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ABSTRACT: PURPOSE:: To describe morphologic alterations of pigment epithelial detachments (PEDs) associated with neovascular age-related macular degeneration during anti-vascular endothelial growth factor upload therapy with ranibizumab. METHODS:: Prospective, single-arm interventional study. Primary outcome was the reduction of height of PED during monthly treatment using ranibizumab. Secondary outcomes were factors influencing the regression of PED. Inclusion criteria were presence of PED associated with naive neovascular age-related macular degeneration, visual acuity of >20/200, and height of PED >150 μm on optical coherence tomography. All eyes (n = 54) received 3 injections of ranibizumab in monthly intervals ("upload therapy"). Last review examination was performed 14 weeks after the initial treatment. RESULTS:: The mean PED height decreased from 515 μm (SD, 268.3) to 294 μm (SD, 201.9) at Week 14 with the highest degree of regression after the first treatment. A complete resolution of PED was noted in 8 eyes (15%). Using conventional regression model, none of the factors investigated, including height of PED, presence of intraretinal or subretinal fluid, intraretinal cysts, macular volume, retinal thickness, presence of foveal depression, presence of hemorrhage, and visual acuity, had a significant impact on the morphologic response. Using a modified binary logistic regression model ("bootstrapping"), presence of foveal depression (P > 0.033), and retinal thickness (P > 0.004) showed statistical significance. CONCLUSION:: This study on the responses and potential predictive factors associated with vascularized PED during the uploading phase of intravitreal ranibizumab shows a complete resolution of the PED in 15% of the cases.
Retina (Philadelphia, Pa.) 04/2013; · 2.93 Impact Factor
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ABSTRACT: Abstract Purpose: Corneal ulceration may be treated with human amniotic membrane (HAM) while neovascularization remains a common complication of corneal ulceration. As several factors contained within HAM may contribute to reduced corneal scarring, we investigated if HAM may be additionally loaded with bevacizumab and potentially serve as a carrier for anti-vascular endothelial growth factor (VEGF) drugs to provide constant VEGF blockade. Material and Methods: Cryo-preserved HAM were incubated with different bevacizumab concentrations in organ culture medium for 2-5 d. Controls were incubated without bevacizumab. Then, all samples were placed into an organ culture medium without bevacizumab for 48 h, 72 h or for 5 d at 37 °C with the medium being changed at all time points. After that, VEGF165 was added to the supernatants for 24 h and free VEGF 165 was measured by ELISA. Results: Free VEGF was significantly blocked at 48 and 72 h (p < 0.01). VEGF blockade was less pronounced after 1 week. However, as compared to control, VEGF was significantly blocked at all times (p < 0.05). Conclusion: In this in-vitro setting, we could demonstrate effective VEGF-blockade for up to 1 week by incubating HAM with bevacizumab. HAMs might be potentially used as a carrier for drugs delivered to the cornea.
Current eye research 02/2013; · 1.51 Impact Factor
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MMW Fortschritte der Medizin 02/2013; 155(2):43-5; quiz 46-7.
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ABSTRACT: PURPOSE: To assess the effect of alkylphosphocholine (APC)-coated intraocular lenses (IOLs) on human lens epithelial cell (LEC) proliferation in vitro and the corneal biocompatibility of APC in an organ culture model of human donor eyes. SETTING: Research Laboratory for Experimental Ophthalmology, Ludwig-Maximilians-University, Munich, Germany. DESIGN: Experimental study. METHODS: Six foldable IOLs differing in optic material were incubated with APC, washed in phosphate-buffered saline, and dried overnight. Intraocular lenses of the same lot served as uncoated controls. Each rehydrated IOL was placed in 1 well of a 24-well plate containing proliferating human LECs. Cell survival was tested by the tetrazolium-dye reduction assay 5 days later. Biocompatibility of the human corneal endothelium was assessed by a 24-hour incubation of human donor corneas with different concentrations of APC before the live/dead assay was performed. RESULTS: Human LEC proliferation was attenuated by APC-coated IOLs (P=.001). Coated hydrophilic acrylic IOLs were more effective inhibitors of human LEC proliferation than coated hydrophobic acrylic or silicone IOLs (P=.001). Alkylphosphocholines were well tolerated by the corneal endothelium in an organ culture model of human donor corneas up to a concentration of 1 mM (n = 12). CONCLUSIONS: Results show that APCs are suitable agents for IOL coating without linker molecules. Coated IOLs can inhibit human LEC proliferation and were well tolerated by human donor corneas in organ culture. FINANCIAL DISCLOSURE: Dr. Eibl-Lindner holds the patent for "Intraocular lenses treated with alkylphosphocholines for pharmacological aftercataract prophylaxis," international application no. PCT/EP2010/051490. No other author has a financial or proprietary interest in any material or method mentioned.
Journal of cataract and refractive surgery 01/2013; · 2.75 Impact Factor
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Aljoscha S Neubauer,
Julian Langer,
Raffael Liegl,
Christos Haritoglou, Armin Wolf,
Igor Kozak,
Florian Seidensticker,
Michael Ulbig,
William R Freeman,
Anselm Kampik,
Marcus Kernt
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ABSTRACT: The purpose of this study was to evaluate and compare clinical outcomes and retreatment rates using navigated macular laser versus conventional laser for the treatment of diabetic macular edema (DME).
In this prospective, interventional pilot study, 46 eyes from 46 consecutive patients with DME were allocated to receive macular laser photocoagulation using navigated laser. Best corrected visual acuity and retreatment rate were evaluated for up to 12 months after treatment. The control group was drawn based on chart review of 119 patients treated by conventional laser at the same institutions during the same time period. Propensity score matching was performed with Stata, based on the nearest-neighbor method.
Propensity score matching for age, gender, baseline visual acuity, and number of laser spots yielded 28 matched patients for the control group. Visual acuity after navigated macular laser improved from a mean 0.48 ± 0.37 logMAR by a mean +2.9 letters after 3 months, while the control group showed a mean -4.0 letters (P = 0.03). After 6 months, navigated laser maintained a mean visual gain of +3.3 letters, and the conventional laser group showed a slower mean increase to +1.9 letters versus baseline. Using Kaplan-Meier analysis, the laser retreatment rate showed separation of the survival curves after 2 months, with fewer retreatments in the navigated group than in the conventional laser group during the first 8 months (18% versus 31%, respectively, P = 0.02).
The short-term results of this pilot study suggest that navigated macular photocoagulation is an effective technique and could be considered as a valid alternative to conventional slit-lamp laser for DME when focal laser photocoagulation is indicated. The observed lower retreatment rates with navigated retinal laser therapy in the first 8 months suggest a more durable treatment effect.
Clinical ophthalmology (Auckland, N.Z.) 01/2013; 7:121-8.
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ABSTRACT: To compare the efficacy and safety of three intravitreal bevacizumab upload injections followed by a dexamethasone implant versus dexamethasone implant monotherapy in eyes with macular edema due to retinal vein occlusion.
Sixty-four eyes of 64 patients were included in this prospective, consecutive, nonrandomized case series: group 1 consisted of 38 patients (22 with central retinal vein occlusion, CRVO, 16 with branch retinal vein occlusion, BRVO) treated using a dexamethasone implant (Ozurdex) alone; group 2 consisted of 26 patients (14 CRVO, 12 BRVO) treated with three consecutive intravitreal bevacizumab injections at monthly intervals followed by a dexamethasone implant. In case of recurrence, both cohorts received further dexamethasone implants. Preoperatively and monthly best corrected visual acuity (BCVA, ETDRS), central retinal thickness (Spectralis-OCT), intraocular pressure, and wide-angle fundus photodocumentation (Optomap) were performed. The primary clinical endpoint was BCVA at 6 months after initiation of therapy. Secondary endpoints were central retinal thickness and safety of the therapy applied.
In group 1, an increase in BCVA of 2.5 (±1.6) letters in the CRVO and of 13.0 (±3.2) letters in BRVO patients was seen after 6 months, in group 2 of 5.9 (±0.4) letters (CRVO) and 3.8 (±2.4) letters (BRVO), which was not statistically significant. When comparing the two treatment groups with respect to the type of vein occlusion, there was a significant advantage for BRVO patients for the dexamethasone implant monotherapy (BRVO patients in group 1, p = 0.005). Central retinal thickness showed a significant reduction after 6 months only in patients of group 1, both for CRVO (p = 0.01) and BRVO (p = 0.003). First recurrence after the first dexamethasone implant injection occurred after 3.8 months (mean) in CRVO and 3.5 months in BRVO patients (group 1), versus 3.2 and 3.7 months, respectively, in group 2. In group 1, 63.6% with CRVO and 50% with BRVO showed an increased intraocular pressure after treatment; in group 2, 57.1% with CRVO and 50.0% with BRVO, respectively.
In CRVO, there was no difference between the two treatment strategies investigated. However, in BRVO, dexamethasone implant monotherapy was associated with better functional outcome.
Ophthalmologica 06/2012; 228(2):110-6. · 1.42 Impact Factor
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ABSTRACT: To assess the effect of ranibizumab treatment for neovascular age-related macular degeneration (nvAMD) on patients' preferences and vision-related quality of life (VRQoL) in a routine clinical setting.
55 treatment naïve patients were examined before and after the initial upload of three monthly injections of 0.5 mg ranibizumab. VRQoL was assessed using a Rasch-adjusted NEI-VFQ-25. Time trade-off (TTO), standard gamble, a visual analogue scale and the European Quality of Life Questionnaire (EQ-5D) were used to calculate utilities, and multiple logistic regression models were conducted to determine independent factors associated with utilities.
Mean ± SD age was 75 ± 7 years, and 40 patients (73%) were female. Mean ± SD best-corrected visual acuity of the treated eye increased from 20/80 at baseline (logMAR 0.60 ± 0.35) to 20/63 (logMAR 0.52 ± 0.36; p=0.020) at follow-up after three injections. Utility score increases ranged from 2 utils (standard gamble anchored for death) up to 6.6 utils (EQ-5D German TTO, p=0.023) and visual functioning improved (Rasch adjusted composite NEI-VFQ score 50 ± 21 to 54 ± 21, p=0.042). Whether the worse or better eye was treated was not significantly associated with improvements in utility or VRQoL, whereas VA improvement in the treated eye was associated with an increase in utility (TTO, p=0.020).
TTO performed best in this sample of elderly nvAMD patients undergoing anti-VEGF therapy. Better or worse eye treatment was not associated with a change in reported utilities or visual functioning in patients with newly diagnosed nvAMD. Directly elicited, vision-specific utilities gained with TTO seem to be sensitive to a change in vision status.
The British journal of ophthalmology 04/2012; 96(7):997-1002. · 2.92 Impact Factor
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ABSTRACT: With increasing numbers of lamellar keratoplasties, eye banks are challenged to deliver precut lamellar donor tissue. In Europe, the most common technique of corneal storage is organ culture which requires a deswelling process before surgical processing. The aim of this study was to investigate the influence of different deswelling times on the cutting plane quality after microkeratome-assisted lamellar dissection.
Eight paired donor corneas (16 specimens) not suitable for transplantation were organ cultured under standard conditions at the Eye Bank of the Ludwig-Maximilians Universität, Munich, Germany. Pairs of corneal buttons were analyzed during the deswelling process in dextrane-containing medium. While one cornea was cut at an early time point during the deswelling process and put back into deswelling medium thereafter, the partner cornea was completely deswollen and dissected after 72 hours. Specimens were then further processed for scanning electron microscopy. Surface quality was assessed both digitally using Scanning Probe Imaging Processing software, and manually by three blinded graders.
The corneal buttons processed at the beginning of the deswelling process had a smoother surface when compared to the partner cornea that was cut at the end of the deswelling process. In our setting, no relevant difference was detectable between manual and automated microkeratome dissection.
For lamellar keratoplasty, organ-cultured corneas should be processed at an early stage during the deswelling process. We interpret the smoother dissection plane during early deswelling as a result of mechanical properties in a highly hydrated cornea.
Clinical Ophthalmology 01/2012; 6:967-72.
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ABSTRACT: This study's objective was to optimize the visualization of three different spectral-domain optical coherence tomography (SD-OCT) display modalities and evaluate enhanced depth imaging (EDI) by comparing the maximum depth of assessment in conventional versus inverted cross-sectional OCT images in healthy subjects and in patients with retinal pigment epithelial detachment (PED).
Cross-sectional SD-OCT conventional and inverted images were obtained with the HRA2 (Heidelberg Retina Angiograph II, Heidelberg Engineering, Heidelberg, Germany). Horizontal as well as vertical sections in three different display modes were blinded for evaluation by three independent, experienced graders for maximal imaging depth of the deep ocular fundus layers.
The mean imaging depth as measured from the inner segment/outer segment (IS/OS) to the outer choroid of all 14 healthy subjects was 197 ± 44 μm vs 263 ± 56 μm for conventional vs EDI scans: in black/white mode, it was significantly lower (P < 0.001) than in white/black mode (249 ± 42 μm vs 337 ± 71 μm) and color/heat mode (254 ± 48 μm vs 354 ± 73 μm). The mean imaging depth of all 14 study eyes with PED was 240 ± 78 μm vs 345 ± 100 μm for conventional vs EDI scans in black/white mode, and was significantly lower (P < 0.001) than in white/black mode (393 ± 104 μm vs 464 ± 126 μm) and in color/heat mode (373 ± 106 μm vs 453 ± 114 μm). In each display modality of healthy subjects and of patients with PED, EDI scans showed a significantly higher imaging depth than the corresponding conventional scans.
White/black and color/heat modes allow increased imaging depth, compared to black/white mode using both conventional or EDI OCT scans in healthy subjects or patients with PED. EDI obtained with HRA2 significantly improves the imaging depth, compared to conventional OCT scans.
Clinical Ophthalmology 01/2012; 6:1915-20.
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ABSTRACT: Purpose: To report the 12 months efficacy of initial intravitreal bevacizumab or intravitreal recombinant tissue plasminogen activator (rtPA) combined with expansile gas in patients with subretinal haemorrhage caused by neovascular age-related macular degeneration (AMD). Methods: Forty-five eyes of 45 patients with subretinal haemorrhage (1-5 disc diameters) involving the fovea secondary to neovascular AMD were evaluated retrospectively consecutively. Thirty-two eyes underwent treatment with rtPA (50 μg/0.05 ml) combined with intravitreal sulphur hexafluoride (SF6). The other 13 eyes were treated with bevacizumab (1.25 mg/0.05 ml) and SF6. Thereafter, all patients received Vascular Endothelial Growth Factor (anti-VEGF) treatment according to modified PrONTO criteria. Main outcome was change of best-corrected visual acuity (VA) at 12 months as determined by Early Treatment Diabetic Retinopathy (ETDRS). Results: There was more improvement in patients initially treated with rtPA and gas (14 letters; bevacizumab and gas eight letters) and not suffering from adverse events. The incidence of vitreous haemorrhages was significantly higher in the rtPA group (nine of 32 versus one of 13, p < 0.01). In both groups, an average of 3.5 anti-VEGF injections were performed per patient during 12 months (no difference between both groups). Conclusion: Both initial treatment regimen lead to improved functional results after 1 year. However, patients, not suffering from adverse events, who underwent initial treatment with rtPA and gas showed better results. To maintain VA, controlling neovascular AMD by anti-VEGF treatment regime after initial treatment with rtPA+gas is important for all cases.
Acta ophthalmologica 09/2011; · 2.44 Impact Factor
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ABSTRACT: PURPOSE. To elucidate the role of Toll-like receptor 3 (TLR3) in the pathogenesis of age-related macular degeneration (AMD) and to investigate the effect of alkylphosphocholines (APCs) on the TLR3-mediated expression of cytokines and growth factors in human retinal pigment epithelial (RPE) cells. METHODS. Confluent cultures of human RPE cells (ARPE-19) were stimulated with poly (I:C) RNA as a well-established ligand for TLR3. Cytokine profiles were determined by RT-PCR on the activation of TLR3. RPE cells were transfected with siRNA specific for TLR3 and RIG-1 to determine the receptors involved. The effect of preincubation of RPE cells with APCs on the expression level of target genes was assessed. RESULTS. Poly (I:C) RNA stimulation led to a dose-dependent increase in the expression of TLR3 and RIG-I. A significant increase in expression levels of IL-6, TNF-α, IL-8, MCP-1, ICAM-1, and BFGF was observed after poly (I:C) RNA stimulation (P < 0.05). This effect was time and dose dependent. No effect on PEDG or VEGF expression was seen. Transfection of RPE cells with siRNA specific for TLR3 reduced poly (I:C) RNA-induced mRNA expression of the genes (P < 0.05). Preincubation of RPE cells with APCs significantly reduced the poly (I:C) RNA-induced expression of the target genes (P < 0.05). CONCLUSIONS. The authors demonstrate that the expression of proinflammatory cytokines and chemokines in RPE cells depends on the activation of TLR3. The induction of downstream gene expression is blocked by siRNA specific for TLR3 and alkylphosphocholines. Therefore, TLR3 should be considered a novel target in AMD therapy.
Investigative ophthalmology & visual science 06/2011; 52(9):6536-44. · 3.43 Impact Factor
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ABSTRACT: To assess the duration of the effect of intracameral bevacizumab in patients presenting with rubeosis iridis and neovascular glaucoma (NVG).
Retrospective analysis of 24 consecutive eyes of 24 patients with decompensated NVG (> 21 mm Hg) treated with a single intracameral injection of bevacizumab over a minimum follow-up of 6 months. The endpoint of the study was the need for retreatment due to recurrence of raised intraocular pressure (IOP). Secondary outcome was the course of visual acuity (VA) and IOP over 6 months.
A Kaplan-Meier calculation revealed a mean duration of the treatment effect of 23 ± 4.4 days. Compared to mean IOP before treatment (26.3 mm Hg), decreases to 17.5 mm Hg at 1 week after treatment (p < 0.002) and to 17.1 mm Hg (p < 0.005) at 6 months following a single injection were seen. At 6 months, additional treatment was performed in 87.5% (n = 21) of eyes. VA remained stable or improved in 75% (n = 18) of all cases.
The IOP-lowering effect of intracameral bevacizumab can be seen 1 week after the injection, but is limited to a period of approximately 3 weeks. However, the fast and effective response to intracameral bevacizumab injection opens a time window for additional treatments, which are often necessary.
Ophthalmologica 05/2011; 226(2):51-6. · 1.42 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the applicability and variability of echographic imaging using 10 mHz and high-resolution 20 mHz B scanning for measurement of intraocular tumors.
This prospective consecutive study comprises 27 eyes in 27 patients with uveal melanoma. Each patient was examined by three experienced examiners independently on three occasions within a two-week time frame in a blinded manner. The height of the lesion was measured by all examiners using the 10 mHz B, 20 mHz B, and 8 mHz A scan probes. Additionally, basal diameter was examined using the 10 and 20 mHz B scan.
Tumor height measurements for all examiners using the standardized A scan tended to be higher than for both B scan measurements. Statistical analysis revealed significant differences in tumor height between B and A scan measurements. No difference in tumor height was found between the two B scan techniques (P = 0.239). Basal tumor diameter measurements revealed significant differences between 10 mHz and 20 mHz B scans (P < 0.001 and P = 0.001, respectively). For the 10 mHz B scan, basal diameter results tended to be larger than for the 20 mHz B scan. No difference was found for interobserver variation in all A scan and B scan examinations. The mean standard deviation of the difference in tumor height measurements between the examiners was ±0.24 mm for the 8 mHz A scan, ±0.46 mm for the 10 mHz B scan, and ±0.42 mm for the 20 mHz B scan. Both the 10 mHz and more precise 20 mHz B scan evaluations underestimated tumor height.
The 20 mHz ultrasound probe, despite its theoretically higher resolution, is not able to replace A scan measurements of tumor height.
Clinical Ophthalmology 01/2011; 5:477-82.
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Marcus Kernt,
Christoph Hirneiss, Armin Wolf,
Raffael Liegl,
Johann Rueping,
Aljoscha Neubauer,
Claudia Alge,
Michael Ulbig,
Arndt Gandorfer,
Anselm Kampik,
Christos Haritoglou
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ABSTRACT: Purpose: Indocyanine green (ICG) is a commonly used vital dye for macular surgery. Recent reports implicate that its use might be associated with less favourable results regarding postoperative visual outcome and damage of retinal cells, and atrophic degeneration of the retinal pigment epithelium (RPE) has been described. This study investigates the effects of ICG on light-induced senescence of RPE cells. Methods: Primary human RPE cells were either pre-incubated with ICG in concentrations of 0.005% and 0.05% or not and then exposed to white light. After 10 min of irradiation viability, induction of intracellular reactive oxygen species (ROS) and senescence-associated β-galactosidase activity (SA β-Gal) were determined. Expression and secretion of matrix metalloproteinases (MMPs) 1 and 3 and their mRNA were determined by RT-PCR and ELISA. Results: Light exposure decreased RPE cell viability by 46%. Treatment with 0.005% and 0.05% ICG alone decreased RPE cell viability by 7% and 21%. In addition, expression of ROS, SA β-Gal, and MMP-1 and 3 was significantly increased. When 0.005% and 0.05% ICG treatments were combined with light exposure, viability decreased by 69% and 82% compared to the untreated control. Effects on the expression of ROS, SA β-Gal, and MMP-1 and 3 were, depending on the ICG dose, significantly increased when cells were pre-incubated with ICG and then illuminated. Conclusion: In this study, pretreatment with ICG significantly increased light-induced oxidative stress and senescence. This might indicate a potential, supplementary mechanism that could explain RPE alterations and reduced functional results after ICG-assisted internal limiting membrane peeling.
Acta ophthalmologica 07/2010; 90(6):571-9. · 2.44 Impact Factor
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ABSTRACT: Our purpose was to compare the effect of triamcinolone and bevacizumab (Avastin) on the retinal thickness and functional outcome in patients with diabetic macular edema.
A collective of 32 patients, who had been treated by a single 4.0-mg intravitreal triamcinolone injection (group 1), was matched to 32 patients ('matched pairs'), who had received 3 injections of 1.25 mg of bevacizumab within 3 months in 4-week intervals (group 2). The outcome variables were changes in best corrected visual acuity (VA) and central retinal thickness 3 months after therapy.
Both groups did not differ regarding preoperative VA and central retinal thickness measured by optical coherence tomography. The baseline mean VA was 0.72 +/- 0.39 logMAR in group 1 and 0.73 +/- 0.39 logMAR in group 2 (p = 0.709). The mean central retinal thickness measured by optical coherence tomography was 548 +/- 185 mum in group 1 and 507 +/- 192 mum in group 2. While the patients in group 1 experienced a slight increase in VA of on average 0.7 lines following a single triamcinolone injection to a mean of 0.64 +/- 0.40 logMAR (p = 0.066) after 3 months, the patients in group 2 showed almost no effect on VA with an average increase of 0.2 lines to a mean VA of 0.72 +/- 0.30 logMAR (p = 0.948) following 3 intravitreal injections of bevacizumab. Comparing the effect on VA between both groups no statistically significant difference (p = 0.115) was noted. Concerning decrease in central retinal thickness both therapies were highly effective (p < 0.001 each), again, without statistically significant difference between the groups (p < 0.128).
Our data suggest that a single triamcinolone injection may be as effective as a 3 times repeated intravitreal administration of bevacizumab for the treatment of diabetic macular edema. Further prospective trials should be performed.
Ophthalmologica 02/2010; 224(4):258-64. · 1.42 Impact Factor
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ABSTRACT: Primary open-angle glaucoma (POAG) is one of the leading causes of blindness. Activation of optic nerve head astrocytes (ONHA) and loss of trabecular meshwork cells (TMC) are pathognomonic for this neurodegenerative disease. Oxidative stress and elevated levels of transforming growth factor beta (TGFbeta) play an important role in the pathogenesis of POAG. This study investigates the possible antiapoptotic and cytoprotective effects of minocycline on TMC and ONHA under oxidative stress and increased TGFbeta levels.
TMC and ONHA were treated with minocycline 1-150 muM. Possible toxic effects and IC(50) were evaluated after 48 hours. Cell proliferation and viability were examined in order to assess the protective effects of minocycline on TMC and ONHA. Expression of Bcl-2, XIAP, and survivin, as well as their mRNA expression, were assessed by real time polymerase chain reaction (RT-PCR) and Western Blot analysis 48 hours after treatment with minocycline alone and additional incubation with TGFbeta-2 or oxidative stress.
Minocycline 1-75 muM showed no toxic effects on TMC and ONHA. Under conditions of oxidative stress, both TMC and ONHA showed an increase in viability and an ability to proliferate when treated with minocycline 20-40 muM. RT-PCR and Western blotting yielded an overexpression of Bcl-2, XIAP, and survivin when TMC or ONHA were treated with minocycline 20-40 muM under conditions of oxidative stress and when additionally incubated with TGFbeta-2.
Minocycline up to 75 muM does not have toxic effects on TMC and ONHA. Treatment with minocycline 20-40 muM led to increased viability and proliferation under oxidative stress and TGFbeta-2, as well as overexpression of Bcl-2, XIAP, and survivin. This protective pathway may help to prevent apoptotic cell death of TMC and ONHA and therefore be a promising approach to avoidance of progression of glaucomatous degeneration.
Clinical Ophthalmology 01/2010; 4:591-604.
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Acta ophthalmologica 10/2009; 88(7):e295-6. · 2.44 Impact Factor
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ABSTRACT: In early exudative age-related macular degeneration (AMD), segmental thinning of Bruch's membrane is associated with ingrowth of choroidal neovascularization into the subretinal space. To determine whether there is a link between oxidative stress and extracellular matrix (ECM) degradation by the retinal pigment epithelium, the present study focused on the effect of oxidative stress on MMP-1 and MMP-3 expression, two enzymes with substrate specificity for components of Bruch's membrane.
Cultured human RPE cells were exposed to oxidative stress. To investigate the role of signal transduction proteins, cells were pretreated with the specific inhibitors SB202190 or PD98059. Secreted MMP-1 and MMP-3 were detected by ELISA, MMP-2, and MMP-9 by zymography. Expression of mRNA was determined by quantitative real-time RT-PCR. ECM degradation by retinal pigment epithelium was assessed by immunofluorescence microscopy.
Oxidative stress increased MMP-1 and MMP-3 protein release but reduced MMP-2 activity. Real-time RT-PCR disclosed increases of MMP-1 and MMP-3 mRNA after oxidative stress with no modulation of TIMP-1. MMP-2 and MMP-9 mRNA was slightly enhanced. PD98059, an inhibitor of ERK1/2, markedly reduced MMP-1 expression, whereas SB202190, an inhibitor of p38 MAPK, was less effective. MMP-3 expression was attenuated by both inhibitors. Oxidative stress-stimulated type I collagen degradation by RPE cells was reduced by simultaneous treatment with a synthetic MMP-inhibitor or a neutralizing antibody against MMP-1.
MMP-1 and MMP-3 in the retinal pigment epithelium are inducible by oxidative stress. The directional shift in the MMP-1,-3/TIMP-1 ratio is associated with increased type I collagen degradation. This may be an important mechanism contributing to the pathogenesis of early exudative AMD.
Investigative ophthalmology & visual science 07/2009; 50(11):5495-503. · 3.43 Impact Factor
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ABSTRACT: During deswelling of organ-cultured human corneas, endothelial cell loss occurs. Therefore, it is necessary to minimize the deswelling time and achieving an optimal central corneal thickness (CCT) of approximately 550 microm at the same time. We investigated the minimal deswelling time necessary and analyzed endothelial cell loss.
Fifty-eight human corneas were stored between 13 and 81 days in organ culture. CCT was measured by optical coherence tomography. Measurements were performed before preparation, during culturing, before deswelling, and after varying deswelling periods (1-72 hours) using 5% dextran. Additionally, vital staining was performed in 6 human corneas to assess endothelial cell loss between 24 and 30 hours of deswelling. To evaluate absolute cell loss, endothelial cells were counted on human corneal pairs after 24 and 30 hours of deswelling.
After organ culture, mean CCT was 1194 microm. After 24 hours of deswelling in dextran-containing medium, mean CCT was 600 microm, whereas after 30 hours, mean CCT was 510 microm and hardly any corneas showed a CCT of more than 550 microm. Almost no further decrease in CCT was observed thereafter. No factors could be identified predicting the necessary deswelling time; however, paired corneas showed significant correlation of deswelling characteristics. We did not see any differences in endothelial cell loss 24 and 30 hours of deswelling or the ratio of living to dead endothelial cell counts.
Deswelling for 24 hours does not provide an optimal corneal thickness. Because endothelial cell loss does not increase between 24 and 30 hours of deswelling, a period of 30 hours is more suitable for obtaining sufficient corneal thickness.
Cornea 05/2009; 28(5):524-9. · 1.73 Impact Factor
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ABSTRACT: Evaluation of the protein osteopontin (OPN) as a potential new marker in comparison to melanoma inhibitory activity (MIA) for screening and detection of metastatic uveal melanoma.
Plasma levels of 32 patients with uveal melanoma were analyzed for OPN and MIA by enzyme-linked immunosorbent assay (ELISA). Fourteen of these patients had clinically detectable liver metastases.
Median plasma concentration of OPN in patients with metastatic disease was 152.01 ng/ml compared to 47.39 ng/ml in patients without clinically detectable metastases (p < 0.001). The difference between the median MIA plasma levels in patients with (13.11 ng/ml) and patients without (5.64 ng/ml) metastatic disease was also statistically significant (p < 0.001). No correlation could be found between MIA or OPN levels and tumor height in patients without clinically detectable metastases.
The proteins MIA and OPN seem to be promising tumor markers for the metastasis screening in patients with uveal melanoma.
Ophthalmologica 03/2009; 223(4):239-43. · 1.42 Impact Factor
