Two patients with epibulbar malignacies were treated by local excision and brachytherapy with ruthenium-106. One patient showed a large melanoma on the epibulbar conjunctiva, the other patient suffered from a recurrent squamous cell carcinoma at the limbus. After excision of the tumor including lamellar sclerectomy and keratectomy, a ruthenium-106 plaque was sutured to the sclera, and a total dose of 290 and 320 Gy, respectively, was delivered to the tumor bed. No severe radiogenic complications were observed except for a rarefaction of the sclera in the treatment area and a slow cataract increase. After a follow-up period of 50 and 22 months, respectively, both patients do not show any recurrence or metastatic disease.

Collagen fibrils with a symmetric banding pattern, an as yet overlooked component of the extracellular matrix, were found in the reticular layer of the basement membrane of human sebaceous glands. In longitudinal sections this newly described banding pattern is D-periodic (D = 67 nm) resembling the period length of native type collagen fibrils. In cross sections the symmetrically banded fibrils are irregularly outlined. The period length and the symmetric banding pattern led to the assumption that collagen molecules are staggered by the distance D, similar to native type collagen fibrils, but are arranged antiparallel. This hypothesis was tested by antiparallel superposing transparent photocopies of native type fibrils. In addition, schematic drawings of the cross striation pattern of native type fibrils were superposed in reverse directions by means of computerized image-manipulation. A model of molecular alignment was evolved from these experiments, which is characterized by two features: 1) pairs of antiparallel collagen molecules are D-staggered and 2) the two molecules of a pair are slightly shifted from precise register. The proposed model is the only one correlating with the data obtained from direct measurements on symmetrically cross striated fibrils. The fibrils described in the present study represent a supramolecular aggregate of collagen previously not observed in vivo.

5-Fluorouracil was used to inhibit experimental intraocular proliferation in rabbit eyes, produced by homologe fibroblast implantation. Two different concentrations were used, 1 and 5 mg in a single intravitreal injection. The eyes were followed up over 4 weeks. Proliferation and resulting traction detachment was reduced from 75% to 30% in the 1-mg 5-fluouracil group. In addition, we observed retinal and vascular changes in a considerable number of eyes treated with 1 mg and much more pronounced alterations in most of the eyes treated with 5 mg fluouracil.

5-Fluouracil, administered at concentrations of 1 and 5 mg to inhibit experimental intraocular proliferation produced by intravitreously implanted fibroblasts in rabbits, produced tissue alterations revealed by TEM. The degranulation and migration of pigment epithelial cells, the incipient degradation of axons and myelin sheets, the migration of glial cells and the prominent edema of the inner layers indicated a non-negligible damage to the retina, suggesting to abstain from its use in human eyes and to search for less neurotoxic drugs, possessing the same inhibitory effect on intraocular proliferation.

We describe the histopathologic results of extracapsular lens extraction and silicone and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation in 36 rabbit eyes. Phase-contrast microscopy was used to examine precipitates on IOL surfaces and posterior capsules. Semithin and ultrathin sections were taken from the central cornea, anterior uvea, capsular bag, and retina near the posterior pole. The follow-up was one to 16 weeks. Silicone IOLs did not cause significantly less precipitation than PMMA IOLs. Precipitates consisted of spindle-shaped fibroblast-like cells, various forms of inflammatory cells and multinucleated giant cells, single melanophages, and irregularly arranged birefringent collagen fibers. Corneal endothelial edema was slightly more prominent in PMMA IOL implanted eyes. Significant retinal edema in the posterior pole area was not observed with either of the two lens types. Severe precipitation in the form of large clusters of pigment cells and inflammatory reactions seemed to depend on mechanical trauma (iris capture and lens dislocation) and individual animal reactions, but not on the lens type used.