Biomedical subjects

K Kubĕna

Publications and source records attributed to K Kubĕna.

At least 19 recordsLinked to original sources

PubMed2002

[Effect of TLT absorptive eyeglasses on progression of myopia in children].

The incidence of myopia is increasing worldwide. At the last VIIIth international conference on myopia held in June 2000 in Boston attention was aroused by the work of Quin et al. on the influence of noctural illumination in rooms where children slept on their subsequent development of myopia. Our working hypothesis presented in Hakone in 1996 presumes also a negative effect of light and heat which initiate the development of myopia but on eyes with an inborn disposition. We considered as a solution wearing spectacles with glass which allow to penetrate only visible light and absorb the other wavelengths. These glasses were supplied by Karel Kubĕna-TL Technologies. The authors followed up for four years two groups of children with progressive myopia. The progression of myopia during the first two years of the follow up was almost identical in the two groups: in the group with the absorption glasses 0.75 D/year and in the control group 0.77 D/year. After two years of wearing the absorption glasses the progression in the group with the absorption glasses was 0.34 D/year and in the control group 0.59 D/year.

Adolescent↗

PubMed1999

[Effect of infrared rays on the eye in progressive myopia].

In the submitted paper the authors pay attention to infrared radiation close to visible light is intensely absorbed by haemoglobin, melanin and xanthophyll whereby part of the radiation energy is transformed into heat. The authors present three series of experiments where they investigated by different methods changes in the vitreous body after exposure to light, infrared radiation or raised temperature. They assume that on the defocused eye with a myopic conus which developed as a result of an inborn inadequate closure of the optic cup the light can cause a rise of temperature in the vitreous body. This leads to metabolic changes characterized by increased activity of lysosomal enzymes causing loss of the spatial structure of hyaluronic acid and collagen biomolecules. Penetration of the altered vitreous fluid thought the conus can lead to degradation of the interstitial substances of the sclera. Suitable absorption glasses filtering infrared light close to visible light could reduce the hyperthermia of the vitreous body.

Humans↗

PubMed1999

[The optic nerve disk in myopic children with elevated intraocular pressure].

The optic nerve disc of short-sighted children with elevated intraocular pressure was investigated to achieve early assessment of glaucoma and to detect signs which differentiate changes in the disc caused by short-sightedness from changes caused by glaucoma. The authors examined 16 eyes of 8 short-sighted children with elevated intraocular pressure. In addition to the basic ophthalmological examination they made a digital analysis of the optic nerve disc incl. planimetric evaluation of the dimensions of the disc, excavation and the neuroretinal rim. In two patients despite the higher intraocular pressure the area of the rim was supraliminal. In three patients the narrower area of the neuroretinal rim increased the probability of glaucoma In two patients with anisometropia on the eye with greater myopia the intraocular pressure was higher and the neuroretinal rim narrower as compared with the other eye. In one patient the area of the rim was very narrow and the diagnosis of glaucoma was confirmed also by arcuate scotoma in the lower part of the visual field corresponding to the narrow rim on top.

Adolescent↗

PubMed1998

[Visual perceptions in ophthalmic migraine].

The number of patients with ophthalmic migraine is steadily increasing. The symptoms of their attacks are dominated by typical visual aura, followed by major or minor headache. The authors present the experience of three physicians who observed the symptoms on themselves. The first one has suffered from the disease already for fifty years, the second and third one 25 years each. In the discussion the authors deal with the differential diagnosis of the disease and its possible treatment.

Aged↗

PubMed1992

Scleroplasty in progressive myopia--selection of materials.

Scleroplastic surgery is known to encounter the pathogenetical agent when the progressive myopia develops. In the first part, the implemented surgical approaches as well as up-to-date surgical techniques are presented. The experimental part is reserved for the selection of material which is necessary to perform scleroplasties. Both the allogenic and xenogenic grafts have been studied for histocompatibility on 20 rabbits. Following materials were used: 2 types of collagenic sponge, native and deproteinated human sclera, modified dura mater as well as both the native and devitalized sclera from rabbits. The best results were obtained with allogenic sclera, deproteinated xenogenic sclera and collagenic sponge. The application of other materials is discussed.

Animals↗

PubMed1992

[Collagen architecture of sclerocorneal trabeculae in relation to age].

The authors investigated the collagen architecture of the sclerocorneal trabeculum in relation to age in eight eyes within the range from a premature infant to a 90-year-old man. All specimens were investigated using a scanning electron microscope of Jeol Co. The appearance of fibrils does not change substantially in relation to age, however, their pattern and distribution change. In a 10-year-old boy Schlemm's canal is wide, oval with thin trabecular plates and wide open spaces surrounding them. In the 90-year-old man the canal is open but the plates on its luminous side are thickened, wrinkled and compressed. On the albuminous side there is a compact wall of compressed collagen layers.

Adolescent↗

PubMed1990