Cases reported "Corneal Diseases"

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1/9. Neurotrophic corneal endothelial failure complicating acute horner syndrome.

    PURPOSE: The authors report the clinical findings of a unique case of rapid corneal endothelial decompensation in association with acute horner syndrome. STUDY DESIGN: Case report and literature review. methods: The authors followed a 38-year-old woman who developed horner syndrome after right jugular vein catheterization during cardiac valvular surgery. Shortly after the operation, horner syndrome accompanied by conjunctival hyperemia and stromal corneal edema developed in the right eye. Over the course of 4 months, the eye became painful, the corneal endothelial cell count dropped precipitously, and the stromal edema worsened, causing a difference of 100 microm in central corneal thickness compared to the unaffected eye. Deep stromal vascularization started at the limbus, resembling interstitial keratitis. RESULTS: A 3-week course of topical steroid treatment resulted in a dramatic improvement in the stromal corneal edema and regression of the deep stromal vascularization. Ocular and right hemicranial pain subsided shortly thereafter. CONCLUSION: The authors hypothesize that corneal endothelial failure in this unique case may have resulted from traumatic sympathectomy. According to experimental evidence in the reviewed ophthalmologic literature, sympathetic innervation may have a neurotrophic role in the cornea. Corneal pathology similar to the authors' case has been described in hemifacial atrophy (Parry-Robson syndrome), a disorder that is assumed to result from sympathetic denervation and that can be produced in animals by cervical sympathectomy. The authors therefore hypothesize that sympathetic denervation of the cornea may rarely cause endothelial decompensation and corneal edema. To the authors' knowledge, this is the first reported case of corneal endothelial failure in horner syndrome.
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keywords = animal
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2/9. herpes simplex virus type 1 corneal infection results in periocular disease by zosteriform spread.

    In humans and animal models of herpes simplex virus infection, zosteriform skin lesions have been described which result from anterograde spread of the virus following invasion of the nervous system. Such routes of viral spread have not been fully examined following corneal infection, and the possible pathologic consequences of such spread are unknown. To investigate this, recombinant viruses expressing reporter genes were generated to quantify and correlate gene expression with replication in eyes, trigeminal ganglia, and periocular tissue. Reporter activity peaked in eyes 24 h postinfection and rapidly fell to background levels by 48 h despite the continued presence of viral titers. Reporter activity rose in the trigeminal ganglia at 60 h and peaked at 72 h, concomitant with the appearance and persistence of infectious virus. Virus was present in the periocular skin from 24 h despite the lack of significant reporter activity until 84 h postinfection. This detection of reporter activity was followed by the onset of periocular disease on day 4. Corneal infection with a thymidine kinase-deleted reporter virus displayed a similar profile of reporter activity and viral titer in the eyes, but little or no detectable activity was observed in trigeminal ganglia or periocular tissue. In addition, no periocular disease symptoms were observed. These findings demonstrate that viral infection of periocular tissue and subsequent disease development occurs by zosteriform spread from the cornea to the periocular tissue via the trigeminal ganglion rather than by direct spread from cornea to the periocular skin. Furthermore, clinical evidence is discussed suggesting that a similar mode of spreading and disease occurs in humans following primary ocular infection.
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ranking = 1
keywords = animal
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3/9. phacoemulsification conditions resulting in thermal wound injury.

    PURPOSE: To determine and model the relationships between phacoemulsification conditions and viscoelastic agents that result in thermal wound injury. SETTING: Animal laboratory, Irvine, california, USA. methods: Mechanical and animal models, various wound sizes, phacoemulsification tips, and dispersive and cohesive viscoelastic agents were evaluated. Settings for phaco power, vacuum, and irrigation levels were controlled within a surgically relevant range. In the mechanical and animal models, incision temperature was assessed as a function of phacoemulsification parameters and time. In the animal model, wound damage was evaluated at the time of surgery. RESULTS: Induced time delays from the onset of phaco power to the onset of irrigation flow caused a thermal rise at the incision site. In these experiments, lack of irrigation and aspiration resulted in the greatest thermal rise and caused wound damage. Both the cohesive and dispersive viscoelastic agents were associated with a delay in the start of irrigation and aspiration, which resulted in similar maximum temperatures. Mathematical models were developed to estimate the maximum incision temperature from the phacoemulsification power, the duration (seconds) of occlusion, the tip gauge and type, and other phacoemulsification parameters. The models predict that under comparable conditions, occlusion with a viscoelastic agent will result in higher incision temperatures than occlusion with a balanced salt solution. CONCLUSION: Under comparable phacoemulsification conditions, both the cohesive and dispersive viscoelastic agents were associated with elevated temperatures that would be preventable by ensuring irrigation and aspiration flow before the onset of phacoemulsification power.
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ranking = 3
keywords = animal
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4/9. Plastic particles at the LASIK interface.

    PURPOSE: To investigate the origin, composition, and persistence of the interface particles that frequently are observed after LASIK. DESIGN: Small case series and experimental animal study. methods: Four patients received LASIK using a Schwind Supratome (Schwind, Kleinostheim, germany) and a MEL 70 G-Scan excimer laser (Asclepion, Jena, germany) and were examined over the course of 1 year using slit-lamp and in vivo confocal microscopy. Four rabbits received a monocular microkeratome incision and were examined immediately after surgery without lifting the flap. After monthly evaluation for 4 months using in vivo confocal microscopy, 2 corneas were processed for histologic analysis and were sectioned serially. To measure the iron content, atomic absorption spectrometry was performed on 2 operated and 2 unoperated rabbit corneas. The chemical composition of the metal and plastic parts of the microkeratome blade was identified using energy dispersive x-ray fluorescence (metal part), and Raman and infrared spectroscopy (plastic part). Before and after oscillation in air, the microkeratome blade and motor-head were examined using light and fluorescence microscopy. In serial sections, interface particles were identified by fluorescence microscopy and their chemical composition was determined using Coherent Antistokes Raman Scattering microscopy. RESULTS: In LASIK patients, thousands of brightly reflecting particles (up to 30 micro m) were observed throughout the interface. The highest particle density was detected where the microkeratome blade had first entered the cornea. Both in the center and at the flap edge, the morphologic features, distribution, and density of these particles remained unaltered throughout the 1-year observation period. In rabbit corneas, interface particles were observed immediately after the microkeratome incision, even though the flap had not been lifted. These particles were similar to those observed in humans and persisted unaltered throughout the study. The operated and unoperated rabbit corneas had comparable iron content, demonstrating that the particles were not fragments of the uncoated steel blade. Only a few particles were observed on the unused microkeratome motor head and blade, whereas numerous fluorescent particles were detected after oscillation in air, the amount of particles increasing with oscillation time. Interestingly, the only fluorescent part of the microkeratome was the plastic segment of the blade. This plastic (polyetherimide) emitted fluorescence identical to that of the observed particles, whereas all metal parts of the microkeratome blade and motor head were nonfluorescent. In serial sections, interface particles showed fluorescent properties equivalent to polyetherimide and exhibited molecular resonance at 1780 and 3100 cm(-1), in accordance with the Raman spectrum of polyetherimide. CONCLUSIONS: Numerous plastic particles are generated during microkeratome oscillation and are deposited at the interface during LASIK. The particles persist unaltered for at least 1 year.
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ranking = 1
keywords = animal
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5/9. Topical application of 5-fluorouracil in premalignant lesions of cornea, conjunctiva and eyelid.

    Local application of 5-fluorouracil was practised on 5 patients. In 3 patients with multiple premalignant oculo-cutaneous lesions, two of whom had also premalignant epibulbar lesions, local 5% 5-Fu cream and/or 1% 5-Fu eyedrops were applied. In 2 other patients who had only premalignant lesions on the cornea and conjunctiva, 1% 5-Fu eyedrops were used only. In animal experiments 1% 5-Fu was not found to cause any damage to normal corneal and conjunctival epithelium. The frequency of the applications and the duration of the treatment were dependent on the location and extent of the lesions. Except for easily treatable lesions, caused by the separation of the tumour epithelium, no complications of local 5-Fu treatment were seen. The visual acuity improved in all 4 patients in whom the cornea was affected. In these premalignant conditions the diagnosis and assessment of the therapy were based on exfoliative cytology and biopsies.
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ranking = 1
keywords = animal
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6/9. An unusual type of keratopathy observed in polyurethane workers and its reproduction in experimental animals.

    We have reported two cases of keratopathy in polyurethane workers that appear to be identical to those described by previous authors. We have been able to produce similar findings in the corneas of cats by exposing the eyes of anesthetized animals to the vapor of two of the amines used as catalysts in polyurethane manufacture. We were unable to reproduce these results with toluene diisocyanate. Therefore we support the previous suggestion that the amine catalysts are responsible for the distinctive keratopathy in polyurethane workers. We are unable to substantiate the claim that toluene diisocyanate is responsible for this phenomenon.
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ranking = 5
keywords = animal
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7/9. Degeneratio corneae nivalis. snow-crystal degeneration.

    Report of an aged woman in whose corneal stroma point and snow crystal-like, ivory-white, opaque granules developed with calcium granules localized under the conjunctiva. The patient suffered further of general arthrosis and osteopoikilosis in the proximal epiphysis of the femur, demonstrable by X-ray examination. The authors compare the syndrome of their patient with the artificially induced calcification syndrome of rats, which was developed by H. Selye et al, after the administration of isoproterenol, 5-hydroxitriptamin, and dihydrotachysterol to the animals. All three compounds inducing the artificial calcification syndrome, or similar ones, are also normally present in the organism. Their application in the described order causes the abnormal calcification of the connective tissues, probably by the metabolic disturbance of the mucopolysaccharides.
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ranking = 1
keywords = animal
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8/9. Human excimer laser keratectomy. Clinical and histopathologic correlations.

    PURPOSE: To understand the healing capabilities of the diseased human cornea after excimer laser photoablation by morphologic analysis of laser-treated corneas. methods: Twelve corneal specimens were obtained 5 to 16 months after lamellar or full-thickness keratoplasty following phototherapeutic keratectomy for undercorrected myopic epikeratoplasty (2 eyes), corneal leukomas (2 eyes), herpes zoster corneal scarring (1 eye), band keratopathy (2 eyes), adenoviral subepithelial opacity (1 eye), keratoconus (1 eye), herpes simplex corneal scarring (2 eyes), granular corneal dystrophy (1 eye), and recurrent lattice dystrophy (1 eye). The morphology of the corneas was examined by light and electron microscopy. RESULTS: Epithelial hyperplasia, abnormal epithelial attachment, and disorganized stromal matrices were observed. Evidence of residual disease frequently observed in these specimens indicated that the pathology either was not excised at the time of laser keratectomy or was recurrent. CONCLUSIONS: The response of the diseased cornea to excimer laser treatment has similar characteristics to the responses previously observed in animal studies. Incomplete ablation of diseased tissue and/or recurrence of the initial disease was the major reason for failure of the treatment. Possible causes for the inability to remove diseased tissues and superficial scars with the excimer laser include (1) insufficiently achieved ablation depth and/or diameter and (2) decreased laser ablation rates of scarred cornea.
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keywords = animal
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9/9. Irreversible bullous keratopathy after air bag trauma.

    PURPOSE. We describe an unusual case of corneal decompensation following air bag trauma in a 38 year-old-female. methods. The patient was followed clinically for 5 months post-injury with persistent corneal edema that failed to resolve, necessitating corneal transplantation. Scanning electron microscopy (SEM) of the corneal button was performed. RESULTS. SEM revealed localized areas of complete endothelial destruction. Other areas of the endothelium had cell counts under 1,000 cells per square millimeter. CONCLUSIONS. This case corroborates animal studies demonstrating endothelial cell loss from direct air bag trauma and stresses the need to possibly redesign this safety device for maximum driver protection.
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keywords = animal
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