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Biomedical subjects

F Daxecker

Publications and source records attributed to F Daxecker.

At least 55 records · Page 3Linked to original sources
PubMed1987

On the threshold radiant exposure for keratitis solaris.

Marked inflammation of the cornea (keratitis solaris) is often observed after exposure to strong solar radiation, especially in high altitudes and snow-covered terrain. Using the action spectrum and the solar spectrum, the radiant exposure causing keratitis solaris was calculated for a horizontal surface. The parameters selected were altitude, season, ozone content and albedo. The radiant exposure of the eye increases approximately 16-fold, comparing terrain without snow-cover and terrain with snow-cover. Radiant exposures in clinically observed cases of keratitis solaris were calculated to range from 1200 to 5600 Jm-2. A discussion on these figures with regard to threshold doses shows a significant difference between long-term exposure to solar radiation and short-term exposure to artificial sources.

Humans↗
PubMed1986

[Sympathetic ophthalmia following interventions for hemorrhagic glaucoma].

A case of sympathetic uveitis which developed after several operations to reduce intraocular pressure is reported. Initially there was a thrombosis of the central vein; secondary glaucoma developed after laser coagulation and iridectomy; six operations followed. Some months later the diagnosis of sympathetic uveitis was established. The pathogenesis of sympathetic uveitis in this case is discussed.

Adult↗
PubMed1986

[Surgical treatment of traumatic amaurosis].

Exploration of the optic canal was performed in 5 patients with traumatic amaurosis. Fractures of the optical canal were found in 4 cases. One case in which the canal was intact was interpreted as evulsion of the optic nerve. Vision improved in one of the cases with a fractured optical canal. Exploration of the optic nerve is recommended in cases of traumatic amaurosis, always provided that the indication is correct.

Adolescent↗
PubMed1985

[Calculation of radiation dose in changes in solar UV-B radiation with regard to keratitis photoelectrica].

With the help of the keratitis action spectrum and the solar spectrum for various elevations, the intensity of solar radiation that produces keratitis is calculated depending on altitude for terrain with and without snow cover. There is a 17-fold increase in midday solar intensity from winter to summer. In summer the intensity increases by 16% for every 1000 meters of altitude. For a subject observing snow-covered terrain, the intensity is 16 times greater than when the same terrain is observed without snow cover. For clinically observed cases of photoelectric keratitis caused by solar radiation it is possible to calculate the doses involved. They range between 1200 J/m2 and 5600 J/m2. These values are discussed in terms of a threshold dose, and it is concluded that this threshold dose is much higher than in the case of short-term irradiation such as occurs during welding. The difference between these two threshold doses is presumably explained by a repair mechanism.

Altitude↗
PubMed1985

[Complications in the implantation of posterior chamber lenses].

Over a period of three years 706 posterior chamber lenses were implanted. The following complications occurred during the operation and the postoperative period. In 19 cases the posterior capsule ruptured and iris-supported lenses were therefore implanted (instead of posterior chamber lenses). In 9 cases where lenses without angled loops were used an iris capture phenomenon was seen. Lenses with angled loops were used in almost all of the authors' cases. Severe intraocular infections occurred in 4 eyes. The authors established that postoperative astigmatism was generally higher than after intracapsular operations. No cases of retinal detachment have been observed to date. Fibrosis of the posterior capsule were treated with a Neodymium-YAG laser.

Aged↗
PubMed1985

Connective tissue changes associated with inferior epiblepharon, epicanthus, and keratoconus.

A 34-year-old woman with bilateral inferior epiblepharon, epicanthus, and keratoconus is presented. Biopsies of right upper arm skin, left lower eyelid, and left cornea were sectioned and examined by electron and indirect immunofluorescent microscopy. Pathologic changes in both the skin and cornea were observed. Indirect immunofluorescent techniques showed an increase in fibronectin and procollagen type I in the subcutaneous tissue of the skin and an increase of procollagen type I in the deep dermis of the right upper arm skin and left lower eyelid. Increased amounts of laminin in the basal epithelium of the cornea and of collagen type III in the stroma and subepithelial components of the stroma were observed. Electron microscopy disclosed disordered arrays of collagen fibers in the right upper arm skin and left lower eyelid, and typical changes of keratoconus, with scars in the cornea. Both the cornea and skin had thin fibrillar extensions between collagen fibers.

Adult↗
PubMed1984

[Vitamin A level and dark adaptation in patients with tumors].

Twenty patients with tumors of the head and neck region were found to have delayed dark adaptation. The serum vitamin A levels in these patients were significantly diminished in comparison with normal controls. Since disturbance of dark adaptation does not occur without prolonged vitamin A deficiency, it was reasonable to assume that the deficiency had been in existence for a long time. The antineoplastic effect of vitamin A is considered an important factor in tumor development and growth. Long-term malnutrition may be the reason for the disturbed vitamin A metabolism. Patients who do not attain mesopic vision should be advised against driving at night.

Adenocarcinoma↗
PubMed1984

[A new formula for determining the refractive power of intraocular lenses].

New, simplified formulas for calculating the refractive power of intraocular lenses are presented. These formulas were derived by mathematical methods. With the aid of these formulas it is possible to calculate an emmetropizing lens, residual refraction and desired postoperative refraction. The error in other formulas used for eyes with short axial lengths can be avoided with this new formula, due to its linearity.

Humans↗
PubMed1983

[A graphic method for determining the refractive power of intraocular lenses].

A nomogram has been developed for determining the refractive power of emmetropic intraocular lenses. Individual deviations of optical dimensions from mean values, such as axis length, anterior chamber depth and corneal curvature are used to find a graphical solution. Errors of measurement of optical dimensions are analyzed with regard to their influence on the refractive power of an intraocular lens; errors in measuring the length of the axis have the greatest influence. The nomogram represents a simple method of determining the refractive power of an emmetropic lens. Furthermore, residual refraction can be determined if an intraocular lens of a given power is used or if postoperative ametropia is desired.

Eye↗
PubMed1983

[Dark adaptation of patients with head and neck tumors].

20 patients with tumors of the head and neck region have a delayed dark adaption. The serum vitamin A levels in these patients are significantly diminished versus controls. Since disturbance of dark adaption does not occur before long during deficiency of vitamin A, it is assumed that the deficiency was existent long time before. With regard to the possible antineoplastic potency of vitamin A, this is considered a possibly important factor in tumor development and growth. The disturbed vitamin A metabolism is possibly due to a long lasting imbalanced diet.

Adenocarcinoma↗