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Biomedical subjects

O F Scheiffarth

Publications and source records attributed to O F Scheiffarth.

27 records · Page 2Linked to original sources
PubMed1987

Release and elimination of methylmethacrylate monomer after intraocular lens implantation.

The potential for certain constituents in intraocular lenses, such as monomer methylmethacrylate (MMM), to induce toxic effects after intraocular implantation not only depends on their toxic potency, but also on the characteristics of their release, accumulation, and elimination from the aqueous humor. A mathematical estimation taking these factors into account shows that for a lens mass of approximately 15 mg, the concentration of MMM in the aqueous humor amounts to about 10(-4) of the respective concentration in the lens, but that value is maintained for several weeks. Therefore, experiments to test the chemical toxicity of MMM or similar lens compounds in eyes must not only take into account the actual concentration limit but also the time of exposure to the substance.

Eye↗
PubMed1987

T lymphocytes of the normal human cornea.

Lymphocytes in the periphery of the normal human cornea are identified as being only T lymphocytes by immunohistochemical methods. OKT-4 positive cells (T-helper/inducer lymphocytes) and OKT-8 positive cells (T-suppressor/cytotoxic lymphocytes) are found in similar numbers in most of the corneas examined. OKT-4 positive cells in the cornea present a risk of transferring HTLV-III (HIV) by corneal grafting.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Chemical studies of intraocular lenses after experimental generation of lesions by a short-pulsed Nd-YAG laser.

It is theoretically possible that lesions generated by a Q-switched Nd-YAG laser could lead to chemical changes in polymethylmethacrylate (PMMA) intraocular lenses. These changes could be of clinical relevance. Therefore, we measured the residual monomer content of intraocular lenses before and after generation of lesions by means of a short-pulsed Nd-YAG laser. Despite the explosive destruction of the lens surface caused by this type of laser, there is no measurable release of monomer in the sense of a depolymerization of the PMMA material, even when over 100 lesions are generated. The lesions generated on intraocular PMMA lenses with the Nd-YAG laser are predominantly of a mechanical nature and include the chipping away of small particles from the intraocular lens.

Lasers↗