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Biomedical subjects

J T Planten

Publications and source records attributed to J T Planten.

18 recordsLinked to original sources
PubMed1981

Changes of refraction in the adult eye due to changing refractive indices of the layers of the lens.

If, in a diaphanous homogeneous medium with a given refractive index, areas with different refractive indices develop, a plane between these areas will become visible provided the difference between the local refractive indices suffices for reflection of light. Conversely, where such planes are observed, a difference between the refractive indices on either side may be assumed. Finally, change of the localization of the planes indicates alteration of the refractive indices. The above approach is applicable to slitlamp images of the lens.

Adult↗
PubMed1979

Pathologico-optic approach to cataract and lens.

From the weight of the lenses of patients with senile cataract, ultrasonic measurements of the eyes of patients with acute diabetic refractive changes, and calculations on the basis of Legrand's theoretical eye, it appears that the conclusion can be drawn that these refractive changes are due to alterations in the refractive indices of the lens.

Acute Disease↗
PubMed1978

Pathological-optic approach of cataract and lens.

By weighing cataractous lenses and by scanning lenses of patients with acute diabetes with an ultrasonic A scan, it is made probable that hypermetropization in those cases is to be atributed to alterations of the refractive index of the lens.

Acute Disease↗
PubMed1966

The second cause.

Explore the source record for details and available documents.

Abortion, Missed↗
PubMed1965

[The 2d cause].

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Adolescent↗
PubMedDate not supplied

Age and the lens--refraction and accommodation.

The increasing radius of the lens surfaces and the development of cortex and nucleus due to the differences in refractive indices, explain the physiological changes in refraction and accommodation which occur during life.

Accommodation, Ocular↗
PubMedDate not supplied

A non-metastatic remote effect of lung carcinoma.

A 37-year-old man, who had an oat cell carcinoma of the left lung, lost in a few months a substantial part of both visual fields, on account of a destructive retinal process. This syndrome is known in the literature as a visual paraneoplastic syndrome, which clinically shows the very rapid development of a pseudoretinitis pigmentosa sine pigmento. For most of the patients described the visual problem was the presenting symptom. In contrast with most other described cases, our patient responded very well to systemic tumor treatment and his ocular process also came to a standstill after some delay. The nature of the relationship between the primary tumor and the photoreceptor destruction is not yet clear in detail. An auto-immune process probably forms the basis of the syndrome, but hormonal activity of the tumor could not be excluded in all cases.

Adult↗