Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 33
Filter
1.
Ophthalmologe ; 111(10): 935-41, 2014 Oct.
Article in German | MEDLINE | ID: mdl-25332044

ABSTRACT

BACKGROUND: High myopia phakic intraocular lenses (IOL) have become an established means of surgical correction for high ametropia. Scheimpflug photography is one of the methods which are frequently applied for postoperative examination of the implants. MATERIAL AND METHODS: Results from published studies employing Scheimpflug photography for examination of anterior chamber angle-fixated, iris-fixated and sulcus-fixated phakic IOLs were evaluated. RESULTS: In several published studies Scheimpflug photography was used to examine the position of the implant and opacification of the crystalline lens. The results provided valuable evidence for the improvement of phakic IOL design. CONCLUSION: Scheimpflug photography offers an easy to use, rapid non-contact examination of phakic IOLs.


Subject(s)
Corneal Topography/methods , Lens, Crystalline/pathology , Myopia/diagnosis , Myopia/therapy , Phakic Intraocular Lenses , Photography/methods , Corneal Pachymetry/methods , Humans , Treatment Outcome
2.
Klin Monbl Augenheilkd ; 228(8): 666-75, 2011 Aug.
Article in German | MEDLINE | ID: mdl-21837581

ABSTRACT

BACKGROUND: A potential option for the correction of presbyopia after cataract extraction or refractive lens exchange is the implantation of accommodative intraocular lenses (IOL). When evaluating these lenses, it is essential to differentiate between accommodative and pseudoaccommodative effects, as both may have a positive impact on near visual acuity and reading performance. Only in this way accommodation can be proved. MATERIAL AND METHODS: This article provides a brief overview on the principles of accommodation and presbyopia. Furthermore, different tests for testing near visual acuity, reading ability and accommodative processes are described, as well as options to perform these in a manner that allows the differentiation between accommodative and pseudoaccomodative effects. Against this background, the current literature has been reviewed regarding the results of potential accommodative IOLs. RESULTS: A differentiation between accommodative effects in clinical practice can be performed using defocus curves or better open field aberrometers or refractometers as well as IOL movement measurements under non-pharmacologically stimulated conditions. Reading charts are not suitable. Currently mainly 7 different potential accommodating IOLs can be found in clinical research literature (5 single-optics, 1 gel-optic and one dual-optic). All of them are based on the principle of using ciliary muscle contraction for moving the IOL or changing its thickness and/or surface radii during accommodation in order to change the ocular refractive power. A proof of principle of such lenses under physiological, non-pharmacologically stimulated conditions is still lacking. However, the evaluated implants show significant improvement in terms of visual acuity in near and especially intermediate distances. CONCLUSION: Using adequate testing procedures it becomes clear that the positive near vision effects achieved with accommodative intraocular lenses are due rather to pseudoaccommodative effects than to accommodative ones.


Subject(s)
Accommodation, Ocular , Lenses, Intraocular , Presbyopia/surgery , Prosthesis Design , Aberrometry , Distance Perception , Humans , Reading , Refraction, Ocular , Visual Acuity
3.
Klin Monbl Augenheilkd ; 227(8): 611-6, 2010 Aug.
Article in German | MEDLINE | ID: mdl-20706968

ABSTRACT

Centration and positional stability of intraocular lenses (IOLs) are crucial factors for optical quality and predictability of the result after IOL implantation. Continuous improvements of IOL design and materials, surgical techniques and measurement methods have contributed to an optimised correction of the presudophakic eye and to a better unterstanding of the effects of IOL positioning. With modern IOLs implanted into the capsular bag, positioning and stability comparable to the natural crystalline lens can be achieved.


Subject(s)
Lens Implantation, Intraocular/methods , Equipment Failure Analysis , Humans , Lenses, Intraocular , Postoperative Complications/etiology , Prospective Studies , Prosthesis Design , Randomized Controlled Trials as Topic , Refraction, Ocular
4.
Klin Monbl Augenheilkd ; 226(9): 752-6, 2009 Sep.
Article in German | MEDLINE | ID: mdl-19750424

ABSTRACT

BACKGROUND: Collagen cross-linking with administration of riboflavin and UV radiation may delay or halt the progression of keratoconus. This study examines the effects of the treatment on the corneal wavefront error. MATERIALS AND METHODS: Twenty eyes of 20 patients with keratoconus received collagen cross-linking with riboflavin administration and 30 min of UV radiation at a wavelength of 365 nm. Preoperatively as well as 1 and 6 months postoperatively, the corneal wavefront error was computed from axial keratometric topography data by Zernike decomposition over a pupil diameter of 6 mm. RESULTS: Preoperative mean keratometric astigmatism was 5.37 +/- 2.36 D. Six months postoperatively it was 5.29 +/- 2.73 D (p = 0.35). Total higher order aberrations were preoperatively 3.35 +/- 1.65 microm and after 6 months 3.31 +/- 1.79 microm (p = 0.116). Coma's root mean square was 2.94 +/- 1.47 microm preoperatively and 2.75 +/- 1.38 microm after 6 months (p = 0.047). CONCLUSION: Within the first 6 postoperative months, collagen cross-linking with riboflavin administration and UVA irradiation does not significantly increase or decrease corneal wavefront aberrations.


Subject(s)
Keratoconus/drug therapy , Photochemotherapy/adverse effects , Refractive Errors/diagnosis , Refractive Errors/etiology , Riboflavin/administration & dosage , Riboflavin/adverse effects , Ultraviolet Therapy/adverse effects , Adult , Collagen/chemistry , Corneal Topography , Cross-Linking Reagents/chemistry , Female , Humans , Keratoconus/complications , Keratoconus/diagnosis , Male , Photochemotherapy/methods , Photosensitizing Agents/therapeutic use , Refractive Errors/prevention & control , Riboflavin/chemistry , Treatment Outcome , Ultraviolet Therapy/methods
5.
Ophthalmologe ; 105(11): 1059-73; quiz 74, 2008 Nov.
Article in German | MEDLINE | ID: mdl-18998143

ABSTRACT

There are two basic approaches for the surgical correction of presbyopia: increasing depth of focus (e.g. by means of multifocal laser abrasion of the cornea), Or restoring accommodation in the sense of a dynamic change in ocular refraction (accommodative intraocular lenses, scleral expansion). Pseudoaccommodative procedures are able to achieve satisfactory near vision, albeit at the price of lower performance in the intermediate range and decreased image quality. The restoration of accommodation remains problematic, partly because the mechanism of accommodation and the development of presbyopia are still not fully understood. Some surgical procedures are based on concepts, the validity of which is not confirmed or which even contradict experimental evidence. Thus, it is necessary to assess the results and presumed mechanisms critically and objectively.


Subject(s)
Accommodation, Ocular , Lens Implantation, Intraocular/instrumentation , Lens Implantation, Intraocular/methods , Lenses, Intraocular , Presbyopia/diagnosis , Presbyopia/surgery , Refractive Surgical Procedures/instrumentation , Refractive Surgical Procedures/methods , Germany , Humans
6.
Ophthalmologe ; 105(6): 597-608; quiz 609-10, 2008 Jun.
Article in German | MEDLINE | ID: mdl-18594896

ABSTRACT

Accommodation is a dynamic change in the dioptric power of the eye. According to the widely accepted and experimentally confirmed theory of Helmholtz, it is achieved by release of zonular tension with contraction of the ciliary muscle and consecutive modelling of the shape of the crystalline lens by the elastic lens capsule. The ability to accommodate is gradually lost with age (presbyopia). Because of difficulties in examining the accommodative apparatus in vivo, many theories, in part contradictory, about the mechanism of accommodation and the origin of presbyopia have been developed. In recent years experimental studies have greatly increased the knowledge about the acommodative apparatus and suggest a multifactorial aetiology of presbyopia. A better understanding of the physiology of accommodation and presbyopia can contribute to the development of effective treatments.


Subject(s)
Accommodation, Ocular/physiology , Presbyopia/physiopathology , Elastic Tissue/physiopathology , Geniculate Bodies/physiopathology , Humans , Lens, Crystalline/physiopathology , Muscle, Smooth/innervation , Muscle, Smooth/physiopathology , Optic Nerve/physiopathology , Presbyopia/etiology , Refraction, Ocular
7.
Ophthalmologe ; 102(10): 1003-7; quiz 1018, 2005 Oct.
Article in German | MEDLINE | ID: mdl-16172789

ABSTRACT

In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or the removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses that are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for anterior chamber lenses these are mainly pupil ovalization and endothelial cell loss.


Subject(s)
Anterior Chamber/surgery , Lens Implantation, Intraocular/methods , Lens, Crystalline , Lenses, Intraocular , Refractive Surgical Procedures , Cataract Extraction , Follow-Up Studies , Humans , Iris/surgery , Lenses, Intraocular/adverse effects , Microscopy, Electron, Scanning , Refraction, Ocular , Rotation , Time Factors
8.
Mutat Res ; 558(1-2): 181-97, 2004 Mar 14.
Article in English | MEDLINE | ID: mdl-15036131

ABSTRACT

Nineteen coded chemicals were tested in an international collaborative study for their mutagenic activity. The assay system employed was the Ames II Mutagenicity Assay, using the tester strains TA98 and TAMix (TA7001-7006). The test compounds were selected from a published study with a large data set from the standard Ames plate-incorporation test. The following test compounds including matched pairs were investigated: cyclophoshamide, 2-naphthylamine, benzo(a)pyrene, pyrene, 2-acetylaminofluorene, 4,4'-methylene-bis(2-chloroaniline), 9,10-dimethylanthracene, anthracene, 4-nitroquinoline-N-oxide, diphenylnitrosamine, urethane, isopropyl-N(3-chlorophenyl)carbamate, benzidine, 3,3'-5,5'-tetramethylbenzidine, azoxybenzene, 3-aminotriazole, diethylstilbestrol, sucrose and methionine. The results of both assay systems were compared, and the inter-laboratory consistency of the Ames II test was assessed. Of the eight mutagens selected, six were correctly identified with the Ames II assay by all laboratories, one compound was judged positive by five of six investigators and one by four of six laboratories. All seven non-mutagenic samples were consistently negative in the Ames II assay. Of the four chemicals that gave inconsistent results in the traditional Ames test, three were uniformly classified as either positive or negative in the present study, whereas one compound gave equivocal results. A comparison of the test outcome of the different investigators resulted in an inter-laboratory consistency of 89.5%. Owing to the high concordance between the two test systems, and the low inter-laboratory variability in the Ames II assay results, the Ames II is an effective screening alternative to the standard Ames test, requiring less test material and labor.


Subject(s)
International Cooperation , Mutagenicity Tests/standards , Mutagens/toxicity , Salmonella typhimurium/genetics
9.
Chemosphere ; 48(1): 75-82, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12137060

ABSTRACT

Head lettuce plantlets (Lactuca sativa L. var. capitata) were potted, treated with vinclozolin at the six-leaf stage according to application standards and allowed to dry for 24 h. The potted plantlets were then placed in either growth chambers with controlled temperature (20 and 25 degrees C, respectively) or in a greenhouse (approximately 12 degrees C), together with untreated spinach (Spinacia oleracea L.) and standardized grass cultures (Lolium multiflorum Lam. ssp.) While the treated lettuce pots remained in the respective growing compartments until the end of the experiments, spinach and grass were exposed to the compartment air for 24 h and their shoot material was analyzed for vinclozolin by GC-ECD and GC-high resolution mass spectrometry. Exposure and analysis of untreated spinach and grass were carried out at two- or three-day intervals during the course of the experiments. Also, air samples were taken from the compartments at intervals and analyzed for vinclozolin. Maximum vinclozolin concentration in the growth chamber air was about 330 ng m(-3) while vinclozolin contamination of the untreated plants ranged from 50 to 200 microg kg(-1) FW (fresh weight). In the greenhouse atmospheric vinclozolin concentration reached approximately 15 ngm(-3) and maximum contamination of spinach and grass were 30-40 microg kg(-1) FW. Our data clearly show that unintended contamination of plants growing in the vicinity of vinclozolin-treated plants can occur even if the fungicide layer is completely dry. Implications for safety testing and food plants are discussed.


Subject(s)
Air Pollutants/analysis , Fungicides, Industrial/chemistry , Oxazoles/chemistry , Chromatography, Gas , Environmental Monitoring , Food Contamination , Fungicides, Industrial/analysis , Lactuca , Lolium , Oxazoles/analysis , Safety , Spinacia oleracea , Volatilization
10.
Ophthalmologe ; 99(3): 176-80, 2002 Mar.
Article in German | MEDLINE | ID: mdl-11917799

ABSTRACT

BACKGROUND: Diffuse lamellar keratitis (DLK) is a sterile inflammation after lamellar corneal surgery. A clinical staging for DLK was recently set up. In this observational case series, the clinical and confocal microscopic findings of stages 1-3 are reported. METHODS: Six eyes of six patients (three eyes with DLK stage 1, two eyes with DLK stage 2, and one eye with DLK stage 3) were examined by slit lamp biomicroscopy and confocal microscopy. RESULTS: In all cases, confocal microscopy showed an infiltration of inflammatory cells into the anterior stroma and the flap interface. The number of cells varied between the eyes with DLK stage 1, and both stage 2 corneas had dense infiltrates. In the eye with stage 3 DLK, an aggregation of decayed cells, most likely granulocytes, was noticed clinically and by confocal microscopy. CONCLUSIONS: The DLK stages represent different clinical intensities of interface inflammation after LASIK. While stages 1 and 2 have a similar confocal microscopic appearance, stage 3 is a result of aggregation of a high amount of inflammatory cells.


Subject(s)
Keratitis/etiology , Keratomileusis, Laser In Situ/adverse effects , Microscopy, Confocal , Adult , Female , Humans , Keratitis/diagnosis , Male , Middle Aged , Time Factors , Visual Acuity
11.
Ophthalmologe ; 98(11): 1044-54, 2001 Nov.
Article in German | MEDLINE | ID: mdl-11729735

ABSTRACT

PURPOSE: Recently laser-in-situ-keratomileusis (LASIK) has been increasingly used to correct refractive errors. The purpose of this investigation was to evaluate the safety, efficacy, predictability, stability and complications using the scanning spot excimer LASIK technology. PATIENTS AND METHODS: The results of 100 consecutive LASIK operations carried out between 2/1998 and 2/1999 on 60 patients (mean age 37 years, range 20-55 years) have been evaluated. The Hansatome microkeratome with a superior hinge (flap diameter: 9.5 mm) and a scanning spot excimer laser (Technolas C-Lasik 217) were used in all cases. The mean spherical equivalent of the subjective manifest refraction was -6.96 +/- 2.87 diopters (D), the mean sphere was -6.47 +/- 2.71 D and the mean astigmatism was -0.98 +/- 0.94 D. In 6% of the eyes preoperative visual acuity was not better than 20/40. Examinations were performed preoperatively, after 1 and 7 days, after 1,4 and 12 months. Safety, efficacy, predictability, stability and complications were calculated using the datagraph software (version 1.11). RESULTS: All 100 eyes were examined after 1 day and 1 week, 96 after 1 month, 95 after 4 months and 92 after 1 year. Following 1 year none of the eyes lost 2 or more lines of best corrected visual acuity, 99% were within +/- 1 line and 1% gained 2 lines (safety index 1.03). In 92% of all eyes an uncorrected visual acuity of > or = 0.5 was reached, in 77% > or = 0.8 and in 51% > or = 1.0 (efficacy index 0.89). For 60 eyes (65.21%) a refractive correction of +/- 0.5 D was necessary, for 82 eyes (89.13%) +/- 1.0 D and for 91 eyes (98.91%) +/- 2.0 D. The mean spherical equivalent after 1 year was -0.15 +/- 1.31 D. Between 1 and 12 months a mean regression of -0.14 D occurred. On the request of the patients, 5 eyes were retreated during the study period for under- or over-correction. Complications due to the microkeratome did not occur. Corneal infections were not observed, a diffuse lamellar keratitis (DLK) was seen in 12 cases, but all cases healed with no loss of visual acuity. In 7 eyes a slight decentration of the ablation was observed using corneal topography, which in one case caused an increase in glare sensitivity. CONCLUSIONS: LASIK with superior hinge and scanning spot excimer photoablation is suitable for the correction of myopia (up to a maximum of -12 D) and for myopic astigmatism (up to a maximum of -5 D). The refractive results showed a high stability during the 12-month study period but there is still room for improvement of the predictability.


Subject(s)
Astigmatism/surgery , Keratomileusis, Laser In Situ , Myopia/surgery , Adult , Age Factors , Follow-Up Studies , Humans , Intraoperative Complications , Keratomileusis, Laser In Situ/adverse effects , Middle Aged , Postoperative Complications , Prospective Studies , Time Factors
12.
J Biol Chem ; 276(49): 45868-75, 2001 Dec 07.
Article in English | MEDLINE | ID: mdl-11577097

ABSTRACT

Normally, Rho GTPases are activated by the removal of bound GDP and the concomitant loading of GTP catalyzed by members of the Dbl family of guanine nucleotide exchange factors (GEFs). This family of GEFs invariantly contain a Dbl homology (DH) domain adjacent to a pleckstrin homology (PH) domain, and while the DH domain usually is sufficient to catalyze nucleotide exchange, possible roles for the conserved PH domain remain ambiguous. Here we demonstrate that the conserved PH domains of three distinct Dbl family proteins, intersectin, Dbs, and Tiam1, selectively bind lipid vesicles only when phosphoinositides are present. While the PH domains of intersectin and Dbs promiscuously bind several multiphosphorylated phosphoinositides, Tiam1 selectively interacts with phosphatidylinositol 3-phosphate (K(D) approximately 5-10 microm). In addition, and in contrast to recent reports, catalysis of nucleotide exchange on nonprenylated Rac1 provided by various extended portions of Tiam1 is not influenced by (a) soluble phosphoinositide head groups, (b) dibutyl versions of phosphoinositides, or (c) lipid vesicles containing phosphoinositides. Likewise, GEF activity afforded by DH/PH fragments of intersectin and Dbs are also not altered by phosphoinositide interactions. These results strongly suggest that unless all relevant components are localized to a lipid membrane surface, Dbl family GEFs generally are not intrinsically modulated by binding phosphoinositides.


Subject(s)
Adaptor Proteins, Vesicular Transport , Carrier Proteins/metabolism , Guanine Nucleotide Exchange Factors/metabolism , Phosphatidylinositols/metabolism , Proteins/metabolism , Immunoblotting , Protein Binding , Rho Guanine Nucleotide Exchange Factors , Surface Plasmon Resonance , T-Lymphoma Invasion and Metastasis-inducing Protein 1
13.
Ophthalmology ; 108(6): 1075-81, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11382632

ABSTRACT

OBJECTIVE: To report the confocal microscopic findings of two different cases of diffuse lamellar keratitis (DLK) after primary laser in situ keratomileusis (LASIK) and LASIK flap relifting. DESIGN: Observational case report of two cases. METHODS: Two cases of DLK with different clinical appearances after primary LASIK and LASIK flap relift were selected. A third case of uneventful LASIK was selected as control case. Examination with a white-light tandem slit-scanning confocal microscope was performed in addition to routinely applied slit-lamp biomicroscopy. RESULTS: In both cases, confocal microscopic examination showed infiltration of cells considered most likely to be mononuclear cells and granulocytes into the flap interface. Under treatment with topical steroids, the inflammation was reduced in both cases, to a minimum within 1 week, without loss of visual acuity. At this stage, only remnants of the granulocytelike cells, but not active inflammation, were imaged by confocal microscopic examination. CONCLUSIONS: Our findings confirm the clinical observation that DLK is an inflammation confined to the flap interface. Confocal in vivo microscopy could be a useful noninvasive tool to study the course of DLK in humans.


Subject(s)
Cornea/pathology , Keratitis/diagnosis , Keratomileusis, Laser In Situ/adverse effects , Microscopy, Confocal/methods , Adult , Cornea/surgery , Female , Granulocytes/pathology , Humans , Keratitis/etiology , Leukocytes, Mononuclear/pathology , Male , Myopia/surgery , Surgical Flaps
14.
Klin Monbl Augenheilkd ; 218(2): 125-30, 2001 Feb.
Article in German | MEDLINE | ID: mdl-11258125

ABSTRACT

BACKGROUND: For the correction of refractive errors lenticular procedures are increasingly used in addition to corneal refractive surgery. One of those techniques is the implantation of intraocular lenses into phakic eyes (pIOL). Due to the close neighborhood of the implant to delicate intraocular structures, exact positioning and high postoperative stability are required. Scheimpflug photography has been shown to be a suitable instrument for the biometry of the anterior eye segment and the examination of IOL position. PATIENTS AND METHODS: Four anterior chamber phakic IOLs (pIOLs) (Bausch & Lomb NuVita) and 7 posterior chamber pIOLs (Staar ICL) were examined 1 week, 1 month and 3-6 months following implantation. At each examination 1 Scheimpflug slit image and 1 infrared retroillumination image were taken using the anterior eye segment analysis system EAS-1000 (Nidek Co., Gamagori, Japan). Evaluation of the images was performed with a personal computer and the software provided by the manufacturer. The distance of the pIOL to cornea and human lens was calculated and incidence and amount of pIOL rotation around the optical axis and potential crystalline lens opacification were assessed. RESULTS: The distance between the anterior chamber pIOL and the cornea 1 week after implantation was 1.61 +/- 0.10 mm. The distances between the myopic posterior chamber pIOL and the human lens were 0.34 +/- 0.11 mm and between the hyperopic posterior chamber pIOL and the human lens 0.26 and 0.29 mm, respectively. The values were constant over a period of 3-6 months. The pIOL showed no movement or change of position around the optical axis. There was no detectable cataract formation in the human lens. CONCLUSIONS: All implanted phakic anterior and posterior chamber IOLs showed a stable position in the eye within the observation period. Scheimpflug photography is proved to be a useful technique for the postoperative evaluation of the positioning of phakic IOLs.


Subject(s)
Hyperopia/surgery , Lens Implantation, Intraocular/methods , Myopia/surgery , Photography/methods , Anterior Chamber , Follow-Up Studies , Humans , Image Processing, Computer-Assisted , Lens Implantation, Intraocular/adverse effects , Photography/instrumentation , Treatment Outcome
15.
Ophthalmologe ; 98(1): 60-5, 2001 Jan.
Article in German | MEDLINE | ID: mdl-11220273

ABSTRACT

PURPOSE: The results of photorefractive/photoastigmatic refractive keratectomy (PRK/PARK) were compared between two patient groups treated consecutively with either broad-beam or scanning-spot technology. PATIENTS AND METHODS: PRK/PARK was performed with a broad-beam excimer laser VISX 20/20 in 46 eyes and with the scanning-spot laser system Keracor 217 in 49 eyes. Preoperative spherical equivalent (subjective manifest refraction) was < or =-6.0 diopter in both groups. Safety, efficacy, predictability, stability, and complications were investigated after 1,4 and 12, months postoperatively. RESULTS: In the broad-beam laser group no eye lost two or more lines of best-corrected visual acuity;in the scanning-spot laser group one eye lost two lines 12 months postoperatively. Efficacy, predictability, and stability were comparable between the two groups. CONCLUSIONS: Both the broad-beam and the scanning-spot laser provided good results after PRK/PARK for low myopia and myopic astigmatism. This study found no fundamental differences between the two laser systems.


Subject(s)
Astigmatism/surgery , Myopia/surgery , Photorefractive Keratectomy/instrumentation , Adult , Female , Follow-Up Studies , Humans , Lasers, Excimer , Male , Middle Aged , Refraction, Ocular , Treatment Outcome
16.
J Immunol ; 166(2): 736-40, 2001 Jan 15.
Article in English | MEDLINE | ID: mdl-11145644

ABSTRACT

Glycosphingolipid-enriched domains (GEDs) are believed to act as platforms for transduction of B cell Ag receptor (BCR)-induced signals from the cell surface. We sought to study whether differential sequestration of BCR into GEDs may contribute to the described intrinsic signaling differences between mature and immature B cells. In this study we found that mature B cells copolarize the BCR with GEDs following BCR aggregation, whereas transitional immature B cells do not. Although anti-BCR treatment leads to receptor aggregation by immature stage B cells, the aggregated complexes do not colocalize with GEDs. We found this difference to be independent of the isotype of the receptor, thereby associating this difference in BCR-GED colocalization to the developmental stage of the B cell. These findings suggest a structural basis for the developmentally regulated differences observed in Ag receptor-mediated signal transduction.


Subject(s)
B-Lymphocytes/metabolism , Glycosphingolipids/metabolism , Membrane Microdomains/immunology , Membrane Microdomains/metabolism , Receptors, Antigen, B-Cell/metabolism , Animals , B-Lymphocytes/cytology , B-Lymphocytes/immunology , Cell Differentiation/immunology , Cell Membrane/immunology , Cell Membrane/metabolism , Cell Polarity/immunology , Female , Immune Sera/pharmacology , Immunoglobulin D/biosynthesis , Immunoglobulin Isotypes/biosynthesis , Immunoglobulin M/biosynthesis , Mice , Mice, Inbred BALB C , Receptors, Antigen, B-Cell/immunology
17.
J Refract Surg ; 17(6): 689-91, 2001.
Article in English | MEDLINE | ID: mdl-11758988

ABSTRACT

PURPOSE: To report the clinical and confocal microscopic characteristics of reticular folds (mudcracks) in a cornea after laser in situ keratomileusis (LASIK). METHODS: A 30-year-old male showed reticular flap folds on slit-lamp examination 1 week after LASIK. In addition to slit-lamp biomicroscopy, confocal in vivo microscopy was performed. RESULTS: Examination with a confocal white-light slit-scanning microscope revealed distinct folds of Bowman's layer and underlying microfolds throughout the flap stroma. After flap re-lifting, no changes could be determined, either clinically or by confocal microscopy. At 12 months following the procedure, best spectacle-corrected visual acuity was slightly improved, but the folds, as imaged by confocal microscopy, still persisted. CONCLUSIONS: In the present case, reticular folds after LASIK involved the entire thickness of the flap. Simple flap lifting was not sufficient for smoothing out the folds.


Subject(s)
Corneal Diseases/diagnosis , Corneal Stroma/pathology , Keratomileusis, Laser In Situ/adverse effects , Surgical Flaps/pathology , Adult , Corneal Diseases/etiology , Corneal Diseases/surgery , Humans , Male , Microscopy, Confocal , Myopia/surgery , Reoperation , Visual Acuity
18.
Ophthalmologe ; 97(10): 669-75, 2000 Oct.
Article in German | MEDLINE | ID: mdl-11105542

ABSTRACT

BACKGROUND: A prospective, randomized study was performed to evaluate intra-individually the biocompatibility of foldable, highly refractive silicone and hydrophobic acrylic intraocular lenses (IOL). MATERIALS AND METHODS: We studied 35 patients who underwent phacoemulsification using a self-sealing tunnel incision. In a randomized fashion one eye received a 6-mm optic IOL made of high-refractive index silicone (Allergan SI40NB) and the other eye a hydrophobic acrylic 6-mm optic IOL (Alcon AcrySof MA60BM). All patients were examined 7 days, 1-3 and 6 months, and 1 year postoperatively. RESULTS: The mean best-corrected visual acuity (BCVA) was 0.9 +/- 0.12 vs. 0.89 +/- 0.13 (SI40NB vs. MA60BM) after 1-3 months. One-year postoperatively BCVA was still 0.9 +/- 0.12 vs. 0.87 +/- 0.14. The flare values (photon counts/ms) increased slightly 7 days after surgery (14.2 +/- 8.68 vs. 15.49 +/- 7.2, n.s.). Three months after surgery these values were again in the normal range. The mean IOL decentration was 0.29 +/- 0.14 vs. 0.3 +/- 0.15 mm 1 year postoperatively. Scheimpflug slit photography showed 40% of MA60BM IOLs to have "glistenings." No significant difference regarding posterior capsular opacification was found. CONCLUSION: One year after implantation of foldable, highly refractive silicone and hydrophobic acrylic IOLs using a self-sealing tunnel incision and phacoemulsification, no significant functional or morphological differences between the two IOL types were observed.


Subject(s)
Acrylates , Biocompatible Materials , Lenses, Intraocular , Silicones , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Male , Postoperative Complications/etiology , Prospective Studies
19.
J Cataract Refract Surg ; 26(6): 859-66, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10889432

ABSTRACT

PURPOSE: To prospectively measure the scotopic pupil diameter in a normal population and to compare 2 infrared pupillometers for these measurements. SETTING: Johann Wolfgang Goethe-University, Department of Ophthalmology, Frankfurt am Main, Germany. METHODS: The Colvard infrared pupillometer was compared to the Video Vision Analyzer (VIVA) infrared pupillometer under scotopic light conditions in 33 participants (aged 19 to 55 years). Reliability was assessed by 2 independent examiners (E1, E2). Statistical analysis was performed using a comparison method by Bland and Altman. RESULTS: Mean pupil diameter was 6.16 mm +/- 1.20 (SD) (range 3.20 to 9.00 mm) with all measurements taken under scotopic illumination. The mean scotopic pupil diameter was 6.08 +/- 1.16 mm (range 3.2 to 8.4 mm) with the Colvard pupillometer and 6.24 +/- 1.28 mm (3.5 to 9.0 mm) with the VIVA pupillometer. The mean differences between the Colvard and VIVA were -0.27 mm (E1) and -0.05 mm (E2). Limits of agreement ranged from 1.4 (Colvard) to 2.4 (VIVA). The coefficients of repeatability ranged from 0.7 (Colvard) to 1.1 (VIVA). CONCLUSIONS: A mean scotopic pupil diameter of 6.15 mm with a maximal pupil size of 9.00 mm can be expected in a normal population; this should be considered in refractive corneal and refractive lens surgery. Measurements with the Colvard pupillometer were more reliable and precise than those with the VIVA pupillometer.


Subject(s)
Dark Adaptation/physiology , Diagnostic Techniques, Ophthalmological/instrumentation , Infrared Rays , Pupil/physiology , Video Recording , Adult , Aging/physiology , Equipment Design , Eye Color , Female , Humans , Male , Middle Aged , Observer Variation , Prospective Studies , Reference Values
20.
Ophthalmology ; 107(5): 934-9, 2000 May.
Article in English | MEDLINE | ID: mdl-10811086

ABSTRACT

OBJECTIVE: To analyze the surface quality of new generation phakic intraocular lenses (IOLs). DESIGN: Experimental materials study. MATERIALS: Three different new generation phakic IOLs: angle-fixated anterior chamber lens Chiron Vision NuVita MA20 (polymethylmethacrylate [PMMAD, iris-fixated anterior chamber lens Ophtec Artisan Iris-Claw (PMMA), posterior chamber lens Staar ICM (polymer from porcine collagen and 2-hydroxyethyl methacrylate [HEMA]). METHODS: Representative samples of three different phakic IOLs underwent surface and edge-finish examination with light microscopy (LM). The phakic IOLs were then examined by use of scanning electron microscopy (SEM), and particular attention was given to optic surface quality, edge finish, haptic, and optic/haptic junction. RESULTS: In all IOLs the LM examination showed a smooth and homogeneous surface. No irregularities, particularly at the optic front and back surface, optic edge, haptic, and the optic/haptic junctions, were detected by SEM. One exception was a minor surface roughness at the claws of an Artisan iris-fixated anterior chamber IOL. CONCLUSIONS: Phakic IOLs are implanted either in the anterior or posterior chamber of healthy eyes, and high standards for their surface quality are required. The evaluation of surface properties with LM and SEM did not reveal any defects that contraindicate the implantation of phakic IOLs.


Subject(s)
Lens, Crystalline , Lenses, Intraocular , Microscopy, Electron, Scanning , Biocompatible Materials , Humans , Methacrylates , Polymethyl Methacrylate , Refractive Surgical Procedures , Surface Properties
SELECTION OF CITATIONS
SEARCH DETAIL
...