Biomedical subjects

K W Jacobi

Publications and source records attributed to K W Jacobi.

At least 19 recordsLinked to original sources

PubMed1998

[Studies of the distribution of lipofuscin in the retinal pigment epithelium using high-resolution TV laser scanning ophthalmoscopy].

BACKGROUND: The fundus autofluorescence imaging technique has been modified allowing improved image resolution (768 x 572 pixel). We present results of fundus autofluorescence studies using this technique. MATERIALS AND METHODS: Fundus autofluorescence was studied in 286 eyes of 143 patients with retinitis pigmentosa, macular dystrophies and age-related macular degeneration using a confocal laser scanning ophthalmoscope prototype (Zeiss, Oberkochen; excitation wavelength: 488 nm, cut-off filter at 521 nm). RESULTS: The spatial distribution of autofluorescence was different in all diseased eyes investigated compared to the normal pattern of fundus autofluorescence. Each disorder showed a specific fundus autofluorescence appearance. CONCLUSIONS: The advanced technique of imaging fundus autofluorescence allows detailed studies of the lipofuscin distribution. In vivo analysis of the dynamics of accumulation and degradation of lipofuscin in eyes with tapeto-retinal dystrophies and age-related macular disease may contribute to elucidation of the pathogenesis of these disorders.

Adolescent↗

PubMed1998

Effect of heparin in irrigating solution on inflammation following small incision cataract surgery.

PURPOSE: To study the effect of heparin-sodium added to the irrigating solution on postoperative inflammation in patients having cataract surgery. SETTING: Department of Ophthalmology, University of Giessen, Giessen, Germany. METHODS: Seventy-two patients having phacoemulsification with posterior chamber intraocular lens (IOL) implantation were randomly assigned to receive regular irrigating solution or solution with heparin-sodium (final diluted concentration 10 IU/mL). In half the patients, poly(methyl methacrylate) (PMMA) IOLs were implanted and in half, foldable silicone IOLs. The patients were examined preoperatively, on days 1 and 3, and 1 year postoperatively. Postoperative inflammation was objectively evaluated by measurement of flare and cells using laser flare-cell photometry. RESULTS: The mean postoperative flare values were significantly lower in the groups with additional heparin-sodium at days 1 and 3 (P < . 01). Flare values were not significantly different 1 year postoperatively. Cell values for the heparin-treated groups were lower, but the difference did not reach statistical significance. Flare and cells values for the two IOL materials were not significantly different during the entire follow-up. CONCLUSION: Heparin-sodium added to the infusion solution during small incision cataract surgery reduced inflammation in the early postoperative period.

Aged↗

PubMed1998

[Early posterior capsule fibrosis after combined cataract and vitreoretinal surgery with intraocular air/SF6 gas tamponade].

BACKGROUND: The surgical approach in treating coexisting vitreoretinal disease and cataract is controversial. We report on patients who developed early posterior capsular fibrosis after combined cataract and vitreoretinal surgery with air/SF6-gas tamponade. PATIENTS AND METHODS: The medical records of 15 consecutive eyes (13 patients) who underwent combined phacoemulsification with intraocular lens implantation and vitreoretinal surgery with intraocular air/SF6-gas tamponade were retrospectively analyzed. The indications for vitreous surgery included: subfoveal neovascular membrane in age-related macular degeneration (5 eyes), macular hole (4 eyes), macular pucker (2 eyes), rhegmatogenous retinal detachment (2 eyes), persistent vitreous haemorrhage after branch retinal vein occlusion (1 eye), persistent vitreous haemorrhage and/or tractional retinal detachment in proliferative diabetic retinopathy (1 eye). The mean follow-up period was 7 months (1-13 months). A control group consisted of 15 eyes (15 patients) who underwent the equal combined operation without intraocular tamponade. The indications for vitreous surgery were persistent vitreous haemorrhage in proliferative diabetic retinopathy (5 eyes), persistent vitreous haemorrhage after branch retinal vein occlusion (5 eyes), asteroid hyalosis (2 eyes), macular pucker (1 eye), posttraumatic vitreous haemorrhage (1 eye), acute retinal necrosis (1 eye). The mean follow-up was 8 months (2-13 months). The posterior capsule was examined at the slit lamp microscopy with maximal dilated pupils. We defined posterior capsular opacification (PCO) as severe if posterior capsule was fibrotic, diffusely thickened and opaque. Modest PCO was characterized by focal fibrotic opacifications at otherwise clear posterior capsule. RESULTS: Severe posterior capsular fibrosis developed in 9 eyes (60%) after 2-14 weeks postoperatively (mean 8 weeks) including 3 of 6 eyes with air tamponade (50%) and 6 of 9 eyes with 20% SF6-gas tamponade (66.7%). In 6 eyes (40%) Nd:YAG-laser capsulotomy was performed 4-14 weeks postoperatively (mean 8.5 weeks). In the control group modest PCO developed in 8 eyes (53.3%) 1-13 months postoperatively (mean 6.5 months) none requiring Nd:YAG-laser capsulotomy during follow-up period. CONCLUSIONS: Combined cataract and vitreoretinal surgery with intraocular air/SF6-gas tamponade induces severe posterior capsular fibrosis in the early postoperative period. The capsular fibrosis is presumably caused by accumulation of fibrin and proliferation stimulating factors in the narrow space between intraocular lens and air/SF6-gas bubble.

Aged↗

PubMed1998

[Fundus autofluorescence in patients with hereditary macular dystrophies, malattia leventinese, familial dominant and aged-related drusen].

PURPOSE: The lack of histopathological material has placed limitation on our knowledge on the composition of focal deposits in eyes with macular dystrophies, malattia leventinese, dominant drusen and age related macular degeneration. This study was designed to study the composition of focal deposits in these eyes by documenting fundus autofluorescence in vivo. METHODS: Fundus autofluorescence was documented in 343 eyes of 199 subjects with macular dystrophies, malattia leventinese, dominant drusen and age-related macular degeneration using a laser scanning ophthalmoscope (Zeiss, Oberkochen; excitation wavelength: 488 nm, barrier filter at 521 nm). RESULTS: Autofluorescence of focal deposits was increased in eyes with macular dystrophies. In eyes with malattia leventinese and dominant drusen autofluorescence intensity of focal deposits showed a wide spectrum. In contrast, autofluorescence of age-related drusen was within normal limits. Background autofluorescence intensity was increased in eyes with macular dystrophies and within normal limits in eyes with malattia leventinese, dominant drusen and age-related drusen. CONCLUSION: The technique of in-vivo recording of fundus autofluorescence allows the differential diagnosis between macular dystrophies/malattia leventinese, dominant drusen/age related drusen when otherwise not possible.

Adult↗

PubMed1998

[Dynamics of accumulation and degradation of lipofuscin in retinal pigment epithelium in senile macular degeneration].

BACKGROUND: It is thought that lipofuscin plays a central role in the pathogenesis of age-related macular degeneration (AMD). The lack of histopathological material has been a severe limitation in our knowledge on lipofuscin in this disease. A new technique has been developed that allows in vivo imaging of fundus autofluorescence derived from lipofuscin in the retinal pigment epithelium (RPE) using a confocal Laser Scanning Ophthalmoscope (LSO). We studied the dynamics of lipofuscin accumulation and degradation in patients with AMD. MATERIALS AND METHODS: Serial examinations of the spatial distribution of fundus autofluorescence were performed in 148 eyes of 74 patients with AMD using a LSO over a period of 1-3.5 years. RESULTS: Fundus autofluorescence changed over time in almost all eyes studied. Areas of increased autofluorescence occurred progressively during follow up in eyes with drusen and hyperpigmentation. The size of pathologic autofluorescence increased over time in almost all eyes with geographic atrophy, subretinal neovascularisations and disciform scars. Irregular autofluorescence was seen over most subretinal neovascularisations. Autofluorescence intensity decreased in old subretinal neovascularisations and disciform scars over time. CONCLUSIONS: Changes of the distribution of autofluorescence occur in eyes with AMD over time. Fundus autofluorescence imaging allows in vivo analysis of the dynamics of accumulation and degradation of lipofuscin in the RPE in eyes with AMD and documentation of metabolic activity of the RPE.

Aged↗

PubMed1997

[Long-term outcome after implantation of various intraocular lenses through a corneal tunnel].

UNLABELLED: A prospective, randomized study was carried out to evaluate functional and biomicroscopic long-term results of different posterior chamber intraocular lenses (IOLs) over a period of two years after clear corneal cataract surgery. PATIENTS AND METHODS: 2 years after phacoemulsification through a temporal two-step clear corneal incision a total of 67 patients were examined. In 26 eyes (group A) a foldable plate-haptic silicone IOL (Chiron Adatomed, C10), in 25 eyes (group B) a foldable disc silicone IOL (Chiron Adatomed, 90D) had been implanted through a 3.5 (group A) or 4 mm (group B) corneal incision using a cartridge injector. In 16 eyes (group C) a one-piece PMMA-IOL (Pharmacia & Upjohn, 809C) had been implanted through a 5 mm incision. All eyes underwent functional and biomicroscopic examinations, as well as computerized videokeratographic analysis to obtain corneal topography data. RESULTS: In group A uncorrected visual acuity valued 0.64 (+/-0.29 SD), in group B 0.59 (+/-0.24) and in group C 0.56 (+/-0.27). Median of uncorrected visual acuity was 0.6 for all groups. Corrected visual acuity was 0.81 (+/-0.29) in group A, 0.8 (+/-0.25) in group B and 0.83 (+/-0.3) in group C. Intraocular pressure (mm Hg) was 13 (+/-2.5) in group A, 14.7 (+/-2) in group B and 15.1 (+/-2.5) in group C. Fibrosis of the anterior capsular rim occurred in 42% of the cases. One eye demonstrated folds in the posterior capsule (group B). Posterior capsular opacification valued 11.9% for all groups. In one eye a Nd:YAG-capsulotomy had already been performed. In group A a decentration of more than 1 mm was objected in one case, in group B in two cases and in group C in one case, but no patient complained about any functional impairment. Two years postoperatively, no signs of a re-flattening in the incision area could be detected using difference mapping tools in the videokeratographic analysis. CONCLUSION: Two years after implantation of foldable silicone IOLs and PMMA-IOLs via a temporal clear corneal tunnel incision after phacoemulsification only slight functional and morphologic differences between the three IOL-types could be observed.

Aged↗

PubMed1996

[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↗

PubMed1996

[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↗

PubMed1996

[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↗

PubMed1996

[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↗

PubMed1995

Comparison of the induced astigmatism after temporal clear corneal tunnel incisions of different sizes.

A prospective, randomized study compared the surgically induced astigmatism after 3.5 mm, 4.0 mm, and 5.0 mm temporal corneal tunnel incisions over six months. We studied 60 eyes of 60 patients who had phacoemulsification through a two-step clear corneal tunnel incision and implantation of one of three posterior chamber intraocular lenses (IOLs). Patients were divided into three groups of 20 each: Group A, cartridge injection of a foldable plate-haptic silicone IOL through a 3.5 mm self-sealing incision; Group B, cartridge injection of a disc silicone IOL through a 4.0 mm self-sealing incision; Group C, 5.0 mm optic poly(methyl methacrylate) IOL through a 5.0 mm incision with one radial suture. Corneal topography data were obtained using a computerized videokeratographic analysis system preoperatively and one week and six months postoperatively. Vector analysis was performed to calculate the surgically induced astigmatism. After the first postoperative week, mean induced astigmatism was 0.63 diopters (D) (+/- 0.41) in Group A, 0.64 D (+/- 0.35) in Group B, and 0.91 D (+/- 0.77) in Group C. After six months, it was 0.37 D (+/- 0.14) in Group A, 0.56 D (+/- 0.34) in Group B, and 0.70 D (+/- 0.50) in Group C. Surgically induced astigmatism was significantly lower in Group A than in Group B (P < .05) and Group C (P < .005) after six months. Vector analysis demonstrated that temporal corneal tunnel incisions induced clinically minimal astigmatism over six months postoperatively depending on incision size.

Aged↗

PubMed1995

[Alterations of heparin coating on intraocular lenses caused by implantation instruments].

BACKGROUND: In the last years heparin surface-modified intraocular lenses (HSM IOLs) were used for special indications like uveitis, synechia, congenital cataract or pseudoexfoliation syndrome. A monolayer of heparin molecules on the surface of PMMA-IOLs causes a reduced postoperative inflammatory reaction and produces a higher long-term biocompatibility than PMMA-IOLs without surface-modification. The study was designed to evaluate the possible damage of this heparin-monolayer on the PMMA-IOL by different metallic implantation forceps and different grasp-pressure. MATERIALS AND METHODS: Different implantation instruments were used to grasp HSM and conventional PMMA-IOLS. We designed a new device to generate and measure the pressure by the implantation forceps on the IOL in online-mode. After staining the heparin-monolayer with toluidin blue the surface alterations on the intraocular lenses were examined for surface alterations, especially of the heparin-monolayer, by light and scanning electron microscopy subsequently. RESULTS: Implant forceps produced defects of the heparin layer and the PMMA-material. Each implantation forceps induced a specific pattern of destructed heparin surface in the grasp area. These defects showed high correlation with the pressure and the morphology of the forceps as shown by light and scanning electron microscopy. CONCLUSIONS: Mechanical irritation during the implantation procedure destroyed the heparin layer on PMMA-IOLs in the grasp-area. Clinical consequences are not yet known, but possible. An instrument with rounded, soft and smooth grasp-surface is required for implantation of HSM IOLs to avoid surface alterations, so that the patients get maximum profit by the heparin-modification.

Cataract Extraction↗

PubMed1995

[Endothelial cell loss after phacoemulsification and 3.5 vs. 5 mm corneal tunnel incision].

This prospective study was performed to compare the central endothelial cell loss (ECL) after phacoemulsification and 3.5 with 5 mm temporal clear-corneal incision. Moreover, the influence of ultrasound time and power on postoperative endothelial cell density was evaluated. PATIENTS AND METHODS. Sixty-two patients (age 71 +/- 7.7 years) without corneal pathology were operated by phacoemulsification (Storz, Premiere) with a temporal, self-sealing, two-step clear-corneal incision followed by posterior chamber IOL implantation under viscoelastic (1% sodium hyal-uronate). Thirty-one one-piece plate-haptic foldable silicone IOLs (Chiron C10; Staar Surgical AA-4203) were implanted by an injector through a 3.5 mm incision (group A). The other 31 PMMA IOLs (Pharmacia 809P) were implanted through a 5 mm incision (group B). One surgeon performed all operations with the same technique (bimanual phacoemulsification in the capsular bag). Sutureless wound closure was performed in group A, while the wounds in patients of group B were closed with a single radial stitch. The central endothelial cell counts were recorded preoperatively, on days 2-5 and 6 months postoperatively using contact specular microscopy. RESULTS. The collective data revealed a cell loss of 7.9% (+/- 4.1 SD) on days 2-5 postoperatively and 6.7% (+/- 2.9) after 6 months. A direct linear relationship was found to exist between ultrasound time (UT) and ECL. In group A (7 patients) the ECL slightly increased from 3.5% in the first week postoperatively to 3.8% after 6 months, operated under UT < or = 1 min 30 sec. The ECL decreased from 8.2% to 6.4% after 6 months in group A (19 patients), operated under UT of 1 min 30 sec, and from 10.8% to 8.9% under UT of 2 min 31 sec-3 min 30 sec (5 patients). The ECL in group B decreased from 6.3% in the first postoperative week to 5.4% 6 months postoperatively, operated under UT < or = 1 min 30 sec (10 patients), from 8.1% to 7%, operated under UT of 1 min 31 sec-2 min 30 sec (14 patients), and from 11.2% to 10.4% under UT of 2 min 31 sec-3 min 30 sec (7 patients). CONCLUSION. Endothelial cell loss of 6.7% after phacoemulsification through a temporal clear-corneal incision compares favorably with other series in which cell loss was determined following cataract surgery with or without IOL implantation. Phacoemulsification and 3.5 mm clear-corneal incision evoked less ECL of 6.2% compared with phacoemulsification and 5 mm clear-corneal incision with ECL of 7.3% after 6 months.

Aged↗

PubMed1995

[Effects of Nd:YAG microexplosions on heparin-coated PMMA intraocular lenses].

UNLABELLED: Surface modification of intraocular lenses (IOL) have improved the quality of cataract surgery. Heparin surface-modified (HSM) IOL are implanted for special indications (e.g., recurrent uveitis, cataract surgery for children, preoperative synechia) because of decreased postoperative inflammatory reactions and higher long-term biocompatibility. Nevertheless, secondary cataract, precipitates and fibrinous membranes appear. The YAG laser is used for treatment. METHODS: PMMA intraocular lenses with or without a heparin monolayer were exposed to Nd:YAG laser. The experiment was performed under BSS using different energy levels and distances to the IOL. The heparin monolayer was stained with toluidin blue. Subsequently, the surface of the intraocular lenses was examined with light and scanning electron microscopy. RESULTS: The YAG laser marks of HSM IOL and PMMA IOL showed no morphological differences. Microexplosions and pressure waves of the Nd:YAG laser cleared parts of the heparin monolayer in the area of the laser spots dependent on energy distance to the IOL. Even "breakdown" behind the HSM IOL without any PMMA lesion shown circular destruction of the heparin monolayer. CONCLUSIONS: The heparin surface defect of HSM IOL after YAG laser treatment should be taken into consideration, because a decreased heparin effect in vivo could be possible.

Heparin↗

PubMed1995

[The anti-inflammatory effect of heparin-containing infusion solutions during phacoemulsification].

UNLABELLED: The use of heparin prevented postoperative intraocular fibrin-clot formation in the rabbit after vitrectomy and cyclocryotherapy. A low rate of postoperative intraocular inflammation was observed in our patients receiving phacoemulsification with heparin infusion solution (slit-lamp examination). To verify this effect a randomized, prospective study was performed using laser-flare cell photometry (LFCP) for measuring protein concentration in the anterior chamber. PATIENTS AND METHODS: Seventy-two patients (49-87 years of age) were randomly assigned to one of the following two surgical groups (temporal clear corneal tunnel incision with phacoemulsification): group A: foldable silicone IOL (Chiron C10), no stitch (3.5 mm incision); group B: PMMA-IOL (Pharmacia 809P) with one radial suture (5 mm incision). Fifty percent of the patients in each group received, in addition to the regular phaco infusion, 1 ml of heparin sodium (-H = without heparin; +H = with heparin). Aqueous flare was measured preoperatively as well as on days 1 and 3 following phaco + IOL with LFCP (Modell FC-1000; Kowa Company). RESULTS: In group A1 (-H) or B1 (-H) the mean flare values (in photon counts/ms) increased from a preoperative value of 7.0 +/- 1.7 (mean +/- SD) or 6.9 +/- 1.2 to 20.2 +/- 3.1 or 20.1 +/- 3.0 on the 1st postoperative day, whereas they decreased again to 13.8 +/- 2.9 or 14.8 +/- 3.1 on day 3 following surgery. In groups with heparin sodium A2(+H) and B2(+H) the flare values only increased from 7.2 +/- 1.3 or 7.1 +/- 1.3 to 12.9 +/- 4.0 or 13.8 +/- 3.8 on day 1, and decreased to 8.0 +/- 2.8 or 8.8 +/- 3.0 on the 3rd postoperative day. The mean postoperative flare values were significantly lower in the groups with additional heparin (p < 0.01). CONCLUSIONS: Heparin sodium in the infusion solution during small incision cataract surgery showed an antiinflammatory effect in the early postoperative period. There was no significant difference between the two IOL materials.

Aged↗

PubMed1994

[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.

Aged↗

PubMed1994

[Systemic complications and side effects of retrobulbar anesthesia in risk patients].

BACKGROUND: Serious systemic complications with possibly lethal exit after retrobulbar anesthesia have been reported. The present study was performed to evaluate the incidence of complications after anesthesia in risk patients with pre-existing diseases. 2.8% of 3000 cataract operations in our department during October 1991 to April 1993 were performed under general anesthesia, 97.2% under local anesthesia. PATIENTS AND METHODS: 1000 anesthesia protocols of these cataract operations under retrobulbar anesthesia and facial block with anesthesia stand-by were analyzed retrospectively. After retrobulbar injection in Atkinson technique we performed a modified O'Brien facial block. The patients were assigned to five different risk groups on the basis of a special point system. RESULTS: The mean age of the patients increased with the risk group from 60.4 years in group 1 to 77.1 years in group 5. Cardiovascular, pulmonary and general risk factors appeared more frequently in the groups of higher risk. The frequency of cardiovascular complications was dependent on affiliation to risk group. The percentual frequency of cardiovascular complications increased from 1.7% in risk group 1 to 7.7% in risk group 5. Decrease of heart rate or blood pressure of more than 30%, or in combination, with the necessity of medical treatment occurred absolutely and relatively most frequently. The frequency of cardiovascular complications amounted 2.2% in the mean. Life-threatening complications with the need of endotracheal intubation or other occurred in 0.1%. CONCLUSION: The relatively high total frequency of systemic complications of 2.4% is related with age and preexisting diseases. The results underline the necessity of anesthesia stand-by in risk patients with the essential requirements for treatment of typical complications.

Aged↗

PubMed1994

[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↗