Background : We have developed a binocular perimetry technique for the quantitative assessment of retinal photoreceptor displacement and metamorphopsia.Objective: To study the direction and amplitude of retinal photoreceptor displacement in eyes with idiopathic macular holes using our binocular perimetry technique.Subjects: Five healthy control subjects and 10 patients with unilateral stage 3 to 4 macular holes in one eye and a healthy fellow eye.Method: Kinetic perimetry using red and green filter glasses, black binocular fixation targets, red and green selective monocular stimuli (Goldmann III-4-e), and fundus image superimposition of perimetry data.
Results:We found no discrepancy between the 2 visual fields in any healthy subjects. In patients with a unilateral macular hole, the central scotoma invariably extended beyond the rim of the hole. In 8 patients, each point on the rim of the scotoma had a perceptually corresponding location in the visual field of the fellow eye that was closer to the center of the visual field. In the 2 patients with the longest duration of symptoms (Ͼ2 years), no such discrepancy was found.Conclusions: Differential perimetry enables the objective study of retinal photoreceptor displacement and metamorphopsia. We found objective evidence for radial centrifugal photoreceptor displacement in most patients with idiopathic macular holes.
Interactions between Yersinia enterocolitica and rabbit ileal mucus were examined. Strains carrying the Yersinia virulence plasmid, pYV, adhered to crude mucus but not to intestinal luminal contents that had been immobilized on polystyrene. Using an Y. enterocolitica 0:9 mutant in which the yadA gene (formerly called yopA), encoding the high-molecular-weight outer membrane protein YadA (formerly called protein P1 or Yopl), had been inactivated and an Escherichia coli strain carrying the cloned yadA gene, we demonstrated that the ability to adhere to mucus correlated closely to expression of YadA. Thereafter, we evaluated possible consequences of binding between pYV-carrying Y. enterocolitica 0:3 strains and constituents in the mucus layer. pYV-carrying strains were able to multiply at a high rate in mucus but not in luminal contents, and the ability to adhere to mucus could therefore facilitate bacterial colonization of the mucosa. However, we also showed in vitro that mucus acted as a barrier for a mucus-adherent, pYV-carrying Y. enterocolitica strain. Furthermore, penetration through, or preincubation with, mucus reduced subsequent adhesion of the pYV-carrying strain to brush border membrane vesicles without simultaneously causing bacterial aggregation. Preincubation with mucus also changed the bacterial surface of the same strain from hydrophobic to hydrophilic. Immunoglobulins present in mucus did not seem to be of importance for our observations. Interaction of Y. enterocolitica with intestinal mucus may thus reflect a host defense mechanism that reduces the pYV-mediated adhesion to the epithelial cell membrane, possibly by rendering the bacteria less hydrophobic.
The indications for penetrating keratoplasty have changed over the past several years. One hundred and eighty cases of penetrating keratoplasty performed in the Department of Ophthalmology, Naestved Centralsygehus, Denmark, from January 1984 to December 1993, were analysed. Overall pseudophakic bullous keratopathy was the most common indication for penetrating keratoplasty (28.3%). This was followed by keratitis (13.9%), Fuchs' dystrophy (13.9%), regraft (11.1%), aphakic bullous keratopathy (10.0%) and keratoconus (6.7%). Pseudophakic bullous keratopathy was the most common indication for penetrating keratoplasty in 1989 and in each year from 1991 to 1993. Before 1989 the most common indications were keratitis (18.0%) and aphakic bullous keratopathy (14.8%). The emergence of pseudophakic bullous keratopathy, as the most common indication for penetrating keratoplasty, correlates well with the dramatic increase in the number of cataract extractions with intraocular lens implantation performed since the early 1980s. Especially semiflexible, closed-loop anterior chamber lenses used in our department in the early years of the period, have been the cause of subsequent corneal edema.
ABSTRACT. A case of severe chemical injury to the eye with persistent corneal epithelial defect and progressive corneal neovascularization treated successfully with limbal autograft transplantation is presented.
Binocular correspondence perimetry enables quantitative mapping of metamorphopsia and stratification of subjects with epiretinal membranes with respect to normative references. Data from healthy subjects appear to describe a physiological level of tolerance for changes in oculocentric direction, which may apply also to the changes induced by retinal traction.
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