[Photographic documentation of image properties of optic media in aphakia correction].
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Aphakia, Postcataract↗
Biomedical subjects
W Kulnig
Publications and source records attributed to W Kulnig.
Inhibition of experimental intraocular proliferation with intravitreous 5-fluouracil. A transmission electron-microscopic study in rabbits.
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.
Animals↗
Inhibition of experimental intraocular proliferation with intravitreal 5-fluouracil.
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.
Animals↗
Secondary corneal amyloidosis: clinical and pathohistological examinations.
A patient suffering from an excentric vascularized tumorlike corneal change is reported who submitted to a penetrating optic keratoplasty. The diagnosis of a secondary corneal amyloidosis was established by histological examination. The clinical course and pathological findings by means of light- and electron microscopy are described and discussed.
Adult↗
[Comparative vision tests using objective and subjective testing methods in amblyopia].
In 20 amblyopic eyes without reading ability a comparison was made between the visual acuity found by subjective tests and with the Catford Visual Acuity Apparatus, Kotowski's Visumeter and Lotmar's Moiré Visometer. These instruments all work on the basis of different physiological functions. The Kotowski Visumeter seems to be the best instrument for an expertise on the visual acuity of an amblyopic eye. With the test pattern moving from nasal to temporal the results corresponded to the patients reading ability in 16 cases (80%); 4 patients had poorer vision. With the checkerboard pattern moving temporonasally the average results were better than the patients' actual vision. The Catford apparatus gave results corresponding to the subjective reading test only in 12 cases (60%). Apparatus with interferometric scales are not suitable for objective visual testing of amblyopic subjects; the results they give are always much better than the actual vision of the patient.
Adolescent↗
[Close-range retinoscopy using integrated optic range finding].
A new type of retinoscope is described which permits all the theoretical advantages of close-range retinoscopy to be exploited in practice thanks to an integrated rangefinder which employs the coincident-image principle.
Fluoroscopy↗
[Disparity between applanation and impression tonometry in corneal edema].
In acute glaucoma with corneal edema the applanationtonometer shows significantly lower values than the Schiötz instrument. In an experiment with rabbit corneae characteristic alterations in the edematous cornea were found, the physical interpretation of which, together with the tonometer specifications, were regarded as the cause of the disparity. The consequences go beyond pure academic interest if high intraocular pressure occurs concomitantly with insufficient retinal vascular function.
Animals↗
[Electron-microscopic and biochemical characteristics of pterygia (author's transl)].
Histologically, pterygium is characterized, apart from the presence of typical collagen fibers, by the appearance of fibres which take up elastic stain but differ from normal elastic tissue, as was confirmed by electron-microscopic investigations. Thus, "elastoid degeneration" of collagen is characterized by the loss of the characteristic periodic fibril structure and by the appearance of coiled and knotty fibres. Collagen types in pterygium were identified biochemically for the first time. The main bulk of collagenous tissue consists of 80-90% Type I collagen, while only 10-20% Type III collagen was detected. Type IV collagen (basal membrane collagen) was present in low amounts. Digestion with elastase resulted in 20% solubilization of pterygium, while bacterial collagenase digested up to 40% of the tissue dry weight.
Chemical Phenomena↗
[Prescription of cylindrical lenses after cataract operations (author's transl)].
As a rule, prescriptions for corrective lenses only reflect two-thirds of the corneal astigmatism measured with the keratometer. The significance of various optical factors was investigated as a possible explanation.
Astigmatism↗
Electron microscopical studies on the resorption of vitreous hemorrhages.
An electron microscopical study of vitreous structure in 14 eyes suffering from different types and durations of vitreous hemorrhages submitted to vitrectomy showed the typical stages of disintegration of erythrocytes. Neither the type (retrovitreal, intravitreal or combined retro- and intravitreal) nor the duration of the vitreous hemorrhages influenced the histological picture significantly. In cases of shrinkage of the vitreous body the collagen fibrillar meshwork showed normal periodicity of 640 A, partly split and irregular.
Adult↗
Ultrastructural sequence of myelin degradation. I. Wallerian degeneration in the rat optic nerve.
The ultrastructural events in myelin degradation in the rat optic nerve following transection have been studied. Myelin debris was found in cells similar to multipotential glia cells (Vaughn and Peters, 1968) as well as in astrocytes and in few oligodendrocytes. The different types of inclusions found during myelin degradation were described in their quantitative relations. Similarities to inclusions described in adrenoleukodystrophy adn multiple sclerosis are discussed. By comparison of the ultrastructural findings with histochemical and biochemical data available a hypothetical model of myelin degradation is presented. The process starts with the degradation of digestible proteins resulting in uniformly layered lipid inclusions. Lipid degradation leads to the formation of unstructured lipid droplets and crystals. During the late stages of Wallerian degeneration numerous polymorph inclusion typed can be found, probably representing poorly digestible lipids or lipoproteins.
Animals↗
Ultrastructural sequence of myelin degradation. II. Wallerian degeneration in the rat femoral nerve.
Myelin degradation in Wallerian degeneration of rat femoral nerves has been studied with the electron microscope. In the initial stages, a decrease of myelin periodicity from 115 A to 88 A was noted, followed by the transformation of the myelin structure into uniformly layered lipid inclusions. 10--14 days after nerve section, most of the inclusions found represented unstructured lipid droplets or crystals. In the later stages of degeneration, numerous pleomorphic lamellar inclusions were found, some of them resembling the structure of pi and micron-granules. Lysosomal enzyme activity was found especially in pleomorphic inclusions during the late stages of myelin degradation. Normal myelin sheaths, as well as unstructured lipid droplets and crystals, were devoid of enzyme activity. The results are compared with alterations found in Wallerian degeneration of the central nervous system.
Animals↗