[Platelet aggregation inhibitors and anticoagulants during ophthalmic interventions].

In ophthalmology many patients undergo surgical treatment who need to take anticoagulant medication due to cardiovascular diseases. The proper handling of these drugs requires both correct assessment of the risk of thromboembolism as well as the rating of the risk of surgery-related hemorrhages. While there are established recommendations for estimation of the risk of thromboembolism based on a large body of prospective randomized trials, data regarding the evaluation of the related complications secondary to ophthalmic surgery are limited.

Comparative glaucomatous diagnosis using macular optical coherence tomography and perimetry with centrally condensed stimuli: English version.

The presentation and measurement of the internal retinal layers by current optical coherence tomography (OCT) instruments allow a precise topographic localization of macular glaucomatous damage. Ganglion cell analysis in particular can reveal slight central defects and can effectively be correlated with perimetric strategies with centrally condensed stimuli, so that small glaucomatous defects can be confirmed earlier and more confidently. Progression can also be verified in the early stages of the disease as enlargement and deepening of small localized defects.

[Correlation of morphological and functional glaucoma diagnostics with macular OCT and perimetry with centrally condensed stimuli: German version].

The presentation and measurement of the internal retinal layers by current optical coherence tomography (OCT) instruments allow a precise topographic localization of macular glaucomatous damage. Ganglion cell analysis in particular can reveal slight central defects and can effectively be correlated with perimetric strategies with centrally condensed stimuli, so that small glaucomatous defects can be confirmed earlier and more confidently. Progression can also be verified in the early stages of the disease as enlargement and deepening of small localized defects.

Fine structure of the developing avian corneal stroma as revealed by quick-freeze, deep-etch electron microscopy.

Corneal transparency depends on the precise organization of the stromal extracellular matrix. The morphology of the extracellular matrix of the embryonic and adult avian secondary posterior cornea was studied in glutaraldehyde-fixed, quick-frozen, deep-etched replicas with the electron microscope. Although the collagen fibrils changed from a loose network to a more ordered parallel lamellar arrangement during development, their mean diameter remained constant between 30.

Endothelin-like immunoreactivity in aqueous humor of patients with primary open-angle glaucoma and cataract.

Background: Experimental evidence suggests a role of endothelin-1 (ET) in the regulation of intraocular pressure (IOP).

Method: Therefore, in patients undergoing cataract surgery, ET-like immunoreactivity (ETIR) was measured by radioimmunoassay in pooled samples of aqueous humor of eyes with primary open-angle glaucoma (POAG) and normotensive eyes with cataract only.

Results: ETIR was significantly (P < 0.

[Oxygen in the anterior chamber before and after cataract operation].

The purpose of the study was to investigate whether removal of the lens would change the physiology of oxygen supply to the anterior segment of the eye. Oxygen partial pressure in the anterior chamber was measured using oxygen-sensitive electrodes during cataract surgery or removal of after-cataracts in aphacic and pseudophacic eyes. We found significantly reduced oxygen tension in the anterior chamber of aphacic or pseudophacic eyes compared to cataractous eyes.

Incomplete belts of tight junctions in cultured non-pigmented human ciliary epithelial cells.

Tight junctions of cultured human non-pigmented ciliary epithelial cells were studied with the freeze-fracture technique and related to the transepithelial electrical resistance of these monolayers. Isolated tight junctional fibrils or small groups and networks of tight junctions sometimes associated with gap junctions were revealed in freeze-fracture images of the lateral plasma membrane. The tight junctions always formed incomplete belts, so that the apical and basolateral plasma membrane domains often were in continuity without morphological evidence of interposed intercellular junctions.

Tight junctions and paracellular permeability in cultured bovine corneal endothelial cells.

Intramembrane specializations of cultured bovine corneal endothelial cells were studied with thin section and freeze-fracture electron microscopy and related to the paracellular permeability and the transendothelial resistance (Rt) of the monolayers. The following intercellular junctions were found: single and discontinuous networks of tight junctions (TJ) which girdle the apico-lateral cell perimeter incompletely, gap junctions, and membrane undulations suggesting intermediate junctions. The macromolecular tracer ruthenium red penetrated into the lateral intercellular space beyond the level of the incomplete belt of TJ.

Tight junctions of the human ciliary epithelium: regional morphology and implications on transepithelial resistance.

The tight junctions of the human ciliary epithelium have been studied using the freeze-fracture technique with particular regard to regional differences in the tight junction networks and implications on the transepithelial resistance. The tight junctions of the non-pigmented epithelium always form continuous networks and consist of from two to more than 20 superimposed strands (mean 3 to 4), suggesting that relatively tight and leaky sites of the paracellular pathway coexist within the same cell perimeter. The tight junction morphology is more complex in the anterior pars plicata than in the posterior pars plicata, but its complexity increases again towards the pars plana.

Tight junctions of the human corneal endothelium: morphological and electrophysiological features.

The corneal endothelium controls the hydration and nutrition of the avascular corneal stroma. To analyze the role of the tight junctions (TJ) for these functions, we examined human corneal endothelium by thin-section and freeze-fracture electron microscopy and by impedance analysis. On thin sections, tannic acid was seen to mark the external leaflet of the lateral plasma membrane also beyond the location of the TJ, indicating a significant macromolecular porosity of the TJ.

Anterior-chamber hypoxia and iris vasculopathy in pseudoexfoliation syndrome.

Iris vasculopathy is a well-recognized clinical feature in pseudoexfoliation syndrome (PES). In the present study we examined the morphology of the iris vasculature in PES using electron microscopy and we tested whether these iris vascular changes were correlated with an impaired oxygen supply to the anterior chamber. In the affected vessels we found a gradual degeneration of vascular cells, progressing from adventitial to endothelial cells, associated with the production of excess extracellular material, including pseudoexfoliative fibers.

HLA-B and -DR match reduces the allograft reaction after keratoplasty.

Since 1983, corneal grafts have been routinely obtained from multiorgan donors and allocated to the patient with the greatest HLA compatibility. At follow-ups in 248 primarily clear corneal grafts, grouping according to the HLA mismatch rate revealed that the incidence of allograft reactions did not differ significantly for HLA-A but certainly did for HLA-B (P < 0.01) and, in patients with a poor prognosis, for HLA-DR as well (P < 0.

Chloral hydrate for pediatric ophthalmologic examinations.

Although chloral hydrate sedation has been recommended as an alternative to general anesthesia for pediatric examinations, we have had inconsistent effects after rectal applications for ophthalmologic examinations. A retrospective analysis of rectal chloral hydrate for computer-assisted tomographic (CT) examinations on 20 pediatric patients revealed that after a single application, sedation was sufficient in only 4 cases. In 14 cases, additional doses and/or drugs were required.

Cycloplegic refraction using atropine minidrops.

Topical application of atropine for cycloplegic refraction may be associated with alarming systemic reactions in infants and children. Cycloplegic refraction and pulse rate were compared after short-term minidrop application of atropine with a calibrated pipette (3 × 5 μl) and standard atropine application from commercial bottles (twice daily 30-36 μ1 for three days) in 30 hypermetropic eyes of children between 1 and 7 years of age. The mean spherical equivalents of cycloplegic refraction achieved after minidrop application was 0.

Endothelin-like immunoreactivity in the aqueous humour and in conditioned medium from cultured ciliary epithelial cells.

Endothelin-like immunoreactivity was detected in human (15.6 +/- 2.7 pg/ml) and bovine (11.

[Multiple evanescent white dot syndrome].

A 38-year-old male patient experienced a unilateral visual acuity decrease to 20/60 and showed white dots at the level of the retinal pigment epithelial interface characteristic of multiple evanescent white dot-syndrome. Fluorescein angiography demonstrated early hyperfluorescent defects and some late staining. In spite of improvement of the visual acuity and the alterations of the fundus, an enlargement of the blind spot and some sharply demarcated depigmentations of the retinal pigment epithelium remain.

Filipin-induced deformations in plasma membranes of cultured bovine corneal endothelial cells with incomplete belts of tight junctions.

Complete belts of intact tight junctions are thought to act as barriers to the movement of cholesterol in the plane of the plasma membrane. As cholesterol can be revealed by filipin-induced membrane deformations on freeze-fracture images, we studied the distribution of these deformation in cultured bovine corneal endothelial cells with incomplete belts of tight junctions. While the extent of filipin-induced deformations differed between individual cells, there is a homogeneous distribution of filipin-induced deformations on both sides of the incomplete junctional belt of endothelial cells.

[Intraocular pressure ten weeks after cataract surgery].

The effect of phacoemulsification and extracapsular cataract extraction on the intra-ocular pressure is analysed for several intra-operative factors. The mean intraocular pressure is significantly reduced ten weeks after the operation in comparison with the preoperative intraocular pressure. This reduction of the intraocular pressure is most significant for eyes with preoperative ocular hypertension and those eyes where leakage of the aqueous humour was evidenced during the immediate postoperative period.

Orthogonal arrays of particles in non-pigmented cells of rat ciliary epithelium: relation to distribution of filipin- and digitonin-induced alterations of the basolateral membrane.

It has been suggested that orthogonal arrays of particles may increase the rigidity of plasma membrane, as does cholesterol. Therefore, using freeze-fractured non-pigmented ciliary epithelium, the distribution of such arrays was compared to the distribution of membrane deformations induced by the sterol-probes filipin and digitonin in different domains of the basolateral plasma membrane. The distribution of orthogonal arrays of particles was homogeneous between different regions of the basolateral membrane of the non-pigmented ciliary epithelium, while the number of filipin-induced alterations was nearly 4 times higher in the membrane domains not in contact with the basal lamina than in domains in contact with it.