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Koelbl PS, Lingenfelder C, Spraul CW, Kampmeier J, Koch FH, Kim YK, Hessling M. An intraocular micro light-emitting diode device for endo-illumination during pars plana vitrectomy. Eur J Ophthalmol 2018; 29:75-81. [PMID: 29592777 DOI: 10.1177/1120672118757618] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE: Development of a new, fiber-free, single-use endo-illuminator for pars plana vitrectomy as a replacement for fiber-based systems with external light sources. The hand-guided intraocularly placed white micro light-emitting diode is evaluated for its illumination properties and potential photochemical and thermal hazards. METHODS: A micro light-emitting diode was used to develop a single-use intraocular illumination system. The light-source-on-tip device was implemented in a prototype with 23G trocar compatible outer diameter of 0.6 mm. The experimental testing was performed on porcine eyes. All calculations of possible photochemical and thermal hazards during the application of the intraocular micro light-emitting diode were calculated according to DIN EN ISO 15007-2: 2014. RESULTS: The endo-illuminator generated a homogeneous and bright illumination of the intraocular space. The color impression was physiologic and natural. Contrary to initial apprehension, the possible risk caused by inserting a light-emitting diode into the intraocular vitreous was much smaller when compared to conventional fiber-based illumination systems. The photochemical and thermal hazards allowed a continuous exposure time to the retina of at least 4.7 h. CONCLUSION: This first intraocular light source showed that a light-emitting diode can be introduced into the eye. The system can be built as single-use illumination system. This light-source-on-tip light-emitting diode-endo-illumination combines a chandelier wide-angle illumination with an adjustable endo-illuminator.
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Affiliation(s)
- Philipp S Koelbl
- 1 Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
| | | | | | | | - Frank Hj Koch
- 5 Clinic of Ophthalmology, Goethe University Frankfurt, Frankfurt, Germany
| | | | - Martin Hessling
- 1 Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany
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Weyrich C, Drögeler M, Kampmeier J, Eschbach M, Mussler G, Merzenich T, Stoica T, Batov IE, Schubert J, Plucinski L, Beschoten B, Schneider CM, Stampfer C, Grützmacher D, Schäpers T. Growth, characterization, and transport properties of ternary (Bi 1-x Sb x ) 2Te 3 topological insulator layers. J Phys Condens Matter 2016; 28:495501. [PMID: 27749271 DOI: 10.1088/0953-8984/28/49/495501] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ternary (Bi1-x Sb x )2Te3 films with an Sb content between 0 and 100% were deposited on a Si(1 1 1) substrate by means of molecular beam epitaxy. X-ray diffraction measurements confirm single crystal growth in all cases. The Sb content is determined by x-ray photoelectron spectroscopy. Consistent values of the Sb content are obtained from Raman spectroscopy. Scanning Raman spectroscopy reveals that the (Bi1-x Sb x )2Te3 layers with an intermediate Sb content show spatial composition inhomogeneities. The observed spectra broadening in angular-resolved photoemission spectroscopy (ARPES) is also attributed to this phenomena. Upon increasing the Sb content from x = 0 to 1 the ARPES measurements show a shift of the Fermi level from the conduction band to the valence band. This shift is also confirmed by corresponding magnetotransport measurements where the conductance changes from n- to p-type. In this transition region, an increase of the resistivity is found, indicating a location of the Fermi level within the band gap region. More detailed measurements in the transition region reveals that the transport takes place in two independent channels. By means of a gate electrode the transport can be changed from n- to p-type, thus allowing a tuning of the Fermi level within the topologically protected surface states.
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Affiliation(s)
- C Weyrich
- Peter Grünberg Institute (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. Helmholtz Virtual Institute for Topological Insulators (VITI), Forschungszentrum Jülich, 52425 Jülich, Germany
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Olbrich P, Golub LE, Herrmann T, Danilov SN, Plank H, Bel'kov VV, Mussler G, Weyrich C, Schneider CM, Kampmeier J, Grützmacher D, Plucinski L, Eschbach M, Ganichev SD. Room-temperature high-frequency transport of dirac fermions in epitaxially grown Sb2Te3- and Bi2Te3-based topological insulators. Phys Rev Lett 2014; 113:096601. [PMID: 25215999 DOI: 10.1103/physrevlett.113.096601] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Indexed: 05/27/2023]
Abstract
We report on the observation of photogalvanic effects in epitaxially grown Sb2Te3 and Bi2Te3 three-dimensional (3D) topological insulators (TI). We show that asymmetric scattering of Dirac fermions driven back and forth by the terahertz electric field results in a dc electric current. Because of the "symmetry filtration" the dc current is generated by the surface electrons only and provides an optoelectronic access to probe the electron transport in TI, surface domains orientation, and details of electron scattering in 3D TI even at room temperature.
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Affiliation(s)
- P Olbrich
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - L E Golub
- Ioffe Physical-Technical Institute, 194021 St. Petersburg, Russia
| | - T Herrmann
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - S N Danilov
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - H Plank
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - V V Bel'kov
- Ioffe Physical-Technical Institute, 194021 St. Petersburg, Russia
| | - G Mussler
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - Ch Weyrich
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - C M Schneider
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - J Kampmeier
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - D Grützmacher
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - L Plucinski
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - M Eschbach
- Jülich Aachen Research Alliance (JARA-FIT), Leo Brandt Straße, 52425 Jülich, Germany
| | - S D Ganichev
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
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Kampmeier J, Cucera A, Fritzsche L, Brau H, Duthweiler M, Lang GK. Eignung monokularer „Augmented Reality”-Technologien in der Automobilproduktion. Klin Monbl Augenheilkd 2007; 224:590-6. [PMID: 17657694 DOI: 10.1055/s-2007-963359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Augmented reality (AR) technologies can enrich the real environment with visual data, which has potential benefits for optimising the operator's working process. It offers the possibility to provide context-sensitive information independently of the user's location and position. Data are presented to the dominant eye on a semi-transparent mirror using a head-mounted display (HMD) unit that works with retinal laser technology. In this study the potential benefits and drawbacks of this new AR technology were evaluated. MATERIALS AND METHODS 45 participants without any visual impairment were randomly assigned to 3 groups and completed a variety of tasks during a simulated working day. Group 1 received conventional working aids (paper-based documents) to support the task processing. Group 2 additionally wore an HMD unit that was switched off. Group 3 wore a functioning HMD without any additional aids. Evaluation was carried out by means of a standardised questionnaire (BMS) and a concentration test ("d2 Aufmerksamkeits-Belastungs-Test"). RESULTS No significant differences between the 3 groups were found in terms of mental strain, concentration-test performance and physical or mental complaints reported in a follow-up interview. Around 20 % of the subjects noticed a higher pressure and blurred vision in both eyes as well as headaches. Half of the participants complained about deficiencies concerning the ergonomic hardware design of the AR system. DISCUSSION Changes in objective ophthalmological investigation parameters were not observed. Subjects reported reduced acceptance of the HMD based on non-ophthalmological reasons, for example, the weight of the unit or the length of the cable. However, for some specific working tasks, advantages in process optimisation and operator support were observed.
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Affiliation(s)
- J Kampmeier
- Augenklinik, Universitätsklinikum Ulm, Ulm, Germany.
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Kampmeier J, Zorn MM, Lang GK, Botros YT, Lang GE. [Comparison of Preferential Hyperacuity Perimeter (PHP) test and Amsler grid test in the diagnosis of different stages of age-related macular degeneration]. Klin Monbl Augenheilkd 2006; 223:752-6. [PMID: 16986086 DOI: 10.1055/s-2006-926880] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Age-related macular degeneration (ARMD) is the leading cause of blindness in people over 65 years of age. A rapid loss of vision occurs especially in cases with choroidal neovascularisation. Early detection of ARMD and timely treatment are mandatory. We have prospectively studied the results of two diagnostic self tests for the early detection of metamorphopsia and scotoma, the PHP test and the Amsler grid test, in different stages of ARMD. PATIENTS AND METHODS Patients with ARMD and best corrected visual acuity of 6/30 or better (Snellen charts) were examined with a standardised protocol, including supervised Amsler grid examination and PHP, a new device for metamorphopsia or scotoma measurement, based on the hyperacuity phenomenon in the central 14 degrees of the visual field. The stages of ARMD were independently graded in a masked fashion by stereoscopic ophthalmoscopy, stereoscopic fundus colour photographs, fluorescein angiography, and OCT. The patients were subdivided into 3 non-neovascular groups [early, late (RPE atrophy > 175 microm) and geographic atrophy], a neovascular group (classic and occult CNV) and an age-matched control group (healthy volunteers). RESULTS 140 patients, with ages ranging from 50 to 90 years (median 68 years), were included in the study. Best corrected visual acuity ranged from 6/30 to 6/6 with a median of 6/12. 95 patients were diagnosed as non-neovascular ARMD. Thirty eyes had early ARMD (9 were tested positive by the PHP test and 9 by the Amsler grid test), and 50 late ARMD (positive: PHP test 23, Amsler grid test 26). The group with geographic atrophy consisted of 15 eyes (positive: PHP test 13, Amsler grid test 10). Forty-five patients presented with neovascular ARMD (positive: PHP test 38, Amsler grid test 36), 34 volunteers served as control group (positive: PHP test 1, Amsler grid test 5). CONCLUSIONS The PHP and Amsler grid tests revealed comparable results detecting metamorphopsia and scotoma in early ARMD (30 vs. 30 %) and late ARMD (46 vs. 52 %). However, the PHP test more often revealed disease-related functional changes in the groups of geographic atrophy (87 vs. 67 %) and neovascular ARMD (84 vs. 80 %). This implies that the PHP and Amsler grid self tests are useful tools for detection of ARMD and that the PHP test has a greater sensitivity in the groups of geographic atrophy and neovascular AMD.
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Kampmeier J, Baldysiak-Figiel A, de Jong-Hesse Y, Lang GK, Lang GE. Effect of growth factors on proliferation and expression of growth factor receptors in a human lens epithelial cell line. J Cataract Refract Surg 2006; 32:510-4. [PMID: 16631066 DOI: 10.1016/j.jcrs.2005.08.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2005] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate the effect of basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), insulin-like growth factor 1 (IGF-1), and transforming growth factor beta 2 (TGFbeta2) on proliferation of a human lens epithelial cell line (HLEC-SRA 01/04); the effect of bFGF and TGFbeta2 on proliferation of human lens epithelial cells (HLECs); and the expression of bFGF, EGF, IGF-1, and TGFbeta2 receptors in an HLEC-SRA 01/04 cell line. SETTING Department of Ophthalmology, University of Ulm, Ulm, Germany. METHODS Both HLEC and HLEC-SRA 01/04 were treated with 1 to 50 ng/mL bFGF and TGFbeta2) Additionally, HLEC-SRA 01/04 were cultured with EGF and IGF-1 at a concentration of 1 to 50 ng/mL for 48 hours in the presence of [3H]-thymidine. In all experiments, untreated serum-free negative controls were used. (3H)-thymidine incorporation as a direct measure of lens epithelial cell proliferation was assessed by liquid scintillation counting. The expression of bFGF, EGF, IGF-1, and TGFbeta2 receptors in HLEC-SRA 01/04 were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR). Statistical analysis was performed using the 2-sample t test for the means. RESULTS Proliferation of HLECs was dose dependently induced by bFGF and TGFbeta2, showing maximum effects at 10 ng/mL (P = .0003) and at 50 ng/mL (P < .0001), respectively. Proliferation of HLEC-SRA 01/04 was also induced by bFGF, showing slight but significant effects (P < .03). Additionally, HLEC-SRA 01/04 proliferation was dose-dependently induced by EGF with a maximum effect at 5 ng/mL (P < .01), IGF-1 with a maximum effect at 5 ng/mL (P < .0001), and TGFbeta2 with a maximum effect at 10 ng/mL (P < .0001) compared with the control. The RT-PCR analysis revealed bFGF, EGF, IGF-1, and TGFbeta2 receptor expression in the HLEC-SRA 01/04 cell line. CONCLUSIONS The data showed that bFGF and TGFbeta2 are strong mitogens for HLEC. The HLEC-SRA 01/04 cell line derived from HLEC reacted to growth factors, with cell proliferation only to a lesser extent. Such quiescence of these cells, when compared with cells in primary culture, cannot be explained by the lack of respective receptors for growth factors. Further investigation of growth factor-induced responses of both cell types will provide new insight into the proliferative processes involved in postoperative secondary cataract formation.
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Abstract
BACKGROUND We have performed an in-vitro examination of the morphology of flap thickness and stromal bed after LASIK in porcine eyes. MATERIALS AND METHODS Freshly enucleated porcine eyes and synthetic eye models were used for cutting flaps with the microkeratomes Hansatome-Excellus (Bausch&Lomb), M2 single use (Moria), Amadeus (AMO), MK-2000 (Nidek) and Carriazo-Pendular (Schwind). The flap thickness of porcine eyes was determined using a non-contact, confocal optical distance measuring device (CHR 150N, Jurca), in the eye models a mechanical thickness measuring device (Käfler) was used. The morphology of the stromal bed was examined by photography, histology, scanning electron microscopy and confocal optical distance measurements. RESULTS The optical/mechanical flap thickness measurements showed an average difference compared to the adjusted thickness of - 3/+ 90 microm (Hansatome-Excellus), + 7/+ 100 microm (M2 single use), - 35/+ 40 microm (Amadeus), - 4/+ 80 microm (MK-2000) and + 11/+ 0 microm (Carriazo-Pendular). Histology showed no mechanical damage and smooth, slightly undulating surfaces with all microkeratomes. In the scanning electron microscopic examination, the stromal surface was found to be homogeneous and smooth for all of the microkeratomes. Average roughness of the ablation surface was 0.27 microm (Hansatome-Excellus), 0.23 microm (M2 single use), 0.21 microm (Amadeus), 0.23 microm (MK-2000) and 0.29 microm (Carriazo-Pendular). CONCLUSION The stromal bed showed in all cases only a slightly roughness, which seems to be acceptable for the clinical outcome. However, the more critical point is the large variations in flap thickness compared to the intended thickness.
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Affiliation(s)
- S Schäfer
- Augenklinik, Universitätsklinikum Ulm.
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Abstract
BACKGROUND Postoperative hyperopia is a frequent result of cataract surgery in eyes after previous myopic kerato-refractive surgery. One reason for the underestimation of intraocular lens (IOL) power is the wrong corneal refractive power measurement obtained by keratometers and corneal topography systems after LASIK. The aim of this study was to compare the precision of measurements of three different keratometers after LASIK. METHOD We studied 58 eyes of 34 refractive patients aged between 20 and 51 years. The preoperative measurements and the measurements one month after LASIK were performed with the Keratometer (Zeiss), the corneal topograph (EyeSys Technologies) and the IOL-Master (Zeiss). We compared our postoperative measurement results obtained with the three keratometers with the results obtained by using the clinical history method (chm). RESULTS The smallest mean deviation was achieved with the IOL-Master (measured mean +/- SD: 38.94 +/- 1.88 D, vs. chm: 38.35 +/- 2.13 D). The Keratometer (Zeiss) showed a larger deviation (measured: 39.12 +/- 1.76 D, chm 38.34 +/- 2.07 D) and the largest deviation was shown with the corneal topograph (measured: 39.84 +/- 1.85 D, chm: 38.86 +/- 2.10 D), which measured in mean one diopter higher than what was obtained utilizing the chm. A positive correlation between corrected myopia and the postoperative difference between the measured and calculated value for each keratometer was found. CONCLUSION This study demonstrates that with common keratometers central corneal power is measured too high after LASIK. For IOL calculation in patients after LASIK, the wrongly positive deviation from measured central corneal power has to be taken into account.
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Affiliation(s)
- S Schäfer
- Augenklinik, Universitätsklinikum Ulm.
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de Jong-Hesse Y, Kampmeier J, Lang GK, Lang GE. Effect of extracellular matrix on proliferation and differentiation of porcine lens epithelial cells. Graefes Arch Clin Exp Ophthalmol 2005; 243:695-700. [PMID: 15702326 DOI: 10.1007/s00417-004-1116-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Revised: 12/01/2004] [Accepted: 12/08/2004] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND Proliferation and differentiation of lens epithelial cells (LECs) are important mechanisms of secondary cataract formation. After extracapsular cataract extraction the extracellular matrix (ECM) around the remaining LECs is altered compared with the intact lens. This study investigated the effects of different ECMs on cell proliferation and alpha-smooth muscle actin (alpha-SMA) expression, a marker for myofibroblasts, in cultured porcine LECs. METHODS Porcine LECs were cultured for 3 days (cell proliferation assay) or 4 days (alpha-SMA expression) on wells and glass cover slips, respectively, coated with laminin, fibronectin, type I collagen or type IV collagen. LECs cultured on uncoated wells or cover slips served as control. Proliferative response was measured by [(3)H]-thymidine incorporation into DNA. alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the relative numbers of alpha-SMA-positive cells were calculated. Statistical analysis was performed using Student's unpaired t-test. RESULTS Cell proliferation was significantly increased by coating with fibronectin (10,320.5+/-6,073 counts per minute; p<0.0001) (mean +/- SD), type I collagen (12,507.3+/-3,914.2 CPM; p<0.0001) and type IV collagen (9,591.4+/-4,088 CPM; p<0.0001) compared with control (1,876.5+/-998 CPM), whereas coating with laminin had no effect (1,760.8+/-812.6 CPM; p=0.7271). The ratio of alpha-SMA-positive LECs cultured on uncoated cover slips for a period of 4 days was 12.2+/-3.51%. This ratio was significantly increased by coating with fibronectin (24.3+/-4.56%; p=0.0001) and type I collagen (21.2+/-8.48%; p=0.0142). Coating with laminin (9.8+/-3.67%; p=0.1682) and type IV collagen (9.0+/-7.09 %; p=0.2491) slightly decreased alpha-SMA expression, but this effect was not statistically significant. CONCLUSIONS Fibronectin and type I collagen stimulated both cell proliferation and alpha-SMA expression in cultured porcine LECs. Because fibronectin and type I collagen are not normally present in the adult lens, their possible introduction into the lens capsule after cataract surgery may play a critical role in the development of posterior capsule opacification.
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Affiliation(s)
- Yvonne de Jong-Hesse
- Department of Ophthalmology, University of Ulm, Prittwitzstrasse 43, 89075 Ulm, Germany
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Müller A, Schnaidt A, Buchwald HJ, Kampmeier J. [Comparison of different methods for pupillometry for mesopic and scotopic conditions]. Klin Monbl Augenheilkd 2004; 221:843-8. [PMID: 15499519 DOI: 10.1055/s-2004-813554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND The aim of the study was to compare different methods for pupillometry, namely the Goldmann perimeter (gp), the Colvard pupillometer (cp) and the Procyon Video pupillometer (pvp). For the pvp three different illuminations were available: mesopic high, mesopic low, and scotopic. PATIENTS The size of the pupil was measured in 100 eyes (50 healthy subjects) with the three different methods. We examined 29 females (58 %) and 21 males (42 %) with an average age of 25.16 years, ranging from 18 to 30 years. RESULTS For the Goldmann perimeter, a mean pupil diameter of 4.39 mm +/- 0.62 mm was found under mesopic conditions (1.40 lux). For the Colvard pupillometer for scotopic conditions (0 lux), a mean pupil diameter of 6.80 mm +/- 0.81 mm was found. For pvp the pupil diameter ranged from 7.06 mm +/- 0.71 mm for scotopic (0.04 lux), over 6.24 mm +/- 0.80 mm for mesopic low (0.40 lux) to 4.65 mm +/- 0.73 mm for mesopic high conditions (4.00 lux). CONCLUSION The comparison of the results showed a high correlation between the Goldmann perimeter and the Procyon Video Pupillometer for mesopic high with a minimum difference of 0.25 +/- 0.69 mm. By addition of 2.67 mm to the mesopic measurement of the Goldmann perimeter, the results for the Procyon Video pupillometer at the scotopic level, by addition of 2.4 mm the scotopic measurement of the Colvard pupillometer could be achieved.
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Affiliation(s)
- A Müller
- Universitätsklinikum Ulm, Augenklinik, Ulm.
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Remsch H, Kampmeier J, Muche R, Lang GE, Lang GK. Vergleich der optischen Kohärenzmethode (Zeiss IOL-Master) mit zwei ultrasonographischen Biometrieverfahren zur Kunstlinsenkalkulation nach Phakoemulsifikation im klinischen Alltag. Klin Monbl Augenheilkd 2004; 221:837-42. [PMID: 15499518 DOI: 10.1055/s-2004-813658] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND The aim of this work was to investigate the accuracy of prediction of three different biometric methods for the calculation of posterior chamber intraocular lenses. METHODS In 59 consecutive patients who underwent extracapsular cataract-extraction with posterior chamber intraocular lens implantation, we compared the refractive results at the first day (D1) and 6 weeks (W6) after surgery with the calculated refraction of three biometric methods: the Carl Zeiss "IOL-Master 99" (IOLM), the Biovision "Echograph Class 1 - Type B" (BIOV) and the Allergan Humphrey "Ultrasonic Biometer Mod. 820" (AHUB). For statistical calculation box-plots, the Wilcoxon signed-rank test and linear regression analysis were used. RESULTS In all patients the mean of the postoperative refraction was - 0.07 D (SD: 1.41) at day 1 and 0.12 D (SD: 1.18) at week 6. Compared to the postoperative refraction at week 6, the calculated refractive values were higher in all three measuring devices: IOLM: + 0.28 D (SD: 0.67), BIOV: + 0.60 D (SD: 0.88), AHUB: + 0.26 D (SD: 0.92). There were no statistically significant differences between IOLM and BIOV, or respectively, AHUB and BIOV (p < 0.0001), but a significant difference was found between IOLM and AHUB, (p = 0.906). To adjust for systematic differences of the agreement, one can calculate the postoperative refraction at week 6 (REF6) from IOLM by using the linear regression formula: REF6 = 1.1 x IOLM + 0.3. CONCLUSION A comparison between the three biometric methods and the refractive results at day 1 and week 6 after cataract surgery with implantation of a posterior chamber intraocular lens showed that the calculated mean values obtained from the three biometric methods are higher than the real postoperative refraction. Calculations using the Zeiss IOL-Master and the Allergan Humphrey Ultrasonic Biometer are closer to the patient's postoperative refraction than calculations using the Biovision Echograph.
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Affiliation(s)
- H Remsch
- Augenklinik, Universitätsklinikum Ulm
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Müller A, Godenschweger L, Lang GE, Kampmeier J. Prospektiver Vergleich des neuen Impressionstonometers TGDc-01 und des Non-Kontakt-Tonometers PT 100 mit der etablierten Goldmann-Applanationstonometrie. Klin Monbl Augenheilkd 2004; 221:762-8. [PMID: 15459844 DOI: 10.1055/s-2004-813566] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND This study aimed to compare the results of newer tonometric techniques with standard tonometry for the examples of the Goldmann applanation tonometry (GAT), the indentation tonometer "TGDc-01" and the non-contact tonometer "PT 100". PATIENTS The study was conducted on a total of 52 healthy subjects. The IOP was measured in each subject on both eyes with all three methods. There were 27 males (51.9 %), 25 females (48.1 %) with an average age of 28.5 years, with a minimum of 13 and a maximum of 79 years. RESULTS There was no statistically significant difference between the non-contact and the Goldmann applanation tonometry. The measurements were 0.4 mmHg lower, no difference for the left or right side was seen. For IOP higher than 15 mmHg - 0.88 mmHg lower and for IOP lower 15 mmHg - 0.15 mmHg. The results for the "TGDc01" were 0.82 mmHg lower than GAT, the standard deviation was a little higher with 2.9 mmHg compared to 2.67 mmHg for GAT. For IOP higher than 15 mmHg they rose up to - 2.28 mmHg, for IOP lower than 15 mmHg the results for "TGDc-01" were only - 0.2 mmHg lower. There was also an effect with respect to the side, on the right eye the difference was significant with 3.03 mmHg (p = 0.006), in contrast to the left eye with 2.69 mmHg (p = 0.235). For "TGDc01" the standard deviation was higher with 2.9 mmHg compared to 2.6 mmHg for "PT 100". CONCLUSIONS The non-contact tonometer showed no clinical relevant difference compared with GAT for measuring IOP. The indentation tonometer showed differences for precision, for higher tension IOP the measurement was lower compared with GAT. There was also a significant side difference using the "TGDc-01".
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Affiliation(s)
- A Müller
- Universitätsklinikum Ulm, Augenklinik, Ulm.
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Jong-Hesse YD, Lang GK, Kampmeier J, Lang GE. Einfluss von Wachstumsfaktoren auf die Differenzierung von porcinen Linsenepithelzellen. Klin Monbl Augenheilkd 2004; 221:175-9. [PMID: 15052522 DOI: 10.1055/s-2004-812882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Besides cell proliferation, transdifferentiation of lens epithelial cells (LECs) to myofibroblasts is one of the mechanisms of secondary cataract formation. This process is characterized by increased expression of alpha-smooth muscle actin (alpha-SMA). This study investigated the influence of bFGF, TGF-beta2, EGF and IGF-1 on the expression of alpha-SMA in porcine LECs. MATERIALS AND METHODS Porcine LECs were cultured for 7 days in serum-free medium without or with 1 to 50 ng/ml bFGF, TGF-beta2, EGF or IGF-I. Alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the relative numbers of alpha-SMA-positive cells were calculated. Statistical analysis was performed using Student's unpaired t-test. RESULTS The ratio of alpha-SMA-positive cells cultured for 7 days in serum-free medium was 36 +/- 11.9 % (mean +/- SD). BFGF significantly reduced this ratio in a dose-dependent manner to 11.2 +/- 7.3 % at a concentration of 50 ng/ml (p < 0.0001). EGF reduced the ratio significantly to 25.1 +/- 15.7 % (p = 0.05) when 50 ng/ml were applied. IGF-1 (10 ng/ml) reduced the relative numbers of transdifferentiated cells to 16.8 +/- 5.8 %, but the reduction was not statistically significant (p = 0.0787). TGF-beta2 (50 ng/ml) slightly increased the relative number of alpha-SMA-positive cells to 44.2 +/- 13.8 %. However, this increase was not significant (p = 0.1202) during a culture period of 7 days. CONCLUSIONS BFGF and EGF significantly reduced the expression of alpha-SMA by LECs while TGF-beta and IGF-1 had no statistically significant effect. These results suggest that bFGF and EGF do not primarily induce secondary cataract formation by the mechanism of cell transdifferentiation.
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Abstract
Ocular diseases such as proliferative diabetic retinopathy are the major cause of blindness in industrialized countries. The main pathologic features of these diseases are hypoxia and overproduction of growth factors resulting in pathologic proliferation of endothelial cells and new vessel formation. Particularly, hypoxia and growth factors, such as VEGF, IGF-1, bFGF and TGF beta(2), show a complex interaction in the onset and progression of the diseases. Therefore, to date, most therapeutic strategies for proliferative retinopathies have targeted proliferation of endothelial cells evoked by growth factors. Recently, a synthetic analog of somatostatin, octreotide, has been shown to inhibit the proliferation of various cells in vitro, including endothelial cells. In this study, we have investigated the proliferative response of bovine retinal endothelial cells (BREC) to growth factors under hypoxic conditions and the modulation by octreotide. We found a dose-dependent increase of cell proliferation with VEGF, IGF-1 and bFGF, and inhibition of hypoxia-induced cell proliferation with TGF beta(2). Moreover, growth factor-induced, but not hypoxia-induced, cell proliferation was attenuated in the presence of octreotide. In contrast, TGF beta(2) abolished hypoxia-induced BREC proliferation. Similar to octreotide BIM23027, a somatastatin receptor subtype 2 (SSTR2) receptor agonist was able to attenuate the growth factor-induced proliferation of BREC expressing mRNA and protein for SSTR2. Therefore, we postulate that octreotide exerts its effects mainly through binding to the SSTR2. Taken together, our findings point to octreotide as a promising candidate for the treatment of eye disorders involving growth factor-dependent proliferation of endothelial cells.
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Kampmeier J, Spraul CW, Buchwald HJ, Lang K. Refraktive Chirurgie. Klin Monbl Augenheilkd 2004. [DOI: 10.1055/s-2004-821346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Kampmeier J, Bentele A, Stock K, Wagner P, Hibst R, Lang GE, Steiner R, Lang GK. [Intracanalicular trabeculostomy with the Er:YAG laser]. Ophthalmologe 2002; 99:927-32. [PMID: 12478379 DOI: 10.1007/s00347-002-0683-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To develop a new ab externo technique for glaucoma trabecular surgery using the infrared Er:YAG laser radiation (2.9 micrometer) guided into Schlemm's canal by an optical fiber. MATERIAL AND METHODS In order to create a drainage canal to the anterior chamber, a quartz fiber (core diameter: 100 micrometer) coupled to an Er:YAG laser was shielded by a metal canula (diameter: 280 micrometer) bent in conformance to the curvature of Schlemm's canal. A 45 degrees -mirror enabled the laser radiation to exit the canula perpendicular to the fiber axis. The complete surgery device was tested on agar medium and enucleated human eyes. RESULTS Using the unshielded quartz fiber, eight pulses of 8 mJ (frequency: 7 Hz, pulse duration: 150 microseconds) were sufficient to perforate the trabecular meshwork of the human eye. Histology showed a rippled canal with 50 micrometer average diameter and a surrounding necrosis zone of 15-35 micrometer. The complete device could be easily inserted into Schlemm's canal similar to the classic trabeculostomy probe and a conical-shaped canal with a length of 2-3 mm could be created in agar medium within a few seconds. CONCLUSIONS Initial experience in an experimental set-up show the ab externo creation of a draining canal between Schlemm's canal and the anterior chamber with only minimal irritation of the surrounding tissue. Further refinements of the laser parameters and the biomechanical set-up resulted in a new hand-held device with improved function. The Er:YAG laser intracanalicular trabeculostomy could become a new ab externo technique for minimal invasive therapy of open angle glaucoma.
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Affiliation(s)
- J Kampmeier
- Universitätsklinikum Ulm, Augenklinik, Germany.
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Kampmeier J, Eisert B, Buchwald HJ, Lang GK, Lang GE. [Prospective randomized comparative study of frequency doubling perimetry vs standard automated perimetry in patients with glaucoma]. Klin Monbl Augenheilkd 2001; 218:157-67. [PMID: 11322052 DOI: 10.1055/s-2001-13075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AIM To compare frequency doubling perimetry (FDP) versus standard automated perimetry in glaucoma. To evaluate the reproducibility of both methods. PATIENTS AND METHODS All the patients were tested (full threshold test) twice with both FDP (N-30) and Humphrey Field Analyzer II model 750 (HFA) (30-2 procedures) in random sequence, within one day. The parameters mean deviation (MD), pattern standard deviation (PSD) and measured thresholds per quadrant and center areas were evaluated for FDP/HFA comparison in 45 glaucoma patients. The same parameters were used for testing the reproducibility of FDP (n = 46) and HFA (N = 39). Additionally, the center and each quadrant area were checked for any deviation in the total deviation probability plots. For statistical analysis Kappa coefficients and Bland/Altman plots were used. RESULTS An average MD (FDP vs HFA) of -7.3 +/- 5.8 dB vs -8.9 +/- 7.6 dB and PSD of 6.9 +/- 2.4 dB vs 6.5 +/- 3.6 dB were found. Kappa coefficients denote marginal accordance (kappa: 0.11-0.38) for area deviations. In a total of 225 areas HFA detected 191 deviations and FDP 165. HFA measured more negative deviation compared with FDP in the case of MD < -15 dB. The reproducibility was 0.98 (MD) and 0.92 (PSD) for FDP and 0.98 (MD) and 0.95 (PSD) for HFA (95% confidence interval). CONCLUSIONS There was great conformity between FDP and HFA in glaucoma patients. HFA detected more deviations in the total deviation probability plots than FDP. There was a high reproducibility of both methods. FDP is an appropriate tool for detecting visual field loss in glaucoma patients.
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Affiliation(s)
- J Kampmeier
- Augenklinik mit Poliklinik der Universität Ulm, Prittwitzstr. 43, 89075 Ulm.
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Rao SN, Fong Y, Kampmeier J, LaBree LD, Tanzer DJ, McDonnell PJ. The effectiveness of a topical antibiotic irrigating solution in a model of staphylococcal keratitis after lamellar keratectomy. Am J Ophthalmol 2000; 130:20-4. [PMID: 11004255 DOI: 10.1016/s0002-9394(00)00397-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To create a model of Staphylococcus aureus keratitis after lamellar keratectomy; to assess the toxicity of an antibiotic irrigating solution on the corneal stromal bed; and to test the chemotherapeutic effectiveness of a topical antibiotic, both alone and with an antibiotic-containing irrigating solution in preventing S. aureus keratitis after lamellar keratectomy. METHODS The right eye of each of 38 rabbits were used in this study. In 18 eyes, a lamellar flap was created with a microkeratome, and an inoculum of S. aureus (either 1,000, 5,000, or 50,000 CFUs) was instilled under each flap; the eyes were examined for signs of infection and inflammation at 24 and 48 hours. In another five eyes, a lamellar flap was created in the same manner and the stromal bed was irrigated with 0.3% ofloxacin; the eyes were assessed for ocular inflammatory changes and evidence of crystalline deposits. Finally, in each of 15 additional eyes, 1,000 CFUs of S. aureus were instilled under a lamellar flap to create experimental infectious keratitis. The keratitis was treated according to three regimens: irrigation of the stromal bed with sterile balanced salt solution; irrigation of the stromal bed with 0.3% ofloxacin, followed by application of topical ofloxacin four times a day; application of topical ofloxacin only, four times a day. Eyes were examined for infection and ocular inflammatory changes at 24 and 48 hours. RESULTS Staphylococcus aureus keratitis can consistently be produced under the stromal flap by inoculation of relatively few organisms. Irrigation of the stromal bed with commercial-strength topical ofloxacin does not appear to be toxic to the stromal bed, with no evidence of crystalline precipitates of the antibiotic. In our model of infectious keratitis after lamellar keratectomy, both topical ofloxacin alone and the combination of topical ofloxacin and irrigation of the stromal bed with 0.3% ofloxacin were effective at preventing S. aureus keratitis. However, the combined treatment of antibiotic irrigation plus topical antibiotic was more effective at preventing inflammation than topical ofloxacin alone. CONCLUSIONS In this model of S. aureus keratitis after lamellar keratectomy, irrigation of the stromal bed with antibiotic plus topical antibiotic appears to be both safe and effective for preventing infection.
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Affiliation(s)
- S N Rao
- Doheny Eye Institute and the Departments of Ophthalmology, University of Southern California School of Medicine, Los Angeles, California, USA
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Abstract
PURPOSE New methods in refractive surgery require a considerable understanding of the material "cornea" and are often studied by theoretical modeling in order to gain insight into the procedure and an optimized approach to the technique. The quality of these models is highly dependent on the preciseness of its input parameters. Porcine cornea often is used as a model in preclinical studies because of its similarity to man and its availability. METHODS The important physical parameters for biomechanical deformation, heat conduction, and collagen denaturation kinetics have been determined for porcine cornea. Experimental methods include densitometry, calorimetry, turbidimetry, tensile tests, stress relaxation, and hydrothermal isometric tension measurements. RESULTS The density of porcine cornea was measured as p = 1062+/-5 kg/m3, the heat capacity gave c = 3.74+/-0.05 J/gK. The stress-strain relation for corneal strips is represented by a third order approximation where the secant modulus yields about Esec approximately equal to 0.4 MPa for small strains less than 2%. The normalized stress relaxation is described by an exponential fit over time. The denaturation process of cornea is characterized by specific temperatures which can be related to the change of the mechanical properties. Denaturation kinetics are described according to the model of Arrhenius yielding the activation energy deltaEa = 106 kJ/mol and the phase transition entropy deltaS = 39 J/(mol x K). CONCLUSIONS The established set of parameters characterizes the porcine cornea in a reliable way that creates a basis for corneal models. It furthermore gives direct hints of how to treat cornea in certain refractive techniques.
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Kampmeier J, Russ D, Schafer S, Lang GE, Lasser T, Steiner R, Lang GK. Corneal Morphology in vitro After Superficial Keratectomy With Q-switched Er:YSGG and Free-running Er:YAG Lasers. J Refract Surg 2000; 16:341-8. [PMID: 10832984 DOI: 10.3928/1081-597x-20000501-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Examination of morphology in corneal ablation induced by a q-switched Er:YSGG (2.79 microm) laser and a free-running Er:YAG laser (2.94 microm). METHODS Defined ablation of 6-mm diameter and 15, 30, 55, 90, and 120-microm depth was performed on freshly enucleated swine eyes. Er:YSGG laser parameters: fluence 1.6 J/cm2, frequency 6 Hz, spot-size 465 microm FWHM, scanning-mode, pulse number 1520 to 6210. Er:YAG laser parameters: fluence 3 J/cm2, frequency 1.5 Hz, spotsize 6 mm, wide area ablation, pulse number 2 to 13. Corneal morphology was analyzed by gross photography, histology, scanning electron microscopy, and scanning nearfield acoustic microscopy. RESULTS Histology showed thermal damage of 5 to 15 microm in depth caused by the Er:YSGG laser in comparison with 10 to 20 microm by the Er:YAG laser. Average roughness of the ablated surface measured with scanning nearfield acoustic microscopy was 20 to 40 microm for the Er:YSGG laser and 5 to 15 microm for the Er:YAG laser. These data confirm the subjective impression of images created by scanning electron microscopy and gross photography. CONCLUSIONS Although the Er:YAG laser system appeared to demonstrate a smoother corneal surface than the q-switched Er:YSGG laser, the thermal damage in either case poses a potential limitation for clinical use in lamellar refractive surgery.
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Affiliation(s)
- J Kampmeier
- Department of Ophthalmology, University Eye Hospital Ulm, Germany.
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Brinkmann R, Radt B, Flamm C, Kampmeier J, Koop N, Birngruber R. Influence of temperature and time on thermally induced forces in corneal collagen and the effect on laser thermokeratoplasty. J Cataract Refract Surg 2000; 26:744-54. [PMID: 10831907 DOI: 10.1016/s0886-3350(00)00310-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To investigate thermomechanical aspects of corneal collagen denaturation as a function of temperature and time and the effect of the induced forces on refractive changes with laser thermokeratoplasty (LTK). SETTING Medical Laser Center Lübeck, Lübeck, Germany. METHODS In a material-test setup, porcine corneal strips were denatured in paraffin oil at various constant temperatures for 10 and 500 seconds, and the temporal course of the contractive forces was studied under isometric conditions. Typical LTK lesions were performed in porcine eyes in vitro with a continuous-wave infrared laser diode at a wavelength of 1.87 microm for 10 and 60 seconds. The laser power was chosen to achieve comparable denatured volumes at both irradiation times. The refractive changes were measured and analyzed by histologic evaluations and temperature calculations. RESULTS The time course of the induced forces was characterized by a maximal force, which increased almost linearly with temperature, and a residual lower force. After 500 seconds of heating, the highest force was achieved with a temperature of 75 degrees C. With a limited heating period of only 10 seconds, the forces steadily increased with temperature over the entire observation period. Laser thermokeratoplasty produced less refractive change after 10 seconds of irradiation than after 60 seconds, although the laser power was 25% higher in the short heating period. Polarization light microscopy of LTK lesions revealed different stages of thermal damage. CONCLUSION The course of the contractive forces during and after heating is a complicated function of the spatial time/temperature profile. Laser thermokeratoplasty lesions produced with 2 irradiation times showed different stages of denaturation and induced refractive change.
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Abstract
PURPOSE We propose a feasibility study of new corneal topography technology with the aim of monitoring intraoperative corneal topography during excimer laser photorefractive keratectomy. The PAR system measures corneal topography with single grid projection and triangulation but requires fluorescent fluid to be deposited on the corneal surface for shape extraction. We propose and demonstrate a novel corneal topography system based on structured incoherent visible light projection and triangulation that does not require addition of fluorescent fluid. METHODS We used a binary liquid crystal spatial light modulator to display multiple fringe patterns onto the cornea. The depth accuracy of the corneal topography system was measured using a white reflected test sphere mounted on a micrometer translation stage. The performance of the corneal topography system was tested on 5 de-epithelialized swine eyes in vitro ablated with a VISX excimer laser. RESULTS Depth accuracy on the test sphere was 0.5+/-0.75 microm over an area of 17.6 mm2. On de-epithelialized swine corneas, ablation at the apex of the cornea treated with an excimer laser was measured without addition of fluorescein. CONCLUSIONS This new corneal topography system achieved an adequate level of accuracy on a test sphere.
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Affiliation(s)
- C Moser
- Holoplex, Inc., Pasadena, CA 91106, USA.
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Kampmeier J, Behrens A, Wang Y, Yee A, Anderson WF, Hall FL, Gordon EM, McDonnell PJ. Inhibition of rabbit keratocyte and human fetal lens epithelial cell proliferation by retrovirus-mediated transfer of antisense cyclin G1 and antisense MAT1 constructs. Hum Gene Ther 2000; 11:1-8. [PMID: 10646634 DOI: 10.1089/10430340050016102] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of this study is to evaluate the potential of gene transfer of cell cycle control genes as treatment of corneal haze or secondary cataract formation. The guiding hypothesis is that strategic modulation of the cyclin G1 or MAT1 gene by retrovirus-mediated gene transfer will inhibit proliferation of rabbit keratocytes (RabK) and fetal human lens epithelial (FHLEpi) cells in vitro. RabK and FHLEpi cell cultures were transduced in triplicate with retroviral vectors bearing either a nuclear-targeted beta-galactosidase, an antisense cyclin G1 (aG1), an antisense MAT1 (aMAT1) construct, or the neo(r) gene. The presence of beta-galactosidase activity in the transduced cultures was detected by immunohistochemical X-Gal staining, while cyclin G1 and MAT1 protein expression levels were evaluated by Western analysis. Proliferation of RabKs and FHLEpi cells was analyzed by counting the number of cells in the aG1 and aMAT1 vector-transduced cultures over 5 days. The mean transduction efficiency was 34.4% (SD 1.41) for RabKs and 19.7% (SD 1.83) for FHLEpi cells. Downregulation of cyclin G1 and MAT1 protein expression was noted 24 hr after transduction of RabK cultures with the respective vectors. Cytostatic effects of the aG1 and aMAT1 vectors in both RabKs and FHLEpi cells were most pronounced on the fifth day (RabKs, p < 0.0007; FHEpi cells, p < 0.001). An increased incidence of apoptosis was identified in both aG1 and MAT1-transduced FHLEpi cells. Taken together, these data suggest the potential utility of developing aG1 and aMAT1 retroviral vectors in gene therapy protocols for corneal haze and secondary cataract formation.
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Affiliation(s)
- J Kampmeier
- Doheny Eye Institute and Department of Ophthalmology, University of Southern California School of Medicine, Los Angeles 90033, USA
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Kampmeier J, Schäfer S, Lang GE, Lang GK. [Photorefractive keratectomy. Free-running vs. q-switched Er:YAG laser (scanning mode)]. Ophthalmologe 1999; 96:805-12. [PMID: 10643315 DOI: 10.1007/s003470050500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Examination of morphology in plane corneal ablation (in vitro) induced by an Er:YAG-laser (2.94 microns) in two modes: free-running (50 microseconds) and q-switched (200 ns). METHODS Sequences of different fluences in each mode were applied to freshly enucleated swine eyes. Parameters of free-running mode: fluences 1.21-4.77 J/cm2, frequency 80 Hz, spot size 500 microns FWHM, hexagonal spot shape. Parameters of q-switched mode: fluences 0.79-2.33 J/cm2, frequency 20 Hz, spot size 500 microns FWHM, round spot shape. RESULTS Histology showed thermal damage of 10-25 microns in depth caused by the free-running mode compared with 4.5-7.5 microns by the q-switched mode. In both gross photography and scanning electron microscopic examination, the surface was found to be more homogeneous and smoother in the q-switched mode. CONCLUSIONS Depending on the different application modes, both laser systems could be used for a defined corneal ablation in photorefractive keratectomy. However, at the moment, results using the Er:YAG laser are not as favorable as with the excimer laser.
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Kampmeier J, Schäfer S, Lang GE, Lang GK. Comparison of free-running vs. Q-switched Er:YAG laser photorefractive keratectomy (scanning mode) in swine eyes. J Refract Surg 1999; 15:563-71. [PMID: 10504081 DOI: 10.3928/1081-597x-19990901-09] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
PURPOSE To examine morphology in plane and incisional corneal ablation (in vitro) induced by an Er:YAG laser (2.94 microm) in two modes: free-running and q-switched. METHODS Sequences of different fluences in each mode were applied to freshly enucleated pig eyes. Parameters of free-running mode were: pulse length 50 micros, fluences 1.21 to 4.77 J/cm2, frequency 80 Hz, spot size 500 microm FWHM, hexagonal spot shape. Parameters of q-switched mode were: pulse length 200 ns, fluences 0.79 to 2.33 J/cm2, frequency 20 Hz, spot size 500 microm FWHM, round spot shape. RESULTS Histology showed thermal damage of 10 to 25 microm in depth caused by the free-running mode compared with 4.5 to 7.5 microm by the q-switched mode. In both gross photography and scanning electron microscopic examination, the surface was more homogeneous and smoother in the q-switched mode. CONCLUSIONS Depending on the different application modes, both laser systems could be used for a defined corneal ablation in photorefractive keratectomy. At present, results using the Er:YAG laser are not as favorable as with the excimer laser.
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Affiliation(s)
- J Kampmeier
- Department of Ophthalmology, University of Ulm, Germany
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Kampmeier J, Tanzer DJ, Er H, Schallhorn SC, LaBree L, McDonnell PJ. Significance of corneal topography in predicting patient complaints after photorefractive keratectomy. J Cataract Refract Surg 1999; 25:492-9. [PMID: 10198853 DOI: 10.1016/s0886-3350(99)80045-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate the sensitivity and specificity of postoperative corneal topography to predict potential patient complaints after photorefractive keratectomy (PRK). SETTING Doheny Eye Institute, Los Angeles, California, USA. METHODS Postoperative tangential corneal topographic maps, in 0.5 and 1.0 diopter (D) relative scales, were obtained from patients (n = 34) at least 4 months after PRK. Topographies of complaining (n = 18) and noncomplaining patients (n = 16) were analyzed by 6 masked examiners with 2 different experience levels in PRK (experts, n = 2; beginners, n = 4), who assigned the topographies to 1 of the 2 groups. RESULTS Topographies of complainers (sensitivity) and noncomplainers (specificity) were correctly classified in 53.2% overall and in 44.0% and 63.5% (P = .06) in complainers and noncomplainers, respectively. Experienced examiners were not significantly more accurate than inexperienced examiners (46.3% and 56.6%, respectively; P = .09). Images of 1.0 D scales received significantly more correct responses than those of 0.5 D scales (56.4% and 50.0% respectively; P = .03). The reproducibility between images for the same patient in both scales was significantly better for the experienced examiners than the inexperienced examiners (kappa coefficient 0.73 and 0.51, respectively; P = .05). CONCLUSIONS Subjective analysis of postoperative corneal topography alone is not sufficient to predict potential patient complaints after PRK. Topographic findings should be interpreted only in the context of a complete clinical examination.
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Affiliation(s)
- J Kampmeier
- Doheny Eye Institute, University of Southern California School of Medicine, Los Angeles, USA
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Bryant MR, Kampmeier J, Er H, Kasetsuwan N, Sanchez-DiMartino D, Shah SS, McDonnell PJ. PRK-induced anisometropia in the rabbit as a model of myopia. Graefes Arch Clin Exp Ophthalmol 1999; 237:161-5. [PMID: 9987634 DOI: 10.1007/s004170050212] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND Current animal models of myopia, such as the chick and the tree shrew, have characteristics that limit their applicability to human myopia and/or their use among researchers. The purpose of this study was to establish a rabbit model of myopia based on photorefractive keratectomy (PRK)-induced anisometropia. METHODS A group of five pigmented rabbits was treated with a monocular -5 D PRK at 5 weeks of age. At 10 weeks of age, two of the eyes were retreated with a second -5 D PRK procedure to compensate for partial regression of the refractive effect. A second group of six pigmented rabbits was treated with a monocular -6 D PRK at 10 weeks of age. Longitudinal measurements of corneal curvature, refraction, and axial length were performed until the rabbits were 13 and 21 weeks of age in groups 1 and 2, respectively. The rabbits in each group were from the same litter. RESULTS Keratometry and retinoscopy measurements confirmed the refractive effect of the PRK procedures. At the final measurement point in group 1, the PRK-treated eyes were significantly longer than the untreated eyes (16.01 +/- 0.45 mm vs 15.45 +/- 0.56 mm). In group 2, the PRK-treated eyes were significantly longer by 0.19 mm and 0.20 mm at ages 19 and 21 weeks, respectively. CONCLUSIONS PRK-induced anisometropia is an effective technique to induce hyperopic error compensation in the rabbit as a model of myopic development. The technique is effective if the PRK procedure is performed at either 5 or 10 weeks of age. However, after PRK at 5 weeks of age, partial retreatment may be necessary due to regression of the PRK effect.
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Affiliation(s)
- M R Bryant
- University of Southern California School of Medicine, Doheny Eye Institute, Los Angeles 90033, USA.
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Brinkmann R, Koop N, Geerling G, Kampmeier J, Borcherding S, Kamm K, Birngruber R. Diode laser thermokeratoplasty: application strategy and dosimetry. J Cataract Refract Surg 1998; 24:1195-207. [PMID: 9768392 DOI: 10.1016/s0886-3350(98)80011-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To investigate suitable application parameters for efficient hyperopic correction by laser thermokeratoplasty (LTK) using mid-infrared laser diodes. SETTING Medical Laser Center Lübeck, Lübeck, Germany. METHOD A tunable continuous-wave laser diode in the spectral range between 1.845 and 1.871 microns was used. Transmitted by waveguides, the laser energy was used to induce coagulations on freshly enucleated porcine eyes to increase corneal curvature. The coagulations were equidistantly applied by a fiber-cornea contact and a noncontact focusing device that were adjusted on a ring concentric to the corneal apex. Different laser parameters and application geometries were evaluated. Refractive changes were measured by computer-assisted corneal topography before and after treatment. Polarization light microscopy and temperature calculations were used to analyze the coagulations. RESULTS Because of the tunability of the laser diode, the influence of the corneal absorption coefficient (between 0.9 and 1.6 mm-1) on the refractive change could be measured. A laser power between 125 and 200 mW was adequate to achieve refractive changes up to 10.0 diopters. In the preferable focusing device, the refractive change increased almost logarithmically with the irradiation time up to 15 seconds. The number of coagulations on a fixed application ring showed no significant influence on refractive change; however, it showed an almost linear decrease with increasing ring diameter from 5.0 to 10.0 mm. Histological analysis revealed 3 stages of thermal damage. CONCLUSION Diode LTK provided defined and uniform coagulations when using a well-adapted focusing device, resulting in sufficient refractive change. The results indicate that diode LTK is superior to pulsed holmium LTK.
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Abstract
BACKGROUND A new "ab externo" technique for glaucoma trabecular surgery creating multiple perforations of the trabeculum to improve outflow facility was tested. MATERIAL AND METHOD In order to perform a draining canal to the anterior chamber, a quartz fiber (phi: 300 microns) with a side-firing tip, coupled to an Er:YAG laser (2.94 microns), was inserted into Schlemm's canal of an enucleated human eye. RESULTS Eight pulses of 8 mJ each were sufficient to perforate the trabecular meshwork. Histologic analysis showed a rippled canal with 50 microns average diameter and a surrounding necrosis zone of 15-35 microns. CONCLUSIONS The Er:YAG laser trabeculostomy, in conjunction with special fibers, shows promise as a new "ab externo" technique for minimally invasive therapy of open angle glaucoma.
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Affiliation(s)
- J Kampmeier
- Universitäts-Augenklinik und Poliklinik, Universität Ulm.
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Kampmeier J, Kurz S, Schütte E. [Intraocular pressure after extracapsular cataract extraction with posterior chamber lens implantation--sulcus versus capsular bag fixation]. Klin Monbl Augenheilkd 1997; 211:101-5. [PMID: 9379634 DOI: 10.1055/s-2008-1035104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND In this retrospective study the postoperative alteration of intraocular pressure after cataract extraction and posterior chamber lens implantation was analyzed statistically. The influence on intraocular pressure between different positions of the loops (sulcus versus bag) was compared. PATIENTS AND METHOD The posterior chamber lens implantation was performed on 267 eyes with 129 sulcus implanted and 138 in-the-bag implanted intraocular lenses. The average age of the patients was 74.8 respectively 71.9 years, with an equal ratio of sex. In surgery the viscoelastic experimentation of the nucleus was done via corneoscleral cut. A x-crossed suture sealed the corneoscleral wound followed by subconjunctival injection of corticosteroids. The postoperative medication for 4-6 weeks consisted of a corticosteroid and antibiotic combination. RESULTS The average intraocular pressure of the sulcus implanted respectively in the bag implanted intraocular lenses increased from 15.4 mm Hg respectively 15.9 mm Hg preoperatively to 16.3 respectively 15.8 mm Hg at the first postoperative day. After two months the intraocular pressure decreased to 14.6 respectively 14.1 mm Hg. That means a pre- to postoperative difference of -0.8 respectively -1.8 mm Hg. CONCLUSIONS In summary both groups showed a slight decrease in average intraocular pressure after two months. In comparison to the sulcus implanted intraocular lens the decrease of intraocular pressure was more than 1 mm Hg in case of the in the bag implanted lens. This decrease was statistically significant but may be considered of less clinical interest.
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Affiliation(s)
- J Kampmeier
- Abt. Ophthalmologie, Bundeswehrkrankenhaus Ulm
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Kampmeier J, Klafke M, Hibst R, Wierschin S, Schütte E, Steiner R. [Modified radiation administration in Er:YAG laser ab externo sclerostomy]. Klin Monbl Augenheilkd 1997; 211:48-52. [PMID: 9340406 DOI: 10.1055/s-2008-1035094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Ab externo sclerostomy enables the restrained aqueous humour drain via a microgram wide corneoscleral canal into the subconjunctival space being an alternative surgical method in glaucoma therapy. The tissue ablative infrared laser radiation (2.94 microgram) was applied until now via a quartz fiber manually pushed forward in permanent tissue contact. Our aim was the development of a new applicator tip without manual feed in order to achieve a reduction in times for construction and maintenance of the former tip as well as in the risk of an infection and mechanical damage of intraocular structures. MATERIAL AND METHOD In pig eye experiments, the laser parameters were varied in histological and scanning electron microscopic evaluation (pulse energy: 10-60 mJ, repetition rate: 5-17.5 Hz, combinations of constant power: 200 mW). Their influence on the canal shape and the morphology of the internal ostium has been proven in special tests. RESULTS The new development of the applicator tip (core diameter: 550 microgram) enables a conical profile of the beam (diameter 500-150 microgram) within a distance of 2-3 mm, now without pushing the fiber forward ("fixed fiber"). Smooth canal surfaces, a small homogeneous necrosis zone (25 microgram) and only few tissue ruptures have been seen histologically and on SEM. The correlations of ablation rates/-speed as well as canal characteristics are more significant to energy densities than to repetition rates. First clinical application was technically successful. CONCLUSIONS The new applicator tip optimizes the method of Er: YAG-laser ab externo sclerostomy from the technical and surgical point of view.
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Affiliation(s)
- J Kampmeier
- Abt. Ophthalmologie, Bundeswehrkrankenhaus Ulm
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Kampmeier J, Klafke M, Hibst R, Wierschin S, Schütte E, Steiner R. [Ab externo sclerostomy with the Er:YAG laser: report of outcome after 2 years]. Klin Monbl Augenheilkd 1996; 208:218-23. [PMID: 8778490 DOI: 10.1055/s-2008-1035199] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECT Results over a period of 24 months of performing the Er:YAG laser ab externo sclerostomy. MATERIAL AND METHODS The procedure was performed 81 times (chronic glaucoma with open angle (n = 55) and narrow angle (n = 15), 6 secondary glaucoma, 4 pigment glaucoma, 1 normal pressure glaucoma) in 74 eyes of 64 patients at the age of 70 +/- 10 years without any peribulbar anesthesia. The pulse energy was 11 mJ with a repetition rate of 7 Hz. Antimetabolites were not applicated. Success was defined as an IOP of less than 22 mm Hg or a decrease of at least 30%, with or without anti-glaucoma medication. RESULTS The mean IOP of all cases decreased from preoperatively 28 +/- 8.1 mm Hg (Success group: 26.7 +/- 7.3 mm Hg) to 15 +/- 8.4 mm Hg (Success group: 14.6 +/- 7.8 mm Hg) on the first postoperative day. The success rate was about 50% within the period of two weeks to six months and decreased to about 15% in the 24th month. Complications were iris incarceration/synechia (n = 33), hypotony (n = 36) with consequent choroidal detachment (n = 8), hyphema (n = 19) and more pronounced inflammation symptoms (n = 10). In most cases, the early postoperative outflow failure is caused by iris incarceration into the internal ostium. The scarring tendency of the episcleral tissue leads to closure of the external ostium after months. Resurgery was necessary in 26 cases. CONCLUSIONS Further efforts should be directed to maintain the intact corneoscleral morphology of the canal, created by an optimized method of the surgical technique. The application of antimetabolites in correct dosage or the implantation of modified silicon draining systems would be helpful.
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Affiliation(s)
- J Kampmeier
- Abt. Ophthalmologie, Bundeswehrkrankenhaus Ulm, Akademisches Krankenhaus, Universität Ulm
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Schrage N, Hjortal J, Kampmeier J, Reim M. 2434 The microtrephine-multiple punctures and local effects. Vision Res 1995. [DOI: 10.1016/0042-6989(95)90233-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Soldati D, Kim K, Kampmeier J, Dubremetz JF, Boothroyd JC. Complementation of a Toxoplasma gondii ROP1 knock-out mutant using phleomycin selection. Mol Biochem Parasitol 1995; 74:87-97. [PMID: 8719248 DOI: 10.1016/0166-6851(95)02487-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The ROP1 gene of Toxoplasma gondii encodes a rhoptry protein that has been implicated in host cell invasion by this obligate intracellular protozoan. To further explore the function of this protein, we created a ROP1 deletion mutant by transfection with a plasmid encoding the bacterial chloramphenicol acetyltransferase (cat) gene flanked by ROP1 genomic sequences. Selection for chloramphenicol resistance yielded the desired ROP1-deleted or 'knock-out' mutant. Analysis of this mutant both in vitro and in vivo shows no significant alterations in growth rate, host specificity, invasiveness or virulence and thus the ROP1 gene is not obligatory for the RH strain, at least under the conditions tested. However, electron microscopy reveals that the mutant strain's rhoptries are altered in ultrastructure; they are thinner and homogeneously electron-dense compared with the thicker and normally mottled or honeycombed appearance of wild-type rhoptries. The knock-out mutant was rescued using co-transfection of a cosmid carrying the ROP1 gene together with a plasmid encoding a new selectable marker for T. gondii, the bleomycin resistance gene (ble) from Streptoalloteichus. Southern blot analysis showed that both DNAs were stably integrated into the Toxoplasma genome, although not into the ROPI locus. The resulting strain showed wild-type levels of ROP1 expression and rescue of the ultrastructural phenotype (i.e., the rhoptries returned to their normal, mottled appearance), thus establishing a cause/effect relationship between the absence of ROP1 and the electron-opacity. These results demonstrate the utility of the reverse genetic approach in the study of Toxoplasma gene function and provide a further selectable marker for such manipulations.
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Affiliation(s)
- D Soldati
- Department of Microbiology and Immonology, Stanford University School of Medicine, CA 94305-5402, USA
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Abstract
The Toxoplasma gondii major surface antigen, called SAG1 or p30, is a highly immunogenic protein which has generated great interest as a diagnostic reagent, as a potential subunit vaccine, and for its role in invasion. Unfortunately, bacterial recombinant protein is grossly misfolded so that, for example, it is not effectively recognized by antibodies to native SAG1. To overcome this, we have turned to expression in CHO cells, using cotransfection of the SAG1 gene and the mouse dihydrofolate reductase (DHFR) gene into CHO cells that are DHFR-. SAG1 expression was amplified by methotrexate coselection of CHO cells in combination with fluorescence-activated cell sorting for SAG1 expression. The resulting population expressed recombinant SAG1 that is recognized by antiserum specific for natural, nonreduced SAG1, indicating that, unlike in bacteria, expression in CHO cells results in proper folding. Processing was at least partially correct in that, like natural SAG1, recombinant SAG1 was attached to the plasma membrane via a glycolipid anchor, although tunicamycin treatment was necessary to prevent N-glycosylation (SAG1 is not glycosylated in the parasite but does have a consensus N-linked site). Finally, purified recombinant SAG1 was recognized by human sera known to be reactive to toxoplasma proteins, indicating that this material has potential as a diagnostic reagent and possibly as a component of a subunit vaccine.
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Affiliation(s)
- K Kim
- Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305-5402
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Kampmeier J, Burgass W, Schütte E, Schröder D, Hibst R, Steiner R. [Comparative study of ab-externo sclerostomy with the excimer and Er:YAG laser]. Ophthalmologe 1993; 90:594-8. [PMID: 8124020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The specific ablative effect of pulsed 308 nm XeCl-excimer laser radiation (4 mJ 80 Hz) on the tissue has proved its worth in clinical use in glaucoma patients. However, the cytotoxic and mutagenic photochemical reactions induced by intraocular ultraviolet irradiation could theoretically be cataractogenic and retinotoxic. Unlike the excimer laser technique, ab externo sclerostomy with the Er:YAG laser (2940 nm/11 mJ, 7 Hz) excludes these risks. Histological and scanning electron microscope analysis of pig eyes showed thin, and smoothly limited zones of necrosis and only minimal irritation of the adjacent tissue and a slightly wavy surface. A newly developed handpiece for the Er:YAG laser enables energy transport via zirconium fluoride fiber and coupling to a quartz fiber tip with a core diameter of 320 microns. Er:YAG laser sclerostomy has so far been performed on 16 eyes in which the average preoperative IOP was 29 mmHg. The procedure took only a few minutes and the patients reported feeling no pain although retrobulbar anesthesia was not induced. The postoperative average IOP was less than 20 mmHg after 6 weeks and for the rest of a maximum observation period of 12 weeks. Reoperation was necessary in 2 cases. Er:YAG laser ab externo sclerostomy could be another alternative for the operative therapy of glaucoma.
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Affiliation(s)
- J Kampmeier
- Abteilung Ophthalmologie, Bundeswehrkrankenhaus Ulm
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Kampmeier J, Schütte E, Schröder D, Meier T, Steiner R. [Excimer laser sclerostomy of secondary glaucoma]. Ophthalmologe 1993; 90:35-9. [PMID: 8443446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Initial results after nine ab externo sclerotomies on seven patients awaiting enucleation because of intensive pain caused by secondary glaucoma have encouraged us to present the methods used for this technique of fistula construction and the course in these patients. A special applicator permits precise manual positioning of the excimer laser beam (lambda = 308 nm) subconjunctivally at the limbus using a quartz-quartz fiber (diameter: 0.32 mm). The energy applied at the fibertip is 4 mJ per pulse, with a repetition rate of 80 Hz. All patients undergoing the operation, which lasted only a few minutes, were treated as out-patients without a retrobulbar anaesthesia. Because of the minimal irritation of the anterior chamber, only antibiotic treatment was required after the operation. The intraocular pressure immediately decreased to normal levels after the operation without any further glaucoma treatment in five cases. In the other two cases reduced, but still minimally elevated, pressure was recorded. In the case of one heavily inflamed eye, which had been subjected to two operations, pain felt by the patient was relieved when the pressure was reduced. The maximum period of post-operative follow-up so far is over 10 months and the decrease of intraocular pressure has remained adequate without any additional antiglaucoma therapy. In all cases enucleation was avoided.
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Bremerich A, Kreidler J, Kampmeier J. [Multiple occurrence of odontogenic keratocysts. Case report]. Dtsch Z Mund Kiefer Gesichtschir 1988; 12:376-9. [PMID: 3268363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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