fibrin and Corneal-Ulcer

Endothelial plaque is an important sign of fungal keratitis and is related to diagnosis, surgical indications, and prognosis. However, bacterial keratitis sometimes involves fibrin formation on the back corneal surface, similar to endothelial plaques. Because corneal infiltration interferes with precise observation of the posterior corneal plaque, distinguishing pathogens with a slitlamp is difficult. We hope to assist clinicians in early diagnosis and timely treatment by observing the connection state of endothelial plaques and the corneal endothelium through anterior segment optical coherence tomography (AS-OCT) and the different forms of endothelial plaques in infectious keratopathy through in vivo confocal microscopy (IVCM).. We analyzed 52 patients in the Eye Hospital of the First Affiliated Hospital of Harbin Medical University who were clearly diagnosed with fungal or bacterial keratitis with endothelial plaques. All patients underwent AS-OCT and IVCM on admission.. According to the smear, IVCM, or fungal and bacterial culture results, the patients were diagnosed with fungal (28 patients) or bacterial keratitis (24 patients). AS-OCT in 25 patients diagnosed with fungal keratitis revealed that the corneal endothelium-endothelial plaque boundary was unclear and wavy, and 24 patients had unclear cell boundaries and a large number of compactly distributed inflammatory cells in the endothelial layer according to IVCM. AS-OCT in 23 patients diagnosed with bacterial keratitis revealed clear corneal endothelium-endothelial plaque boundaries, and insufficient endothelial cell boundaries with a large number of visible and scattered inflammatory cell structures were observed through IVCM in 22 patients.. Corneal endothelial plaque detection by AS-OCT and IVCM can be used for early diagnosis of infectious keratitis.

Topics: Corneal Diseases; Corneal Ulcer; Eye Infections, Bacterial; Eye Infections, Fungal; Fibrin; Humans; Keratitis; Microscopy, Confocal; Tomography, Optical Coherence; Vision Disorders

To evaluate the safety and efficacy of the surgical use of autologous plasma rich in growth factors fibrin membrane (mPRGF) in improving corneal wound healing and regeneration in a variety of complex ocular surface defects.. Chart review on 15 eyes of 14 included patients undergoing ocular surface intervention using intraoperative mPRGF at the Bascom Palmer Eye Institute and at the Instituto Oftalmológico Fernández-Vega was performed. Patients were grouped based on type of intervention or condition (penetrating keratoplasty, superficial keratectomy, neurotrophic or persistent corneal ulcers, and corneal perforation). Patients were followed for an average of 11 ± 5 months. Main outcomes measured were mPRGF dissolving time, best-corrected visual acuity, and evidence of any persistent epithelial defects, rejections, or complications.. All 15 eyes underwent successful placement of mPRGF. Average dissolving time for fibrin membrane was 21 ± 3 days. mPRGF resulted in total healing of the corneal defects in 13/15 (86.7%) of the treated eyes and partial healing in 2/15 (13.3%) eyes in which persistent epithelial defects were noted on follow-up. Visual acuity improvement was seen in 9/15 (60%) of the cases.. The use of autologous mPRGF in the healing and regeneration of the ocular surface is a secure and efficacious surgical option. Our data demonstrate that PRGF fibrin membrane should be contemplated as an important tool to optimize ocular surface regeneration in complex cases.

Topics: Corneal Diseases; Corneal Ulcer; Eye Diseases; Fibrin; Humans; Intercellular Signaling Peptides and Proteins; Wound Healing

The combined use of autologous fibrin membrane and the eye platelet-rich plasma (E-PRP) clot could be considered as a new surgical alternative for the closure of corneal perforations.. To evaluate the use of autologous solid platelet-rich plasma in combination with an autologous fibrin membrane as a surgical alternative for wound closure in perforated corneal ulcers.. Both the fibrin membrane and the E-PRP clot were prepared with the patient's own blood just before the operation. Nylon stitches were used to fixate the fibrin membrane to the conjunctiva and then the E-PRP clot was placed over the corneal perforation, underneath the fibrin membrane. A temporal partial tarsorrhaphy was performed at the end of the procedure. We conducted postoperative monitoring for 3 months. SETTING Vissum Corporacion Oftalmologica, Alicante, Spain.. Eleven patients with perforated corneal ulcers.. Surgical alternative for the closure of corneal perforation.. Corneal biomicroscopy, fluorescein test, digital tonometry.. In all cases the corneal perforation was sealed. The fibrin membrane was present over the corneal surface for the first 3 to 5 days and then gradually disappeared. No evidence of infection or inflammation was detected. Digital tonometry confirmed acceptable levels of ocular tonus in all cases from day 2 after the operation. No patients reported pain, discomfort, or other symptoms, and no complications were observed. After 3 months' follow-up, there was no evidence of relapses or perforations. Corneal grafting was eventually performed in 7 of the 11 cases.. The combined use of autologous fibrin membrane and E-PRP clot is a safe and effective surgical alternative for the closure of corneal perforations. This technique can be considered as a temporary measure until the condition of the cornea permits definite intervention.

Topics: Aged; Aged, 80 and over; Biocompatible Materials; Corneal Perforation; Corneal Transplantation; Corneal Ulcer; Female; Fibrin; Fluorescein; Fluorescent Dyes; Humans; Male; Membranes, Artificial; Microscopy, Acoustic; Middle Aged; Pilot Projects; Platelet-Rich Plasma; Predictive Value of Tests; Reoperation; Spain; Suture Techniques; Time Factors; Tonometry, Ocular; Treatment Outcome; Wound Healing; Young Adult

Treatment of bacterial keratitis requires frequent application of topical antibiotics. We studied the efficacy of a single topical administration of tobramycin incorporated in large multivesicular liposomes and enmeshed in a fibrin sealant on rabbit corneas infected with Pseudomonas aeruginosa. One cornea each of 25 New Zealand albino rabbits was infected with P. aeruginosa. Twenty-four hours later, the animals were randomly divided into five groups of five. Group A received single hourly drops (50 microliters) of fortified tobramycin (14.5 mg/ml, total of 17.4 mg). Group B received a single topical application of 3.5 mg tobramycin, in 0.1 ml multivesicular liposomes, enmeshed in a fibrin sealant with an overlaying bandage contact lens. Group C was treated in the same manner as group B without the addition of fibrin sealant. Groups D and E served as nondrug-treated controls, with group D receiving topical fibrin-enmeshed liposomes devoid of tobramycin and group E receiving hourly topical balanced salt solution (BSS) drops. All animals were killed 24 h after initiation of therapy. Significantly fewer colonies of Pseudomonas were present in corneas of all three treated groups, as compared with the two nondrug-treated control groups (p less than 0.02). There were significantly fewer colonies of Pseudomonas in groups A and B as compared with group C (p less than 0.02). No significant difference was noted between a single administration of topical fibrinen-meshed tobramycin-encapsulated liposomes (group B) and 24 doses of hourly fortified topical tobramycin (group A, p greater than 0.05). Tobramycin-encapsulated megaliposomes may serve as a useful adjunct in treatment of Pseudomonas keratitis.

Topics: Administration, Topical; Animals; Colony Count, Microbial; Cornea; Corneal Ulcer; Disease Models, Animal; Drug Carriers; Eye Infections, Bacterial; Fibrin; Liposomes; Pseudomonas aeruginosa; Pseudomonas Infections; Rabbits; Random Allocation; Tobramycin

Topics: Aged; Anterior Chamber; Corneal Ulcer; Eye Infections, Bacterial; Fibrin; Fibrinolysis; Humans; Injections; Keratoplasty, Penetrating; Male; Pseudomonas Infections; Tissue Plasminogen Activator

Fibrin sealant is used to close perforated or preperforated corneal ulcers. In addition to the usual advantages of cyanoacrylates it is degraded physiologically and provides a good support for corneal healing. Corneal grafting can be avoided when contraindicated or postponed when conditions allow. This technique has been successful in nine eyes of eight patients.

Topics: Adolescent; Aged; Aged, 80 and over; Calcium Chloride; Corneal Ulcer; Female; Fibrin; Fibrin Tissue Adhesive; Humans; Male; Middle Aged; Tissue Adhesives

Previous studies of alkali burns have provided evidence for an important role of the plasminogen activator (PA)/plasmin system in corneal ulceration. Current studies have utilized a sensitive, plasminogen-dependent fluorescent assay to demonstrate that PA is present mostly in a latent (trypsin- or plasmin-activatable) form (proactivator) in cultures of rabbit corneal epithelial cells or normal corneas. Cultures of ulcerating corneas demonstrate only active PA early in organ culture, whereas, latent PA levels increase later in culture. Thus, ulceration is correlated with the apparent conversion of latent to active PA. Moreover, profiles of proactivator and latent collagenase and of active PA and active collagenase in vitro, respectively, are similar, suggesting that activator and collagenase are under coordinate control. Cultures of normal epithelial cells and nonulcerating corneas contain PA molecular weight species of 72,000 and 46,000 MW, and ulcer corneas, species of 72,000, 46,000, and 35,000 MW. Double-diffusion analysis indicates that rabbit epithelial cells, fibroblasts, and ulcer corneas produce urokinase (UK)-like PA; and human cornea extracts and tears also contain PA immunoreactive with anti-UK antibodies. The existence of PA in a latent form identifies another level of regulation in the cascades that lead to stromal ulceration.

Topics: Adsorption; Animals; Cells, Cultured; Cornea; Corneal Ulcer; Enzyme Precursors; Epithelium; Fibrin; Fibrinolysin; Fibrinolysis; Fluorescent Antibody Technique; Microbial Collagenase; Molecular Weight; Organ Culture Techniques; Plasminogen Activators; Rabbits; Tears; Trypsin

The vernal ulcer is a peculiar corneal complication of vernal conjunctivitis. Clinically, the ulcer is oval, grey, and resistant to medical treatment. Histological study by light and electron microscopy reveal the lesion to be composed of fibrin deposits adherent to a well-preserved Bowman's membrane. These deposits impede lateral progression of the epithelium, thus, opposing spontaneous healing. Resolution of the ulcer can be obtained, however, by superficial keratectomy.

Topics: Adolescent; Conjunctiva; Conjunctivitis, Allergic; Cornea; Corneal Stroma; Corneal Ulcer; Epithelium; Fibrin; Humans; Male; Microscopy, Electron

Although ulceration of the corneal stroma after alkali burns is known to be correlated with persistent epithelial defects, the relationship between a defect and the mediators thought to contribute to stromal destruction (plasminogen activator, plasmin, collagenase) has not been understood. This report demonstrates that fibrin and fibronectin appear on the stromal surface after an alkali burn, and that those substratum, matrix components disappear in correlation with the appearance of plasminogen activator on the stromal surface, re-surfacing by the epithelium and a persistent epithelial defect. The facts that epithelium releases plasminogen activator and that plasmin, generated from plasminogen by an activator, can degrade both fibrin and fibronectin, as well as the laminin component of the subepithelial basement membrane, would suggest that the plasminogen activator-plasmin system effect degradation of those macromolecules, thus initiating the events that lead to eventual, frank stromal ulceration. It is hypothesized that stromal ulceration is initiated by the chronic secretion from an epithelium with a persistent defect of a protease (plasminogen activator) involved in wound healing.

Topics: Animals; Basement Membrane; Burns, Chemical; Cornea; Corneal Ulcer; Fibrin; Fibrinolysin; Fibronectins; Male; Neutrophils; Plasminogen Activators; Rabbits; Wound Healing

A patient with a progressive Mooren's ulcer of the cornea was successfully treated utilizing a peritomy with limbal conjunctival excision and cryotherapy. The limbal conjunctiva contained a band of IgG beneath the epithelium as well as complement and fibrin in the wall of small blood vessels. This implies Mooren's ulcer is an immune mediated process.

Topics: Adult; Complement C3; Cornea; Corneal Ulcer; Fibrin; Humans; Immunoglobulin G; Male

Topics: Administration, Topical; Adult; Basement Membrane; Collagen; Cornea; Corneal Ulcer; Edema; Epithelium; Fibrin; Gentamicins; Humans; Inclusion Bodies; Leukocytes; Macrophages; Male; Microscopy, Electron; Pseudomonas aeruginosa; Pseudomonas Infections