ABSTRACTS

179

glucose-6-phosphate, fructose-6-phosphate, fructose-l, 6diphosphate, dihydroxy-acetone-phosphate, pyruvic acid, lactate and urea in the aqueous were investigated. Distinct differences could be observed 3 hr after carotid ligation. The possible causes of these changes are discussed.

Cornea1 Thickness and Intraocular Pressure N. EHLERS.

Arhus

In Reveral groups of non-glaucomatous patients a positive statistical correlation was found between central cornea1 thickness and intraocular pressure. Normal cornea1 thickness was found in glaucoma simplex, a thick cornea was found in ocular hypertension and a thin cornea in low tension glaucoma. On the assumption that the cornea1 thickness influences the measured value of the IOP, as emphasized in the original papers of Goldmann on applanation tonometry, the correlation between cornea1 thickness and the pressures measured manometrically and by applanation tonometry was studied in rabbits and in humans. The findings of these are studies presented.

Hexokinase Activity and Cornea1 Nutrition M. REIM,

K. GROIMU

AND

M.

KUHR,

Aache?l

The Michaelis constant of this enzyme for glucose was found to be 3.4kO.4 x 10-5~ (n = 7) for rabbit and l.ljO.1 x lO-%f for bovine cornea1 epit,helium. The optimum concentration of ATP was 1.8 X lop3M. These results indicate that the cornea1 epithelial cells do not suffer from glucose deficiency so long as the level in the stroma, which is the main source of supply, does not fall below 1 x LO-%. However, ATP levels are required which can ueually be maintained only by oxidative metabolism in the intact epithelial cells.

Endocrine Influences on the Refraction of the Eyes of Young Rats C. C. KOK-VAN

ALPHEN

AND

E. L. NOACH,

Leiden

Ambinon can alter the refraction of rats’ eyes in a dose-dependent manner and in hypophysectomized rats this occurs at doses which have no clear influence on the body weight or the tail length. The alteration in the refractive power was not due to changes in the axis of the eye or in the weight of the lens, measured by adjusting methods. Further investigation will show whether the optical properties of the refract,ive media can alter under the influence of Ambinon.

Permeability of the Isolated Bovine Lens Capsule for Environmental Chemicals R. lSMIaIL,

0.

HOCKWIN,

E‘. KORTE

AND

W. KLEIN,

Bonn

and Munich

Recent studies have indicated that environmental chemicals may also be responsible for lens opacities. To exclude a possible injury of the lens we first examined the permeability of isolated bovine lens capsules for different environmental chemicals. Chemicals such as trichlorethylene, 3, 4ehloroaniline. 3,4-dichloroaniline, trichlorophenol, Buturon, Monolinuron. Sencor, Tribunil. Aldrin and Toxaphen were tested. The permeability of such components in relation to their chlor-substitution or their solubilitp is deescribed. Experiments on the effect of environmental chemicals on the carbohydrate and protein metabolisms in vitro will give some preliminary indication of biochemical changes in lens metabolism.

Experimental Cataracts Induced by a Tryptopban-free Diet C. OHRLOFF,

C. STOFFEL,

H-R.

KOCH,

U. WEFERS,

J. Bouns

AND

The localization of a lens opacity often gives some indication inducing the cataract. Opacities of the posterior pole, always

0. HOCKWIN, as to the factor orcurring after

Bonw responsible for a long latency