PubMed Health⌕ Search

Biomedical subjects

W Ehrich

Publications and source records attributed to W Ehrich.

At least 19 recordsLinked to original sources
PubMed1990

[Biocompatibility and pharmacokinetics of hydroxypropyl methylcellulose (HPMC) in the anterior chamber of the rabbit eye].

The biocompatibility and pharmacokinetics of hydroxypropylmethylcellulose (HPMC) 2% (Adatocel) and Tylose 2% (MH 1000) were investigated. A modified anterior chamber implantation test on the rabbit eye is suitable for testing both the biocompatibility and the pharmacokinetics of visco-surgical substances. Both substances were well tolerated. From the fourth day onward, HPMC was no longer detectable in the anterior chamber by infrared spectroscopy.

Animals↗
PubMed1989

[Intraocular lens materials in the anterior chamber implantation test].

The biocompatibilities of two silicones ("Homburg" and "St. Wendel" silicone) and "Perspex CQ" (Titmus Eurocon Kontaktlinsen GmbH, Aschaffenburg) were tested in rabbits' eyes using the anterior chamber implantation test. Test criteria were iris folds, corneal opacification, fibrin flocks, and iris hyperemia. All the materials proved to be sufficiently biocompatible for use in the production of intraocular lenses. The two silicones appear to cause corneal opacification more often than "Perspex CQ". "Homburg" silicone only rarely seems to cause iris folds. There are no statistically significant differences in the biocompatibility of the tested materials. Clinical observations were in agreement with the test results.

Animals↗
PubMed1985

[Polyvinylpyrrolidone iodine and arginase: effect on corneal regeneration and its antiviral effect].

PVP-iodine was found to be virucidal for adenoviruses and herpes simplex virus in a concentration of 0.5%, i.e., a 1:20 dilution of Betaisodona. Similar concentrations did not delay the healing of corneal epithelium of the rabbit after experimental lesions (Ullerich and Durchschlag, 1953), although the eyes were slightly irritated. However, a higher concentration (1.25%) caused considerable ocular irritation, and healing of the cornea was delayed or completely inhibited. Arginase, which inhibited the multiplication of adenoviruses and herpes simplex virus in cell culture, did not impair corneal healing in solutions of up to 5%.

Adenoviridae↗
PubMed1984

[Regeneration of the corneal endothelium in the rabbit--preliminary trials--I].

It has been demonstrated in a long-term experiment that the corneal endothelium of the rabbit is capable of repairing severe mechanical lesions several times. The more severe the lesion, the longer it takes to heal. The endothelium "broke down" for the first time after the sixth endothelial lesion was inflicted and so on after the tenth, eleventh and twelfth endothelial lesion. The regeneration time was prolonged considerably. Sometimes a "restitutio ad integrum" occurs and the cornea clarifies; sometimes one sees a retrocorneal membrane, which can also lead to clarification of the cornea. Plastic platelets implanted in addition (PVAL or HEMA copolymers) do not influence the time required for regeneration of the endothelium. In other tests these plastics proved to be nontoxic to the endothelium.

Animals↗
PubMed1979

[HEMA-contact lens and HEMA-dressing lens-damage to the eye (author's transl)].

3 cases in which HEMA-contact lens, and 2 cases in which HEMA-dressing lens caused corneal damage were analyzed with regard to symptomatology, etiology and sequence of events. Hyperemia of the limbus is the main symptom. Avoidable causes are exaggerated tightness, overwearing, storing up of proteins, rough surface, and incompatibility of soft-lens solutions. Irreversible and largely resistant to therapy is, damage resulting from the synthetic itself.

Acrylic Resins↗
PubMed1978

[Biological compatibility of polyurethan (PUR) (author's transl)].

After implantation of a disc (thickness: 0.25 mm, diam: 1.5 mm) of PUR in the anterior chamber of rabbits through a lancet incision, the reactions of iris, aqueous, and cornea were observed for six months at regular intervals using slit-lamp photography. 'Steeping' materials were as compatible as nonsteeping materials. At the place where the disc touched the iris one could see during a half-year period hyperemia iridis and foreign-substance granuloma of the iris. The cause of these reactions is a toxin in the PUR. Mechanical irritants as a cause could be excluded through the method utilized in the experiment.

Animals↗
PubMed1977

[Biological compatibility of soft contact lens materials (HEMA) (author's transl)].

After implanting a disc (0,25 mm thickness and 1,5 mm diameter) of soft contact lens materials ("Soflens", "Hydroflex", "Hydron") in the anterior chamber of rabbits through a lancet incision, the reactions of iris, aqueous and cornea were observed for six months at regular intervals with slit lamp photograph. At the place where the disc touched the iris one could see during half a year periodic hyperaemia iridis and foreign-substance-granuloma of the iris. The cause of these reactions is a toxin in the HEMA. The reactions are more intense than with PMMA.

Animals↗
PubMed1976

[Plexiglas (PMMA) in the anterior chamber. An experimental study on biological compatibility].

For six months the anterior chambers of rabbits were examined at regular intervals with the slit-lamp photograph. The reactions of iris, aqueous, and cornea were observed after implanting one PMMA-disc (0.25 mm thickness and 1.5 mm diameter) through a lancet incision. At the place where the disc touched the iris one could see during the half year period hyperaemia iridis, ciliary injection, atrophia iridis, and foreign-substance-granuloma of the iris with partial adhesion of the iris wrinkles. The cause for these reactions is a toxin in the PMMA. Mechanical irritation and plastic alteration could be excluded by the experimental method.

Animals↗