[en] One of the factors important for the maintenance of eye lens transparence is its water content which is controlled by the active transport of Na⁺ and K⁺ in the lens epithelium. In early phases of ontogenesis the rat lens is highly sensitive to various cataractogenic impulses (e.g., selenium induced cataract). In the present study, the question was studied of whether the ion turn-over in the lens changes during ontogenesis. Experiments were done on Wister rats of age span from 1 prenatal day to 2 years. The uptake was measured of ⁸⁶Rb which in the lens is transported analogously to K⁺. The rats were decapitated and extracted lenses were incubated in a MEM medium supplemented with bovine fetal serum and ⁸⁶Rb. ⁸⁶Rb uptake was expressed as a ratio of ⁸⁶Rb concentration in lens water to its concentration in the medium at the beginning of incubation. The ⁸⁶Rb was found to differ substantially in different age groups. A rapid drop in the uptake of ⁸⁶Rb was found in the lens in the critical period of lens development when the lens grows intensively and displays the highest sensitivity to exogenous metabolic disturbances. The developmental changes in the uptake of ions by the lens can reflect changes in the synthesis of both enzymes and crystallines. (author)

[en] A new method is described of measuring ocular hydrodynamics using a short-time contact application of ²²NaCl to the corneal surface and following its subsequent clearance by means of external gamma counters. Clearance of ²²NaCl reflected the aqueous outflow by conventional and uveoscleral routes. Sodium diffusion into the ocular lens, vitreous body and retina did not significantly interfer with the rate of aqueous outflow. In the present study authors investigated the sodium corneal permeability and its diffusion into different compartments of the enucleated rabbit eyes. During the followed interval of 60. min. the corneal radioactivity decreased, activity in anterior chamber aqueous, sclera, iris, ciliary body and choroid achieved maximal values, in ocular lens, vitreous body and retina radioactivity steadily increased. After corneal deepithelization a fourfold increase of ²²NaCl transcorneal permeability was observed. (author)

[en] The possible applications are discussed of radionuclides in the diagnosis of eye and orbital tumors, in the determination of the cerebrovascular blood flow disturbances and in the scintigraphy of the lacrimal ducts. In view of the small size of the eye, special Geiger-Mueller tubes and semiconductor detectors, especially Li-drifted silicon detectors complete with microcollimators if required, are used for examinations. The choice of a suitable radiopharmaceutical containing a short-lived radionuclide is essential. Phosphorus 32, iodine(131)-diiodofluorescein, technetium(99m)-pertechnate and chloroquine iodinated with ¹³¹I are mainly used for tumor diagnosis. Technetium 99m in the form of pertechnate is mainly used for the study of the cerebrovascular blood flow and the lacrimal duct scintigraphy. Examinations using radionuclides has a number of advantages over contrast radiography. (Ha)

[en] It is shown that the use of ionizing radiation allows healing the conditions which are uncurable using other means. Beta radiation therapy is suitable for grave eye conditions in which eyesight is endangered. It is not recommended in cases when other methods are available. The application of local cobalt radiators is only indicated in neoplastic diseases endangering both the eyesight and the life of the patient. (Ha)

[en] Changes of corneal permeability for ²²Na caused by benzalkonium chloride (BAC) and the Czechoslovak detergent Jar were tested in vitro as well as in vivo. Experiments in vitro were performed on corneas of bovine eyes incubated at 37 degC. During a 10 min span the corneal surface was wetted with nine drops of aqueous solutions of BAC (0.001%, 0.01%, 0.1%, 1% and 10.0%, resp.) and Jar (0.01%, 0.1%, 1.0%, 10.0% and 100.0%, i.e., commercialy available compound, resp.). Changes of corneal permeability caused by detergents were demonstrated by an increaseJ uptake of ²²Na transferred from the paper strips stretched over the corneal surface. For the controls, saline was used instead of detergents. The corneal permeability for ²²Na increased with increasing detergent concentration. Significant changes of corneal permeability were caused by Jar diluted to 0.01%. Experiments in vivo were carried out on rabbits. Both detergents were tested in above mentioned concetrations using always two drops during a 1 min exposure. The eyes were observed for 6 days. Heavy keratitis with corneal edema, purulent conjunctival discharge and blepharitis was caused by 10% BAC and to a lesser degree also by 1% BAC or undiluted Jar. On the seventh day the permeability of the rabbit corneas was tested applying the paper strips soaked with ²²Na. After 30 min the rabbits were dissected and the radioactivity of the isolated tissues and aqueous has been evaluated. After the six days delay the functional changes of the epithelial barrier were still observable manifesting itself by changed permeability and ocular distribution of ²²Na. (author)

[en] Dynamic changes in corneal nerves caused by various types of radiation were studied in rabbits. The was irradiated using ophthalmic ⁹⁰Sr and ⁹⁰Y applicators and contact X-rays or from sources used for radiation therapy, i.e. X-rays (250 keV) and high energy gamma radiation (¹³⁷CS - 660 keV and ⁶⁰Co - 1.27 MeV). Dose distribution inside the eye was calculated or exposures used for local irradiation were measured in the target tissue by ionization chambers. After the contact application of beta radiation, incidence and intensity of changes were directly proportional to the amount of the absorbed dose. For a given value of the radiation dose the intensity increased with the time of latency. In high exposures the contact X-ray irradiation caused significant changes in the corneal stroma and disintegration of neural fibres. Results effected by high energy radiation are important for the study of the therapeutic application of ionizing radiation in medicine, occupational exposure of workers and exposure caused in extraordinary situations. The results of this study proved that changes in the corneal inervation caused by the above types of radiation are significant and sometimes irreversible. (author)

[en] In a 22-year old patient deep peripapillar drusen were observed accompanied by bilateral papillo-edemas and unilateral papillar and peripapillar haemorrhages and bilateral defects of the visual fields which in certain stages assumed the character of left-side hemianopia. The importance is evaluated of computer tomography in the diagnosis of deep peripapillar drusen and the following conclusions are arrived at: 1. computer tomography (CT) has an immense differential diagnosis significance in their quiescent stage; 2. in the acute stage accompanied by vascullar and perimetric symptoms, even though deep papillar drusen are accurately shown by CT, further examinations are required to exclude the possibility of simultaneous intracranial lesions. (author)

[en] The level is assessed of cellular autoreactivity against retinal antigens in patients with detachment of the retina. A test was selected which can record the first stage of the immunological response, i.e., the bond of sensitized lymphocytes with antigen (mixture of antigens in the form of crude extract), in this case with antigen from the human chorioretina. Two modifications of the test were used: the bond of ¹²⁵I-labelled extract from the human chorioretina with isolated lymphocytes, and the bond of the same extract with lymphocytes of whole blood. Using the first modification, a total of 17 patients with detachment of the retina and 17 controls were examined. Usxng the second modification, 15 patients with detachment of the retina and 15 controls were examined. From the results of the test ensued that lymphocytes of patients with detachment of the retina do not differ from lymphocytes of controls in the capacity to bind ¹²⁵I-labelled extract from the human chorioretina. The method is described in detail. (author)

[en] 53 cranial computed tomographic scans were performed and the contribution of this new radiographic method is emphasized to ophthalmologic diagnosis, especially to the differential diagnosis of proptoses and orbital lesions. Computerized tomography is a noninvasive method easily tolerated by patients. Rapid diagnosis and exclusion of pathological processes shorten. The duration of the hospital treatment of patients. (author)

[en] Rapid penetration was shown of radioactivity into the cornea, lens, eye bulb, and by axoplasma transport and by the blood stream into the optic nerve, the visual pathways and into the occipital lobe - the cortical part of the visual pathway. With the application of a corneal hydrophylic lens saturated with tritiated water the penetration of radioactive water into the CNS was rapid and did not exceed 5 minutes in the experimental animals. Attention is drawn to the danger of easy contamination with radioactive water and to the fact that the eye represents a significant entrance for the penetration of radioactivity into eye tissue and into the central nervous system. (author)