RESUMEN
Infectious crystalline keratopathy (ICK) is a chronic corneal infection characterized by interlamellar plaques of gram-positive coccal bacteria in the absence of inflammatory cells. It generally occurs within a corneal graft. Viridans streptococci are usually isolated, but the clinical response to antibiotics is poor and disparate with the in vitro antimicrobial sensitivities. These features suggest the possibility of unusual bacterial factors in pathogenesis. Four cases caused by nutritionally variant viridans streptococci are described. The organisms were fully characterized. They have a rare nutritional requirement for pyridoxal and require defined culture conditions and specific identification. Nutritional variant streptococci (NVS) are principally described as causing endocarditis, another infection involving an avascular collagenous tissue, and exhibiting similar biologic behavior. Electronmicrographic evidence is also adduced that suggests the possible importance of intracorneal glycocalyx deposition. Such factors might explain the anomalous clinical characteristics of this condition.
Asunto(s)
Enfermedades de la Córnea/microbiología , Infecciones Bacterianas del Ojo/microbiología , Infecciones Estreptocócicas/microbiología , Streptococcus/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Proteínas de la Membrana Bacteriana Externa/metabolismo , Enfermedades de la Córnea/tratamiento farmacológico , Enfermedades de la Córnea/patología , Infecciones Bacterianas del Ojo/tratamiento farmacológico , Infecciones Bacterianas del Ojo/patología , Femenino , Humanos , Queratoplastia Penetrante , Piridoxal/metabolismo , Infecciones Estreptocócicas/tratamiento farmacológico , Infecciones Estreptocócicas/patología , Streptococcus/aislamiento & purificación , Streptococcus/metabolismoRESUMEN
Twenty-nine consecutive patients with vitreous incarceration in the wound after cataract surgery and cystoid macular edema (Irvine-Gass syndrome) were treated with Nd:YAG laser anterior vitreolysis. Fifty-five percent (55%) achieved two or more lines of stable visual improvement; 17% improved but with fluctuating levels of vision and persistent edema; 28% failed to improve, half of them because of coexisting ocular pathology. Visual improvement was achieved an average of 3.5 months after treatment. Persistent macular edema was associated with several types of anterior chamber intraocular lenses.
Asunto(s)
Terapia por Láser , Edema Macular/cirugía , Vitrectomía , Segmento Anterior del Ojo , Extracción de Catarata , Angiografía con Fluoresceína , Humanos , Indometacina/uso terapéutico , Agudeza VisualRESUMEN
A provisional fibronectin (Fn)-fibrinogen (Fg) matrix forms de novo on the bare basement membrane (BM) surface of superficial epithelial scrape wounds in rabbit and guinea pig (GP) corneas. We determined whether such a substrate is essential for epithelial cell adhesion and migration, using three different approaches. (1) Polyclonal and monoclonal IgG reactive against GP Fn were topically administered to inhibit Fn formation in a GP epithelial scrape wound model. Immunofluorescence studies showed that deposition of both Fn and Fg was inhibited in antibody-treated corneas. During the first 38 hr after wounding, the healing rates were 0.46 +/- 0.06 mm2/hr in control eyes, 0.43 +/- 0.05 mm2/hr in those treated with rabbit polyclonal IgG anti-GP Fn and 0.45 +/- 0.09 mm2/hr in those treated with murine monoclonal IgG anti-GP Fn (P greater than 0.4). (2) In a rabbit epithelial scrape wound model, ancrod was administered intravenously to induce systemic Fg depletion. Fg deposition was completely inhibited on the wound surface, but Fn deposition was not suppressed. The healing rate was 1.24 +/- 0.41 mm2/hr in ancrod-treated corneal wounds and 1.19 +/- 0.29 mm2/hr in control eyes during the first 48 hr after wounding (P greater than 0.5). These data from the antibody and ancrod inhibition indicate that Fg binds to Fn and that Fn binds to components other than Fg.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Lesiones de la Cornea , Fibrinógeno/fisiología , Fibronectinas/fisiología , Cicatrización de Heridas , Heridas Penetrantes/fisiopatología , Ancrod/farmacología , Animales , Anticuerpos Monoclonales/inmunología , Córnea/patología , Córnea/fisiopatología , Epitelio/fisiopatología , Fibrinógeno/antagonistas & inhibidores , Fibronectinas/antagonistas & inhibidores , Fibronectinas/inmunología , Cobayas , Inmunoglobulina G/inmunología , Inmunohistoquímica , Técnicas de Cultivo de Órganos , Heridas Penetrantes/patologíaRESUMEN
We studied seven cases of severe gram-negative microbial keratitis associated with the use of contaminated topical ocular medications. Five cases involved Pseudomonas aeruginosa, one involved Serratia marcescens, and one involved Proteus mirabilis. In each case the same organism was cultured from corneal scrapings and from the medication. Either prednisolone acetate (one case) or timolol maleate (seven cases) was implicated in all instances.
Asunto(s)
Contaminación de Medicamentos , Queratitis/etiología , Prednisolona/análogos & derivados , Infecciones por Pseudomonas , Timolol , Administración Tópica , Anciano , Anciano de 80 o más Años , Úlcera de la Córnea/etiología , Úlcera de la Córnea/patología , Femenino , Humanos , Queratitis/complicaciones , MasculinoRESUMEN
A Q-switched neodymium-YAG laser was used to cut experimental vitreous membranes in rabbit eyes. We were able to cut vitreous membranes up to 4 mm from the retinal surface using single pulse energies of up to 4 mJ without fluorescein angiographic evidence of retinal injury. When cutting membranes between 1.5 and 3 mm from the retinal surface, injury was documented in five of seven cases. The most frequently observed fundus injury was choroidal hemorrhage. The neodymium-YAG laser may be useful in cutting avascular membranes in the posterior segment of the eye.
Asunto(s)
Terapia por Láser , Retina/lesiones , Cuerpo Vítreo/cirugía , Animales , Oftalmopatías/cirugía , Angiografía con Fluoresceína , Membranas/cirugía , Oftalmoscopía , ConejosRESUMEN
Five patients with the Eaton-Lambert syndrome were examined neuro-ophthalmologically. Three were studied using electro-oculographic saccadic velocity recordings. Four complained of blurred vision and all complained of ptosis during the course of their disease. Clinical examination revealed mild ptosis in three of the five patients. Saccadic velocities before exercise were normal. After saccadic exercise, an increase in velocity of up to 40% was noted in two of the three patients studied.