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Biomedical subjects

I Kreissig

Publications and source records attributed to I Kreissig.

At least 19 recordsLinked to original sources
PubMed1995

Indocyanine green angiographically well-defined choroidal neovascularization: angiographic patterns obtained using the scanning laser ophthalmoscope.

Several studies have shown that indocyanine green (ICG) angiography improves the detection of occult choroidal neovascularization (CNV). However, uncertainty remains about the angiographic patterns of CNV in ICG angiography. We examined the ICG angiographic findings of 104 patients (average age, 72.4 years) with newly diagnosed neovascular age-related macular degeneration and well-defined CNV in ICG angiography using the scanning laser ophthalmoscope. CNVs were grouped into one of three categories according to their appearance on biomicroscopy and fluorescein angiography: I, early CNV measuring less than half a disc diameter in size (7 eyes); II-1, advanced nonhemorrhagic CNV (44 eyes); II-2, advanced hemorrhagic CNV (29 eyes); and III, fibrovascular CNV (24 eyes). Of the 104 CNV, 36 demonstrated well-defined CNV and 68 ill-defined or occult CNV in fluorescein angiography. CNV in patients suffering from advanced nonhemorrhagic CNV (group II-1) demonstrated a thick, branching, early hyperfluorescent vascular pattern (27 of 44 eyes). In group III, CNV was depicted as thin, slightly branching vascular structures (16 of 24 eyes). In group I, dye leakage was found in all affected eyes, and in group II-2 it was present in 20 of 29 eyes. However, dye exudation was rare in group II-1 and group III. Feeder vessels were detected in 16 of 104 eyes. The structure and permeability of CNV can vary substantially in ICG angiography, depending on the stage of development or regression.

Aged↗
PubMed1992

[Metastatic eyelid tumors--description of clinical aspects and histology based on three cases].

Clinical findings and histology of secondary lid tumors are described by example of three cases. The rare lid metastases appear mainly in three different patterns. Except cytology, which depends on the primary tumor, their morphology is quite uniform. Lid metastases of a cutaneous melanoma, a contralateral uveal melanoma and, probably reported for the second time, a leiomyosarcoma are presented.

Adult↗
PubMed1992

Minimized surgery for retinal detachments with segmental buckling and nondrainage. An 11-year follow-up.

A prospective study was conducted of 107 retinal detachments operated on between August 1979 and January 1980, with a complete follow-up period ranging from 11 years to 11.5 years. Proliferative vitreoretinopathy (PVR) stage C1 or C2 was seen in 16 detachments. Surgery consisted of cryopexy and segmental buckling (limited to the area of breaks) with nondrainage. Of the surgical procedures, 71% were radial buckles, 19% circumferential, and 10% radial combined with circumferential buckles. The primary reattachment rate was 92.6%, and 97% after reoperation. During the long-term follow-up period, redetachment occurred in 12.1% of the eyes: 5.6% were classified as early redetachments (between 2 and 4 months), and 6.5% as late redetachments (between 3 and 7 years). Early redetachment was caused by PVR, and late redetachment by new holes. After reoperation, reattachment occurred in 92.6% of the eyes. The predominant cause of final failure was PVR (3.7%). Only one eye had two reoperations. There was a highly significant (P less than 0.001) improvement between preoperative visual function (mean 0.32) and postoperative visual function (mean 0.56) in all 99 reattached eyes during the follow-up period (Mann-Whitney U test).

Adolescent↗
PubMed1992

[Changes in the invasion front of uveal melanomas].

Central and peripheral cells of 12 uveal melanomas were compared by electron microscopy to determine whether infiltrating melanoma cells have special characteristics (e.g., loss of cell adherence, changes in the cytoskeleton, increase of cell organelles). No significant differences were found. The two theories of tumor invasion ("mechanical" and "locomotive" theory) and the light microscopical findings that occur in the invasion zone of uveal melanomas are discussed.

Choroid↗
PubMed1992

A colour-flicker analysis of visual function in patients with retinal detachment.

Patients with a history of retinal detachment were examined by the following tests: (1) setting of an isoluminant match between yellow and green constituent squares of a checkerboard and (2) measurement of the flicker fusion frequency for a contrast-reversal of this yellow-green pattern. The results suggest that the test may provide useful data for assessing the severity of any damage to a given part of the retina. The fusion frequencies range from over 10 Hz (normal) to about 2 Hz for a severely impaired retina. The data for the relative amounts of red and green light needed to achieve a match rarely show any abnormality; thus, a standard anomaloscope test or pseudoisochromatic plates would not detect these deficiencies.

Adult↗
PubMed1991

[Principles of treatment of detachment using minimal retinal surgery].

Minimization of detachment surgery became feasible by: (1) omitting drainage of subretinal fluid by using elastic plombages limited to the area of the break and (2) meticulous search for the retinal break(s). On this premise the extent of the operation is solely determined by the size of the break(s) and no longer by the extent of the detachment. There were conceived: (1) the cryosurgical detachment operation in treating detachments with several breaks by single sponges (radial buckles whenever possible) by being permanent plombages and (2) the balloon operation in treating detachments with a single break by using a temporary plombage. These operations, being extraocular, can be applied in more than 9 of 10 rhegmatogenous detachments and the retina will be reattached in more than 9 of 10 cases. -However, in the presence of a problematic break (giant tear, posterior hole) an intraocular operation by using expanding gases (SF6, Perfluorocarbons) is indicated: (3) the expanding gas operation and (4) the balloon-gas procedure. By using the balloon-gas procedure (reducing the number of gas injections for treating a giant tear to one injection by providing a sufficiently large gas plombage) and (5) the modified balloon-gas operation with a retrohyaloidal injection of gas instead, a decrease of vitreoretinal complications, otherwise the main cause of failure, seems apparent.

Cryosurgery↗
PubMed1990

A fiberoptic stylette for localizing the balloon buckle.

A third-generation balloon catheter that accepts a fiberoptic has been developed. The fiberoptic is inserted through the catheter to the center of the balloon when the balloon is in the area of the retinal break. Viewed with the ophthalmoscope light at dim to off, the balloon can be seen glowing through the wall of the eye. The position of the balloon can then be shifted until the glow is precisely under the retinal break.

Catheterization↗
PubMed1990

[The TV head ophthalmoscope for videodocumentation of fundus changes].

The present paper describes the TV head ophthalmoscope, a logical further development in indirect ophthalmoscopy. It comprises a modern indirect binocular head ophthalmoscope and a micro-CCD color camera. The instrument enables all structures on the fundus to be observed as far as the periphery. Objects seen dynamically include detached retina and vitreous membranes. Practical fields of application are retinal detachment surgery and for demonstration and training in indirect ophthalmoscopy.

Humans↗
PubMed1990

[The expanding gas operation after a 15-year use. Animal experiment studies, subsequent developments of the method and clinical results in the treatment of ablatio retinae].

The expanding-gas-operation, a detachment surgery consisting in an intraocular (i.o.) injection of an expanding gas such as SF6 (without drainage and without vitrectomy) in combination with cryo or laser, was described by Kreissig in 1979. The method was used in the treatment of tears problematic for tamponading by extraocular (e.o.) plombages (giant tear, hole in posterior pole, scattered groups of breaks). With the introduction of the perfluorocarbon gases (CF4, C2F6, C3F8, C4F10) by Lincoff and his group in the beginning of the eighties the use of the gas-operation was improved: the expansion of the new gases ranged from 1.9x to 5x and their i.o. duration, defined as half time volume, from 6 to 45 days. However, animal experiments confirmed that an expanding i.o. gas bubble induces a break-down of the blood aqueous barrier, an increase of protein, an infiltration of cells into the vitreous and a compression of vitreous membranes against the retina implying the threat of subsequent proliferative vitreoretinopathy (PVR). The expanding-gas-operation is contraindicated in a detachment with PVR stage C and D. In spite of a recent renaissance of the expanding-gas-operation by Dominguez and Hilton in the middle of the eighties, the issue is still valid: in the treatment of a detachment an e.o. plombage is better than an i.o. gas bubble; this is especially pertinent for uncomplicated retinal detachments representing the indication of choice for a temporary e.o. plombage without drainage, the balloon-operation. As a consequence, at present the expanding-gas-operation is only justified for problematic retinal tears.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Epidemiology, invasion and growth of non-iridic choroid melanomas and associated intraocular changes: histologic study of 223 eyes].

223 complete eyes enucleated because of a malignant uveal melanoma were studied histologically to evaluate patterns of growth and invasion and secondary intraocular changes. Eyes with primary iris melanomas or with a previous operation were excluded. The most important secondary changes are the retinal detachment usually responsible for the loss of visual function as well as the direct tumor invasion of the chamber angle and the rubeosis iridis, both able to cause a secondary glaucoma, which is often difficult to treat. The rubeosis iridis increased in frequency with increasing tumor prominence and was in no case combined with preretinal neovascularisations. The growth of malignant uveal melanomas may occur in three directions, i.e. outwards (through the outer envelope of the eye), inwards (towards the vitreous) or in the uveal plane. In any case intraocular borders manifesting different resistance against tumor invasion and thereby influencing prognosis of the disease have to be penetrated. Changes at the front of tumor invasion like loosening of the cellular union and transformation to a higher malignant cell type seem plausible but could not be demonstrated light-microscopically.

Adult↗
PubMed1989

Results of a temporary balloon buckle in the treatment of 500 retinal detachments and a comparison with pneumatic retinopexy.

Five hundred detachments with a single break or a group of breaks close together were treated with parabulbar balloon and cryopexy in Tübingen between November 1980 and September 1986. Follow-up ranged from six to 91 months. Primary attachment was achieved in 466 eyes (93%). Twelve (2.4%) redetached after the balloon was removed. After a second operation, 490 eyes (98%) were attached and after a third, 493 (99%) were attached. The results with the extraocular balloon were compared with results of a similar group of detachments treated with an intraocular gas bubble. The primary attachment rate with the expanding gas operation was 91%; 11% of these eyes redetached. Although the final attachment rate was 99%, the complications after gas were much more frequent and of serious consequence.

Adolescent↗
PubMed1989

[2 new possibilities for using balloon occlusion in relation to the indentation effect].

Two new applications of the balloon are described which exploit its variable indentation: in the first case, the volume is reduced by withdrawal of fluid; in the second it is increased by additional injection. In both cases the procedure consists in two steps performed in subconjunctival anesthesia. In the first case the balloon provides intraocular space prior to gas injection (giant tear detachment). In the first step the balloon is inserted into the parabulbar space. After one to two hours this results in a deep indentation of the globe. In the second step the balloon indentation is used to compensate for the rise in IOP induced by the gas injection. With this "balloongasprocedure", a kind of fluid-gas-exchange is performed by injecting 1.0 ml of an expanding perfluorocarbon gas without prior drainage or pars plana vitrectomy. In the second case, the balloon is used in cases of detachment to interrupt retinal circulation prior to occlusion of a recurrently hemorrhaging vessel using the laser. In the first step, the tear is tamponaded by the parabulbar balloon and with this, the artery crossing the horseshoe tear is attached as well. In the second step, by increasing the balloon volume, retinal circulation is interrupted prior to occlusion of the artery by laser with reduced risk of hemorrhage. In both applications of the balloon a relatively complex detachment operation is divided into two smaller principle of less risky procedures on the surgery in small steps.

Catheterization↗
PubMed1989

[10 years' experience with balloon procedures: skepticism at the beginning, further development of the method, practical references for the balloon technician].

The author discusses four fundamental aspects of the balloon procedure in which it contradicts conventional detachment surgery, but which are preconditions for accepting this procedure: (1) the balloon is unsecured by sutures, (2) disappearance of subretinal fluid is induced by a balloon being compressed in the parabulbar space, (3) the balloon implies a temporary tamponade of the break and (4) after the first week the break is secured only by thermally induced adhesions. New instruments for the balloon procedure are introduced: the balloon forceps, the Kombideller (a special indentor), and the Lincoff-Kreissig balloon, which is supplemented by a removable stylette and markings on the catheter. The guidelines for the balloon surgeon are described in detail and summarized in six rules.

Balloon Occlusion↗
PubMed1989

[Minimalizing surgery of retinal detachment].

The prerequisites for minimizing detachment surgery are (1) dispensing with drainage by using elastic plug materials limited to the area of the tear and (2) improved diagnostic methods for detecting retinal tears. Various procedures are being developed on this basis in which the extent of surgery is dictated by the size of the tear alone, and no longer by the extent of the detachment. These procedures include (1) the cryosurgical detachment operation for treating several tears with individual, permanent plugs and (2) the balloon operation for single-tear detachments, with a temporary plug; both are extraocular procedures. However, for retinal tears which are difficult to plug (giant tear, tear at the posterior pole), intraocular procedures are indicated, namely (3) surgery with expanding gases and (4) the balloon gas method, with intravitreal or retrohyaloid injection of the gas. If the gas injection is combined with a parabulbar balloon, the number of such injections can be reduced to one; the gas tamponade is nevertheless sufficiently large. With the modified balloon gas procedure with retrohyaloid gas injections the number of vitreous complications can be reduced. The procedures described can be used in more than nine out of ten cases of rhegmatogenous detachment. Postoperative results with this minimum detachment surgery are good: in more than nine out of ten cases the retina is reattached. The operation is a minor one, can always be performed under local anesthesia, and is of short duration, with a minimum of trauma and complications.

Humans↗
PubMed1989

Irradiation of choroidal melanomas before enucleation?

The eyes of 26 patients with choroidal melanomas were irradiated before enucleation at the University Eye Clinic in Tübingen. Preoperative external beam radiation therapy (PERT) was administered between July 1980 and July 1986. Follow-up ranged from 25 months to 8 years, 4 months with a mean follow-up of 53 months. The average diameter of the tumor base was 15 mm and the height 10 mm. Before enucleation vertical stationary electron beam irradiation (10-12 meV) was applied to the tumor-containing eye and the orbit. The dose was increased during the course of the study from 12 to 40 Gy. Enucleation was performed by a technique that cauterized the vasculature before severing it and avoided maneuvers that would cause changes in intraocular pressure. The patients were reexamined between August and November 1988. Nine (34.6%) had died of metastases of melanoma, six of them during the second postoperative year; one patient was alive with metastases. Subsequent death occurred in all patients who had melanomas of epithelioid cell type (3 of 3) and in no patients who had melanomas of spindle A cell type (0 of 3). In this small series PERT had no apparent beneficial effect on the patient's life expectancy.

Adult↗
PubMed1989

Panuveitis with positive serological tests for syphilis and Lyme disease.

The Treponema pallidum hemagglutination test and the fluorescent treponemal antigen absorption test are commonly considered highly specific serologic tests for syphilis. We describe a patient with panuveitis and a positive serologic result for syphilis; however, in the absence of clinical findings, additional tests for Lyme disease (borreliosis) were positive as well, although by Western blot test the diagnosis was tentative. The clinical appearance of the panuveitis was similar to that of syphilitic uveitis accompanied by pseudopigmentosa-like areas in the anterior retina. In the presence of uveitis with an otherwise unexplained positive serologic result for syphilis, the differential diagnosis of Lyme disease should be considered.

Diagnosis, Differential↗
PubMed1988

Retinoschisis associated with optic nerve pits.

Stereoscopic transparencies studied with magnification and projection suggest that the retinal elevation that communicates with optic pits is frequently a schisislike separation of the internal layers of retina. Thirteen of 15 eyes with optic pits and maculopathy fit the schisis pattern. Separation of the outer layers of the retina is a secondary phenomenon that starts in the macula.

Adult↗