Biomedical subjects

R Gockeln

Publications and source records attributed to R Gockeln.

8 recordsLinked to original sources

PubMed2006

[Intermittent ciliary block as a result of haemodialysis].

We report the case of a patient who experienced recurrent elevations of intraocular pressure during haemodialysis. We measured a rise in intraocular pressure of 10-12 mmHg after dialysis. The lens showed intumescence, and a ciliary block was detected by means of Orbscan II. Within 6 h findings had normalized. Changes in serum osmolarity due to haemodialysis may result in fluid shifts between different compartments. Decrease of serum osmolarity during dialysis may lead to lens swelling and thus cause a ciliary block. This may end with regression of the lens swelling.

Aged↗

PubMed2005

[Differentiation between pupillary and ciliary block by means of the Orbscan II in a patient with angle block glaucoma].

BACKGROUND: A ciliary block is the rarer cause of angle block glaucoma. In order to choose the appropriate therapy, however, it is crucial to make the correct diagnosis. We report on a patient who suffered from recurrent increases of intraocular pressure while having renal dialysis. In his case the use of the Orbscan II made the differentiation between a pupillary and a ciliary block easier. CASE REPORT: In addition to basic ophthalmological examinations we performed a topographic analysis using Orbscan II before and after renal dialysis. Since intraocular pressure rise during renal dialysis had been proven, iridotomies on both eyes and an iridectomy on the left one had been performed before the patient was referred to us. In spite of these open shunts we measured an increase of intraocular pressure values of 10 to 12 mmHg directly after renal dialysis had been completed. The anterior chamber became shallower both at its centre and the periphery, thus its volume diminished analogously. Measurements by the Orbscan II showed that the lens swelled up and was displaced anteriorly as well, so that a ciliary block mechanism had to be assumed. CONCLUSIONS: Since the Orbscan II is capable of collecting topometric data of the cornea, anterior chamber and also lens, it is helpful in differentiating a pupillary from a ciliary block in angle block glaucoma.

Aged↗

PubMed2001

[Autogenous bone transplants in repair of the traumatically damaged orbit. Functional and esthetic results in 42 cases].

BACKGROUND: Autogenous bone transplantation is a well established aspect of craniofacial traumatology. This study evaluated functional and esthetic success in repairing traumatically damaged orbits by autogenous bone transplantation. PATIENTS AND METHODS: We repaired 102 osseous orbital defects by autogenous bone transplantation, 98 by calvarium split graft and 4 by iliac crest transplant. Of 42 surgical patients 34 were followed up. RESULTS: Autogenous bone transplants have proven themselves for repair of traumatically damaged orbits. Calvarium split grafts are particularly suitable for this purpose. Good esthetic and functional results can usually be achieved with primary osseous defect repair. However, more protracted functional defects can often no longer be helped. CONCLUSION: Autogenous bone transplants can be broadly recommended for providing primary care.

Bone Transplantation↗

PubMed2001

[The Titmus Fly Test--evaluation of subjective depth perception with a simple finger pointing trial. Clinical study of 73 patients and probands].

BACKGROUND: Subjects with different binocular defects were tested for their stereoscopic achievement. The determination of the subjects limiting disparity (in seconds of arc) was not used to characterize their stereoscopic acuity, but the subjective depth perception as a simple clinical method. METHODS: 52 subjects with different binocular defects and 21 normosensoric volunteers were examined for their stereoscopic achievement. In our stereoscopic measurement we ask the subjects to indicate the subjective plane of the fly's wings manually by their own finger, or by a hand-held plastic card, or with the aid of a mechanic instrument. The results of the different methods were compared with each other. RESULTS: There were no differences between the results within the group of normosensoric subjects. The patients with reduced abilities exhibit significantly different results in depth perception when measured manually or by machinery. The subjective depth localization correlates well with the binocular defect and is independent of the used stereoscopic method. CONCLUSIONS: The basic finger test of the subjective level of the Fly's wings gives a quite reasonable approximation of local stereoscopic depth perception. In terms of practical investigation the finger test shows in convincing manner whether the individual stereoscopic ability is based on normal, subnormal or anomalous binocular interaction.

Adolescent↗

PubMed2000

Clinical applications of multifocal electroretinography.

The multifocal ERG using the m-sequence stimulation technique allows the derivation of 61 - 241 local ERG signals in a central visual field of about 60 degree diameter in a short time between 4 and 16 min. A recording in a light adapted state offers local information comparable to cone responses in the full-field ERG. Retinal functional losses due to regional disorders in outer retinal layers can be described in detail with this technique. In maculopathies decreased or absent central ERGs are found surrounded by normal ERG. The extent of the central lesion can be estimated. In diseases of the outer retina the pattern of distribution of multifocal ERG activity is similar to the the pattern of the visual field defect. In addition to decreased ERG amplitudes a delay of implicit time may be an important sign of pathology, i.e. the pronounced delay of implicit times in the periphery in retinitis pigmentosa and the implicit time delays in regions associated with retinal edema like CRVO and cystoid macula edema in intermediate uveitis. No simple correlation of the first order kernel multifocal ERG and field defects could be found in disorders of the ganglion cell layer. The multifocal ERG is therefore useful in the differential diagnosis of retinal and optic nerve diseases.

Diabetic Retinopathy↗

PubMed2000

Minimal invasive decompression of the orbit in Graves' orbitopathy.

BACKGROUND: Surgical decompresssion of the orbit may be considered as a suitable form of therapy if, as a result of the increased volume inside the orbit, there are motility disorders such as diplopia or a progressive decrease in visual acuity. In view of the fact that this operation will not cure the underlying disease, the treatment should be as mild as possible. METHODS: In five subjects with Graves' orbitopathy we managed to extend the volume of the intraconal orbit by microsurgical liposuction. We carried out a lateral canthotomy to approach the orbit behind the globe. After decompression of the soft tissue, the lateral palpebral ligaments were refixed. To assess the scale of the functional rehabilitation we compared preoperative parameters (visual acuity, Hertel's index, visual field, motility) with the postoperative results. RESULTS: In all cases we found a significant improvement of position and motility without signs of diplopia. There was a postoperative increase in the visual field and visual acuity was 0.4 and the protusion of the globe could be decreased by 3-6 mm (Hertel's index). Furthermore, the ocular hypertension we found preoperatively could no longer be detected after the operation. CONCLUSIONS: Microsurgical decompression of the soft tissue via an approach from behind the globe proved to be a very gentle alternative to conventional methods of orbital decompression because of the satisfying functional and esthetic rehabilitation in selected cases.

Adult↗

PubMed1997

[Measuring depth perception in stereoamblyopia by using a suprathreshold stimulus].

BACKGROUND: Stereotests based on random distribution pattern (global stereopsis) show disadvantages when giving larger disparation, because subjects with limited fusion-ability do not recognize them, while realistic shapes of objects (contour stereopsis) are usually fused. Because of this random dot tests can not always be utilized to verify subnormal stereo-ability. SUBJECTS AND METHODS: This paper describes a way of testing stereo-ability not by approaching stereo-angle-thresholds but by presenting supra-threshold stimuli and evaluating the emphasized subjective "elevation level" readings. With this method I examined normosensoric healthy subjects and compared them to subjects with different binocular defects. RESULTS AND CONCLUSIONS: The subjective sensations correlate well with the clinical impression of what those patients, known at the department for long periods, should be able to differentiate. There is no evidence that healthy people are fully competent while "cured" strabismus cases should be incompetent. Indeed a gradual decrease of stereo-ability is seen. We strive for a really simple finger test in terms of subjective depth perception as a quick halfprecise office check.

Adolescent↗

PubMed1996

[Effect of interpupillary distance on acuity of depth perception].

BACKGROUND: Until today it is not really known, what kind of influence the interpupillary distance (IPD) has on depth perception. Actual literature says that haploscopic separation of pictures is of disadvantage for subjects with small IPD. This study intended to verify the influence of IPD on stereopsis in order to get valid and comparable results when testing the depth perception of different subjects. SUBJECTS AND METHODS: We examined 58 normosensoric soldiers for their stereoscopic sensation while changing their individual IPD. By using flexible flat plates of glass, the subjects' IPD could be changed infinitely variable to fix depth perception in haploscopic stereotesting. RESULTS: The variety of the interpupillary distance (IPD) of different people has to be strictly differentiated from the intraindividual changes of interpupillary distance, which, by a change of convergence, lead to a change of depth perception. A decrease in intraindividual IPD reveals an increase of depth perception. This change of perception follows, in mathematical terms, the law of logarithm. In case of intraindividual change of IPD the size of objects is also influenced. CONCLUSIONS: Using conventional stereotests, the IPD of different subjects has negligible influence on the depth perception. Different results of depth perception obtained with the help of stereoscopic examination of normosensoric subjects probably correspond with an individual and egocentric dealing with the visual localization of distances (distance between objects, size of objects, depth of objects).

Adult↗