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Biomedical subjects

C Teping

Publications and source records attributed to C Teping.

35 records · Page 2Linked to original sources
PubMed1987

Evidence of pericentral stereopsis in random dot VECP.

Dynamic random dot patterns generated on a TV screen by a special pattern generator are proven to be adequate stimuli for testing stereopsis. In our experimental set-up we use red-green coded striped or checkered patterns of various size and disparity as stimuli, which are viewed through red-green glasses (anaglyph method). The registration of transient visual evoked cortical potential (VECP) to these random dot stimuli offers objective proof of stereopsis. There is a typical amplitude behavior with maximum amplitudes at medium disparities. By recording the specific stereo VECP while masking the central retinal areas stepwise (artificial central scotoma) we can objectively show intact stereopsis of corresponding pericentral retinal areas. This peripheral stereopsis is demonstrable in the VECP by central scotomas up to eight degrees.

Cerebral Cortex↗
PubMed1987

[Biomicroscopy of an intraocular lens. Comparison of specular microscopy findings with the cytologic specimen].

Seventeen months after implanting an anterior chamber intraocular lens the lens had to be removed because of secondary glaucoma and retinal hemorrhage. The lens had been examined 5 days prior to surgery. It appeared that histiocytic giant cells and fibroblasts had settled on its surface. This was subsequently confirmed by cytological studies. It therefore appears possible to describe an in vivo differential cytology and to diagnose the type of inflammatory reaction in vivo.

Aged↗
PubMed1982

[Electroophthalmological findings in optic atrophies of different etiology (author's transl)].

The recording of visually evoked cortical potentials in response to pattern stimuli of different brightness contrast permits functional examination of the optic nerve. This procedure has already been shown to be useful in inflammatory diseases of the optic nerve. Clinical case studies are presented showing that optic atrophies, independent of their etiology, can be ascertained by visually evoked cortical potentials elicited by pattern stimuli, occasionally also by the application of homogeneous light flashes (brightness responses). The technique is shown to be useful especially in early stages of disorders of the optic nerve.

Adolescent↗
PubMed1981

[Determination of visual acuity by the visually evoked cortical potential (author's transl)].

Monocularly evoked cortical potentials were recorded monopolarly (3 cm above Prot. occ. ext. sup.) to steady-state checkerboard stimuli (check sizes 1.4 to 26 min, rev. freq. 7/s, mean luminance 10.8 cd/m2, field diameter 4.5 deg., centr. fix.). For a number of visual acuities (obtained by inserting plus lenses up to 3.0 dpt) the smallest check size evoking reliable VECPs was related to the visual acuities obtained at a visual test chart. The use of 20 instead of 100 per cent contrast stimuli provided a significant decrease of slope of threshold check size versus visual acuity, resulting in a three-fold increase in the resolution of data. The method permits the evaluation of visual acuities between 0.1 and 1.0 in normals and patients within limits of +/- log 0.1 (1 sigma) and +/- log 0.2 visual acuity (2 sigma).

Adult↗
PubMed1981

[Visually evoked cortical potentials (VECP) in patients with doubtful impairment of central vision (author's transl)].

Visual evoked cortical potential (VECP) to non-structured, brightness (luminance) stimuli do not provide an appropriate means for assessing the degree of impaired central vision. In comparison, visually evoked cortical potentials to structured (patterned) stimuli presented by pattern reversal of equal mean luminance are highly susceptible to visual changes caused by reduced central vision. Employing different check sizes, the use of checkerboard pattern reversal VECPs permits, independently of the patient, to assess the impairment of central vision.

Accommodation, Ocular↗
PubMed1977

[Alterations in the metabolism of cornmeal epithelium during medium-term storage (author's transl)].

Freshly prepared bovine corneas were stored in medium TC 199 with penicillin and fetal calf serum at +4 degrees C over a storage period of 168h. Every 24h, the levels of glucose, lactate, and pyruvate in the corneal epithelium were estimated. Also the glucose levels in the corneal epithelium and stroma were compared at the same time intervals. Furthermore, alterations in the enzyme pattern of the epithelial cells during storage were observed.

Animals↗