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Biomedical subjects

A Mathis

Publications and source records attributed to A Mathis.

At least 73 records · Page 4Linked to original sources
PubMed1985

Some ultrastructural aspects of the vitreoretinal juncture.

The ultrastructural study of the vitreoretinal juncture was carried out by comparing two groups of patients: 6 young subjects under 25 years and 6 older subjects over 70. Retinal samples were taken from the posterior pole, the equator and the extreme periphery. Our work shows that the morphological modifications of the vitreoretinal juncture during the aging process vary following location. The most original alteration, never observed before, appears in the equatorial region: it consists of a widening of the intercell space filled with fibrils adhering to Müller's cells. It builds up an adhesion zone between the vitreous and the retina which is not visible during clinical investigations; it can create a tear during the posterior vitreous detachment.

Adolescent↗
PubMed1985

[Lattice degeneration of the peripheral retina: ultrastructural study].

The ultrastructural study of a case of snail track degeneration shows the presence of lipid inclusions in both the glial and the macrophage cells in every layer of the retina, and the existence of intraretinal fibers different from collagen fibers appearing to be glial filaments similar to those found in astrocytic gliomes and to the Rosenthal fibers observed in senile nervous cells. Other features were thinning of the retina and absence of blood vessels in the retina. There are no abnormalities of the vitreo-retinal juncture. All the lesions are in agreement with those observed by Daicker [Ophthalmologica, Basel 165: 360-365, 1972; Klin. Mbl. Augenheilk. 172: 581-583, 1978] with some differences, however. They are different from those found in lattice degeneration. They show that snail track degeneration is a specific form of peripheral retinal degeneration which is quite different from lattice degeneration and must not be considered similar.

Choroid Neoplasms↗
PubMed1985

[Changes in perimetric defects in chronic open-angle glaucoma studied by automated perimetry (Octopus)].

The Octopus automatic perimeter was used to determine changes in visual field of 90 patients with chronic open angle glaucoma. Mean sensitivity value calculated from 62 of the 73 points of the apparatus program 33 - after elimination of those 11 points corresponding to Mariottes's zone and the central 10 degrees - provides an effective paracentral visual field monitoring numerical parameter. The authors named the parameter "global value". Statistical analysis of "global value" variations between two successive examinations showed: significant improvement between the first and the second tests; disappearance of the phenomenon between two further successive tests. The reasons for this pseudo-improvement remain unclear: perhaps the patients experience gained from the precious tests plays a part in the phenomenon. This should in any case be taken into account when assessing possible aggravation between two tests. Analysis of results suggests that, as a standard evaluation method, any "global value" degradation of the order of 1 db between the first two tests and 3 db between two successive tests performed after the second one is significant of a visual field degradation with a 1% range of error.

Analysis of Variance↗
PubMed1985

[Significance of electrocochleography within the scope of audiologic diagnosis].

Despite the extensive applicability of brainstem evoked response audiometry (= BERA), electrocochleography (= ECochG) occupies an undisputed place among audiological diagnostic methods. It is useful, among other things, in the early identification or confirmation of hearing defects in children, since it permits measurement of the auditory threshold and of the characteristics of the suprathreshold area, and may aid in excluding ambiguous findings resulting from subjective audiometric or other objective audiometric methods in certain cases. In this regard, it makes possible a valid early prescription of hearing aids to children with auditory defects; in addition, in certain cases it provides valuable additional information and can be employed in solving simulation and masking problems. The diagnostic validity of ECochG in Menière's disease requires continued investigation. To sum up, we can say that ECochG should be performed only at centres where the frequency of examinations guarantees the necessary expert knowledge.

Audiometry↗
PubMed1984

Optic nerve head drusen. High-resolution computed tomographic approach.

Optic nerve head drusen are rare, inherited concretions, which are almost always calcified; their appearance must be known because they represent one of the major causes of pseudopapilledema. The computed tomographic (CT) scan can show small and buried drusen, which are sometimes difficult to diagnose by the ophthalmoscopic examination. Four cases of drusen (two bilateral and two unilateral) were confirmed or diagnosed by high-resolution CT. The CT appearance of drusen is characteristic because the calcifications are well defined, punctate, and strictly located in the optic disc. The use of high-resolution CT scanners is very helpful.

Adult↗
PubMed1984

Retinitis pigmentosa associated with astrocytic hamartomas of the optic disc.

A case of retinitis pigmentosa associated with astrocytic hamartomas of the optic disc is described. The rarity of tuberous sclerosis in this association is discussed, as well as differences between optic nerve head drusen and astrocytic hamartomas ('giant drusen') which can both be associated with retinitis pigmentosa.

Adolescent↗
PubMed1984

[Hemorrhage in the vitreous and retinal venous loop in a diabetic subject].

A vitrectomy was performed in a diabetic patient because of unilateral vitreous hemorrhage, which persisted for six months. There was only background retinopathy in the other eye. In the operated eye, no proliferative retinopathy was found. During surgery a partial posterior vitreous detachment was noted with persistent vitreoretinal attachment to the superotemporal vascular arcade. Postoperative fundus examination and fluorescein angiography showed background retinopathy and the presence of a venous loop involving the superotemporal vein. Histologic description of venous loops with vitreoretinal adhesion was recently reported and it was suggested that this could lead to vitreous hemorrhage even in absence of severe proliferative retinopathy. To our knowledge, there is no previous report of diabetic vitreous hemorrhage probably due to a venous loop with vitreoretinal attachment.

Adult↗