as a function of IOP, and whole globe stress-strain curves were calculated. Instillation of riboflavin-dextran solution reduced corneal thickness (by 281 +/- 5 microm). Cross-linking produced a 1.54x reduction in corneal thinning and 2.8x reduction in corneal apical rise with increased IOP. Anterior and posterior cornea flattened with increased IOP (less flattening in CXL eyes) and became steeper with decreased IOP. The horizontal meridian flattened significantly (P Cross-linking stiffened porcine corneas significantly. Both experimental data and stress-strain analysis are valuable for finite element models to improve understanding of CXL and its predictability. Although differences are expected between human corneas in vivo and porcine corneas ex vivo, the results are consistent with clinical data found in patients. The apparent biomechanical anisotropy of pig corneas must be confirmed in humans.
Carbonaro, Francis; Hysi, Pirro G; Fahy, Samantha J; Nag, Abhishek; Hammond, Christopher J
To determine whether corneal hysteresis and central corneal thickness are independent risk factors for glaucoma. A cross-sectional population-based cohort study. Associations were tested between corneal hysteresis, measured in 1754 population-based subjects from the TwinsUK cohort, and glaucoma-related endophenotypes, including intraocular pressure (IOP), vertical cup-to-disc ratio, optic disc area, and optic disc cup area. Corneal hysteresis, IOP, and central corneal thickness (CCT) were measured; optic disc photographs were analyzed; and multivariable linear regression analysis was performed. Data were available on 1645 individuals. Multiple regression analysis showed corneal hysteresis to be significantly negatively associated with age (beta coefficient = -0.03, P Corneal hysteresis was also found to be associated with CCT (beta coefficient = 0.02, P corneal hysteresis and optic disc area (P = .6), cup area (P = .77), vertical cup-to-disc ratio (P = .51), or spherical equivalent (P = .08). CCT was also found to be significantly associated with IOP (beta coefficient = 3.3, P corneal hysteresis (beta coefficient = 9.4, P corneal hysteresis or CCT and quantitative measures of optic disc cupping, suggesting that corneal hysteresis and CCT are not independent risk factors for glaucoma. Copyright © 2014 Elsevier Inc. All rights reserved.
Kawamoto, Koji; Morishige, Naoyuki; Yamada, Naoyuki; Chikama, Tai-Ichiro; Nishida, Teruo
To investigate whether corneal epithelial cells of individuals with lattice corneal dystrophy (LCD) possess an intrinsic defect. Retrospective case-control study. The medical charts of nine individuals with LCD and those of 14 patients with keratoconus and 11 patients with corneal leukoma (controls), all of whom underwent penetrating keratoplasty (PKP) in one eye at Yamaguchi University Hospital between February 1998 and November 2001, were examined for the time for epithelial resurfacing after surgery. The time required for resurfacing of the corneal epithelium after PKP was significantly greater in LCD patients (8.56 +/- 4.95 days, mean +/- SD) than in patients with either keratoconus (1.71 +/- 0.91 days, P = .006) or corneal leukoma (3.00 +/- 1.95 days, P = .03). Corneal epithelial wound healing was delayed in LCD patients after PKP, suggesting that the keratoepithelin gene mutations responsible for this condition affect corneal epithelial cells.
Mangouritsas, George; Morphis, George; Mourtzoukos, Spyridon; Feretis, Elias
We aimed to determine corneal hysteresis values (CH) using the ocular response analyser (ORA) in non-glaucomatous and glaucomatous eyes and their relationship with central corneal thickness (CCT). Corneal hysteresis, intraocular pressure (IOP) as measured by Goldmann applanation tonometry (GAT) and CCT were prospectively evaluated in 74 non-glaucoma subjects with IOP Corneal hysteresis was significantly lower in eyes with treated POAG than in non-glaucomatous eyes. The corneal biomechanical response was strongly associated with CCT in non-glaucoma subjects, but only moderately so in glaucoma patients. It can be assumed that diverse structural factors, in addition to thickness, determine the differences in the corneal biomechanical profile between non-glaucomatous and glaucomatous eyes. Corneal hysteresis could be a useful tool in the diagnosis of glaucoma.
Full Text Available Abdourahman Cham,1,2 Mayank Bansal,3 Himanshu K Banda,4 Young Kwon,1 Paul S Tlucek,1 Alexander G Bassuk,5 Stephen H Tsang,6,7 Warren M Sobol,8 James C Folk,1 Steven Yeh,4 Vinit B Mahajan1,2 1Department of Ophthalmology and Visual Sciences, 2Omics Laboratory, University of Iowa, Iowa City, IA, USA; 3Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India; 4Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, 5Department of Pediatrics, University of Iowa, Iowa City, IA, 6Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, 7Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, 8Retina Physicians & Surgeons, Inc., Dayton, OH, USA Objective: The objective of this study was to review the treatment outcomes of patients with secondary glaucoma in cases of autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, a hereditary autoimmune uveitis due to mutations in CAPN5. Patients and methods: A retrospective, observational case series was assembled from ADNIV patients with secondary glaucoma. The main outcome measures were intraocular pressure (IOP, visual acuity, use of antiglaucoma medications, ocular surgeries, and adverse outcomes. Perimetry and optic disk optical coherence tomography (OCT were also analyzed. Results: Nine eyes of five ADNIV patients with secondary glaucoma were reviewed. Each received a fluocinolone acetonide (FA implant for the management of posterior uveitis. Following implantation, no eyes developed neovascular glaucoma. Five eyes (in patients 1, 2, and 5 required Ahmed glaucoma valve surgery for the management of steroid-responsive glaucoma. Patient 2 also developed angle closure with iris bombe and underwent laser
Vinayak, R.C.; Puttananjaiah, S.; Chatterji, A.; Salimath, B.
in the area under the cover slip and photographed. Corneal Neovascularization (CNV) The rat corneal micro-pocket assay was performed as described previously . In brief, hydron polymer (poly hydroxyl ethyl- methacrylate was dissolved in ethanol to a... final concentration of 12%. A 5 μl aliquot of this mixture was then pipetted onto Teflon pegs. Aliquots of 10 μl of 12% Hydron/Ethanol alone (group 1), with 1 μg of cytokine VEGF (group 2) and VEGF + 5 μg seaweed extract (group 3) was added to each...
Full Text Available symmetric conicoid : (x xo) 2+(y yo) 2+(1+Q)(z zo) 2 2R(z zo) 2 = 0; (2) c SACAM 2012 25 Top view Isometric view Initial corneal curvature z y x x y z Fig. 3: Finite element model of the vertical corneal strip, including the orthogonal...
Lapid-Gortzak, Ruth; Nieuwendaal, Carla P.; Slomovic, Allan R.; Spanjaard, Lodewijk
PURPOSE: The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline. METHODS: A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of
Full Text Available We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT. To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.
Deol, Madhvi; Taylor, David A.; Radcliffe, Nathan M.
Purpose of review Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that roughly 60.5 million people had glaucoma in 2010 and that this number is increasing. Many patients continue to lose vision despite apparent disease control according to traditional risk factors. The purpose of this review is to discuss the recent findings with regard to corneal hysteresis, a variable that is thought to be associated with the risk and progression of glaucoma. Recent findings Low corneal hysteresis is associated with optic nerve and visual field damage in glaucoma and the risk of structural and functional glaucoma progression. In addition, hysteresis may enhance intraocular pressure (IOP) interpretation: low corneal hysteresis is associated with a larger magnitude of IOP reduction following various glaucoma therapies. Corneal hysteresis is dynamic and may increase in eyes after IOP-lowering interventions are implemented. Summary It is widely accepted that central corneal thickness is a predictive factor for the risk of glaucoma progression. Recent evidence shows that corneal hysteresis also provides valuable information for several aspects of glaucoma management. In fact, corneal hysteresis may be more strongly associated with glaucoma presence, risk of progression, and effectiveness of glaucoma treatments than central corneal thickness. PMID:25611166
Qiu, Kunliang; Lu, Xuehui; Zhang, Riping; Wang, Geng
Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer™ and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH), corneal resistance factor (CRF), cornea-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure (IOPg) were determined with the Reichert Ocular Response Analyzer (ORA). Univariate and multivariate regression analyses were performed to investigate factors associated with corneal biomechanics. Results. The mean CH and CRF were 9.82 ± 1.34 mmHg and 9.64 ± 1.57 mmHg, respectively. In univariate regression analysis, CH was significantly correlated with axial length, refraction, central corneal thickness (CCT), and IOPg (r = −0.27, 0.23, 0.45, and 0.21, resp.; all with p ≤ 0.015), but not with corneal curvature or age; CRF was significantly correlated with CCT and IOPg (r = 0.52 and 0.70, resp.; all with p corneal curvature, or age. In multivariate regression analysis, axial length, IOPcc, and CCT were found to be independently associated with CH, while CCT and IOPg were associated with CRF. Conclusions. Both CH and CRF were positively correlated with CCT. Lower CH but not CRF was associated with increasing degree of myopia. Evaluation of corneal biomechanical properties should take CCT and myopic status into consideration. PMID:27525109
Deol, Madhvi; Taylor, David A; Radcliffe, Nathan M
Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that roughly 60.5 million people had glaucoma in 2010 and that this number is increasing. Many patients continue to lose vision despite apparent disease control according to traditional risk factors. The purpose of this review is to discuss the recent findings with regard to corneal hysteresis, a variable that is thought to be associated with the risk and progression of glaucoma. Low corneal hysteresis is associated with optic nerve and visual field damage in glaucoma and the risk of structural and functional glaucoma progression. In addition, hysteresis may enhance intraocular pressure (IOP) interpretation: low corneal hysteresis is associated with a larger magnitude of IOP reduction following various glaucoma therapies. Corneal hysteresis is dynamic and may increase in eyes after IOP-lowering interventions are implemented. It is widely accepted that central corneal thickness is a predictive factor for the risk of glaucoma progression. Recent evidence shows that corneal hysteresis also provides valuable information for several aspects of glaucoma management. In fact, corneal hysteresis may be more strongly associated with glaucoma presence, risk of progression, and effectiveness of glaucoma treatments than central corneal thickness.
Park, Young-Woo; Kang, Byung-Jae; Lim, Jae Hyun; Ahn, Jung-Mo; Lim, Hyun Sook
A 13-year-old castrated male Yorkshire terrier developed a corneal ulcer 2 weeks after intracapsular lens extraction (ICLE) in the right eye. The corneal ulcer was treated with levofloxacin eye drops. A plaque with a white luster developed in the central cornea 2 weeks after treatment with levofloxacin eye drops. The corneal plaque was surgically removed under inhalant anesthesia. The corneal plaque displayed antimicrobial activity against Escherichia coli. Furthermore, levofloxacin content in the plaque was confirmed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS). The corneal ulcer completely resolved 2 weeks after the surgical removal of the corneal lesion and replacement of levofloxacin eye drops with tobramycin eye drops. Although the topical use of levofloxacin is unlikely to lead to corneal chemical deposits due to the high water solubility of the drug compared to other topical fluoroquinolones, this patient developed corneal plaque of the antibiotic drop. © 2015 American College of Veterinary Ophthalmologists.
Full Text Available Naidu Vinuthinee,1,2 Anuar Azreen-Redzal,1 Jaafar Juanarita,1 Embong Zunaina2 1Department of Ophthalmology, Hospital Sultanah Bahiyah, Alor Setar, 2Department of Ophthalmology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia Abstract: A 5-year-old boy presented with right eye pain associated with tearing and photophobia of 1-day duration. He gave a history of playing with a river crab when suddenly the crab clamped his fingers. He attempted to fling the crab off, but the crab flew and hit his right eye. Ocular examination revealed a right eye corneal ulcer with clumps of fibrin located beneath the corneal ulcer and 1.6 mm level of hypopyon. At presentation, the Seidel test was negative, with a deep anterior chamber. Culture from the corneal scrapping specimen grew Citrobacter diversus and Proteus vulgaris, and the boy was treated with topical gentamicin and ceftazidime eyedrops. Fibrin clumps beneath the corneal ulcer subsequently dislodged, and revealed a full-thickness corneal laceration wound with a positive Seidel test and shallow anterior chamber. The patient underwent emergency corneal toileting and suturing. Postoperatively, he was treated with oral ciprofloxacin 250 mg 12-hourly for 1 week, topical gentamicin, ceftazidime, and dexamethasone eyedrops for 4 weeks. Right eye vision improved to 6/9 and 6/6 with pinhole at the 2-week follow-up following corneal suture removal. Keywords: corneal ulcer, pediatric trauma, ocular injury
Background: Complications from infective corneal conditions are an important cause of blindness in adults and children. The eyelids play a major role in the pathogenesis of staphyloma and the perforation of descemetoceles. Tarsorrhaphy could, therefore, be beneficial in treating serious complications from infective corneal ...
... the Cornea and Corneal Disease Facts About the Cornea and Corneal Disease What is the cornea? The cornea is the eye’s outermost layer. It ... your vision. What are the parts of the cornea? Although the cornea may look clear and seem ...
153 CME April 2013 Vol. 31 No. 4. Corneal ulcers: For the general practitioner. A corneal ulcer is a defect in the epithelial layer of the cornea. e general practitioner may play an important role in early management and appropriate referral. Incidence varies and depends on aetiology. S Ballim, MB ChB, Dip Ophth (SA), FC ...
Wang, Fan; Miao, Zhuang; Lu, Chengwei; Hao, Jilong
To investigate the capability of human corneal endothelial cells serving as immunological cells. Expression of HLA-DP, -DQ, -DR, CD40, CD80, and CD86 was determined by immunohistochemical methods. Meanwhile, purified peripheral blood mononuclear cells were cocultured with human corneal endothelial cells which were pre-treated with and without -IFN respectively, activation of lymphocytes was determined by FACS analysis. In coculture system, T lymphocyte was activated by corneal endothelial cells, HLA-DP, -DQ, -DR and CD40 expression were increased by - IFN induction. Costimulatory molecular CD80 was shown on the endothelial cells. Human corneal endothelial cells were assumed to be involved in the corneal transplantation rejection process as potential antigen presenting cells.
Full Text Available Purpose: To report a case of subfoveal choroidal neovascularization (CNV in a patient with Crohn's disease (CD and to discuss a possible association between these two conditions. Methods: This is an observational case report. Results: A 69-year-old male affected by CD was referred to our department because of sudden visual acuity drop in the left eye. A subfoveal CNV was diagnosed based on slit-lamp fundus biomicroscopy and fluorescein angiography. Color fundus photography, infrared autofluorescence and spectral-domain optical coherence tomography imaging of both eyes were also performed. Following six intravitreal ranibizumab injections, visual improvement was obtained with no related adverse events. Conclusion: We report a case of CNV as a possible rare extraintestinal manifestation of CD. The use of ranibizumab successfully impacted on CNV, while not affecting CD, which remained quiescent.
Klingbeil, Ulrich; Puliafito, Carmen A.; McCarthy, Dan; Reichel, Elias; Olk, Joseph; Lesiecki, Michael L.
Dye-enhanced diode laser photocoagulation, using the dye indocyanine green (ICG), has shown some potential in the treatment of choroidal neovascularizations (CNV). A diode laser system was developed and optimized to emit at the absorption maximum of ICG. In a clinical study at two retinal centers, more than 70 patients, the majority of which had age-related macular degeneration, were treated. Eighteen cases with ill-defined subfoveal CNV were followed an average of 11 months after laser treatment. The results show success in resolving the CNV with an average long-term preservation of visual function equal to or superior to data provided by the Macular Photocoagulation Study for confluent burns of low intensity applied to the CNV. Details of the technique and discussion of the controversies inherent in such a treatment strategy will be presented.
Kishan, Amar U. [Harvard Medical School, Boston, Massachusetts (United States); Modjtahedi, Bobeck S.; Morse, Lawrence S. [Department of Ophthalmology and Vision Sciences, University of California, Davis, Sacramento, California (United States); Lee, Percy, E-mail: email@example.com [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States)
In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.
Gamze Ozturk Karabulut
Full Text Available The purpose of this study is to investigate the effect of thyroid eye disease (TED on the measurement of corneal biomechanical properties and the relationship between these parameters and disease manifestations. A total of 54 eyes of 27 individuals with TED and 52 eyes of 30 healthy control participants were enrolled. Thyroid ophthalmopathy activity was defined using the VISA (vision, inflammation, strabismus, and appearance/exposure classification for TED. The intraocular pressure (IOP measurement with Goldmann applanation tonometer (GAT, axial length (AL, keratometry, and central corneal thickness (CCT measurements were taken from each patient. Corneal biomechanical properties, including corneal hysteresis (CH and corneal resistance factor (CRF and noncontact IOP measurements, Goldmann-correlated IOP (IOPg and corneal-compensated IOP (IOPcc were measured with the Ocular Response Analyzer (ORA using the standard technique. Parameters such as best corrected visual acuity, axial length, central corneal thickness, and corneal curvature were not statistically significant between the two groups (p > 0.05. IOP measured with GAT was higher in participants with TED (p < 0.001. The CH of TED patients was significantly lower than that of the control group. There was no significant difference in the corneal resistance factor between groups. However, IOPg and IOPcc were significantly higher in TED patients. CH and VISA grading of TED patients showed a negative correlation (p = 0.007. In conclusion, TED affects the corneal biomechanical properties by decreasing CH. IOP with GAT and IOPg is found to be increased in these patients. As the severity of TED increases, CH decreases in these patients.
Kheirkhah, Ahmad; Casas, Victoria; Li, Wei; Raju, Vadrevu K; Tseng, Scheffer C G
To report the corneal manifestations in eyes with Demodex infestation of the eyelids. Noncomparative, interventional case series. This retrospective review included six patients with Demodex blepharitis who also exhibited corneal abnormalities, which led to suspicion of limbal stem cell deficiency in three cases. All patients received weekly lid scrubs with 50% tea tree oil and a daily lid scrubs with tea tree shampoo for a minimum of six weeks. Improvement of symptoms and corneal and conjunctival signs were evaluated. All six patients exhibited ocular irritation and conjunctival inflammation, while meibomian gland dysfunction (n = 5), rosacea (n = 4), and decreased vision (n = 3) also were noted despite prior treatments with oral tetracycline, topical steroids with antibiotics, and lid scrub with baby shampoo. These patients were proven to have Demodex folliculorum (n = 6) and Demodex brevis (n = 3) by microscopic examination of epilated lashes. Their corneal manifestation included superficial corneal vascularization (six eyes of five cases), marginal corneal infiltration (two eyes of two cases), phlyctenule-like lesion (one eye of one case), superficial corneal opacity (two eyes of two cases), and nodular corneal scar (two eyes of two cases). After treatment, the Demodex count was reduced from 6.8 +/- 2.8 to 1 +/- 0.9 (standard deviation; P = .001). All patients showed dramatic resolution of ocular irritation, conjunctival inflammation, and all inflammatory, but not scarred, corneal signs; three patients showed improved vision. A variety of corneal pathologic features together with conjunctival inflammation, commonly noted in rosacea, can be found in patients with Demodex infestation of the eyelids. When conventional treatments for rosacea fail, one may consider lid scrub with tea tree oil to eradicate mites as a new treatment.
Bagheri, Abbas; Hasani, Hamid R; Karimian, Farid; Abrishami, Mohammad; Yazdani, Shahin
To evaluate refractive and corneal topographic changes following excision of chalazia. This prospective noncomparative quasi-experimental clinical trial includes consecutive patients older than 7 years with chalazia of minimum duration of 1 month who underwent excision of the lesions by an internal or external approach. Overall, 253 lids from 228 eyes of 195 patients including 110 female subjects with mean age of 31-/+14 years (range 7-71) were studied. Mean duration of presenting symptoms was 4-/+2.8 months (range 1-24). Lesions were equally distributed in medial, central, and lateral areas of the eyelids. The chalazia were single in 172 (88.2%) and multiple in 23 (11.8%) patients. Mean change in best-corrected visual acuity, spherical equivalent refractive error, and difference of keratometry (corneal astigmatism) were 0.0004-/+0.007 logMAR (p=0.3), -0.06-/+0.6 D (p=0.1), and 0.34-/+0.35 (pChalazion excision can decrease corneal astigmatism and irregularity, which is more prominent in single, firm, and central upper lid lesions. These findings may have implications in pediatric patients at risk for amblyopia.
Twa, Michael D.; Vantipalli, Srilatha; Singh, Manmohan; Li, Jiasong; Larin, Kirill V.
Corneal biomechanical properties are influenced by several factors, including intraocular pressure, corneal thickness, and viscoelastic responses. Corneal thickness is directly proportional to tissue hydration and can influence corneal stiffness, but there is no consensus on the magnitude or direction of this effect. We evaluated the influence of corneal hydration on dynamic surface deformation responses using optical coherence elastography (OCE). Fresh rabbit eyes (n=10) were prepared by removing the corneal epithelium and dropping with 0.9% saline every 5 minutes for 1 hour, followed by 20% dextran solution every 5 minutes for one hour. Corneal thickness was determined from structural OCT imaging and OCE measurements were performed at baseline and every 20 minutes thereafter. Micron-scale deformations were induced at the apex of the corneal tissue using a spatially-focused (150μm) short-duration (corneal thickness due to hydration process. Corneal thickness rapidly increased and remained constant following epithelium removal and changed little thereafter. Likewise, corneal stiffness changed little over the first hour and then decreased sharply after Dextran application (thickness: -46% [-315/682 μm] RR: - 24% [-0.7/2.88 ms-1]; GV: -19% [-0.6/3.2 m/s]). Corneal thickness and corneal stiffness (RR) were well correlated (R2 = .66). Corneal biomechanical properties are highly correlated with tissue hydration over a wide range of corneal thickness and these changes in corneal stiffness are quantifiable using OCE.
Myrowitz, Elliott H; Kouzis, Anthony C; O'Brien, Terrence P
The purpose of this study was to assess interocular corneal symmetry in average simulated keratometry, corneal thickness, and posterior corneal elevation. This retrospective analysis included data from scanning slit topography (Orbscan II; Bausch and Lomb, Rochester, NY) on 242 eyes from 121 consecutive patients undergoing standard evaluation for consideration of elective laser vision correction. The symmetry between the right and left eye in average simulated keratometry, minimum central corneal thickness, and posterior corneal elevation was assessed by comparative data analysis. Simulated keratometry ranged from 39.9 to 48.6 D. The interocular difference in average simulated keratometry was 0.47 D (standard deviation [SD] 0.43). The interocular Pearson correlation coefficient for average simulated keratometry was 0.90 (p central corneal thickness was 0.95 (p symmetry in all these parameters was very high in this group of consecutive patients. Asymmetry of these interocular parameters may warrant repeat clinical testing for accuracy and may predict corneal abnormalities. Normative data on posterior cornea elevation is presented. This study points out potentially clinically important high interocular corneal symmetry data in simulated keratometry, corneal thickness, and posterior corneal elevation.
Tempel, D.; de Boer, M.; van Deel, E.D.; Haasdijk, R.A.; Duncker, D.J.G.M.; Cheng, C.; Schulte-Merker, S.; Duckers, H.J.
RATIONALE: Neovascularization stimulated by local or recruited stem cells after ischemia is a key process that salvages damaged tissue and shows similarities with embryonic vascularization. Apelin receptor (Aplnr) and its endogenous ligand apelin play an important role in cardiovascular development.
Tempel, D.; Boer, de M.; Deel, van E.D.; Haasdijk, A.; Duncker, D.J.; Cheng, C.; Schulte-Merker, S.; Duckers, H.J.
Rationale: Neovascularization stimulated by local or recruited stem cells after ischemia is a key process that salvages damaged tissue and shows similarities with embryonic vascularization. Apelin receptor (Aplnr) and its endogenous ligand apelin play an important role in cardiovascular development.
Corbelli, Eleonora; Sacconi, Riccardo; Querques, Lea; Carnevali, Adriano; Giuffrè, Chiara; Rabiolo, Alessandro; Bandello, Francesco; Querques, Giuseppe
To report the clinical course of focal choroidal excavation associated with choroidal neovascularization in a case of choroidal inflammation. Case report. A 41-year-old man presented with blurred vision and metamorphopsia in his left eye. Multimodal imaging including optical coherence tomography angiography showed nonconforming focal choroidal excavation in the setting of choroidal inflammation and the presence of choroidal neovascularization at the border of the excavation, nicely visualized by optical coherence tomography angiography. Pattern alteration from nonconforming to conforming focal choroidal excavation and choroidal neovascularization involution were observed after treatment with oral steroids. Multimodal imaging, including optical coherence tomography angiography, allowed to detect and monitor pattern focal choroidal excavation transformation and choroidal neovascularization reduction after treatment with oral steroids.
Larsen, Michael; Schmidt-Erfurth, Ursula; Lanzetta, Paolo
To compare the efficacy and safety of same-day verteporfin photodynamic therapy (PDT) and intravitreal ranibizumab combination treatment versus ranibizumab monotherapy in neovascular age-related macular degeneration....
Kessel, Line; Theil, Pernille Koefoed; Sørensen, Torben Lykke
Purpose To examine the outcome after cataract surgery in patients with neovascular age-related macular degeneration (AMD) treated with intravitreal anti-vascular endothelial growth factor (VEGF) injections in routine clinical practice. Methods We extracted information about patients recorded...
Pankratz, Franziska; Bemtgen, Xavier; Zeiser, Robert; Leonhardt, Franziska; Kreuzaler, Sheena; Hilgendorf, Ingo; Smolka, Christian; Helbing, Thomas; Höfer, IE; Esser, Jennifer S; Kustermann, Max; Moser, Martin; Bode, Christoph; Grundmann, Sebastian
BACKGROUND: Adaptive neovascularization after arterial occlusion is an important compensatory mechanism in cardiovascular disease and includes both the remodeling of pre-existing vessels to collateral arteries (arteriogenesis) and angiogenic capillary growth. We now aimed to identify regulatory
Augustin, Marco; Wechdorn, Matthias; Pfeiffenberger, Ulrike; Fialová, Stanislava; Werkmeister, René M.; Hitzenberger, Christoph K.; Baumann, Bernhard
A multi-functional OCT approach is used to identify different tissue types during the early development of spontaneous neovascularizations in the mouse retina based on their intrinsic optical properties.
Full Text Available We have observed that the commonly used ketamine/xylazine anesthesia mix can induce a focally severe and permanent corneal opacity. The purpose of this study was to establish the clinical and histological features of this deleterious side effect, its sensitivity with respect to age and anesthesia protocol, and approaches for avoiding it.Young C57BL/6J, C57BLKS/J, and SJL/J mice were treated with permutations of anesthesia protocols and compared using slit-lamp exams, optical coherence tomography, histologic analyses, and telemetric measurements of body temperature.Ketamine/xylazine induces corneal damage in mice with a variable frequency. Among 12 experimental cohorts, corneal damage associated with ketamine/xylazine was observed in 9 of them. Despite various treatments to avoid corneal dehydration during anesthesia, the frequency of corneas experiencing damage among responding cohorts was 42% (26% inclusive of all cohorts, which is significantly greater than the natural prevalence (5%. The damage was consistent with band keratopathy. It appeared as a white or gray horizontal band located proximal to the pupil and was positive for subepithelial calcium deposition with von Kossa stain.The sum of our clinical and histological observations is consistent with ketamine/xylazine-induced band keratopathy in mice. This finding is relevant for mouse studies involving the eye and/or vision-dependent behavioral assays, which would both be prone to artifact without appreciation of the damage caused by ketamine/xylazine anesthesia. Use of yohimbine is suggested as a practical means of avoiding this complication.
Yang, Yang; Xu, Cunliang; Deng, Shijing; Xiao, Jingjing
Due to differences in corneal grafting microsurgery between manual and robotic suturing, new challenges have arisen in testing the insertion force and torque of corneal tissue acting on suturing needles in order to guarantee successful completion of surgical procedures. In order to measure the force during the insertion operation, from the needle entering the cornea through the entry point until the puncturing of the exit point along the circular trajectory, a force measurement system was established, including fresh porcine cornea, a corneal-suturing robot, a circular needle, a micro-forceps manipulator with a force transducer, a computer with a data acquisition board and a medical microscope. The force values in the needle coordinate frames were obtained on the basis of a sensor coordinate frame through D-H coordinate transformation, and an index is proposed here to evaluate the insertion performance. Experiments on both manual and robotic suturing were carried out for comparison. The scale and changes of the needle insertion force were obtained using two different suturing methods. The maximal tangent force in robotic suturing is a little larger than in manual suturing, and the maximal resultant force in robotic suturing is somewhat smaller. Although the difference is not very significant, robotic suturing performs in a more stable way. Moreover, the performance evaluation index M(dmax) (the maximum of square root of the quadratic sum of torque components M(OX) and M(OY)) in robotic suturing is much smaller than that in manual suturing. The force measurement system has been verified to be feasible through experimentation. Compared with conventional manual surgery, robotic suturing has some advantages: more stable suturing, smaller distortion torque and fewer invasions to the corneal tissue, showing that its application in minimally invasive surgery is practical. Copyright © 2011 John Wiley & Sons, Ltd.
Tsubota, K; Mashima, Y; Murata, H; Yamada, M; Sato, N
This study was designed to observe any changes to the corneal epithelium after penetrating keratoplasty. The corneal epithelia of 26 patients were observed by specular microscopy 1 week, 1 month, 3 months, and 6 months following penetrating keratoplasty. After re-epithelialisation was confirmed by biomicroscopy 1 week after surgery, specular microscopy revealed many abnormal cells, including spindle shaped cells, nucleated cells, large cells, as well as irregular cell configurations. Although these abnormal findings tended to decrease with time, they were still present in some cases as much as 6 months postoperatively. Computerised morphometric analysis yielded mean cell areas of 1121 (SD 168) microns 2, 1139 (675) microns 2, 1712 (496) microns 2, and 1400 (377) microns 2 at 1 week, 1 month, 3 months, and 6 months respectively, all significantly greater than that of age matched controls (710 (151) microns 2). The shape factor decreased with time, but was still greater than the control level at 6 months. This study demonstrates that epithelial abnormalities persist longer than expected after penetrating keratoplasty, and that these subtle changes can be detected by specular microscopic observation, potentially allowing for modification and enhancement of the wound healing process.
Tan, Donald T H; Por, Yong-Ming
The approach to the management of various forms of corneal ectasia is changing, with the advent of new surgical and nonsurgical options. The purpose of this review is to summarize and evaluate relevant studies on new treatments for keratoconus, postrefractive surgery keratectasia, and peripheral ectatic corneal disorders. Various alternatives to corneal transplantation for the management of keratoconus aim to enhance corneal rigidity by means of nonsurgical collagen cross-linking, or with the use of intrastromal corneal ring segments, and studies suggest that these treatments may reduce astigmatism or ectatic progression to varying degrees. Recent developments in anterior lamellar keratoplasty enable targeted replacement or augmentation of corneal stroma without replacement of endothelium, and include procedures such as deep anterior lamellar keratoplasty, microkeratome or laser-assisted anterior lamellar surgery, and peripheral tectonic lamellar keratoplasty procedures demonstrate successful reinforcement of peripheral stroma to reduce astigmatism. These new forms of surgery are viable alternatives to conventional penetrating keratoplasty and bring added safety profiles for long-term visual rehabilitation and restoration of tectonic integrity in central and peripheral forms of corneal ectasia.
Wang, Jia-Kang; Huang, Tzu-Lun; Pei-Yuan Su; Chang, Pei-Yao
To investigate the correlation of various corneal hysteresis (CH) factors in Chinese adults. From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the study. Goldmann-correlated intraocular pressure (IOPG) and CH were measured using an ocular response analyzer (ORA). Central corneal thickness was measured using the ORA's integrated handheld ultrasonic pachymeter. The IOLMaster was used to obtain the ocular biometric measurements including axial length, anterior chamber depth, and keratometric values. The Pearson correlation coefficient was used to test correlations between CH and quantitative factors. The chi-square test was used to detect differences in categorical values. Longer axial length (P = 0.0001), lower IOPG (P = 0.03), older age (P = 0.003), and thinner central corneal thickness (P = 0.0001) were significantly associated with lower CH. The anterior chamber depth (P = 0.34), gender (P = 0.23), and corneal curvature (P = 0.18) had no relationship to CH. Various factors including axial length, intraocular pressure, age, and central corneal thickness can affect measurement of corneal biomechanical properties in Chinese adults. But the anterior chamber depth, gender, and corneal curvature were irrelevant to CH.
Oh, Joo Youn; Yu, Ji Min; Ko, Jung Hwa
Ethanol is widely used in ocular surface surgeries and for the treatment of corneal diseases. However, ethanol is a toxic agent that is related to the development of a number of alcohol-related diseases. Despite the common use of ethanol for therapeutic purposes in ophthalmology, effects of ethanol on the ocular surface have been poorly defined. Hence, we performed this study to investigate effects of ethanol on corneal epithelium from various aspects. We exposed corneal epithelial cells in culture to different concentrations of ethanol for 30 seconds and evaluated the cells for toxicity, survival, and expression of cell-specific markers and inflammatory cytokines at 24, 48, and 72 hours after ethanol exposure. We found that ethanol markedly decreased the viability of cells in a concentration-dependent manner by causing cell lysis, suppressing proliferation, and inducing apoptosis. Also, expression of corneal epithelial cell-specific markers, both stem cell and differentiation markers, was significantly reduced by ethanol exposure. Expression of proinflammatory cytokines and chemokines was highly increased in corneal epithelial and stromal cells that were exposed to ethanol. Together, data suggest that brief exposure of the corneal surface to ethanol may have long-term effects by disrupting the integrity of corneal epithelium and generating inflammation, both of which are precursors to a number of ocular surface diseases.
Bin Kong; Shengli Mi
Corneal diseases constitute the second leading cause of vision loss and affect more than 10 million people globally. As there is a severe shortage of fresh donated corneas and an unknown risk of immune rejection with traditional heterografts, it is very important and urgent to construct a corneal equivalent to replace pathologic corneal tissue. Corneal tissue engineering has emerged as a practical strategy to develop corneal tissue substitutes, and the design of a scaffold with mechanical pro...
Urbich, Carmen; Heeschen, Christopher; Aicher, Alexandra; Sasaki, Ken-ichiro; Bruhl, Thomas; Hofmann, Wolf K.; Peters, Christoph; Reinheckel, Thomas; Pennacchio, Len A.; Abolmaali, Nasreddin D.; Chavakis, Emmanouil; Zeiher, Andreas M.; Dimmeler, Stefanie
Infusion of endothelial progenitor cells (EPCs), but not of mature endothelial cells (ECs), promotes neovascularization after ischemia. We performed a gene expression profiling of EPCs and ECs to identify genes, which might be important for the neovascularization capacity of EPCs. Intriguingly, the protease cathepsin L (CathL) was highly expressed in EPCs as opposed to ECs and is essential for matrix degradation and invasion by EPCs in vitro. CathL deficient mice showed impaired functional recovery after hind limb ischemia supporting the concept for an important role of CathL in postnatal neovascularization. Infused CathL deficient progenitor cells failed to home to sites of ischemia and to augment neovascularization. In contrast, over expression of CathL in mature ECs significantly enhanced their invasive activity and induced their neovascularization capacity in vivo. Taken together, CathL plays a crucial role for the integration of circulating EPCs into the ischemic tissue and is required for neovascularization mediated by EPCs.
He, Lizhi; Marneros, Alexander G.
Macrophages occur along a continuum of functional states between M1-type polarized macrophages with antiangiogenic and antitumor activity and M2-type polarized macrophages, which have been implicated to promote angiogenesis and tumor growth. Proangiogenic M2-type macrophages promote various pathologic conditions, including choroidal neovascularization in models of neovascular age-related macular degeneration, or certain cancers, such as glioblastoma multiforme. Thus, a potential novel therapeutic approach to target pathological angiogenesis in these conditions would be to inhibit the polarization of macrophages toward the proangiogenic M2-type. However, no pharmacological inhibitors of M2-type macrophage polarization have been identified yet. Here we performed an unbiased pharmacological and small chemical screen to identify drugs that inhibit proangiogenic M2-type macrophage polarization and block pathologic macrophage-driven neovascularization. We identified the well tolerated and commonly used antibiotic doxycycline as a potent inhibitor of M2-type polarization of macrophages. Doxycycline inhibited, in a dose-dependent manner, M2-type polarization of human and bone marrow-derived mouse macrophages without affecting cell viability. Furthermore, doxycycline inhibited M2-type macrophage polarization and subsequent neovascularization in vivo in a laser injury model of choroidal neovascularization. Thus, doxycycline could be used to enhance current antiangiogenic treatment approaches in various conditions that are promoted by proangiogenic M2-type macrophages, including neovascular age-related macular degeneration and certain cancers. PMID:24505138
Full Text Available Neeraj Pandey, Ayachit GuruprasadMM Joshi Eye Institute, Hubli, Karnataka, IndiaAbstract: An otherwise healthy 27-year-old woman presented with complaints of sudden painless blurred vision in the right eye for one week. On examination, visual acuity was 20/30 in the right eye and 20/20 in left eye. Fundus examination OS was normal, but OD demonstrated an elevated, opaque, yellowish parapapillary choroidal lesion with grayish membrane associated with minimal subretinal fluid, suggestive of a choroidal neovascular membrane in the center. B-scan ultrasonography revealed findings consistent with a choroidal osteoma. Fundus fluorescein angiography of the right eye revealed a relatively well defined area of hyperfluorescence that increased in size and intensity in the later phases, suggestive of active extrafoveal choroidal neovascular membrane. Optical coherence tomography confirmed the extrafoveal choroidal neovascular membrane with subfoveal fluid. She was treated with intravitreal bevacizumab OD. At the two-week visit, vision OD improved to 20/20. Fluorescein angiography and optical coherence tomography revealed a resolved choroidal neovascular membrane. Intravitreal bevacizumab may be an effective alternative in the management of choroidal neovascular membrane secondary to choroidal osteoma.Keywords: osteoma, choroidal neovascular membrane, optical coherence tomography, bevacizumab
Laibson, Peter R
The corneal endothelium is the most important single layer in corneal transplantation. In his Castroviejo Lecture, William Bourne, MD, summarizes his work on the corneal endothelium and its importance to corneal transplantation. Almost half the corneal transplants performed in the United States are done so because of malfunctioning, diseased, or absent endothelial cells. If just this layer could be transplanted, the long wait for better vision after keratoplasty (up to two years in some countries) can be eliminated, as well as the problems of epithelial and subepithelial graft rejection. The significant astigmatism after keratoplasty could also be reduced. Transplantation of the endothelium in deep lamellar keratoplasty is being done in limited fashion throughout the world and the first patients have now been done in the United States. In many countries where corneal tissue is difficult to obtain, keratoplasty is only performed on one eye, even though both eyes may need it. One article this year discusses binocular vision recovery in bilateral keratoplasty and the objective and subjective improvements after bilateral keratoplasty. Patients who are bilaterally blind from diseases such as Stevens-Johnson syndrome, and ocular pemphigoid have little hope of visual recovery from conventional corneal transplants. The use of a keratoprosthesis to bypass the totally abnormal conjunctival surface has helped many people in the past. The preoperative prognostic categories of patients who may benefit from keratoprosthesis has been carefully reviewed in a large number of keratoprosthesis patients and this information will help ophthalmologists decide who will benefit the most benefit from keratoprosthesis. This year, articles on corneal transplantation after conjunctival flaps, suture-related complications in keratoplasty, the implantation of an intraocular lens after penetrating keratoplasty, and long-term results of penetrating keratoplasty with glaucoma drainage tube
Can, Mehmet Erol; Erten, Sukran; Can, Gamze Dereli; Cakmak, Hasan Basri; Sarac, Ozge; Cagil, Nurullah
To investigate the variations in biomechanical properties of the cornea in rheumatoid arthritis (RA) patients. A total of 53 RA patients, and 25 healthy individuals (control group) were enrolled. Rheumatoid arthritis patients were classified as in active phase (group 1; n=24) or in remission phase (group 2; n=29). Corneal biomechanical parameters including corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure (IOPcc), and Goldmann-correlated IOP (IOPg) were measured with the Reichert Ocular Response Analyzer. Topographical measurements, including central corneal thickness (CCT), anterior chamber depth, iridocorneal angle, and corneal volume were measured using a Sirius corneal topographer. The mean CH was 9.43±1.17 mm Hg in group 1, 9.42±1.84 mm Hg in group 2, and 10.47±1.68 mm Hg in the control group (P=0.03). The mean IOPcc was 17.85±3.2 mm Hg in group 1, 17.95±3.49 mm Hg in group 2, and 15.36±3.11 mm Hg in the control group (P=0.008). The CH showed a significant positive correlation with CRF (P=0.000, r=0.809) and CCT (P=0.000, r=0.461), and a significant negative correlation with IOPcc (P=0.000, r=-0.469). Decrease in the mean CH measurements indicates that ultrastructural changes in the cornea may occur in the active phase, and these changes persist in the remission period. In addition, IOPcc is significantly affected by the corneal biomechanical properties. In RA patients, it is important to control the corneal parameters and IOP measurements against the irreversible changes on the optic nerve.
Vaddavalli, Pravin K.; Yoo, Sonia H.
Corneal transplant surgery has undergone numerous modifications over the years with improvements in technique, instrumentation and eye banking. The main goals of corneal transplantation are achieving excellent optical clarity with long-term graft survival. Penetrating, anterior and posterior lamellar surgery along with femtosecond laser technology have partially met these goals, but outcomes are often unpredictable and surgeon dependent. Technology to predictably separate stroma from Descemet's membrane, techniques to minimize endothelial cell loss, improvements in imaging technology and emerging techniques like laser welding that might replace suturing, eventually making corneal transplantation a refractively predictable procedure are on the wish list of the cornea surgeon.
Kilavuzoglu, Ayse Ebru; Celebi, Ali Riza Cenk; Altiparmak, Ugur Emrah; Cosar, Cemile Banu
To determine the effect of smoking on corneal biomechanical behavior. The medical records of consecutive patients that presented to the ophthalmology department were reviewed. History of smoking and ophthalmological examination findings were recorded. The smoking group met the following criteria: a clear history of and present smoking habit, negative history of corneal disease and surgery, ocular response analyzer measurement at the time of examination, and a waveform score ≥3.7. Nonsmokers (never smoked or quit smoking ≥6 months earlier) that met the same criteria constituted the control group. Corneal biomechanical parameters were measured using ocular response analyzer. Data were analyzed using Pearson's χ(2) test, Mann-Whitney U test, and Spearman's correlation coefficient. The smoking group included 166 eyes of 166 patients with a mean age of 38.7 ± 11.95 years, and the control group consisted of 170 eyes of 170 patients with a mean age of 38.40 ± 12.2 years. Mean cumulative smoking dose in the smoking group was 9.59 ± 11.87 pack-years (0.04- 75.00). There was no significant correlation between cumulative smoking dose and corneal hysteresis and corneal resistance factor (P = 0.382 and 0.074, respectively). There were no significant differences in corneal hysteresis or the corneal resistance factor between the two groups (P > 0.05). There was no significant difference in corneal hysteresis between those in the smoking group aged 18-44 years and those aged 45-64 years (P = 0.258), whereas in the control group mean corneal hysteresis was significantly lower in the 45-64 year olds than in the 18-44 year olds (P = 0.034). Although there was no significant difference in corneal biomechanics between smoking and control groups, the decrease in corneal hysteresis with aging was less apparent in the smoking group, which may be due to the potential changes in the cornea's microstructure induced by smoking during aging and the effect of smoking in aged corneal
Jackson, H.; Bosanquet, R.
Three groups of patients who had undergone cataract extraction through a corneal incision closed with 10/0 nylon sutures one, two, and three years previously were recalled to determine the incidence of suture related complications. Broken corneal sutures were found in 87.5% of patients after two years and 90% after three years and were causing symptoms in over half the patients. It is recommended that 10/0 nylon corneal sutures be routinely removed no later than one year after surgery. Images PMID:1751460
Fu-Hong Liao; Zi-Zhong Yu; Bin Hu
AIM: To observe the transplantation of acellular porcine corneal stroma on the treatment of superficial keratitis by drug-resistant fungal. METHODS: We performed a retrospective analysis of 16 cases of fungal keratitis received the transplantation of acellular porcine corneal matrix from June 2015 to March 2016 with a follow-up of 6mo. We analyzed on items as postoperative visual acuity, corneal graft status, postoperative recurrence and postoperative complications. RESULTS: We observed a hea...
Camellin, Massimo; Guidotti, Jacopo Maria; Arba Mosquera, Samuel
Purpose To evaluate the efficacy and safety of Corneal-Wavefront guided transepithelial photorefractive keratectomy (TransPRK) after corneal collagen cross linking (CXL) in keratoconic patients. Methods In this retrospective, non-comparative, consecutive case series, 39 keratoconic eyes underwent Corneal-Wavefront guided TransPRK for the correction of aberrations at least 4 months after conventional CXL at SEKAL Rovigo Microsurgery Centre, Rovigo, Italy. Two eyes (5%) underwent a secondary la...
Xiangchen Tao; Haiqun Yu; Yong Zhang; Zhiwei Li; Vishal Jhanji; Shouxiang Ni; Ya Wang; Guoying Mu
Purpose. To evaluate the role of corneal epithelium in riboflavin/ultraviolet-A (UVA) mediated corneal collagen cross-linking treatment. Methods. Fifty New Zealand rabbits were divided into 5 groups: UVA treatment with or without corneal epithelium, UVA+riboflavin treatment with or without corneal epithelium, and control without any treatment. All rabbits were sacrificed after irradiation and subsequently 4?mm???10?mm corneal strips were harvested for biomechanical evaluation. Results. UVA ir...
Bulusu, Kartik V.; Alibouzar, Mitra; Castro, Nathan J.; Zhang, Lijie G.; Sarkar, Kausik; Plesniak, Michael W.
Degradable polymer-based prosthetics for the treatment of osseous tissue defects, maxillo-/cranio-facial trauma and brain injury face two common clinical obstacles impeding efficient tissue engraftment i.e., controlled material release and neovascularization. Ascertaining the time scales of polymer degradation for controlled delivery of drugs and nutrients is critical to treatment efficacy and strategy. We incorporated multiple experimental methodologies to understand the driving forces of transport mechanisms in polyvinyl alcohol-based (PVA) 3D-printed scaffolds of different porosity. Scaffold degradation was monitored various pulsatile flow conditions using MEMS-based pressure catheters and an ultrasonic flow rate sensor. Ultrasonic properties (bulk attenuation and sound velocity) were measured to monitor the degradation process in a static, alkaline medium. Viscosity and the absorption spectra variations with PVA-solute concentrations were measured using a rheometer and a spectrophotometer, respectively. A simple mathematical model based on Fick's law of diffusion provides the fundamental description of solute transport from the scaffold matrices. However, macroscopic material release could become anomalous or non-Fickian in complex polymeric scaffold matrices. Supported by the GW Center for Biomimetics and Bioinspired Engineering and NIH Director's New Innovator Award 1DP2EB020549-01.
Stanescu-Segall, Dinu; Balta, Florian; Jackson, Timothy L
Large submacular hemorrhage, an uncommon manifestation of neovascular age-related macular degeneration, may also occur with idiopathic polypoidal choroidal vasculopathy. Submacular hemorrhage damages photoreceptors owing to iron toxicity, fibrin meshwork contraction, and reduced nutrient flux, with subsequent macular scarring. Clinical and experimental studies support prompt treatment, as tissue damage can occur within 24 hours. Without treatment the natural history is poor, with a mean final visual acuity (VA) of 20/1600. Reported treatments include retinal pigment epithelial patch, macular translocation, pneumatic displacement, intravitreal or subretinal tissue plasminogen activator, intravitreal anti-vascular endothelial growth factor (VEGF) drugs, and combinations thereof. In the absence of comparative studies, we combined eligible studies to assess the VA change before and after each treatment option. The greatest improvement occurred after combined pars plana vitrectomy, subretinal tissue plasminogen activator, intravitreal gas, and anti-vascular endothelial growth factor treatment, with VA improving from 20/1000 to 20/400. The best final VA occurred using combined intravitreal tissue plasminogen activator, gas, and anti-vascular endothelial growth factor therapy, with VA improving from 20/200 to 20/100. Both treatments had an acceptable safety profile, but most studies were small, and larger randomized controlled trials are needed to determine both safety and efficacy. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.
Full Text Available AIM: To investigate the effect of soft corneal contact lens on the recovery of corneal epithelial defects and the comfort in patients with diabetic retinopathy after vitrectomy. METHODS: Twenty patients(20 eyeswith diabetic retinopathy whose corneal epithelium defected after vitrectomy were randomly divided into 2 groups. The trial group(10 eyesreceived the combination treatment of wearing soft corneal contact lenses and eyedrops to promote corneal epithelial repair, and the control group(10 eyesonly received eyedrops. The corneal epithelial healing time was observed postoperatively. And the scores of the comfort in patients between two groups were compared. RESULTS: The average duration of corneal epithelial defects was 4.1±1.20d in the trial group, and 14.2±6.07d in the control group, which was statistically significant different between the two groups(PP>0.05. CONCLUSION: The soft corneal contact lens could effectively treat patients with corneal epithelial defects after vitrectomy, and improve their comfort.
Peinado, Teresa Fernández; Piñero, David P; López, Ignacio Alcaraz; Alio, Jorge L
We report a case of corneal ectasia in a 25-year-old man after myopic laser in situ keratomileusis in which a complete characterization of the corneal structure was performed by means of a Scheimpflug photography-based system. The patient presented in the ectatic eye with a subjective refraction of +0.50 to 6.00 × 100°, which with correction gave a visual acuity of 20/25. With the topographic analysis, corneal shapes from both corneal surfaces at the four different quadrants were found to be complementary, maintaining the meniscus-shaped profile of the cornea. This correlation between the anterior and posterior corneal surfaces was also confirmed with an optical tomography evaluation. Corneal biomechanics was also evaluated by means of the Ocular Response Analyzer (Reichert), which confirmed the biomechanical alteration. In summary, biomechanical changes leading to corneal ectasia in this case affected the global corneal structure, inducing alterations in the shape of both anterior and posterior corneal surfaces.
Hager, A; Loge, K; Kutschan, A; Wiegand, W
Intraocular irrigating solutions remain for several hours beyond the actual time of surgery in the eye. The irrigating solution ought to resemble biochemically aqueous humor and vitreous and offer protection for sensitive structures of the eye, such as the corneal endothelium. Impairment of the corneal endothelium may lead to corneal oedema and biomechanical alterations of the cornea. 54 eyes after pars-plana vitrectomy (PPV) in elective macular surgery were evaluated by measuring corneal thickness (CCT) using ultrasound pachymetry (20 MHz) and corneal hysteresis (CH) using the ocular response analyser (Reichert Ophthalmic Instruments, Buffalo, NY, USA). Measurements were performed not earlier than 2 weeks prior to surgery and 1 to 3 days after surgery. Results were compared to a control group (n = 39) and to 101 eyes after clear cornea cataract extraction (KAT). The two groups (PPV and KAT) did not differ with respect to age (p = 0.555). Corneal thickness has increased significantly in both groups (p corneal hysteresis decreased significantly postoperatively (p corneal thickness but also by biomechanical parameters such as corneal hysteresis.
Gatinel, Damien; Chaabouni, Slim; Adam, Pierre-Alexandre; Munck, Jacques; Puech, Michel; Hoang-Xuan, Thanh
To measure prospectively the early changes in corneal hysteresis, topography, and pachymetry after the creation of a stromal flap cut without laser photoablation. A 37-year-old man was referred for a bioptic procedure to correct for compound myopic astigmatism in the left eye. A 159-microm-thick 8x8.5-mm superior hinged flap was created with a mechanical microkeratome in the left cornea. Changes in the corneal hysteresis, corneal resistance factor, Goldmann correlated intraocular pressure (lOP), corneal compensated IOP, anterior and posterior topography, and optical and ultrasound pachymetry were monitored prospectively before and at 1 hour, 1 day, 5 days, and 25 days after flap creation. The right eye served as a control. In the left eye, corneal hysteresis and corneal resistance factor decreased immediately after the flap cut and remained lower than preoperatively at 1 hour, 1 day, 5 days, and 25 days. Corneal compensated IOP varied significantly less than Goldmann correlated IOP in both eyes. Central flattening of the horizontal meridians was observed on the difference topography maps. The values of the left eye posterior best fit sphere increased after the flap cut. Increased central corneal thickness occurred immediately after the flap cut and decreased over time without returning to its preoperative value. The creation of a stromal flap can modify the biomechanical properties of the cornea, including a reduction in corneal hysteresis. The topographic changes were consistent with previously reported cases of flap cut in normal corneas.
Full Text Available AIM: To describe the outcomes of corneal stromal lenticules in repairing of corneal ulcer and/or perforation. METHODS: This was a retrospective chart review of 6 eyes of 6 patients from January to June 2017,who underwent corneal ulcer repair with the corneal, stromal lenticules harvested from femtosecond laser refractive surgery and kept in pure glycerin for use. Three cases of infectious corneal ulcers were bacterial, fungal, and infection with foreign bodies in corneal deep layer, one each. The other 3 were corneal ulcer perforation. Making sure no air bubble between donor graft and Descemet membrane. The mean follow-up time was 3.71±1.56mo(range 1-6mo. RESULTS: All eyes were successfully treated under control of infection without intra-operative complications, and early postoperative evaluation showed a clear graft in all cases. The last follow-up visit showed the mean best corrected visual acuity(VAsignificantly improved after surgery. There was significant difference from 0.48±0.12 to 1.50±0.08(PCONCLUSION: The preliminary results suggest that the use of corneal stromal lenticules may be a safe and effective surgical alternative for corneal ulcer, even though the long-term outcome of the graft needs to be further observed.
Albietz, Julie M; Lenton, Lee M
Corneal oedema is a common post-operative problem that delays or prevents visual recovery from ocular surgery. Honey is a supersaturated solution of sugars with an acidic pH, high osmolarity and low water content. These characteristics inhibit the growth of micro-organisms, reduce oedema and promote epithelialisation. This clinical case series describes the use of a regulatory approved Leptospermum species honey ophthalmic product, in the management of post-operative corneal oedema and bullous keratopathy. A retrospective review of 18 consecutive cases (30 eyes) with corneal oedema persisting beyond one month after single or multiple ocular surgical procedures (phacoemulsification cataract surgery and additional procedures) treated with Optimel Antibacterial Manuka Eye Drops twice to three times daily as an adjunctive therapy to conventional topical management with corticosteroid, aqueous suppressants, hypertonic sodium chloride five per cent, eyelid hygiene and artificial tears. Visual acuity and central corneal thickness were measured before and at the conclusion of Optimel treatment. A temporary reduction in corneal epithelial oedema lasting up to several hours was observed after the initial Optimel instillation and was associated with a reduction in central corneal thickness, resolution of epithelial microcysts, collapse of epithelial bullae, improved corneal clarity, improved visualisation of the intraocular structures and improved visual acuity. Additionally, with chronic use, reduction in punctate epitheliopathy, reduction in central corneal thickness and improvement in visual acuity were achieved. Temporary stinging after Optimel instillation was experienced. No adverse infectious or inflammatory events occurred during treatment with Optimel. Optimel was a safe and effective adjunctive therapeutic strategy in the management of persistent post-operative corneal oedema and warrants further investigation in clinical trials. © 2015 The Authors. Clinical and
Muñoz Cardona, Marta Lucia
Full Text Available Peripapillary neovascular membrane is a rare complication of chronic papiledema. When the latter is due to idiopathic intracranial hypertension, neovascularization is even rarer. Because of this low occurrence, it is difficult to design studies to define the most appropriate treatment. We report the case of a woman who developed papiledema by idiopathic intracranial hypertension with peripapillary neovascular membrane, and who was successfully treated with intravitreal ranibizumab.
Das, Sujata; Sharma, Savitri; Priyadarshini, Omega; Sahu, Srikant K; Kar, Sarita; Vemuganti, Geeta K
To correlate the culture results of corneal scrapings with culture and histopathology results of corneal tissues in therapeutic keratoplasty. A retrospective analysis of the culture results of corneal scrapings and corneal tissues of eyes that received therapeutic penetrating keratoplasty at a tertiary eye care center between December 2006 and November 2008 was conducted. As per the preferred practice, those cases that did not respond to appropriate antimicrobial therapy and/or presented with a large infiltrate/perforation received therapeutic keratoplasty. The microbiology and histopathology findings of the corneal tissues were compared. Thirty-eight therapeutic keratoplasties were performed on 36 patients. Although all cases had histopathology and culture of the corneal tissue, corneal scrapings were not performed in 4 cases. Corneal scrapings and corneal tissues were culture-positive in 76% (26 of 34) and 60% (23 of 38) of cases, respectively. In 8 cases, the corneal scrapings and corneal tissues yielded identical organisms, whereas different organisms grew in 4 cases. In 6 cases, the corneal tissues were culture-positive but the corneal scrapings were sterile. In 20 cases, the corneal tissues were culture-positive for fungus and also showed fungal filaments in their corresponding histopathology specimens. Corneal tissue culture can provide additional information in cases undergoing therapeutic keratoplasty. It helps to determine the management of patients after keratoplasty.
Full Text Available Paolo Milani,1 Amedeo Massacesi,1 Stefania Moschini,1 Marco Setaccioli,1 Ennio Bulone,1 Gemma Tremolada,1 Stefano Ciaccia,1 Elena Mantovani,1 Daniela Morale,2 Fulvio Bergamini1 1Ophthalmology Department, Istituto Auxologico, 2Institute of Mathematics, Universita’ degli Studi di Milano, Milan, Italy Purpose: To investigate myopic choroidal neovascularization (mCNV by fluorescein angiography (FA, spectral-domain optical coherence tomography (SD-OCT, near-infrared (NIR reflectance, and autofluorescence (AF. Methods: This retrospective study included 65 eyes of 62 Caucasian patients with a mean age of 66.72 years (95% confidence interval [CI] 63–70 years and a mean refraction of -9.72 diopters (95% CI -8.74 to -10.70 diopters. Results: Most of the mCNV cases were foveal-juxtafoveal (60/65, 92.3%, with thickening of the corresponding retina (62/65, 95.3% and leakage on FA (44/65, 67.6%. No retinal fluid was detectable in 32 (49.2% eyes and there was no hemorrhage in 25 (38.4% eyes. Papillary chorioretinal atrophy was evident in 58 (89.2%, a shadowing effect in 48 (73.8%, and an epiretinal membrane in 38 (58.4% eyes. If an area of macular chorioretinal atrophy was present, mCNV frequently developed adjacent to it and was hyperfluorescent rather than with leakage (P<0.001. In eyes with edema or hemorrhage, hyper-reflective foci were more frequent (P<0.005. NIR and AF features were indeterminable in 19 (29.2% and 27 (41.5% eyes, respectively. The predominant feature was black or grayish on NIR (34/65, 52.3% and patchy (hypo- and hyperfluorescence was observed on AF (25/65, 38.4%. FA and SD-OCT correctly detected mCNV in 49 (75.3% and 48 (73.8% eyes, respectively, whereas NIR and AF exhibited limited diagnostic sensitivity. Doubtful diagnosis was associated with hyperfluorescent mCNV (P<0.001, absence of retinal fluid and epiretinal membrane (P<0.05, and presence of macular chorioretinal atrophy (P<0.01. Conclusion: Tomographic, angiographic, AF
Faridi, Ambar; Jia, Yali; Gao, Simon S; Huang, David; Bhavsar, Kavita V; Wilson, David J; Sill, Andrew; Flaxel, Christina J; Hwang, Thomas S; Lauer, Andreas K; Bailey, Steven T
To determine the sensitivity and specificity of optical coherence tomography angiography (OCTA) in the detection of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). Prospective case series. Prospective series of seventy-two eyes were studied, which included eyes with treatment-naive CNV due to AMD, non-neovascular AMD, and normal controls. All eyes underwent OCTA with a spectral domain (SD) OCT (Optovue, Inc.). The 3D angiogram was segmented into separate en face views including the inner retinal angiogram, outer retinal angiogram, and choriocapillaris angiogram. Detection of abnormal flow in the outer retina served as candidate CNV with OCTA. Masked graders reviewed structural OCT alone, en face OCTA alone, and en face OCTA combined with cross-sectional OCTA for the presence of CNV. The sensitivity and specificity of CNV detection compared to the gold standard of fluorescein angiography (FA) and OCT was determined for structural SD-OCT alone, en face OCTA alone, and with en face OCTA combined with cross-sectional OCTA. Of 32 eyes with CNV, both graders identified 26 true positives with en face OCTA alone, resulting in a sensitivity of 81.3%. Four of the 6 false negatives had large subretinal hemorrhage (SRH) and sensitivity improved to 94% for both graders if eyes with SRH were excluded. The addition of cross-sectional OCTA along with en face OCTA improved the sensitivity to 100% for both graders. Structural OCT alone also had a sensitivity of 100%. The specificity of en face OCTA alone was 92.5% for grader A and 97.5% for grader B. The specificity of structural OCT alone was 97.5% for grader A and 85% for grader B. Cross-sectional OCTA combined with en face OCTA had a specificity of 97.5% for grader A and 100% for grader B. Sensitivity and specificity for CNV detection with en face OCTA combined with cross-sectional OCTA approaches that of the gold standard of FA with OCT, and it is better than en face OCTA alone. Structural OCT alone
Huang, Yi-Hsun; I, Ching-Chang; Kuo, Cheng-Hsiang; Hsu, Yun-Yan; Lee, Fang-Tzu; Shi, Guey-Yueh; Tseng, Sung-Huei; Wu, Hua-Lin
To determine the role of thrombomodulin (TM) in corneal epithelial wound healing, and to investigate whether recombinant TM epidermal growth factor-like domain plus serine/threonine-rich domain (rTMD23...
Marino, Gustavo K; Santhiago, Marcony R; Wilson, Steven E
Our purpose is to present a broad review about the principles, early history, evolution, applications, and complications of femtosecond lasers used in refractive and nonrefractive corneal surgical procedures. Femtosecond laser technology added not only safety, precision, and reproducibility to established corneal surgical procedures such as laser in situ keratomileusis (LASIK) and astigmatic keratotomy, but it also introduced new promising concepts such as the intrastromal lenticule procedures with refractive lenticule extraction (ReLEx). Over time, the refinements in laser optics and the overall design of femtosecond laser platforms led to it becoming an essential tool for corneal surgeons. In conclusion, femtosecond laser is a heavily utilized tool in refractive and nonrefractive corneal surgical procedures, and further technological advances are likely to expand its applications. Copyright 2017 Asia-Pacific Academy of Ophthalmology.
Al Mahmood, Ammar M; Al-Swailem, Samar A; Behrens, Ashley
Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature.
Karabulut, Gamze Ozturk; Kaynak, Pelin; Altan, Cıgdem; Ozturker, Can; Aksoy, Ebru Funda; Demirok, Ahmet; Yılmaz, Omer Faruk
The purpose of this study is to investigate the effect of thyroid eye disease (TED) on the measurement of corneal biomechanical properties and the relationship between these parameters and disease manifestations...
Full Text Available A 68-year-old man presented with redness of left eye since six months. Examination revealed bilateral corneal furrow degeneration. Left eye lesion was suggestive of conjunctival squamous cell carcinoma, encroaching on to cornea. Anterior segment optical coherence tomography (AS-OCT confirmed peripheral corneal thinning. Fluorescein angiography confirmed intrinsic vascularity of lesion. Patient was managed with "no touch" surgical excision, dry keratectomy without alcohol, cryotherapy, and primary closure. Pathologic examination of removed tissue confirmed clinical diagnosis. Management of this particular case required modification of standard treatment protocol. Unlike the alcohol-assisted technique of tumor dissection described, ethyl alcohol was not used for risk of corneal perforation due to underlying peripheral corneal thinning. Likewise, topical steroids were withheld in the post-operative period. Three weeks post-operatively, left eye was healing well. Hence, per-operative usage of absolute alcohol and post-operative use of topical steroids may be best avoided in such eyes.
Konstantopoulos, Aris; Mehta, Jodhbir S
Presbyopia, the physiological change in near vision that develops with ageing, gradually affects individuals older than 40 years and is a growing cause of visual disability due to ageing demographics of the global population. The routine use of computers and 'smartphones', combined with the affluence of the 'baby boomers' generation has set high standards for near vision correction. Corneal inlays are a relatively new treatment modality that is effective at compensating for presbyopia. The dimensions of these devices vary from 2 to 3.8 mm in diameter and 5 to 32 μm in thickness. They are implanted in the anterior corneal stroma of the non-dominant eye, most commonly, in a femtosecond laser created corneal pocket. They improve near vision by increasing the depth of focus, creating a hyper-prolate region of increased central cornea power or providing a refractive add power. This article reviews the literature on the efficacy and safety of corneal inlays.
Maddalena De Bernardo; Luigi Capasso; Luisa Caliendo; Francesco Paolercio; Nicola Rosa
Purpose. To describe the different formulas that try to overcome the problem of calculating the intraocular lens (IOL) power in patients that underwent corneal refractive surgery (CRS). Methods. A Pubmed literature search review of all published articles, on keyword associated with IOL power calculation and corneal refractive surgery, as well as the reference lists of retrieved articles, was performed. Results. A total of 33 peer reviewed articles dealing with methods that try to overcome the...
M. M. Bikbov; V. K. Surkova
Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, co...
Ozkok, Ahmet; Hatipoglu, Esra; Tamcelik, Nevbahar; Balta, Burcu; Gundogdu, Ahmet Sadi; Ozdamar, Mehmet Akif; Kadioglu, Pinar
Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) excess in acromegaly have various effects on many organs. The ophthalmologic effects of GH and IGF-1 excess have not yet been investigated in detail. The aim of the current study is to compare the corneal biomechanical properties of patients with acromegaly and those of healthy subjects. 45 patients with acromegaly (F/M=27/18) and 42 age-matched and gender-matched healthy individuals (F/M=24/18) were enrolled in this cross-sectional study. Central corneal thickness (CCT), corneal resistance factor (CRF), corneal hysteresis (CH), corneal compensated intraocular pressure (IOPcc) and Goldmann correlated IOPG were measured in patients with acromegaly and in healthy individuals using the Ocular Response Analyser (ORA). GH and IGF1 values were also determined in the study group. The mean CH and CRF values were higher in acromegalic patients (12.1±2.2 and 12.3±2.4, respectively) than in healthy subjects (11.0±1.6 and 10.8±1.5, respectively; for CH, p=0.014; for CRF, p=0.001). Mean IOPG measurement was higher in the acromegaly group than in the control group (p=0.017). There was no statistically significant difference in measured CCT (p=0.117) and IOPcc (p=0.594) values between acromegalic patients and healthy subjects. These findings indicate that acromegaly has target organ effects on the eye. Consequently, it can change corneal biomechanical properties such as corneal hysteresis and the CRF. Corneal biomechanical properties are known to affect the accuracy of IOP measurements. These findings should be taken into account when measuring IOP values in acromegaly patients, as IOP readings may be overestimated.
Full Text Available Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer™ and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH, corneal resistance factor (CRF, cornea-compensated intraocular pressure (IOPcc, and Goldmann-correlated intraocular pressure (IOPg were determined with the Reichert Ocular Response Analyzer (ORA. Univariate and multivariate regression analyses were performed to investigate factors associated with corneal biomechanics. Results. The mean CH and CRF were 9.82±1.34 mmHg and 9.64±1.57 mmHg, respectively. In univariate regression analysis, CH was significantly correlated with axial length, refraction, central corneal thickness (CCT, and IOPg (r=-0.27, 0.23, 0.45, and 0.21, resp.; all with p≤0.015, but not with corneal curvature or age; CRF was significantly correlated with CCT and IOPg (r=0.52 and 0.70, resp.; all with p<0.001, but not with axial length/refraction, corneal curvature, or age. In multivariate regression analysis, axial length, IOPcc, and CCT were found to be independently associated with CH, while CCT and IOPg were associated with CRF. Conclusions. Both CH and CRF were positively correlated with CCT. Lower CH but not CRF was associated with increasing degree of myopia. Evaluation of corneal biomechanical properties should take CCT and myopic status into consideration.
Fahnehjelm, Kristina Teär; Chen, Enping; Winiarski, Jacek
High intraocular pressure (IOP) and glaucoma are often suspected in patients with mucopolysaccharidosis (MPS). To determine corneal hysteresis (CH) and IOP in children with mucopolysaccharidosis I-Hurler (MPS I-H) and MPS VI. Clinical measurements with ocular response analyzer (ORA). In seven patients, five with MPS I-H treated with stem cell transplantation (SCT), and two with MPS VI, one treated with SCT and the other with enzyme therapy, the IOP was examined with ORA. Ocular response analyzer measurements were made at a median age of 8.7 years in the patients with MPS I-H and at a median age of 9.3 years in the patients with MPS VI. Earlier measurements had raised suspicion of high IOP in one patient. The ORA showed an increased CH and a falsely high IOP values in all 14 eyes. The recalculated IOPs were normal in all 14 eyes. Mild to severe corneal opacities were present in all 14 eyes. Optic disc areas, borders and cupping were clinically normal in the 12 of 14 eyes that were possible to examine. Severe corneal opacities hampered optic disc evaluation in the older patient with MPS VI. Three eyes in two patients had normal thickness of the retinal nerve fibre layer measured with scanning laser polarimetry with corneal compensation (GDx VCC). No patient was diagnosed or treated for glaucoma. The IOPs are often falsely high because of an increased resistance of the cornea and correlate to the extent of corneal clouding. In this small, cross-sectional study, it appears that corneal resistance is directly correlated with corneal clouding, although a longitudinal study that evaluates resistance as the cornea clears with treatment would provide more direct evidence that corneal deposits are directly related to resistance. A correct measured IOP can avoid unnecessary medical or surgical hypotensive treatment. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.
Young, Graeme; Schnider, Cristina; Hunt, Chris; Efron, Suzanne
To determine which ocular topography variables affect soft contact lens fit. Fifty subjects each wore three pairs of soft lenses in random succession (Vistakon Acuvue 2, Vistakon Acuvue Advance, Ciba Vision Night & Day), and various aspects of lens fit were evaluated. The steeper base curves of each type were worn in one eye and the flatter base curves in the other eye. Corneal topography data were collected using a Medmont E300 corneal topographer (Camberwell, Australia). Corneal curvature, shape factor (SF), and corneal height were measured over a 10 mm chord and also over the maximum measurable diameter. These were measured in the horizontal, vertical, steepest, and flattest meridians. With each lens type, the steeper base curve provided the best fit on the greatest proportion of eyes and the significant differences in various aspects of fit were noted between base curves. For each lens type, there was no significant difference in mean K-reading between those eyes best fit with the steeper base curve and those eyes best fit with the flatter base curve. Two of the lenses showed a positive correlation between centration and horizontal corneal height (maximum), whereas one lens showed a negative correlation between centration and horizontal SF (SF = e). Several lenses showed a positive correlation between post-blink movement and horizontal or vertical corneal SF. The measurement of corneal topography using current Placido disc instrumentation allows a better prediction of soft lens fit than by keratometry, but it is not reliable enough to enable accurate selection of the best fitting base curve. Some correlations are evident between corneal measurements; however, trial fitting remains the method of choice for selection of soft lens base curve.
Jankov II,Mirko R.; Jovanovic,Vesna; Delevic, Sladjana; Coskunseven, Efekan
Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen cross-linking with riboflavin and UVA (CXL) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. The studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduc...
Bao, F; Jiang, L; Wang, X; Zhang, D; Wang, Q; Zeng, Y
This study aims to obtain the biomechanical properties of porcine cornea so as to provide necessary biomechanical experimental basis for pig-to-human corneal xenotransplantation. Seventeen fresh porcine corneal specimens obtained from pigs aged 4-6 months were examined under inflation conditions to determine the constitutive relationships of the material through dynamic loading conditions (pressure range: 1.47-42.66 mmHg). The forward deflection of porcine anterior corneal apex was measured by the laser displacement sensor. The pressure deformation results were analysed on the basis of shell theory to estimate Young's modulus of the cornea and derive its relationship with intraocular pressure (IOP). The porcine corneas showed a nonlinear corneal forward displacement/IOP and stress/strain relationship with an initial low stiffness stage and a later high stiffness stage. In spite of the nonlinearity between the internal pressure and apex forward deflection, the relationship between the Young's modulus and the IOP was almost linear. Compared with human corneas, porcine corneas exhibited a similar nonlinear behaviour but lower stiffness values. The biomechanical parameters of porcine cornea obtained from this test could be applied to numerical simulations of refractive surgery procedures and lay a foundation for pig-to-human corneal xenotransplantation. Copyright © 2012 Informa UK, Ltd.
Li, Fengfu; Carlsson, David; Lohmann, Chris; Suuronen, Erik; Vascotto, Sandy; Kobuch, Karin; Sheardown, Heather; Munger, Rejean; Nakamura, Masatsugu; Griffith, May
Our objective was to determine whether key properties of extracellular matrix (ECM) macromolecules can be replicated within tissue-engineered biosynthetic matrices to influence cellular properties and behavior. To achieve this, hydrated collagen and N-isopropylacrylamide copolymer-based ECMs were fabricated and tested on a corneal model. The structural and immunological simplicity of the cornea and importance of its extensive innervation for optimal functioning makes it an ideal test model. In addition, corneal failure is a clinically significant problem. Matrices were therefore designed to have the optical clarity and the proper dimensions, curvature, and biomechanical properties for use as corneal tissue replacements in transplantation. In vitro studies demonstrated that grafting of the laminin adhesion pentapeptide motif, YIGSR, to the hydrogels promoted epithelial stratification and neurite in-growth. Implants into pigs' corneas demonstrated successful in vivo regeneration of host corneal epithelium, stroma, and nerves. In particular, functional nerves were observed to rapidly regenerate in implants. By comparison, nerve regeneration in allograft controls was too slow to be observed during the experimental period, consistent with the behavior of human cornea transplants. Other corneal substitutes have been produced and tested, but here we report an implantable matrix that performs as a physiologically functional tissue substitute and not simply as a prosthetic device. These biosynthetic ECM replacements should have applicability to many areas of tissue engineering and regenerative medicine, especially where nerve function is required. regenerative medicine | tissue engineering | cornea | implantation | innervation
Carlos Alexandre de A. Garcia Filho
Full Text Available PURPOSE: Low intraocular pressure (IOP measured by Goldmann applanation tonometry (GAT is one of the ocular manifestations of Steinert's myotonic dystrophy. The goal of this study was to evaluate the corneal-compensated IOP as well as corneal properties (central corneal thickness and corneal hysteresis in patients with myotonic dystrophy. METHODS: A total of 12 eyes of 6 patients with Steinert's myotonic dystrophy (dystrophy group and 12 eyes of 6 age-, race-, and gender-matched healthy volunteers (control group were included in the study. GAT, Dynamic Contour Tonometry (DCT-Pascal and Ocular Response Analyzer (ORA were used to assess the IOP. Central corneal thickness was obtained by ultrasound pachymetry, and corneal hysteresis was analyzed using the ORA device. In light of the multiplicity of tests performed, the significance level was set at 0.01 rather than 0.05. RESULTS: The mean (standard deviation [SD] GAT, DCT, and corneal-compensated ORA IOP in the dystrophy group were 5.4 (1.4 mmHg, 9.7 (1.5 mmHg, and 10.1 (2.6 mmHg, respectively. The mean (SD GAT, DCT, and corneal-compensated ORA IOP in the control group was 12.6 (2.9 mmHg, 15.5 (2.7 mmHg, and 15.8 (3.4 mmHg, respectively. There were significant differences in IOP values between dystrophy and control groups obtained by GAT (mean, -7.2 mmHg; 99% confidence interval [CI], -10.5 to -3.9 mmHg; P<0.001, DCT (mean, -5.9 mmHg; 99% CI, -8.9 to -2.8 mmHg; P<0.001, and corneal-compensated ORA measurements (mean, -5.7 mmHg; 99% CI, -10.4 to -1.0 mmHg; P=0.003. The mean (SD central corneal thickness was similar in the dystrophy (542  µm and control (537  µm groups (P=0.65. The mean (SD corneal hysteresis in the dystrophy and control groups were 11.2 (1.5 mmHg and 9.7 (1.2 mmHg, respectively (P=0.04. CONCLUSIONS: Patients with Steinert's myotonic dystrophy showed lower Goldmann and corneal-compensated IOP in comparison with healthy individuals. Since central corneal thickness and
Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David
Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates ("wave-plate-enhanced RBS") that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia.
Full Text Available AIM:To explore the corneal biomechanical properties of the elderly with different axial length(ALand corneal curvature by corneal visualization Scheimpflug Technology(Corvis ST. METHODS: Cross-sectional study. A total of 161 patients(297 eyesundergoing phacoemulsification were collected in this study. They were divided into 22-24mm, 24-26mm, more than 26mm groups according to axial length(190 eyes, 54 eyes and 53 eyes, respectively. Those of whom axial length was 22-24mm and the corneal curvature was 42-44D were divided into male and female groups(44 eyes and 49 eyes, respectively. Those of whom axial length was 22-24mm were divided into 42-44D group, more than 44D group according to corneal curvature(88 eyes, 102 eyes, respectively. Corvis ST was used to measure the biomechanical parameters of the cornea. The differences in the parameters between different groups were analyzed using the independent-samples t test or one-way analysis of variance and correlation analyses were performed using Pearson correlation analysis. RESULTS: When comparing the corneal biomechanical parameters, no statistically significant differences were found between male and female groups(P>0.05. The first applanation length and second applanation length among different corneal curvatures were statistically significant(PPr=0.429, 0.278; Pr=-0.291, -0.415; PCONCLUSION: The corneal curvature and ocular axial length may be the factors affecting the corneal biomechanical characteristics. The longer axial length, the thinner corneal thickness, the more easily the corneal is deformed, and with the increase of the axial length, intraocular pressure also increases.
Enyr Saran Arcieri
Full Text Available Os autores apresentam um caso de glaucoma neovascular secundário à síndrome ocular isquêmica como manifestação inicial de doença oclusiva de artérias carótidas. O exame de Doppler colorido das carótidas e órbitas mostrava presença de todos os fatores associados a um maior risco de desenvolver a síndrome: estenose carotídea grave bilateral, alto grau de estenose da artéria carótida interna e fluxo reverso na artéria oftálmica. Os autores discutem o fato do glaucoma neovascular ter sido controlado com apenas uma medicação tópica.The authors present a case of neovascular glaucoma secondary to ocular ischemic syndrome as the initial manifestation of carotid occlusive disease. Color Doppler imaging of the carotids and orbit showed all the factors associated with a greater risk of developing this syndrome: severe bilateral carotid stenosis, high-grade carotid stenosis, and reversed ophthalmic artery blood flow. The authors also discuss how the neovascular glaucoma was controlled with only one topical medication.
Marsiglia, Marcela; Boddu, Sucharita; Chen, Christine Y; Jung, Jesse J; Mrejen, Sarah; Gallego-Pinazo, Roberto; Freund, K Bailey
To investigate the association between the type of neovascularization (NV) and the clinical characteristics of nonneovascular fellow eyes in patients with unilateral, neovascular age-related macular degeneration. Eighty-three patients with treatment-naive, unilateral, neovascular age-related macular degeneration were retrospectively analyzed. Neovascular lesions were classified using both fluorescein angiography and optical coherence tomography as Type 1 (subretinal pigment epithelium), 2 (subretinal), 3 (intraretinal), or mixed NV. The associations between NV lesion type and baseline clinical and imaging characteristics of the fellow eye, including central geographic atrophy, noncentral geographic atrophy, pigmentary changes, soft drusen, cuticular drusen, reticular pseudodrusen, and subfoveal choroidal thickness, were examined. Subfoveal choroidal thickness was defined as thin if thickness was macular degeneration, Type 3 NV had an increased adjusted odds ratio of reticular pseudodrusen (15.361, P macular degeneration, certain nonneovascular features of the fellow eye correlate with the NV lesion composition based on type, as anatomically classified utilizing both fluorescein angiography and optical coherence tomography. Patients with Type 3 NV were more likely to have reticular pseudodrusen and/or thin subfoveal choroidal thickness in the fellow eye compared with those with Type 1 NV. Patients with Type 3 NV also showed a trend toward increased central geographic atrophy in the fellow eye.
Zhao, Xuan; Liu, Yang; Li, Weichang; Long, Kai; Wang, Lin; Liu, Sa; Wang, Yingjun [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China); Ren, Li, E-mail: firstname.lastname@example.org [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China)
Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)–citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col–CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS = 60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30 ± 5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin–eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col–CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications. - Highlights: • Adding different amounts of citric acid could change the properties of films. • The crosslinked films had better mechanical property than non-modified films. • Crosslinked collagen–citric acid films could tolerate suture during operation. • The films showed good ability of epithelial and stromal repair.
Giacomin, Natalia T; Mello, Glauco R; Medeiros, Carla S; Kiliç, Alyin; Serpe, Cristine C; Almeida, Hirlana G; Kara-Junior, Newton; Santhiago, Marcony R
To provide an overview of the predictability, safety, and efficacy of intrastromal corneal ring segment (ICRS) implantation as a tool to improve visual acuity and its association with other techniques such as corneal collagen cross-linking (CXL), addressing biomechanical outcomes, models, surgical planning and technique, indications, contraindications, and complications in ectatic corneas. Literature review. ICRSs have been used to regularize the corneal shape and reduce corneal astigmatism and higher order aberrations, improve visual acuity to acceptable limits, and delay, or eventually prevent, a corneal keratoplasty in keratoconic eyes. Changes in ICRS thickness and size, combination of techniques, and the addition of femtosecond lasers to dissect more foreseeable channels represent an improvement toward more predictable results. Several studies have shown, over time, the long-term efficacy and safety of ICRS treatment for keratoconus, with variable predictability, maintaining the early satisfactory outcomes regarding visual acuity, keratometry, and corneal thickness. It is just as important to ensure that the disease will not progress as it is to improve the visual acuity. Therefore, many studies have shown combined techniques using ICRS implantation and CXL. Also, further limitations of ICRS implantation can be addressed when associated with phakic intraocular lens implantation and photorefractive keratectomy. ICRS implantation has shown effectiveness and safety in most cases, including combined procedures. In properly selected eyes, it can improve both refraction and vision in patients with keratoconus. [J Refract Surg. 2016;32(12):829-839.]. Copyright 2016, SLACK Incorporated.
Full Text Available Background: We report 3 patients with laser-induced choroidal neovascularization (CNV. Method: Retrospective, observational case series. Medical charts and photographs were reviewed. Results: Two patients with central serous chorioretinopathy who developed iatrogenic CNV after focal laser photocoagulation were treated with intravitreal ranibizumab injections. One patient with CNV secondary to thermal laser photocoagulation for diabetic macular edema was treated with photodynamic therapy (PDT. Visual improvement has been demonstrated in the patients treated with intravitreal ranibizumab injections, and their successful visual outcome was stable for more than 2 years. Stable visual acuity was also observed in the patient treated with PDT, no visual improvement was observed possibly due to the macular scar and macular ischemia. No systemic or ocular complications were detected among the 3 cases. Conclusion: To prevent a laser-induced CNV, it is critical to avoid heavy small-spot laser burns and repeated application. Patients should be monitored carefully for CNV after laser treatment. In our cases, PDT and intravitreal ranibizumab injections were effective for the treatment of laser-induced CNV.
Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746
Flavia Gazze Ticly
Full Text Available The purpose of this study was to describe a prospective case series of 5 eyes treated with intravitreal ranibizumab injection for neovascular glaucoma (NVG. Five patients with clinically uncontrolled NVG secondary to proliferative diabetic retinopathy (4 patients and central retinal vein occlusion (1 patient, non-responsive to maximal tolerable medication and panretinal photocoagulation, received intravitreal ranibizumab injection (0.5 mg. Patients were seen at 1st, 3rd and 7th day after the ranibizumab injection and when it was necessary. Success was defined as intraocular pressure (IOP 21, despite maximal tolerable medication, underwent trabeculectomy with 0.5mg/ml mitomycin C (MMC for 1 minute. Failure was defined as IOP > 21 mmHg, phthisis bulbi, loss of light perception or additional glaucoma surgery. The primary outcome was 6-month IOP control. Mean IOP before the ranibizumab injection was 37 mmHg (7 mmHg SD. Two out of five eyes underwent only ranibizumab injection, having an IOP control after the procedure. Three patients were submitted to trabeculectomy with MMC on the 7th day after the injection. At 6-month follow-up, the mean IOP was 12mmHg (3 mmHg SD. All eyes showed regression of rubeosis iridis and IOP control. Visual acuity improved in 2 eyes worsened in 1 eye, and remained stable in 2 eyes. These data suggest that intravitreal ranibizumab injection may be a useful tool in the treatment of NVG.
Almila Sarıgül Sezenöz
Full Text Available A 47-year-old female patient presented with a complaint of decreased vision in the right eye. Her visual acuity was 0.16 in the right eye and 1.0 in the left eye. Fundus examination revealed a slightly elevated, yellowish-white lesion with regular borders at the macula of the right eye. Early and late hyperfluorescence related with choroidal neovascularization (CNV was detected in the right eye on fundus fluorescein angiography. B-scan ultrasonography revealed a hyperechoic choroidal lesion with acoustic shadowing. The lesion was diagnosed as choroidal osteoma. The patient received 3 injections of intravitreal ranibizumab. After 4 months, the visual acuity of the right eye was 0.9 and the CNV had regressed. Follow-up at about 7 months revealed reduced visual acuity in the right eye with an increase in subretinal fluid. An additional ranibizumab injection was administered. In this case report, we discuss the findings and treatment of a rare case of choroidal osteoma with secondary CNV.
Simhaee, Daniel; Dolz-Marco, Rosa; Freund, K Bailey
To report two cases of choroidal nevi associated with focal choroidal excavation (FCE) and polypoidal choroidal neovascularization (PCN). Report of two patients with choroidal nevi showing FCE and PCN who underwent multimodal imaging including color fundus photography, fluorescein angiography, indocyanine green angiography, fundus autofluorescence, spectral domain optical coherence tomography, swept-source optical coherence tomography, and optical coherence tomography angiography. Two patients presented with choroidal nevi associated with FCE and PCN. In the first case, a 74-year-old woman, the nevus had sharp margins, a deep FCE, surrounding drusen, and subretinal exudation at its inferior edge due to PCN that responded well to intravitreal anti-vascular endothelial growth factor therapy. In the second case, a 64-year-old woman, the nevus had ill-defined margins, a shallow FCE, and angiographic evidence of PCN without associated exudation. There have been several reports showing an association of either choroidal nevi or FCE with PCN. To our knowledge, there have been no previous reports of FCE identified within choroidal nevi, with or without associated PCN. Since, in one of our cases, the FCE was not apparent on clinical examination, the prevalence of FCE within nevi may be underdiagnosed.
Full Text Available The frequency of mammary tumors in canines is three times higher than in women. Contrast enhanced ultrasonography (CEUS is a noninvasive clinical method, that uses special contrast agents (CAs, their role being to layout the microvasculature of different lesions. The aim of this particular method, in this case, was to establish if we can evaluate the malignancy of a mass, given the fact that neovascularization is a malignancy marker. The case is represented by a Silky Terrier breed female dog, 5 years old, that was presented initially with an enlarged polycystic mammary gland and a nervous lactation. The female was initially diagnosed with polycystic mastosis. After 2 more months the mass became denser and enlarged. Before the ovariohisterectomy and unilateral mastectomy surgeries have taken place, a B-Mode standard ultrasound, CEUS and a pulmonary X-ray were performed. Our results integrate this case in “fast in” and “slow in” (type 2 curve. The histological diagnosis was established as a simple cystic papillary carcinoma with a malignancy grade 2. The mean value of the MVD was 13.75 which is a low MVD. We cannot determine a correlation between CEUS and a tumor’s malignancy, and so further studies are needed.
Notarnicola, Angela; Fischetti, Francesco; Gallone, Donato; Moretti, Lorenzo; Pignataro, Pasquale; Tafuri, Silvio; Moretti, Biagio
In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.
Full Text Available Abstract Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7% than middle hitters (53.7% (p = 0.01, opposite hitters (55.5% (p = 0.02 and libero players (54.4% (p = 0.008, whereas there were no differences in setters (56.2% (p > 0.05. Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.
Karti, Omer; Zengin, Mehmet Ozgur; Cinar, Esat; Tutuncu, Merve; Karahan, Eyyup; Celik, Asl; Kucukerdonmez, Cem
To study the effect of 1- and 6-hour-delayed corneal collagen cross-linking (CXL) on wound-healing of experimental alkali burns of the cornea. Twenty-four albino rabbits were used. Alkali burns were created using 1 M NaOH. The animals were divided randomly into 2 groups: group 1 (control group, n = 6) and group 2 (experimental group, n = 18). The experimental group was further divided into 3 subgroups as follows: group 2A, untreated (non-CXL) subgroup; group 2B, 1-hour-delayed CXL treatment subgroup; and group 2C, 6-hour-delayed CXL treatment subgroup. All rabbits were examined periodically for 21 days after treatment and then killed. The corneas were excised and histologically examined. Corneal ulceration, edema, and opacity scores were 4.0 ± 1.64, 1.6 ± 0.65, and 3.5 ± 1.21 in group 2A, 1.5 ± 1.76, 1.3 ± 0.87, and 3.1 ± 1.12 in group 2B, and 2.0 ± 1.90, 1.5 ± 0.79, and 3.3 ± 1.09 in group 2C, respectively. These scores were significantly less in groups 2B and 2C than in group 2A (P = 0.023, P = 0.043, and P = 0.034, respectively). Corneal epithelialization, evident upon staining, was best in group 2B and worst in group 2A (P = 0.012). Histopathology revealed that destruction of corneal collagen fibers and infiltration of inflammatory cells into corneal tissue were reduced in groups 2B and 2C compared with group 2A. We found that CXL treatment exerted positive effects on severe alkali-induced corneal burns. However, the effects were more pronounced in the 1-hour treatment group. We believe that CXL treatment may be a possible treatment for corneal alkali burn.
Full Text Available AIM: To investigate the effects of pirfenidone(PFDon the proliferation and transfomring growth factor-β1(TGF-β1expression in vitro culture rat corneal stromal cells. METHODS: Corneal stromal cells from 8 to 10wk SD rats were isolated, cultured and treated with different concentrations of PFD 0mg/mL(control group, 0.15mg/mL(experimental group Ⅰ, 0.3mg/mL(experimental group Ⅱ, 1mg/mL(experimental group Ⅲfor 48h. CCK-8 assay was performed to assess cell proliferation, while immunocytochemistry and Western Blot were used to detect the expression of ki-67 and TGF-β1 expression, respectively. RESULTS: Compared with control group, PFD significantly inhibited the proliferation in a dose-dependent manner(all P1 in a dose-dependent manner(PCONCLUSION: Pirfenidone can significantly inhibit the proliferation of rat corneal stromal cell by down regulating TGF-β1 expression, therefore, it has potential prospect in lightening the corneal wound healing reaction.
Sadık Görkem Çevik
Full Text Available Purpose. To investigate the relationship between corneal biomechanical parameters, anterior segment parameters, and geometric corneal parameters in a healthy Caucasian group. Methods. This retrospective study included the healthy eyes with best corrected visual acuity of at least 20/40 of 122 Caucasian subjects. The anterior segment parameters and geometric corneal parameters such as corneal volume, central corneal thickness, horizontal and vertical corneal radii, anterior and posterior steep, and flat keratometric values were measured with a Scheimpflug camera. The biomechanical properties were measured with Ocular Response Analyzer. Results. One hundred and twenty-two healthy Caucasian subjects (67 males, 55 females with a mean age of 45.32±20.23 were enrolled. Both corneal hysteresis and corneal resistance factor were positively correlated with CCT (r=0.529, p<0.001; r=0.638, p<0.001 and CV (r=0.635, p<0.001; r=0.579, p<0.001 and negatively correlated with age (r=-0.373, p<0.001; r=-0.249, p<0.001. Both in age-gender and multivariate models, CH and CRF had statistically significant negative association with the posterior steep K value. Conclusions. CH and CRF are negatively correlated with posterior steep and average posterior K values.
Liliensiek, S J; Campbell, S; Nealey, P F; Murphy, C J
The cornea is a complex tissue composed of different cell types, including corneal epithelial cells and keratocytes. Each of these cell types are directly exposed to rich nanoscale topography from the basement membrane or surrounding extracellular matrix. Nanoscale topography has been shown to influence cell behaviors, including orientation, alignment, differentiation, migration, and proliferation. We investigated whether proliferation of SV40-transformed human corneal epithelial cells (SV40-HCECs), primary human corneal epithelial cells (HCECs), and primary corneal fibroblasts is influenced by the scale of topographic features of the substratum. Using basement membrane feature sizes as our guide and the known dimensions of collagen fibrils of the corneal stroma (20-60 nm), we fabricated polyurethane molded substrates, which contain anisotropic feature sizes ranging from 200-2000 nm on pitches ranging from 400 to 4000 nm (pitch = ridge width + groove width). The planar regions separating each of the six patterned regions served as control surfaces. Primary corneal and SV40-HCEC proliferation decreased in direct response to decreasing nanoscale topographies down to 200 nm. In contrast to corneal epithelial cells, corneal fibroblasts did not exhibit significantly different response to any of the topographies when compared with planar controls at 5 days. However, decreased proliferation was observed on the smallest feature sizes after 14 days in culture. Results from these experiments are relevant in understanding the potential mechanisms involved in the control of proliferation and differentiation of cells within the cornea. (c) 2006 Wiley Periodicals, Inc
Hager, A; Schroeder, B; Sadeghi, M; Grossherr, M; Wiegand, W
The influence of central corneal thickness (CCT) on the measurement of intraocular pressure (IOP) has been discussed extensively in recent years. The problem, however, has not been solved so far. In addition to CCT there are probably further biomechanical properties that play a role in IOP measurement. We wanted to find out whether these properties are related to Goldmann applanation tonometry (GAT), noncontact tonometry (NCT), or CCT. Biomechanical properties of the cornea such as corneal hysteresis (CH) and corneal resistance factor (CRF) can be measured with the Ocular Response Analyzer (ORA, Reichert Ophthalmic Instruments, Depew, NY, USA). Furthermore, a corneal compensated IOP (IOPcc) is given. We examined 156 normal eyes of 80 patients who did not show corneal pathology nor glaucoma. In each eye GAT, NCT, and ORA data as well as CCT were measured. Data were statistically analyzed with respect to agreement and the influence of CH and CRF on IOP measurement. In our patients the following average values were calculated: GAT 14.8+/-3.0 mmHg, NCT 16.4+/-3.9 mmHg, IOPcc 16.2+/-4.1 mmHg, CH 10.6+/-2.3 mmHg, CRF 10.9+/-2.4 mmHg, and CCT 557+/-36 microm. IOPcc was not related to CCT in normal eyes and the only IOP value related to CH (pcorneal thickness. Corneal hysteresis and corneal resistance factor provide further information about biomechanical properties of the cornea beyond central corneal thickness.
Full Text Available Objectives: To monitor the corneal thickness change during the dextran-free isotonic riboflavin solution-aided corneal collagen crosslinking procedure in keratoconus patients. Materials and Methods: Corneal thickness measurements during the corneal collagen cross-linking (CXL treatment for progressive keratoconus were evaluated. The corneal thickness measurements were obtained with ultrasonic pachymetry device at five different time points: 0, 15, and 30 minutes after epithelial removal and 15 and 30 minutes after the initiation of UVA irradiation. Results: Twenty-four eyes of 24 patients with progressive keratoconus were included in the study. The thinnest pachymetric values obtained at the 0, 15, and 30 minute measurements after corneal deepithelisation were 409.38±10.43 µm (383-435 µm, 434.56±17.68 µm (400-485 µm, and 457.44±21.78 µm (428-516 µm, respectively. Pachymetric values obtained at 15 and 30 minutes after UVA application to the cornea were 471.69±23.38 µm (439-526 µm and 482.63±23.69 µm (436-524 µm, respectively. The gradual increase was found to be statistically significant when each measurement was compared with the previous values (p<0.001. Conclusion: We found that the corneal thickness was not decreased during the CXL with dextran-free isotonic riboflavin solution; on the contrary, corneal thickness was increased regularly during the procedure. (Turk J Ophthalmol 2014; 44: 272-4
Doane, K J; Ting, W H; McLaughlin, J S; Birk, D E
The development of the avian corneal stroma occurs in discrete developmental stages. During this sequence of events, the neural crest-derived corneal fibroblast precursor cells are surrounded by distinct extracellular matrices which change both spatially and temporally. To elucidate the role of these matrices, extracellular matrix components in the periocular mesenchyme and cornea were analysed prior to and during migration and differentiation of corneal fibroblasts using antibodies against collagens, proteoglycans and glycoproteins. Previous work has concentrated on the matrix of the corneal stroma rather than the matrix of the periocular mesenchyme. Since the precursors of the corneal fibroblasts are present within the must migrate through the periocular mesenchyme prior to entry into the cornea proper, this environment was fully evaluated. The present study documents the matrix composition of both the cornea and periocular mesenchyme at developmental stages that are prior to and after initiation of corneal invasion by the corneal fibroblast precursors. Variations in matrix molecules comprising both the periocular mesenchyme and cornea were demonstrated. These include changes in the distribution of collagen types I, II, III, IV and VI; the proteoglycans decorin and lumican; as well as the adhesive glycoproteins tenascin, fibronectin and laminin. It is hypothesized that the variations in matrix localization are important in the regulation of cell migration and differentiation during normal corneal development. Any regulation is likely to involve a combination of components found in the extracellular matrices and therefore, a consideration of the matrix rather than isolated components is required.
Raza Syed A
Full Text Available Abstract Background Shoulder dysfunction is common and pathology of the rotator cuff tendons and subacromial bursa are considered to be a major cause of pain and morbidity. Although many hypotheses exist there is no definitive understanding as to the origin of the pain arising from these structures. Research investigations from other tendons have placed intra-tendinous neovascularity as a potential mechanism of pain production. The prevalence of neovascularity in patients with a clinical diagnosis of rotator cuff tendinopathy is unknown. As such the primary aim of this pilot study was to investigate if neovascularity could be identified and to determine the prevalence of neovascularity in the rotator cuff tendons and subacromial bursa in subjects with unilateral shoulder pain clinically assessed to be rotator cuff tendinopathy. The secondary aims were to investigate the association between the presence of neovascularity and pain, duration of symptoms, and, neovascularity and shoulder function. Methods Patients with a clinical diagnosis of unilateral rotator cuff tendinopathy referred for a routine diagnostic ultrasound (US scan in a major London teaching hospital formed the study population. At referral patients were provided with an information document. On the day of the scan (on average, at least one week later the patients agreeing to participate were taken through the consent process and underwent an additional clinical examination prior to undergoing a bilateral grey scale and colour Doppler US examination (symptomatic and asymptomatic shoulder using a Philips HDI 5000 Sono CT US machine. The ultrasound scans were performed by one of two radiologists who recorded their findings and the final assessment was made by a third radiologist blinded both to the clinical examination and the ultrasound examination. The findings of the radiologists who performed the scans and the blinded radiologist were compared and any disagreements were resolved
Garcia Filho, Carlos Alexandre de A; Prata, Tiago Santos; Sousa, Aline Katia Siqueira; Doi, Larissa Morimoto; Melo Jr, Luiz Alberto Soares
Low intraocular pressure (IOP) measured by Goldmann applanation tonometry (GAT) is one of the ocular manifestations of Steinert's myotonic dystrophy. The goal of this study was to evaluate the corneal-compensated IOP as well as corneal properties (central corneal thickness and corneal hysteresis) in patients with myotonic dystrophy. A total of 12 eyes of 6 patients with Steinert's myotonic dystrophy (dystrophy group) and 12 eyes of 6 age-, race-, and gender-matched healthy volunteers (control group) were included in the study. GAT, Dynamic Contour Tonometry (DCT-Pascal) and Ocular Response Analyzer (ORA) were used to assess the IOP. Central corneal thickness was obtained by ultrasound pachymetry, and corneal hysteresis was analyzed using the ORA device. In light of the multiplicity of tests performed, the significance level was set at 0.01 rather than 0.05. The mean (standard deviation [SD]) GAT, DCT, and corneal-compensated ORA IOP in the dystrophy group were 5.4 (1.4) mmHg, 9.7 (1.5) mmHg, and 10.1 (2.6) mmHg, respectively. The mean (SD) GAT, DCT, and corneal-compensated ORA IOP in the control group was 12.6 (2.9) mmHg, 15.5 (2.7) mmHg, and 15.8 (3.4) mmHg, respectively. There were significant differences in IOP values between dystrophy and control groups obtained by GAT (mean, -7.2 mmHg; 99% confidence interval [CI], -10.5 to -3.9 mmHg; Pcorneal-compensated ORA measurements (mean, -5.7 mmHg; 99% CI, -10.4 to -1.0 mmHg; P=0.003). The mean (SD) central corneal thickness was similar in the dystrophy (542  µm) and control (537  µm) groups (P=0.65). The mean (SD) corneal hysteresis in the dystrophy and control groups were 11.2 (1.5) mmHg and 9.7 (1.2) mmHg, respectively (P=0.04). Patients with Steinert's myotonic dystrophy showed lower Goldmann and corneal-compensated IOP in comparison with healthy individuals. Since central corneal thickness and corneal hysteresis did not differ significantly between groups, the lower IOP readings documented in this
Georgiadis, Odysseas; Kabanarou, Stamatina A; Batsos, Georgios; Feretis, Elias; Xirou, Tina
To present the case of a patient with bilateral hypertensive retinopathy complicated with retinal neovascularization who received anti-VEGF intravitreal injection in one eye and panretinal photocoagulation (PRP) in the fellow eye. A 33-year-old male patient presented with gradual visual loss in both eyes for the last 5 months. At that time, he was examined by an ophthalmologist and occlusive retinopathy due to malignant systematic hypertension was diagnosed. He was put on antihypertensive treatment but no ophthalmic treatment was undertaken. At presentation, 5 months later, best-corrected visual acuity (BCVA) was 0.1 in the right eye (RE) and 0.9 in the left eye (LE). Fundus examination was compatible with hypertensive retinopathy complicated with retinal neovascularization. Fluorescein angiography (FFA) revealed macular ischemia mainly in the RE and large areas of peripheral retinal ischemia and neovascularization with vascular leakage in both eyes. The patient was treated with two anti-VEGF (ranibizumab) injections with 2 months interval in the RE and PRP laser in the LE. Follow-up examination after 12 months showed mild improvement in BCVA, and FFA documented regression of retinal neovascularization in both eyes. Hypertensive retinopathy can be rarely complicated with retinal neovascularization. Treatment with PRP can be undertaken. In our case, the use of an intravitreal anti-VEGF agent seemed to halt its progression satisfactorily.
Naysan, Jonathan; Jung, Jesse J; Dansingani, Kunal K; Balaratnasingam, Chandrakumar; Freund, K Bailey
To report the association of pure type 2 neovascularization (NV) in age-related macular degeneration occurring almost exclusively in patients with reticular pseudodrusen. An observational retrospective cohort study of all eyes receiving antivascular endothelial growth factor therapy for newly diagnosed neovascular age-related macular degeneration by a single practitioner over a 6-year period. Only patients with treatment-naive, pure type 2 NV who also had either pre-neovascular imaging of the study eye or imaging of a nonneovascular fellow eye available to determine baseline characteristics including drusen type and choroidal thickness were incuded. Of 694 patients treated for neovascular age-related macular degeneration, only 8 met the inclusion criteria with pure type 2 NV. Of these, 7 (88%) had exclusively reticular pseudodrusen (5 in the nonneovascular fellow eye, 2 in the study eye before developing NV). Six (75%) patients in the affected neovascular eye and 6 (75%) in the fellow nonneovascular eye had choroidal thickness age-related macular degeneration, occurring almost exclusively in patients with reticular pseudodrusen and thin choroids.
ZIEBART, THOMAS; ZIEBART, JOHANNA; GAUSS, LEONIE; PABST, ANDREAS; ACKERMANN, MAXIMILIAN; SMEETS, RALF; KONERDING, MORITZ A.; WALTER, CHRISTIAN
Bisphosphonates (BPs) are potent drugs, used in metastatic cancer-like prostate or breast carcinoma. In recent studies, besides reduced bone remodeling, influences on angiogenesis and neovascularization were reported. Since BPs have the tendency to accumulate in the bones, the biological effect of various nitrogen- and non-nitrogen BPs on endothelial progenitor cells (EPCs) that originated from bone marrow and mobilized under physiological and pathophysiological conditions, such as tumor neovascularization, was investigated. EPCs subsequent to 72-h treatment with different concentrations of bisphosphonates comprised the non-nitrogen-containing BP clodronate and the nitrogen-containing BPs ibandronate, pamidronate and zoledronate. After incubation, biological activity was measured by using the migration boyden chamber assay and measurement of the colony-forming ability. Nitrogen-containing BPs inhibited the migration ability and differentiation of EPCs in a dose-dependent manner, as compared to the non-treated control groups. More specifically, the nitrogen-containing BP zoledronate significantly inhibited angiogenesis and neovascularization. Clodronate was less distinct on EPC function. To underline the importance of neovascularization in the context of tumor angiogenesis, EPC functions were significantly influenced in a dose-dependent manner by nitrogen-containing BPs. From these findings, we conclude that especially the nitrogen-containing BPs, such as zoledronate, are potential anticancer agents through the inhibition of neovascularization. PMID:24649016
Mohammad Reza Sedaghat
Full Text Available Background: The aim of this study was to determine the correlation between corneal hysteresis (CH and the corneal resistance factor (CRF, which are both novel methods of analyzing ocular rigidity/elasticity, and various corneal cha-racteristics, mainly corneal volume in normal subjects. Methods: This cross-sectional study included 500 normal eyes of volunteers. An ocular response analyzer (ORA was used to measure CH and CRF. Patient age and the Pentacam-measured corneal volume (CV, posterior elevation, ante-rior elevation, corneal curvature, central corneal thickness (CCT, corneal thickness of apex (CTA, and corneal thinnest thickness (CTT were compared with CH and CRF. Statistical significance was defined at p < 0.05. Results: The mean CH and CRF for all eyes were 9.9 ± 1.4 mmHg and 10.1 ± 1.6 mmHg, respectively. The mean CVs of the 3, 5, 7, and 10 mm zones for all eyes were 3.8 ± 0.2 mm3, 11.2 ± 0.6 mm3, 24.3 ± 1.4 mm3, and 60.1 ± 3.5 mm3, respectively. The correlations between CV and the hysteresis or CRF were significant in all zones. The CV of the 7-mm zone had the strongest correlation with CH (r = 0.438 and the CV of the 5-mm zone had the strongest correlation with CRF (r = 0.574. Conclusions: CH and CRF correlate with CV. Moreover, the correlation between CV and CRF is stronger than that between CV and CH. The CV may be valuable for determining patient′s qualification for and predicting the outcome of refractive surgery. It would also be helpful in other cases in which corneal biomechanics are important.
Romano, Vito; Steger, Bernhard; Chen, Jern Y; Hassaan, Sherif; Batterbury, Mark; Willoughby, Colin E; Ahmad, Sajjad; Elsheikh, Ahmed; Kaye, Stephen B
To investigate the effect of artificial anterior chamber (AAC) pressure and corneal drying on the graft thickness in preparation for Descemet stripping automated endothelial keratoplasty. Twenty-seven corneoscleral discs were placed in an AAC. The AAC pressure (15, 45, 92, 109, and 198 mm Hg) was controlled using the height of an infusion bottle and a roller clamp. The endothelium was removed in 1 subgroup. Corneas were exposed to room air or repeatedly dried using cellulose spears. Central corneal thickness was measured every 90 seconds for the first 15 minutes and again at 20 minutes using an ultrasound pachymeter (SP-100, Tomey). There was a significant linear relationship between the corneal thickness and both AAC pressure and corneal drying. Very high coefficients of determination and narrow 95% confidence intervals were present, in particular for high pressures and drying. The rate of thinning increased with increasing pressure and drying to 1.6% per minute. At the maximum rate of thinning, a 10% reduction in corneal thickness occurred in 6 minutes or 100 μm in 8.8 minutes. Removal of the corneal endothelium reduced the rate of thinning to 0.3% per minute (R = 0.72). Increasing AAC pressure and corneal drying reduced the graft thickness at a very predictable rate. Adequate corneal thinning can be achieved by increasing the pressure in the AAC by closing the clamp followed by removal of the residual corneal epithelium and repeated drying with a cellulose spear for 5 to 10 minutes, depending on the initial corneal thickness. This method is simple and is both suitable for use in the eye bank and by the surgeon.
Elsheikh, Ahmed; Geraghty, Brendan; Rama, Paolo; Campanelli, Marino; Meek, Keith M
An experimental study has been conducted to determine the stress-strain behaviour of human corneal tissue and how the behaviour varies with age. Fifty-seven well-preserved ex vivo donor corneas aged between 30 and 99 years were subjected to cycles of posterior pressure up to 60 mm Hg while monitoring their behaviour. The corneas were mechanically clamped along their ring of scleral tissue and kept in physiological conditions of temperature and hydration. The tissue demonstrated hyper-elastic pressure-deformation and stress-strain behaviour that closely matched an exponential trend. Clear stiffening (increased resistance to deformation) with age was observed in all loading cycles, and the rate of stiffness growth was nonlinear with bias towards older specimens. With a strong statistical association between stiffness and age (p ages between 30 and 99 years. These equations, which closely matched the experimental results, depicted corneal stiffening with age in a form suitable for implementation in numerical simulations of ocular biomechanical behaviour.
Khalid Al Arfaj
Full Text Available Purpose Compare the effectiveness of Phototherapeutic keratectomy (PTK in treatment corneal dystrophies versus superficial corneal scars: visual outcomes, recurrence rate and safety profile. Methods PTK was performed in 51 eyes of 51 patients. Data regarding the indications for PTK, ablation depth, symptomatic relief, pre-and postoperative best spectacle-corrected visual acuity (BSCVA, spherical equivalent changes, recurrence and complications were analyzed. The indications for PTK in our study were classified into two categories – group A: patients with corneal dystrophies (n = 23 and the other group B (n = 28 with other indications. Results The average age of the patients was 47 years (±16.4. The mean follow up period was 15.16 months (±10.01 months. Post operatively, there were no significant complications. While the overall BSCVA in the patients improved from 20/41 (0.484 to 20/32 (0.645, group A showed improvement from 20/35 (0.561 to 20/29 (0.687, as compared to group B in which BSCVA improved from 20/47 (0.421 to 20/33 (0.611. The most common indication in group A was granular corneal dystrophy (n = 10 and the most common indication in group B was post traumatic/infectious corneal scar or opacity (n = 10. Eighty-six percent (n = 44 of all patients had alleviation of symptoms. Recurrence of symptoms was seen in 3 eyes of recurrent corneal erosions which required retreatment. Conclusion PTK is a safe and effective procedure. The outcome of this study suggests that PTK improves BSCVA. PTK appears to improve ocular surface health. Furthermore, PTK can be recommended to most patients with corneal dystrophies as a treatment modality prior to other more invasive procedure (viz. penetrating keratoplasty.
Schick, T.; Ersoy, L.; Hoyng, C.B.; Kirchhof, B.; Liakopoulos, S.
PURPOSE: To investigate phenotype characteristics of fellow eyes in patients with early onset of neovascular age-related macular degeneration (NVAMD). METHODS: Patients with new-onset unilateral NVAMD between 50 and 65 years (n = 57, early-onset choroidal neovascularization [CNV] group) or >80
Xu, Yong-Gen; Xu, Yong-Sheng; Huang, Chen; Feng, Yun; Li, Ying; Wang, Wei
The tissue equivalent that mimics the structure and function of normal tissue is a major bioengineering challenge. Tissue engineered replacement of diseased or damaged tissue has become a reality for some types of tissue such as skin and cartilage. The tissue engineered corneal epithelium, stroma, and endothelium scaffold are promising concepts in overcoming the current limitations of a cornea replacement with an allograft. The acellular corneal matrix from porcine (ACMP) was examined as a potential corneal cell sheet frame. The physical and mechanical properties of strength, expansion, transparency, and water content of the ACMP were measured. The major antigens of the cell components were completely removed with series of extraction methods, the major antigens of the cell components were identified by hematoxylin and eosin (HE), immunofluorescence staining, and scanning electron microscopy. The structural properties were investigated by HE stain and scanning electron microscopy. The three types of rabbit corneal cells were cultured in vitro, and characteristics were investigated by colony formation efficiency (CFE), BrdU staining, immunofluorescence staining, and western blot assay of keratin 3 (K3), vimentin, and aquaporin A. The biocompatibility of the ACMP was investigated for one month using rabbit corneal stroma and three types of cultured corneal cells both in vivo and in vitro. The three types of cultured rabbit corneal cells were seeded onto ACMP of each side at a cell density of 5.0 x 10(3) cells/mm(2). The optical and mechanical properties of the ACMP were similar to the normal porcine cornea. The collagen fiber interconnected to the network, formed regular collagen bundles of the ACMP, and was parallel to the corneal surface. The ACMP was transferred to the rabbit cornea stroma, which showed an intact epithelium and keratocytes in the implant region. There were no inflamed cells or new vessel invasion one month after transplantation. The three types of
Xu, Suzhong; Xu, Aiqin; Tao, Aizhu; Wang, Jianhua; Fan, Fan; Lu, Fan
To investigate corneal biomechanical properties and intraocular pressure (IOP) in patients with high myopic anisometropia. Patients with high myopic anisometropia (n = 23) and emmetropic subjects (n = 55) were enrolled. Corneal hysteresis (CH), Goldmann-correlated intraocular pressure (IOPg), corneal resistance factor, and corneal-compensated IOP (IOPcc) were measured with Ocular Response Analyzer. Central corneal thickness was measured by optical coherence tomography. Zeiss IOL-Master determined the values of corneal refractive power and ocular axial length. Significant differences were presented in CH, IOPg, and IOPcc among the high myopic, contralateral, and normal eyes (analysis of variance, Panisometropia. High myopic eyes showed decreased CH, but not corneal resistance factor, which indicates that some aspects of corneal biomechanical properties may be altered in high myopic eye of anisometropia. It is also suggested that anisometropic eyes with different refractive errors do not share the same biomechanical properties, which may impact IOP measurement.
Mitsui, Iwane; Yamada, Yoshiya
To evaluate the corneal thickness and curvature changes after Orthokeratology contact lens wear, using the ORBSCAN II corneal topography system, corneal thickness and corneal curvature were measured on one hundred and twenty eyes of sixty patients before and after wearing the custom rigid gas permeable contact lenses for Orthokeratology. The contact lenses were specially designed for each eye. The subjects wore the orthokeratology lenses for approximately Four hours with their eyes closed. The corneal thickness of the subjects was increased on fifty-five eyes at not only the peripheral zone but also the center of the cornea. The average increase of central and peripheral corneal thickness was 18 micrometer and 22micrometer, respectively. The mean anterior curvature of corneal surface changed 1.25D. The mean posterior curvature of corneal endothelium side changed 0.75D.
Chawla, Rohan; Mittal, Kanhaiya; Vohra, Rajpal
The authors report the use of optical coherence tomography angiography (OCTA) (DRI OCT Triton; Topcon, Tokyo, Japan) to localize, characterize, and confirm the presence of a choroidal neovascular membrane in a patient of focal choroidal excavation (FCE) with recent-onset metamorphopsia and visual blurring. En face OCTA images just above the level of the retinal pigment epithelium-Bruch's membrane complex typically showed the presence of a glomerulus-like neovascular network with an adjacent dark area suggestive of a Type 2 choroidal neovascularization (CNV). OCTA was found to be a very useful, noninvasive, and quick imaging modality to detect secondary CNV formation in a case of FCE. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:969-971.]. Copyright 2016, SLACK Incorporated.
Insull, Elizabeth; Nicholas, Simon; Ang, Ghee Soon; Poostchi, Ali; Chan, Kenneth; Wells, Anthony
To examine the relationships between optic disc area and parameters measured at the cornea; central corneal thickness (CCT), corneal hysteresis (CH) and ocular pulse amplitude (OPA) in glaucoma subjects and controls. In this prospective experimental study, patients underwent measurement of CCT, OPA, CH and optic disc imaging with the Heidelberg Retina Tomograph II (HRT-II). Pearson's correlation coefficient was calculated to assess the associations between optic disc area and CCT, OPA and CH. A total of 100 patients, 38 with glaucoma and 62 controls were examined. In a univariate analysis of this group, CCT and CH were significantly lower in glaucoma patients (P = 0.01). CCT was inversely correlated with optic disc surface area (Pearson's correlation coefficient r = -0.200; P = 0.05). This inverse correlation did not achieve statistical significance when glaucoma patients and controls were analysed separately. There was no statistically significant association between optic disc area and OPA or CH. There was an inverse relationship between CCT and optic disc area in this study group. No association was found between optic disc area and OPA or CH. © 2010 The Authors. Clinical and Experimental Ophthalmology © 2010 Royal Australian and New Zealand College of Ophthalmologists.
Koop, N; Brinkmann, R; Schirner, G
Refraction of the cornea head been generally measured with ophthalmometers or computer disk keratometers. We therefore used a confocal laser scanning system for measurement of the corneal topography. Enucleated tonicized pig eyes were measured before and after laser thermokeratoplasty (LTK). The topographical data were used to determine refraction and refractive change; the data were stored digitally. The single images and their differences were displayed on a PC. Unlike conventional ophthalmometry, confocal laser scanning can demonstrate the topographical shape, showing the overall topography of the cornea and local corneal effects, e.g., coagulation, mechanical lesions or high-energy laser effects. Topographical laser scanning has proven to be a generally useful method of determining refraction and surface alterations in corneal refractive surgery.
Full Text Available Olli ArjamaaDepartment of Biology, University of Turku, Turku, FinlandAbstract: Almost 300 million people are visually impaired worldwide due to various eye diseases such as cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy, and corneal diseases. Notably, ten million people are blind because of severe ocular surface diseases and the majority of cases occur in developing countries. Blinding ocular surface diseases have, however, become treatable by grafting of surface layers, or by full-thickness transplantation of the cornea. As the demand for human corneal tissue for surface reconstruction and transplantation far exceeds the supply, methods are being developed to supplement tissue donation. Xenotransplantation of the cornea or cells from genetically modified pigs may become one of the solutions. Transplantation of limbal stem cells within tissue biopsies, to restore the transparency of the cornea is another remarkable method, which has shown its potential in several clinical studies. The combination of stem cell technology and engineering of biocompatible tissue equivalent, still at preclinical stage, has shown us how synthetic corneal tissue is able to guide cultured corneal stromal stem cells of human origin, to become native-like stroma, the most important layer of the cornea. These findings give hope for a large-quantity production of biomaterial for corneal reconstruction. As such, clinical ophthalmologists should become more familiar with the methods of laboratory science.Keywords: eye, grafting, keratoplasty, xenotransplantation, cell reservoir, biocompatible tissue equivalent
Jankov Ii, Mirko R; Jovanovic, Vesna; Delevic, Sladjana; Coskunseven, Efekan
Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen cross-linking with riboflavin and UVA (CXL) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. The studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative SEQ was reduced by an average of more than 1 D, and refractive cylinder decreased by about 1 D. No eyes lost any line of BCDVA. Moreover, there was no significant decrease in endothelial cell density. It was also found that CXL treatment was effective with reducing corneal and total wavefront aberrations. Corneal cross-linking has also led to an arrest and/or even a partial reversal of keratectasia in the treatment of iatrogenic ectasia after excimer laser ablation. A primary intervention such as CXL should be considered to potentially increase the biomechanical stability of the corneal tissue and postpone the need of lamellar or penetrating keratoplasty.
Ple-Plakon, Patricia A; Shtein, Roni M
To describe trends in corneal transplantation surgery, including indications for surgery, evolution of lamellar keratoplasty, current surgical techniques, and future directions. Over the past decade, anterior and posterior lamellar keratoplasty have begun to supplant penetrating keratoplasty. Surgical techniques continue to change and improve outcomes. In recent years, Descemet membrane endothelial keratoplasty (DMEK) has gained interest as it eliminates the corneal stromal interface, which may limit visual acuity after Descemet stripping automated endothelial keratoplasty. Despite the promising results with improved visual acuity and decreased rejection, the technical challenges associated with DMEK have limited widespread acceptance. With technical refinements and more eye banks providing precut tissue for both Descemet stripping automated endothelial keratoplasty and DMEK, it is likely both procedures will continue to increase over time. Corneal transplantation has evolved rapidly over the past decade, from full-thickness penetrating keratoplasty towards lamellar keratoplasty to only remove and replace damaged layers of the cornea. Achieving minimal induced astigmatism with excellent visual acuity remains a challenge in corneal transplantation. Further refinements in surgical technique may help improve technical challenges and visual outcomes. In this article, we review changing trends in corneal transplantation and highlight developing medical treatments that may be available in the future.
Amiri, Fardin; Ghiyasvandian, Shahrzad; Navab, Elham; Zakerimoghadam, Masoumeh
The consequences of a corneal transplant are evaluated and classified by care providers, but understanding and interpretation of the results varies between patients, and creates different views for them and influences their lives in different ways while these influences are largely unknown. This study aimed to explore understanding of new life in patients after corneal transplantation. This qualitative study was conducted using a hermeneutic phenomenological approach in Tehran in 2016. Twelve corneal transplant recipients (7 men, 5 women) who were chosen purposefully from penetrating corneal transplant recipients, participated in this study. Semi-structured interviews were used to collect data. The content of the interviews was transcribed and analyzed using Van Manen's methodology. Data analysis led to the emergence of several main themes, among which "having a new sense" and "fear and hope" were two of the most important themes. It can be inferred from the overall participants' experiences that corneal transplant has brought about a new look at life for patients. However, transplant-related issues are endless and continuous, and a sense of fear and hope has always surrounded them.
Grimaldo, Sammy; Yuen, Don; Theis, Jaci; Ng, Melissa; Ecoiffier, Tatiana; Chen, Lu
MicroRNAs are a class of small noncoding RNAs that negatively regulate gene expression by binding to complimentary sequences of target messenger RNA. Their roles in corneal lymphangiogenesis are largely unknown. This study was to investigate the specific role of microRNA-184 (mir-184) in corneal lymphangiogenesis (LG) in vivo and lymphatic endothelial cells (LECs) in vitro. Standard murine suture placement model was used to study the expressional change of mir-184 in corneal inflammatory LG and the effect of synthetic mir-184 mimic on this process. Additionally, a human LEC culture system was used to assess the effect of mir-184 overexpression on cell functions in vitro. Expression of mir-184 was significantly downregulated in corneal LG and, accordingly, its synthetic mimic suppressed corneal lymphatic growth in vivo. Furthermore, mir-184 overexpression in LECs inhibited their functions of adhesion, migration, and tube formation in vitro. These novel findings indicate that mir-184 is involved critically in LG and potentially could be used as an inhibitor of the process. Further investigation holds the promise for divulging new therapies for LG disorders, which occur inside and outside the eye.
Ventura, Liliane; da Costa Vieira, Marcelo A.; Isaac, Flavio; Chiaradia, Caio; Faria de Sousa, Sidney J.
A system for measuring the average corneal transparency of preserved corneas has been developed in order to provide a more accurate and standard report of the corneal tissue. The donated cornea transparency is one of the features to be analyzed previously to its indication for the transplant. The small portable system consists of two main parts: the optical and the electronic parts. The optical system consists of a white light, lenses and pin-holes that collimate white light beams that illuminates the cornea in its preservative medium. The light that passes through the cornea is detected by a resistive detector and the average corneal transparency is shown in a display. In order to obtain just the tissue transparency, the electronic circuit was built in a way that there is a baseline input of the preservative medium, previous to the measurement of the corneal transparency. Manipulating the system consists of three steps: (1) Adjusting the zero percentage in the absence of light (at this time the detectors in the dark); (2) Placing the preservative medium in the system and adjusting the 100% value (this is the baseline input); (3) Preserving the cornea and placing it in the system. The system provides the tissue transparency. The system is connected to an endothelium evaluation system for Slit Lamp, that we have developed, and statistics about the relationship of the corneal transparency and density of the endothelial cells will be provided in the next years. The system is being used in a public Eye Bank in Brasil.
O'Brart, D P S
Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A (UVA) radiation is the first therapeutic modality that appears to arrest the progression of keratoconus and other corneal ectasias. Riboflavin is central to the process, acting as a photosensitizer for the production of oxygen singlets and riboflavin triplets. These free radicals drive the CXL process within the proteins of the corneal stroma, altering its biomechanical properties. Riboflavin also absorbs the majority of the UVA radiation, which is potentially cytotoxic and mutagenic, within the anterior stroma, preventing damage to internal ocular structures, such as the corneal endothelium, lens and retina. Clinical studies report cessation of ectatic progression in over 90% of cases and the majority document significant improvements in visual, keratometric and topographic parameters. Clinical follow-up is limited to 5-10 years, but suggests sustained stability and enhancement in corneal shape. Sight-threatening complications are rare. The optimal stromal riboflavin dosage for CXL is as yet undetermined. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.
Haeussler, David J; Rodríguez, Laura Muñoz; Wilkie, David A; Premanandan, Chris
To report a case of primary central corneal hemangiosarcoma in the dog. An 11-year-old, neutered, female, German shepherd mixed breed dog was referred to the Hospital Veterinario Sierra de Madrid (Spain) for evaluation of an enlarging corneal mass of the left eye (OS). The dog was predominantly housed outdoors and was diagnosed with a history of chronic superficial keratitis of both eyes (OU) by the referring veterinarian. The corneal mass was resected by routine superficial keratectomy and submitted for histopathology and Factor VIII immunohistochemical staining. The mass was diagnosed as a corneal hemangiosarcoma with complete excision. Postoperatively, the keratectomy site healed without complication and there was no evidence of recurrence three and a half months postoperatively. Complete systemic evaluation, including abdominal ultrasound and CT scan of the head and thorax, indicated no other detectable neoplasia in the dog. Outdoor housing and ultraviolet exposure, breed, and chronic superficial keratitis were all suspected as contributing factors to the development of a primary corneal hemangiosarcoma. Surgical removal and postoperative treatment for chronic superficial keratitis provided effective therapy. © 2011 American College of Veterinary Ophthalmologists.
Full Text Available The development and maintenance of retinal vasculature require a precise balance between pro-angiogenic and anti-angiogenic factors. However, mechanisms underlying normal homeostasis of retinal vasculature and pathological changes of disrupted retinal vessel development are not fully understood. Recent studies of the low-density lipoprotein receptor-related protein 5 (LRP5 and the very low-density lipoprotein receptor (VLDLR mutant mice indicate that LRP5 mediates a pro-angiogenic signal while VLDLR mediates an anti-angiogenic signal in retinal vasculature. Mice with a loss of LRP5 display underdeveloped intraretinal vasculature associated with endothelial cell (EC clustering and failed EC migration into deep retinal layers. In contrast, VLDLR knockout mice show overgrown intraretinal vasculature and subretinal neovascularization. To understand the mechanisms for the opposite retinal vascular abnormalities between LRP5 and VLDLR mutant mice and to test how a loss of LRP5 perturbs subretinal neovascularization caused by a loss of VLDLR, we have generated and characterized the retinal vasculature in LRP5/VLDLR double knockout (DKO mice. Our data show that DKO mice develop substantial EC clustering without subretinal neovascularization. The absence of subretinal neovascularization in DKO mice is associated with inhibited migration of ECs into the photoreceptor cell layer. In addition, the transcription level of Slc38a5, which encodes a Müller cell specific glutamine transporter, is significantly reduced in DKO mice, similar to previously reported changes in LRP5 single knockout mice. Thus, LRP5 signaling is a prerequisite for neovascularization in VLDLR knockout mice. LRP5 may be an effective target for inhibiting intraretinal neovascularization.
Ambr?sio, Jr, Renato; Correia, Fernando Faria; Lopes,Bernardo; Salom?o, Marcella Q.; Luz,Allan; Daniel G Dawson; Elsheikh, Ahmed; Vinciguerra, Riccardo; Vinciguerra, Paolo; Roberts, Cynthia J.
Background: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. Method: The advent of 3D tomography is proven as a ...
Garg, P; Krishna, P V; Stratis, A K; Gopinathan, U
To analyse the role of keratoplasty in reducing world blindness due to corneal diseases. Review of published literature. We collected and analysed articles published in the English language literature related to the prevalence and causes of blindness in different parts of the world, causes of corneal blindness, and outcome of corneal transplantation for various corneal diseases. A total of 80% of the world's blind live in developing countries. Retinal diseases are the most important causes of blindness (40-54%) in established economy nations while cataract (44-60%) and corneal diseases (8-25%) are the most common causes of blindness in countries with less developed economies. Keratitis during childhood, trauma, and keratitis during adulthood resulting in a vascularized corneal scar and adherent leucoma are the most frequent causes of corneal blindness in developing countries. Corneal diseases are responsible for 20% of childhood blindness. Nearly 80% of all corneal blindness is avoidable. The outcome of keratoplasty for vascularized corneal scar and adherent leucoma is unsatisfactory, necessitating repeat surgery in a high proportion of these cases. Other barriers for keratoplasty in these nations are suboptimal eye banking, lack of trained human resources, and infrastructure. Since the developing world carries most of the load of corneal blindness and the major causes of corneal blindness are corneal scar and active keratitis, development of corneal transplantation services need a comprehensive approach encompassing medical standards in eye banking, training of cornea specialists and eye banking personnel and exposure of ophthalmologists to care of corneal transplants for better follow-up care. However, concerted efforts should be made to develop and implement prevention strategies since most corneal blindness is preventable.
Agca, Alper; Demirok, Ahmet; Celik, Haci Ugur; van de Pol, Corina; Cankaya, Kadir Ilker; Celik, Nimet Burcu; Yasa, Dilek; Yilmaz, Ihsan; Yilmaz, Omer Faruk
To compare the postoperative corneal hysteresis (CH) and corneal resistance factor (CRF) of eyes implanted with a small aperture corneal inlay versus fellow eyes. Medical records of patients who underwent small aperture corneal inlay (KAMRA; AcuFocus, Inc., Irvine, CA) implantation were retrospectively reviewed. There were two groups: the implanted and non-implanted. Main outcome measures were CH, CRF, Goldmann-correlated intraocular pressure (IOPg), corneal-compensated IOP (IOPcc), and Goldmann applanation tonometry measurements performed preoperatively and at postoperative week 1 and months 1, 3, and 6. The study included 68 eyes of 34 patients. CH was higher in the implanted group when compared with the non-implanted group at postoperative week 1 (12.2 ± 3.1 vs 10.9 ± 1.7 mm Hg; P = .007) and month 1 (12.3 ± 2.5 vs 10.9 ± 1.8 mm Hg; P = .001). CRF was higher in the implanted group when compared with the non-implanted group at postoperative week 1 (11.9 ± 2.9 vs 10.7 ± 1.6 mm Hg; P = .003) and month 1 (12.5 ± 2.5 vs 10.4 ± 1.8 mm Hg; P .05). At the 3-month postoperative visit, all parameters had returned to baseline and there was no change at the 6-month visit. Implantation of the KAMRA corneal inlay does not induce a permanent change in CH or CRF. A transient increase in both was seen in the early postoperative period. Copyright 2014, SLACK Incorporated.
Full Text Available AIM:To evaluate the clinical effect of therapeutic soft corneal contact lens in combination with fresh amniotic membrane transplantation in the treatment of pterygium and its clinical value.METHODS:This study was a retrospective analysis of 200 pterygium excision patients(200 cases, 220 eyesin hospital from January 2010-June 2011. The patients were divided into two groups. Group 1(100 cases, 110 eyeswere patients treated with fresh amniotic membrane transplantation and therapeutic soft corneal contact lens while group 2(control group, 100 cases, 110 eyesdid not use corneal contact lens. The clinical outcomes in these two groups were compared in a 6-18mo postoperative follow-up observation.RESULTS:In control group using corneal contact lens the epithelium repair time ranged from 2-7d with an average time of 3.8d; in group 1 the epithelial repair time ranged from 1-5d with an average time of 2.5d. The patients were followed up for 6-18mo, 9 recurrent eyes were found in control group, the recurrence rate was 8.2%; 5 recurrent eyes were found in experimental group the recurreat rate was 4.5%. There were significant differences in the 2 groups comparing treatment outcomes(PCONCLUSION:The therapeutic effect of fresh amniotic membrane transplantation after pterygium excision is enhanced by the therapeutic application of corneal contact lens. The epithelial repair time is shortened, the recurrence rate is reduced after pterygium excision and stimulative symptoms including photophobia, tearing, foreign body sensation and ophthalmodynia caused by corneal epithelial defect can be relieved.
Full Text Available AIM: To investigate the expression of triggering receptor expressed on myeloid cells-1 (TREM-1 in the aberrant inflammation within the corneal epithelium at early period of fungal infection. METHODS: A total of 65 Wistar rats were randomly divided into control group, sham group and fungal keratitis (FK group, in which the cornea was infected by Aspergillus fumigatus (A. fumigatus. After executed randomly at 8, 16, 24, 48 and 72h after experimental model being established, the severity of keratomycosis in rats was scored visually with the aid of a dissecting microscope and slit lamp. Then corneas in three groups were collected to assess the expression of TREM-1 through quantitative reverse transcription-polymerase chain reaction (RT-PCR, immunofluorescence technique and Western blot analysis. The correlation between FK inflammation and expression of TREM-1 was also analyzed. RESULTS: Corneal inflammation scores increased with time after fungal infection (F=49.74, P=0.000. The inflammation scores in FK group were obviously higher than those in sham group on the whole (F=137.78, P=0.000. Levels of TREM-1 in the infected rat corneal epithelium had elevated at 8h and peaked at 48h (P<0.001, compared with control group. Western blot analysis also showed an obviously elevated TREM-1 level in rat corneal epithelium at 24h and 48h after fungal infection. Immunofluorescence technique showed that TREM-1 mainly existed in corneal epithelium and infected corneal stoma of rat. TREM-1 protein expression was enhanced after fungal infection. Moreover, severity of FK inflammation was significantly related to TREM-1 expression in FK (r=0.942, P=0.000. CONCLUSION: TREM-1 may contribute to amplify the inflammation in the cornea infected with A. fumigatus and play critical roles in the battle against A. fumigatus in the innate immune responses.
Full Text Available AIM: To investigate the repair efficacy of recombinant human epidermal growth factor on corneal epithelium after corneal foreign body eliminating operation. METHODS: There were 102 patients with corneal foreign body(188 affected eyeschosen for the study. All patients were divided into treatment group and control group according to the random number table. Both groups received corneal foreign body elimination by slit lamp. Postoperatively, the treatment group was given eye drops containing epidermal growth factor(JinYinShucombined with tobramycin while the control group was only administrated with tobramycin. Treatment effects were compared 3d after treatment. RESULTS: Three days after treatment, the cure rate in the treatment group(93.7%, was significantly higher than that in the control group(76.6%(PPCONCLUSION: The recombinant human epidermal growth factor is capable of integrating with corneal epithelial cells and endothelial cell receptor, shortening healing time of corneal epithelial wound, thus making it an effective treatment of traumatic corneal epithelial defect.
Coste, V; Schweitzer, C; Paya, C; Touboul, D; Korobelnik, J-F
To compare corneal biomechanical properties measured with Corvis Scheimpflug technology (Corvis ST) between a group of patients with chronic open-angle glaucoma and a group of control patients. Prospective observational case-control study. This study enrolled 56 right eyes of 56 patients (G1 [chronic open-angle glaucoma] n=37/G2 [control] n=19). Each patient underwent measurement of corneal biomechanical properties by dynamic Scheimpflug (Corvis ST) camera and the Ocular Response Analyser (ORA), then a measurement of intraocular pressure (IOP) by Goldmann applanation tonometry (GAT) and measurement of central corneal thickness (CCT) by optical coherence tomography during the same visit, by a single clinician. The parameters determined by Corvis ST are: Corvis IOP (IOP Corvis ST), the corneal deformation amplitude (CDA), corneal velocity, the time at highest concavity (TIME CONCAV), the lengths of applanation and their corresponding applanation time. Those studied by ORA are: compensated IOP (IOPcc),