Cartridge cracks with different viscoelastic agents.
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Cataract Extraction↗
Biomedical subjects
D Eisenmann
Publications and source records attributed to D Eisenmann.
[Peak pulse blood volume and topical antiglaucoma drugs in rhesus monkeys with experimental open angle glaucoma].
BACKGROUND: The present study was designed to investigate the effect of topical antiglaucoma drugs on Peak Pulse Blood Volume (PPBV; German abbreviation: PGBV) in cynomolgus monkey eyes without (CMNG; German abbreviation: RA-KTL) and with lasersurgically induced glaucoma (CMG; German abbreviation: RA-LHDG). METHODS: CMG unilaterally received 2-3 laser treatments so as to develop the lasered-eye glaucoma model. Intraocular pressure (IOP; German abbreviation: IOD) and Ocular Pulse Amplitude were measured and PPBV was determined until the glaucoma model had stabilized. Consecutively topical antiglaucoma drugs (epinephrine, paraaminoclonidine, pilocarpine, timolol) were investigated in 4-8 animals in CMNG and CMG eyes. RESULTS: IOP and PPBV were not significantly altered in CMNG. In the CMG eyes epinephrine and paraaminoclonidine did not significantly alter IOP or PPBV, whereas pilocarpine and timolol sig. (p < 0.01) reduced IOP and significantly (p < 0.05) increased PPBV. CONCLUSION: With respect to improved PPBV in the CMG eye the rank order of drug effectiveness is timolol > pilocarpine > paraaminoclonidine > epinephrine.
Animals↗
[Contrast vision and contrast sensitivity after binocular implantation of multifocal or monofocal intraocular lenses].
BACKGROUND: Multifocal intraocular lenses show a reduction of contrast due to the simultaneous projection of different images to the retina. In this study we examined if there is also a loss of contrast in bilateral implantation of multifocal lenses. MATERIAL AND METHODS: We examined 22 patients with bilateral AMO ARRAY multifocal intraocular lens and compared these to 20 patients with bilateral monofocal intraocular lens. We performed a monocular and binocular examination of contrast acuify by means of Regan's contrast charts and contrast sensitivity by means of B-VAT-II-SG-Video-acuity-tester. RESULTS: Monocular examination of contrast acuity showed significant superiority of the monofocal intraocular lens at the lowest contrast. Bilateral examination of contrast acuity did not show any significant difference. Monocular contrast sensitivity of the monofocal intraocular lens was significantly superior to the multifocal intraocular lens at two spatial frequencies, but under the bilateral condition there was only a significant difference between the two lenses at the highest spatial frequency. CONCLUSIONS: Bilateral implantation of multifocal intraocular lenses enables contrast acuity and contrast sensitivity that comes very close to the performance of the monofocal intraocular lenses.
Aged↗
[Reflections on Nd:YAG capsulotomy in lens opacity after multifocal lens implantation].
BACKGROUND: Posterior capsule opacification (PCO) after implantation of a multifocal intraocular lens (MIOL) reduces the visual acuity (VAF) for the far, as well as for the near (VAN). There is no report on results and techniques for Nd:YAG capsulotomy in the presence of PCO after MIOL implantation. PATIENT AND METHODS: Therefore, 31 Nd:YAG capsulotomies in 29 patients with PCO after MIOL implantation were analysed concerning number of expositions, energy, MIOL-damage, results as well as complications after capsulotomy in order to derive individual laser strategies. RESULTS: Nd:YAG capsulotomy was performed after a mean of 14 (+/- 12.5) months. All capsulotomies resulted in a central opening of the posterior capsule. 42 (+/- 25.1) impulses in mean were necessary at a total energy of 71.7 (+/- 47.8) mJ. An average of 4 hits of the MIOL optic occurred and in 5 cases the MIOL remained undamaged. Three capsulotomies were difficult to perform. In eight cases, a dense PCO was present. All capsulotomies were performed without any immediate complication. In 93.6% VAF and in 96.8% VAN increased postoperatively, while in the remaining cases VA did not increase due to other reasons. In one case intraocular pressure increased after YAG laser treatment for a short period of time. In another case, a retinal detachment occurred 5 months postoperatively. No cystoid macular edema occurred until 6 months postoperatively. CONCLUSION: Nd:YAG capsulotomy in PCO after MIOL implantation is a relatively safe, non-invasive method to improve visual acuity. After capsulotomy, the optically effective area of the MIOL mainly depends on the diameter of the pupil, the anterior and posterior capsular opening. Therefore, the opening of the posterior capsule should depend on the individual MIOL design and should include the main MIOL portion for the far and near focus. This allows the patient an unaided profit from the multifocality of the IOL postoperatively.
Aged↗
A new method for direct detection of heparin on surface-modified intraocular lenses. A modification of Jaques' toluidine blue staining method.
BACKGROUND: Examination of surface-bound heparin on synthetic polymers can only be performed by few staining methods. These methods are limited by an only approximate detection of heparin visible at high magnification. Other methods only measure heparin quantitatively (per square dimension) and are rather sensitive to artifacts. Due to its homogeneous staining pattern, the modified toluidine blue staining technique, using a non-protein-based substance, allows examination and analysis of the homogeneity of the monomolecular heparin layer even under critical conditions like scanning electron microscopy. MATERIALS AND METHODS: For critical examination of the heparin layer, this method was used for 5 sterile heparin surface-modified (HSM) monofocal (Pharmacia, 809C, 5 mm optical zone), 2 multifocal PMMA (Pharmacia, 811E, 6 mm optical zone) and 1 standard PMMA intraocular lenses (IOLs; Pharmacia, 809P, 5 mm optical zone). A special mixture containing a sodium borate buffer was used to avoid cross-reactions of toluidine with phenylimines, which permit a covalent surface linkage of heparin to synthetic polymeric materials via reductive amination. This resulted in less coarse-grained complex agglutination. After light and spectral microscopy of the surface of stained IOLs, scanning electron microscopy was performed to investigated the reliability and validity of this modified staining method. RESULTS: All HSM IOLs showed a homogeneous heparin structure and coating, which could be demonstrated even under critical photographic circumstances. CONCLUSIONS: The modification of the original toluidine blue staining method introduced by Jaques in 1943 is a reliable and reproducible technique for the detailed in vitro analysis of surface-bound heparin with a low artifact rate. Because of the detailed detection of heparin on polymeric surfaces, this staining method is recommended for special problems, e.g. in cataract surgery.
Coloring Agents↗
[Glare sensitivity of phakic and pseudophakic eyes].
BACKGROUND: Glare disability and appearance of halos may be side-effects of cataract, but were also described in patients with multifocal IOLs. The aim of this study was to compare glare sensitivity and halo size in phakic and pseudophakic eyes. PATIENTS AND METHODS: Contrast sensitivity without and with glare and halos around a light source were measured by means of a new computerized test in patients with cataract, monofocal IOLs, multizonal progressive and diffractive multifocal IOLs as well as in a younger control group of subjects with clear lenses. Glare acuity was measured at three different luminance settings. RESULTS: Patients with cataract showed the most important reduction in contrast sensitivity, noticed significantly larger halos and were more impaired in glare acuity than patients with monofocal or multizonal progressive IOLs. There was no significant difference in any criteria between these two pseudophakic groups. Subjects with a clear cristalline lens had statistically significant better results compared with all other groups. CONCLUSION: An increase in glare sensitivity and the appearance of halos are more important in patients with even minor cataracts than in any pseudophakic population. As a consequence of this study, night driving ability should be carefully examined in any pseudophakic patient, but also in any subject with even beginning cataract.
Adult↗
[The "Array" silicone multi-focal lens: experiences after 150 implantations].
BACKGROUND: The Array-MIOL offers the advantage of an increased depth of focus; the aim of our study was to compare other functional results with those of a monofocal IOL. METHODS: Uncorrected and corrected distance and near visual acuity were measured in the early postoperative period and after 3 months. Results of contrast acuity (Regan charts) and contrast sensitivity (BVAT II-SG video acuity tester) of the Array-MIOL and a monofocal IOL were compared at the 3-months follow-up. RESULTS: Distance visual acuity of the multifocal group did not differ from the monofocal results; uncorrected and distance corrected near acuity were significantly superior in Array patients. The monofocal IOL showed a superior contrast acuity only at the 11% level and a superior contrast sensitivity only at one spatial frequency (20 cpd). Bilateral implantation of the Array-MIOL seems to further improve functional results. CONCLUSION: Implantation of the Array silicone multifocal IOL offers the advantage of pseudoaccommodation without relevant impairment of other visual functions.
Aged↗
[Resources on the Internet in Ophthalmology].
BACKGROUND: In the age of information, the Internet became a powerful, fast and international information resource. The ease with which individuals can access the Internet and with which institutions can make information available explains its exponential growth in the past few years. It is our purpose to provide ophthalmologists with new opportunities and to explore the potential and different functions for the information superhighway with a focus on information resources available to the ophthalmologist like the World Wide Web. RESULTS: By using the computer programme Netscape one can send or obtain reports or images, consult colleagues, perform a literature search, take part in an ophthalmological congress or discussion- and newsgroup, get information about past and ongoing ophthalmological events or, moreover, achieve product and company information. CONCLUSIONS: The Internet transformed the way we view and use information by a dramatic expansion of the ways ophthalmologists interact with their colleagues. Thereby, the use of the Internet and its vast resources will greatly improve the quality of patient care.
Computer Communication Networks↗
[Objective determination of refractive changes in silicon oil filled eyes--effect of head position on refraction].
BACKGROUND: The refraction of the eye is altered significantly after silicone oil instillation into the vitreous cavity due to its high refractive index. The degree of the refractive change varies during the daily course and depends on the position of the head. PATIENTS AND METHODS: To analyze the degree and time course of the refractive change depending on the head position we performed refractive measurements in 5 aphakic and 5 phakic silicone oil-filled eyes with attached macula by an automatic handrefractometer. This new device was used for 25 measurements at short intervals in each patient at different eye positions (supine position, prone position and primary eye position). RESULTS: Mean visual acuity in all patients valued 0.14 (+/- 0.05). The highest shift in refraction of +5.95 (+/- 2.63) dpt in spherical equivalents occurred in the aphakic eyes and of +2.45 (+/- 0.71) dpt in the phakic eyes after position change from face up to face down. Three minutes after position change the refraction remained stable in nearly all eyes. Only slight changes in cylinder and corresponding axis were found during the measurements with a mean axial shift of 10.1 (+/- 5.1) degrees. CONCLUSION: Immediately after change of the head position especially aphakic eyes demonstrated remarkable refractive shifts. The results of this study explain patients' complaint of visual changes during the daily course after intraocular silicone oil injection. Refractive alterations evoked by silicone oil stabilized a few minutes after change of the head position.
Adult↗
[Computer-assisted multimedia interactive learning program "Primary Open-Angle Glaucoma"].
INTRODUCTION: Advances in the area of information technology have opened up new possibilities for the use of interactive media in the training of medical students. Classical instructional technologies, such as video, slides, audio cassettes and computer programs with a textbook orientation, have been merged into one multimedia computer system. The medical profession has been increasingly integrating computer-based applications which can be used, for example, for record keeping within a medical practice. The goal of this development is to provide access to all modes of information storage and retrieval as well as documentation and training systems within a specific context. MATERIAL AND METHODS: Since the beginning of the winter semester 1995, the Department of Ophthalmology in Giessen has used the learning program "Primary Open Angle Glaucoma" in student instruction. One factor that contributed to the implementation of this project was that actual training using patients within the clinic is difficult to conduct. Media-supported training that can provide a simulation of actual practice offers a suitable substitute. The learning program has been installed on Power PCs (Apple MacIntosh), which make up the technical foundation of our system. The program was developed using Hypercard software, which provides userfriendly graphical work environment. This controls the input and retrieval of data, direct editing of documents, immediate simulation, the creation of on-screen documents and the integration of slides that have been scanned in as well as QuickTime films. All of this can be accomplished without any special knowledge of programming language or operating systems on the part of the user. RESULTS: The glaucoma learning program is structured along the lines of anatomy, including an explanation of the circulation of the aqueous humor, pathology, clinical symptoms and findings, diagnosis and treatment. This structure along with the possibility for creating a list of personal files for the user with a collection of illustrations and text allows for quick access to learning content. The program is designed in such a way that working with and through it is done in a manner conducive to learning. Student response to the learning program as an accompaniment to instruction has been positive. CONCLUSION: Independent, supplemental student learning by means of an interactive learning program has raised the quality of study within the sciences. The use of a pedagogically sound multimedia program, that is oriented toward problem solving and based on actual cases offers students the opportunity to actively work ophthalmological material. An additional benefit is the development of competence in working with computer-support information systems, something that is playing an ever-increasing role within the medical profession.
Computer-Assisted Instruction↗
[Digital exchange of clinical findings and letters using an international network. Applications of information systems in ophthalmology].
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Computer Communication Networks↗
[Effect of diffractive multi-focal lenses on contrast vision, glare sensitivity and color vision].
BACKGROUND: Due to theoretical considerations an increase in the depth of field of the diffractive IOL may be combined with a reduction in contrast sensitivity, glare sensitivity and colour perception. PATIENTS AND METHODS: A comparative analysis of both eyes was performed in ten patients with a diffractive multifocal IOL (3M 815LE) in one eye and a monofocal IOL in the other eye. Contrast sensitivity was examined by computer generated sine wave gratings of 6 different spatial frequencies; visual acuity with glare and glare sensitivity were determined under 7 different levels of field luminance; colour vision was examined using the Farnsworth-Munsell-100-Hue-test. RESULTS: Contrast sensitivity of the diffractive lens was reduced for intermediate spatial frequencies, but not for low and high frequencies. Visual acuity with glare was only reduced at maximum field luminance; no differences were found in glare sensitivity and colour perception between monofocal and multifocal. CONCLUSION: Altogether, the diffractive lens did not show a dramatic reduction in the examined visual functions compared with the monofocal IOL.
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[Theoretical and clinical image properties of refractive 3-zone multifocal lenses with different distribution of far and near focus].
BACKGROUND: The optic of common multifocal IOLs (MIOLs) is effecting an even light distribution to far and near focus. New MIOL designs were developed by Jacobi to improve distance or near contrast, by favouring the far or near focus with 60-70% of the light energy. For binocular implantation, an "asymmetrical" MIOL-combination is possible with accentuation of distance focus in one eye and near focus in the other eye. METHODS: By means of an optical system described by Jacobi and Reiner "artificial eyes" with the new MIOLs were implanted in 7 young healthy subjects and contrast sensitivity was measured for distance and near. Clinical implantation was performed in 46 patients and visual acuity, contrast sensitivity, depth of focus and binocular functions were determined after 6 months. RESULTS: MIOL designs with accentuation of distance vision did not show a significant reduction of distance contrast compared with a monofocal IOL. Asymmetrical binocular implantation of the new lenses resulted in a better distance and near contrast sensitivity than implantation of MIOLs with an even light distribution. Binocular functions were not impaired. CONCLUSION: Asymmetrical implantation of the new MIOLs with uneven light distribution to far and near focus enables distance vision comparable to monofocal IOLs, but with the advantage of an increased depth of focus.
Adult↗
[Mesoptic vision in multi- and monofocal pseudophakia and in phakic control eyes].
UNLABELLED: The mesopic visual acuity (MVA) after intraocular lens (IOL) implantation is reduced compared to phakic patients of the same age. However, previous studies from our clinic have shown no significant MVA difference between multi- and monofocal IOLs. In the present study (with the patients matched exactly for age), this topic was reevaluated. PATIENTS AND METHODS: We investigated three groups, each consisting of 28 persons, 51 to 60 years of age. Group I consisted of healthy phakic volunteers, group II of patients 3 months after cataract extraction and implantation of a monofocal posterior chamber IOL (Pharmacia 720A) and group III of patients 3 months after implantation of a diffractive multifocal posterior chamber IOL with biconvex optic configuration (3M 825X). The MVA was examined using the "Ocutrast," described by Nowak. The Ocutrast, a modification of the Mesoptometer II, provides a field luminance of 1 cd/m2 and a contrast of 1:23 between test optotype and background; the intensity of illumination under glare conditions amounts to 0.35 lx at the level of the pupil. RESULTS: The MVA without glare amounted to 0.50 +/- 0.12 (group I, healthy phakic eyes), 0.45 +/- 0.15 (group II, monofocal IOLs) and 0.32 +/- 0.11 (group III, multifocal IOLs). The MVA with glare amounted to 0.47 +/- 0.08 (group I), 0.35 +/- 0.12 (group II) and 0.24 +/- 0.10 (group III). Both for the MVA with and without glare there was a significant group difference (P < 0.05; two-factor analysis of covariance with repeated measurements). CONCLUSIONS: After implantation of diffractive multifocal IOLs of the presently used type (3M 825X), the mesopic vision--both with and without glare--is even more reduced than after monofocal IOL implantation. These findings are particularly relevant for aged pseudophakic car drivers, especially for driving at night.
Dark Adaptation↗
[Use of the Ellmann Surgitron in eyelid and plastic surgery].
BACKGROUND: The Ellman Surgitron is a new electrosurgical device with high frequencies (4 MHz) for special use in oculoplastic surgery. Four different operational functions are available: (1) cutting with minimal coagulation, (2) combined cutting and coagulation, (3) coagulation and (4) fulguration. METHODS: The Ellman Surgitron was used in plastic eyelid surgery (blepharoplasty of the upper lid) and in resection of tumors of the upper and lower lid. Histological sections of the excised tumours and skin were performed with special respect to the cut tissues. RESULTS: Blepharoplasty in the cutting mode was performed in nearly complete haemostasis. Histological sections of the excised skin documented better perpendicularity of the cut tissues after electrosurgery than after conventional surgery. Superficial or complete resection of small and larger tumours was performed in haemostasis of deep and superficial vessels. Perfect evaluation of histological sections of the cut tissue was possible after dissection in the cutting mode or the combined cutting and coagulation mode. Per primam postoperative wound healing was observed in all subjects. CONCLUSION: Use of the Ellman Surgitron decreases operating time and permits efficient tissue dissection, excellent haemostasis and perfect wound healing in oculoplastic surgery.
Basal Cell Carcinoma↗
[Asymmetric multizone lenses--a new concept in multifocal intraocular lenses].
BACKGROUND: Asymmetrical multifocal lenses (MIOLs) represent a new concept for binocular implantation of MIOLs: one asymmetrical IOL--destined for implantation in the dominant eye--is favouring distance vision by assuring that 60-70% of the light rays coming from an object will pass through the distance part of the optic. The other IOL--destined for implantation in the second eye--is favouring near vision, enabling that 60-70% of the light energy will be focused by the near zone(s) of the IOL. METHODS: Modulation transfer function (MTF), Strehl-Ratio (SR) and resolution efficiency (RE) were determined in both foci by in vitro measurement. Defocus curves were performed after clinical implantation as well as after "optical implantation" by means of an optical device developed by Reiner. RESULTS: In vitro measurements showed superior results of SR and RE in the favoured focus of the MIOL. Defocus curves after clinical and "optical" implantation yielded higher peaks for visual acuity and contrast in the favoured focus. CONCLUSION: First theoretical and clinical results do confirm the new concept of asymmetrical multifocal IOLs.
Contrast Sensitivity↗
[Multifocal intraocular lenses--an assessment of current status].
UNLABELLED: Besides the diffractive multifocals, which produce a second focus for near vision by means of diffraction rings, there are different refractive multifocal IOL types with 2-7 refractive zones or an aspheric/spherical construction principle. Long-term results: 2 years after implantation of diffractive multifocal IOLs, the corrected distance and near acuities were unchanged compared to the 3-month results. The uncorrected distance acuity was, however, slightly decreased due to a minus shift of refraction to -1.2 D. The contrast sensitivity was improved after 2 years. Multi- versus monofocal IOLs: After diffractive multifocal IOL implantation, the near acuity with distance correction only was markedly improved compared to monofocal IOLs. All other acuity data did not differ between multi- or monofocal lenses. The contrast sensitivity (at low contrasts and high spatial frequencies) and mesopic visual acuity (without and with glare) were reduced compared to monofocal pseudophakic eyes. Near aniseikonia and binocular functions: In unilateral multifocal pseudophakia (monofocal IOL in fellow eye), a near aniseikonia up to 8% was found. The width of fusion was significantly lower than in bilateral multifocal pseudophakia, whereas the stereopsis showed no difference. Determinants of bifocal function: In 7.1% of our cases, no bifocal function (BFF) was present after implantation of diffractive multifocal IOLs. These patients exhibited a significantly higher age as well as higher pre- and postoperative astigmatism, when compared to patients with good BFF. Optical performance of different multifocal IOLs: By means of an optical system, described by Reiner, images of intraocular lenses can be projected into the eye ("optical implantation"); thus, the optical performance of IOLs can be judged subjectively. Using this method, the refractive 2- and 3-zone models performed best within the multifocal group (contrast sensitivity not significantly worse than that of monofocal IOL), when viewing a low-contrast chart (Regan 4%). All other multifocal lenses (diffractive, aspheric/spherical, refractive 5- and 7-zone models) were significantly inferior to the monofocal IOL. CONCLUSIONS: Implantation of multifocal IOLs should presently be restricted to special indications, particularly to the distinct patient request to dispense with wearing near or bifocal glasses, if possible. Because of the reduction in contrast sensitivity and mesopic vision and the increased glare sensibility, multifocal IOLs should not be implanted especially in professional car drivers. There are, however, differences in optical performance between the various multifocal IOL types. Further improvements, in particular concerning lens technology, will presumably extend the present spectrum of indications.
Contrast Sensitivity↗
[The Array multifocal lens--functional principle and clinical results].
BACKGROUND: Common refractive bifocal IOLs feature 2 or 3 spherical zones with different refraction; the design of the Array multifocal IOL consists of 5 concentric zones, each of them providing a progressive near addition with multiple foci by means of an aspherical surface. METHODS: As a part of a prospective study, distance and near visual acuity, contrast sensitivity, glare and depth of field were examined in 15 patients with the Array lens and a monofocal control group 12 months after implantation. Subjective assessment of the optical quality was performed by detailed asking for optical symptoms. Results were retrospectively compared with the one year follow-up of 15 patients with diffractive bifocal IOLs. RESULTS: No difference was found for best corrected far and near visual acuity and sensitivity for high contrasts. Glare and sensitivity for low contrasts of the monofocal IOL was significantly superior to both multifocal models. Array IOL and diffractive IOL achieved a near acuity of Nieden 2-1 with only distance correction; defocus curves revealed an increase in the depth of field, but with a superiority of the Array lens in intermediate imaging. Optical symptoms as halos were much more frequent in patients with the diffractive IOL than in the Array group. CONCLUSIONS: Functional results of the Array multifocal IOL seem to be comparable to those of the diffractive bifocal IOL, but with the advantage of an improved intermediate imaging and a reduction of optical side effects.
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