PubMed Health⌕ Search

Biomedical subjects

G Duncker

Publications and source records attributed to G Duncker.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Results of scanning electron microscopy following internal laser sclerostomy].

An experimental glaucoma-filtering procedure ab interno, laser sclerostomy, can be performed using the argon and Q-switched Nd:YAG laser. Compared with surgical techniques the advantages of laser sclerostomy are: minor trauma to the conjunctiva and no risk of infection. In this study 28 rabbit eyes were examined by histological techniques and by scanning electron microscopy 2 days or 4 months following laser sclerostomy. The internal fistular ostium as well as the scleral tunnel showed a relatively smooth margin. Two days after laser sclerostomy, endothelial cell damage was found in only a small area directly surrounding the internal ostium; 4 months later all of this damage was repaired.

Animals↗
PubMed1990

[Lens position following planned capsular sac fixation: results of 200 consecutively surgically treated phacoemulsifications].

A total of 200 phacoemulsifications with planned in-the-bag fixation of one piece PMMA posterior chamber lenses implanted consecutively by one surgeon were examined on postoperative days 3-7. Special attention was given to both position of the haptics and centering of the lens. No sodium hyaluronate or other viscoelastic materials were used in any of the operated eyes. After capsulorhexis and phacoemulsification inside the bag we were able to confirm in-the-bag fixation in 190 implants (95%). In 197 of the 200 patients centering of the IOL was excellent. The capsular rim of the circular capsulorhexis was preserved in all cases due to phacoemulsification within the capsular bag. This procedure meets the best conditions for a secure in-the-bag insertion of the posterior chamber lens. Expression of the lens nucleus after capsulorhexis or through the so-called letter-box technique leads to a remarkably lower percentage of proven bag-bag fixation of the haptics.

Cataract Extraction↗
PubMed1989

On the ocular distribution of cardiac glycosides in guinea pigs following acute administration.

Tritiated ouabain, digitoxin, and digoxin were given IV to anesthetized guinea pigs. The tritium content of the ocular tissues (cornea, iris, lens, vitreous body, retina, choroid, sclera, and optic nerve) was measured after 1 and 3 h and compared with the amount of tritium found in the brain and some peripheral organs. High levels of digitoxin were found in the brain and retina. Digoxin was detected in large quantities in the retina, but only small levels were found in brain tissue. Ouabain was nearly absent in the retina and cerebrum, whereas in most other ocular and peripheral tissues the three cardiac glycosides were present in comparable quantities. The IP injection of tritiated digoxin resulted in lower absolute tissue levels, but a pattern of distribution similar to that observed in anesthetized guinea pigs was found in conscious animals.

Animals↗
PubMed1989

[Laser sclerostomy: an alternative to current surgical filtering procedures. Experimental studies].

A new filtering procedure, laser sclerostomy, was performed in 12 rabbit eyes by combined application of an argon and a YAG laser. In 10 cases an open fistula connecting the anterior chamber and the subconjunctival space could be demonstrated histologically. As neither the conjunctiva nor the globe are incised "ab externo," the possibility of an intraoperative infection is excluded and the risk of postoperative scar formation is minimized. Consequently, laser sclerostomy promises a new approach to glaucoma control in human eyes, too.

Animals↗
PubMed1989

[Ocular outflow resistance and rate of secretion of aqueous humor following iridotomy and posterior capsulotomy with the Nd:YAG laser].

When the Nd:YAG laser is used for iridotomy and posterior capsulotomy an elevation in the intraocular pressure (IOP) is often found within the first few postoperative hours and in some cases for even 1-3 days. In 39 eyes the changes in postoperative intraocular pressure were noted and the preoperative as well as the postoperative outflow facility and aqueous secretion flow measured by oculopressiontonometry. The results demonstrated that in both iridotomy and posterior capsulotomy a reduction in the outflow facility caused the postoperative rise in IOP. Aqueous secretion flow did not increase. Most iridotomy patients had glaucoma and consequently reduced preoperative outflow facility. This determined the postoperative IOP elevation. In capsulotomy patients, no such correlation was evident, but the role of the laser energy applied seems to be more important according to our results.

Aqueous Humor↗
PubMed1989

[Retinotoxicity of intravitreous injection of cefmenoxime].

The semisynthetic third generation cephalosporin cefmenoxime was injected through the pars plana into the mid-vitreous in seven rabbit eyes. The drug dosage varied between 0.5 and 15 mg. Seven control eyes were injected only with 0.9% NaCl-solution. Electroretinography was performed before injection and 1 week post injection. The rabbits were anesthetized by intramuscular application of ketanine (Ketanest). Immediately after the second ERG the eyes were enucleated and prepared for both light and electron microscopy. Light microscopy showed only slight retinotoxic effects. Electron microscopy revealed beginning toxic necrosis of the outer segments of the photoreceptors following drug doses equal to or greater than 2 mg. Significant changes in the ERG were not noted in any of the treated eyes. The toxicity of cefmenoxime and other cephalosporins reported in the literature is discussed together with the clinical relevance of the findings.

Animals↗
PubMed1988

Modified temporary keratoprosthesis in the triple procedure: a new surgical technique.

We present a new surgical technique for use in the triple procedure. After trephining the cornea, we sutured a temporary keratoprosthesis made of silicone rubber into the corneal bed. The prosthesis provided a clear view with excellent depth of focus. By creating an artificial anterior chamber, the operative procedure resembled a normal extracapsular cataract extraction procedure. The keratoprosthesis made complete aspiration of all cortical material easier.

Cataract Extraction↗
PubMed1988

[Disorders of color perception in subtoxic and toxic digoxin and serum digoxin concentrations].

Using the Farnsworth-Munsell 100-hue test, investigations were carried out in 14 patients with subtoxic to toxic serum concentrations of digoxin (greater than 2.0 ng/ml) and 13 patients with subtoxic to toxic serum concentrations of digitoxin (greater than 30 ng/ml), in order to detect color vision deficiencies related to serum levels of digitalis. As compared to the control group (n = 24) the total error scores were significantly increased for both glycosides and all serum level ranges. No evidence was found indicating that digoxin and digitoxin influence color vision differently. The FM 100-hue test indicated definite improvements in the digoxin group within one day of discontinuing the glycosides, while the digitoxin group only started to normalize a week later. The results are discussed, taking the different pharmacokinetics of the two digitalis glycosides into account.

Aged↗
PubMed1987

[A new seromarker: an aid in the differential diagnosis of unclear scleral processes].

Ocular involvement occurs in 40% to 50% of patients with Wegener's granulomatosis. The frequent involvement of the eyes in Wegener's disease is largely based on the anatomical contiguity of the orbit and the upper airways. On the other hand, it is also attributable to an isolated ocular involvement in the form of a focal necrotizing vasculitis. In about 60% of patients suffering from Wegener's granulomatosis there are anticytoplasmic antibodies. There seems to be a correlation between the serum level of ACPA and disease activity. In 10 patients out of 12 with ocular vasculitis due to Wegener's granulomatosis positive ACPA titers were found.

Autoantibodies↗