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I Knauer

Publications and source records attributed to I Knauer.

4 recordsLinked to original sources

[Trypan blue and alizarin red S sequential staining with subsequent fixation. A modified technic for the study of the corneal endothelium].

A sequential corneal endothelium staining technique with trypan blue (TB)--alizarin red S (ARS)--ethanol-trypan blue is described which can be performed in a few minutes. The first step permits the TB exclusion to be determined as a criterion of normal endothelial cell function. The two following steps permit intercellular staining by ARS and nuclear staining by TB. After each staining procedure, fixation can be performed by methanol or ethanol, both with full-thickness corneal preparations or endothelial flat mounts. In flat preparations, the focussing problems and optical artifacts of full-thickness mounts can be avoided. These modifications render simple sequential staining with subsequent fixation a complement and alternative to specular microscopy and to the customary complicated silver staining of corneal endothelium.

Animals↗

[Clinical specular microscopy. Technic, organization and simple calculator morphometry].

The use of specular microscopy (SM) as a routine clinical method for qualitative morphological and quantitative morphometric analysis of the corneal endothelium requires a standardized examination technique. Organizational and apparative means are necessary for the analysis, documentation and storage of the data. The results of the immediate analysis are documented on a result form. The morphological changes are classified in 4 different groups (endothelial, pre-endothelial, retro-endothelial, and non-endothelial changes). The morphometric analysis is performed immediately: the mean cell density (mcd) is estimated by comparing the endothelial mosaic in the camera viewfinder with 3 standardized specular micrographs with known cellular density. The good correlation between the results of estimation and definite counting allows this rapid method to be used as a simple clinical screening techniques. The definitive morphometric analysis is carried out directly from the photographic negative using the fixed frame principle. The mcd and mean cell area (mca), m +/- sd, are determined by a simple method which saves time and money, using a scientific pocket calculator programmed in Basic. A specially designed slide rule serves to define the frame. The calculator may also be used for statistical analyses. This is demonstrated in a group of 127 patients (aged 51-87) before IOL implantation. The mcd and mca of the examined population is 2249 +/- 290 cells/mm2 and 444 +/- 57 microns 2. There is no statistically significant difference in mcd between the right and left eye (t-test: p = 0.93). Although statistically mcd decreases significantly with advancing age (p = 0.05), there is a large range of results in this population.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Count↗