Stephanie C Joachim

Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, North Rhine-Westphalia, Germany

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Publications (54)73.54 Total impact

  • Tim Schultz, Stephanie C Joachim, Iris Tischoff, H Burkhard Dick
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    ABSTRACT: To compare histologically the size and appearance of capsule disks after femtosecond laser-assisted cataract surgery and conventional cataract surgery.
    European journal of ophthalmology 07/2014; · 0.91 Impact Factor
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    ABSTRACT: Although an elevated intraocular pressure (IOP) is known as the main risk factor for glaucoma, many studies also showed an involvement of the immune system in this disease. In this study we investigated if a moderate increase in IOP leads to activation of the complement system.
    Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft. 06/2014;
  • Heiko Schmid, Marina Renner, H Burkhard Dick, Stephanie C Joachim
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    ABSTRACT: Purpose: Ischemia is a risk factor for eye diseases like ocular vein occlusion or glaucoma. To investigate effects of ischemia-reperfusion (I/R) a lot of different animal models are used, studying one or two different cell types, which creates heterogeneity of data. Aim of this study was to investigate the function and morphology of the whole retina and different retinal cell types in an ischemia-reperfusion (I/R) model. Methods: I/R was induced by elevating the intraocular pressure in the right eyes of rats. 21 days after ischemia, electroretinogram measurements were performed. Changes in layer thickness were investigated. Changes of RGC, amacrine-, rod bipolar-, and glia cells as well as presence of apoptosis was analyzed immunohistologically. Results: A-wave- and b-wave amplitudes were decreased; histology showed a reduction of RGC- and inner plexiform layer thickness and a 29% loss of RGCs occurred in ischemic eyes (p=0.016). An increase of apoptotic cells was detected in the GCL and INL of ischemic retinas (p<0.05). Also, a loss of cholinergic amacrine cells (Control: 11±1 cells/mm, I/R: 4±1 cells/mm, p<0.001), but no change in rod bipolar cell numbers was noted. Conclusions: Our study allowed a comparison of the effects of I/R for different retinal cell types. Cells in the outer retina seemed to be more resistant to ischemic damage compared to cells of the inner retina. We hypothesize that a degenerative process, like a secondary wave of apoptosis, occurs 21 days after I/R, causing progressive damage in the retina.
    Investigative ophthalmology & visual science 04/2014; · 3.43 Impact Factor
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    ABSTRACT: To evaluate the feasibility and safety of femtosecond laser-assisted capsulotomy in eyes with intumescent white cataract. Ruhr University Eye Clinic, Bochum, Germany. Prospective clinical trial. After femtosecond laser-assisted capsulotomy (Catalys Precision system), phacoemulsification was performed using pulsed ultrasound energy and the effective phacoemulsification time was evaluated. The lenticular capsule disk was stained intraoperatively with trypan blue and pulled out using a microsurgical forceps for further analysis of form and shape. Twenty-five eyes were included in this trial. Automatic optical coherence tomography detection of the anterior capsule was performed successfully in all eyes. Radial anterior tears occurred in 2 eyes, an adherent tongue-like capsule adhesion in 9 eyes, and an incomplete capsulotomy button in 3 eyes. In all cases, the intraocular lens was centered and the implantation was uneventful. The mean deviation from the target diameter of the extracted capsule disks was 60 μm ± 44 (SD). The use of the femtosecond laser-assisted system for capsulotomy in surgery for intumescent white cataract appears to be safe and technically feasible. Dr. Dick is a member of the medical advisory board of Optimedica Corp. No other author has a financial or proprietary interest in any material or method mentioned.
    Journal of Cataract and Refractive Surgery 11/2013; · 2.75 Impact Factor
  • Tim Schultz, Stephanie C Joachim, Mathias Kuehn, H Burkhard Dick
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    ABSTRACT: To investigate the intraocular prostaglandin concentrations after femtosecond laser treatment and the potential relationship to miosis. Aqueous humor was collected from patients after femtosecond laser pretreatment and at the beginning of routine cataract surgery. The total prostaglandin and the prostaglandin E2 concentrations were measured in two independent studies using an enzyme-linked immunoassay. A significantly higher level of prostaglandins was noted in the aqueous humor of patients immediately after femtosecond laser treatment. This could be confirmed in two studies consisting of independent patient populations (study I: control = 17.3 ± 4.0 pg/mL [n = 22], femtosecond laser [femto] = 182.1 ± 38.1 pg/mL [n = 22], P = .0001, and study II: control = 17.5 ± 1.4 pg/mL [n = 37], femto: 377.1 ± 83.6 pg/ mL [n = 35], P = .00004). A significant increase of prostaglandin E2 was noted in two measurements (study III: control = 4.5 ± 1.9 pg/mL [n = 13], femto: 19.2 ± 2.5 pg/mL [n = 20], P = .0002, and study IV: control = 11.3 ± 1.6 pg/mL [n = 35], femto: 60.3 ± 16.1 pg/mL [n = 36], P = .004). No correlation was noted between age or cataract density and prostaglandin/prostaglandin E2 level or between corneal incision, suction time, or laser time in the femto groups and prostaglandin/prostaglandin E2 level. Prostaglandins rise immediately after femtosecond laser treatment. Future patients should perhaps be treated with non-steroidal anti-inflammatory drugs to maintain mydriasis before undergoing femto-second laser treatment for cataract surgery. [J Refract Surg. 2013;29(11):742-747.].
    Journal of refractive surgery (Thorofare, N.J.: 1995) 11/2013; 29(11):742-7. · 2.47 Impact Factor
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    ABSTRACT: Multiple sclerosis (MS) is often accompanied by optic nerve inflammationAndsome patients experience permanent vision loss. We examined if the grade of optic nerve infiltration and demyelination affects the severity of clinical signs in an experimental autoimmune encephalomyelitis (EAE) model. The loss of retinal ganglion cells (RGC) and alterations in glia activity were also investigated. C57BL/6 mice were immunized with peptide MOG35-55in complete Freund's adjuvant (CFA) and controls received PBS in CFA. Then 23 days post immunization eyes were prepared for flatmounts and stained with Nissl to evaluated neuronal density. Clinical EAE symptoms as well as cell infiltration and demyelination in the optic nerve were examined. Retinal sections were stained with hematoxylin and eosin and silver stain. Immunohistochemistry was usedto label RGCs (Brn-3a), apoptotic cells (caspase 3), macroglia (glial fibrillary acidic protein (GFAP)), microglia (Iba1), macrophages (F 4/80) and interleukin-6 (IL-6) secretion. EAE symptoms started at day 8 and peaked at day 15. Cell infiltrations (P = 0.0047) and demyelination (P = 0.0018) of EAE nerves correlated with the clinical score (r> 0.8). EAE led to a significant loss of RGCs (P< 0.0001). Significantly more caspase 3+ cells were noted in these animals (P = 0.0222). They showed an increased expression of GFAP (P< 0.0002) and a higher number of microglial cells (P< 0.0001). Also more macrophages and IL-6 secretion were observed in EAE mice. MOG immunization leads to optic neuritis and RGC loss. EAE severity is related to the severity of optic nerve inflammation and demyelination. EAE not only affects activation of apoptotic signals, but also causes a glial response in the retina.
    Journal of Neuroinflammation 10/2013; 10(1):120. · 4.35 Impact Factor
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    ABSTRACT: Glaucoma is characterized by death of retinal ganglion cells (RGC), but its cause is still unknown. We used an autoimmune glaucoma model to study (1) apoptosis, (2) antibody occurrence, and (3) gliosis by immunohistochemistry. Rats were immunized with optic nerve homogenate (ONA). At 8 days no significant apoptosis or difference in RGCs was noted, but ONA retinas had a significantly higher GFAP(+) area (p = 0.02). At 14 days, significantly more TUNEL(+) (p = 0.0002) and caspase 3(+) (p = 0.004) were detected in ONA animals, but no difference in RGC density. Distinct IgM and IgG deposits (p = 0.04) were observed in ONA retinas. At 22 days, a significantly higher number of TUNEL(+) cells (p = 0.0002), caspase 3(+) cells (p = 0.0007), and concurrent a lower RGC density (p = 0.04) was noted in ONA animals. IgM and IgG deposits were observed in the ganglion cell layer of ONA retinas. The largest percentage of GFAP(+) area in the ONA group was observed at 22 days (p = 0.02). This data suggest that immunization with ocular antigens leads to apoptotic retinal ganglion cell death. Based on the co-localization of antibody deposits and apoptotic cells, we conclude that antibodies are engaged in eliciting RGC apoptosis in this animal model.
    Journal of Molecular Neuroscience 10/2013; · 2.89 Impact Factor
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    ABSTRACT: In recent years, numerous studies have investigated the involvement of immunological mechanisms in glaucoma. Until now, it has not been determined whether the altered antibody pattern detected in patients is harmful to retinal ganglion cells (RGCs) or triggers disease formation in any way. In a model of experimental autoimmune glaucoma, RGC loss can be induced through immunization with certain ocular antigens. In the current study, the time course of the levels of autoreactivity against ocular tissues after immunization was examined. Intraocular pressure was measured regularly. Ten weeks after immunization with an optic nerve homogenate antigen (ONA), the number of RGCs was determined. Immunoglobulin G levels in aqueous humor were measured via enzyme-linked immunosorbent assay at the same time point. Serum from different time points was used to analyze the possible occurrence of autoreactive antibodies against the retina or optic nerve in this autoimmune glaucoma model. Additionally, optic nerve and brain sections were evaluated for possible pathological findings. Intraocular pressure stayed within the normal range throughout this study. A continuous increase of autoreactive antibodies against the optic nerve and retina sections was observed. At 4, 6, and 10 weeks, antibody reactivity was significantly higher in ONA animals (p<0.01). Aqueous humor immunoglobulin G levels were also significantly higher in the ONA group (p=0.006). Ten weeks after immunization, significantly fewer RGCs were noted in the ONA group (p=0.00003). The optic nerves from ONA animals exhibited damaged axons. No pathological findings appeared in any brain sections. Our findings suggest that these modified antibodies play a substantial role in mechanisms leading to RGC death. The slow dissolution of RGCs observed in animals with autoimmune glaucoma is comparable to the slow progressive RGC loss in glaucoma patients, thus making this a useful model to develop neuroprotective therapies in the future.
    Molecular vision 01/2013; 19:1804-14. · 1.99 Impact Factor
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    ABSTRACT: Both the innate and the adaptive immune systems are involved in the pathogenic processes following ischemia-reperfusion injury. We analyzed the possible correlation between the duration of ischemia and autoantibody diversification in a model of ocular ischemia. Rats were subjected to 30, 45, or 90 min of ischemia, and retinal ganglion cell (RGC) density and antibody reactivity were analyzed via customized protein microarray slides. After ocular ischemia, significant alterations in antibody response were observed, while increasing exposure caused more severe RGC damage. Distinct antibody responses after ischemia were detected; these alterations comprised decreased reactivities against cyclophilin A and glyceraldehyde-3-phosphate dehydrogenase, possibly due to increased binding of circulating antibodies to debris material. Other antibodies, like those against α(5)β(1)-integrin or β(2) -adrenergic receptor, were upregulated after ischemia.
    Ophthalmic Research 03/2012; 48(2):67-74. · 1.56 Impact Factor
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    ABSTRACT: PurposeUntil now it is not known if antibodies detected in patients with glaucoma are harmful to retinal ganglion cells or trigger disease formation in any way. In a model of experimental autoimmune glaucoma retinal ganglion cell (RGC) loss can be induced through immunization with certain ocular antigens. MethodsRats were injected with optic nerve homogenate (ONA, n=11) in Freund's adjuvant (FA) and pertussis toxin (PTX; both Sigma-Aldrich). Animals of the control group (CO, n=9) received FA and PTX in sodium chloride. Booster injections were given after 4 and 8 weeks. Intraocular pressure measurements were performed throughout the study using a Tonopen. Serum from different study points was used to analyze the occurrence of autoreactive antibodies against retina or optic nerve tissue. The antibody staining intensity was scored by 3 examiners from 0 (=no) to 3 (=severe stain). For each point in time p-value was calculated via student t-test. 10 weeks after immunization RGC density was evaluated via retinal flatmounts. Additionally brain sections were evaluated for possible pathological findings using H&E and LFB stain and antibodies to CD68 and CD45 (after 12 and 70 days). ResultsOcular pressure stayed within the normal range (CO=15.3mmHg; ONA=14.8mmHg; p=0.9). A continuous increase of autoreactive antibodies against optic nerve as well as retina sections could be observed. At 4, 6 and 10 weeks antibody reactivities were significantly higher in immunized animals (p<0.01). The following mean scores were recorded at 10 weeks for retina: CO: 0.3{+/-}0.1; ONA: 2.2{+/-}0.2 (p=0.00001) and optic nerve: CO: 0.3{+/-}0.2; ONA: 2.7{+/-}0.1 (p=0.00001). Density of RGCs was significantly decreased in ONA animals (p=0.009), especially in peripheral regions of the retina (p=0.003). No pathologic finding was noted on brain sections, no mononuclear cell infiltrates consisting of macrophages or lymphocytes were detectable. ConclusionsOur findings suggest that these antibodies play a substantial role in the mechanisms leading to retinal ganglion cell death. This autoimmune model should be helpful to develop more causative glaucoma therapies.
    Invest. Ophthalmol. Vis. Sci.; 01/2012
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    ABSTRACT: PurposeAutoimmune lymphocyte-proliferations were shown in blood of patients with normal pressure glaucoma (NPG). In previous studies systemic immunization with ocular antigens like optic nerve homogenate (ONA) led to an immune-mediated retinal ganglion cell (RGC) loss in rodents. MethodsRats were immunized with antigens (ONA, S100) in Freund's Adjuvants (FA) and Pertussis Toxin (PTx). S100 belongs to a neural, low weight protein family with a calcium binding side. Both groups were compared to NaCl-controls (Co). The intraocular pressure (IOP) was measured for four weeks. After 28 days the RGC density of six eys per group was quantified using cresyl stained retinal flatmounts and six cryo-sectioned eyes were fluorescence stained with Brn3a-antibody (Santa Cruz). CD3-FITC/CD45R-PE ratio (both eBioscience) were analyzed in spleen, cervical lymph nodes, blood and retina (n=5 per group) using a Cyflow-FACS (Partec) after 14 days. Groups were compared with student t-test. ResultsNo significant changes in the IOP of S100 (p=0.3) and ONA group (p=0.5) in correlation to Co rats were measured. In contrast to the Co group a significant RGC loss in both groups could be investigate (S100: p=0.005; ONA: p=0.0005). A little population of CD3+-cells (~6%) and almost no CD45R+-cells migrated in the retina of S100 and ONA animals after 14 days. The alteration of CD3/CD45R-ratio seems antigen dependent in the immunized groups in the different organs. ConclusionsImmunization with ONA and S100 led to a RGC-loss without changes in IOP in this autoimmune model. The T-cells likely overcame the blood-retina-barrier after immunization, while the B-cells proliferated and stayed systemically. Autoimmune T-cells seem to play an important role in the course of RGC death. It is unknown, if T-cells participate in the first degeneration period or follow a chemotaxis signal and trigger a second degeneration.
    Invest. Ophthalmol. Vis. Sci.; 01/2012
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    ABSTRACT: Antibodies against retinal and optic nerve antigens are detectable in glaucoma patients. Recent studies using a model of experimental autoimmune glaucoma demonstrated that immunization with certain ocular antigens causes an immun-mediated retinal ganglion cell loss in rats. Rats immunized with a retinal ganglion cell layer homogenate (RGA) had a reduced retinal ganglion cell density on retinal flatmounts (p = 0.007) and a lower number of Brn3(+) retinal ganglion cells (p = 0.0001) after six weeks. The autoreactive antibody development against retina and optic nerve was examined throughout the study. The levels of autoreactive antibodies continuously increased up to 6 weeks (retina: p = 0.004; optic nerve: p = 0.000003). Additionally, antibody deposits were detected in the retina (p = 0.02). After 6 weeks a reactive gliosis (GFAP density: RGA: 174.7±41.9; CO: 137.6±36.8, p = 0.0006; %GFAP(+) area: RGA: 8.5±3.4; CO: 5.9±3.6, p = 0.006) as well as elevated level of Iba1(+) microglia cells (p = 0.003) was observed in retinas of RGA animals. Our findings suggest that these antibodies play a substantial role in mechanisms leading to retinal ganglion cell death. This seems to lead to glia cell activation as well as the invasion of microglia, which might be associated with debris clearance.
    PLoS ONE 01/2012; 7(7):e40616. · 3.53 Impact Factor
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    ABSTRACT: PurposeUnder pathological conditions glia cell invasion is associated with neuronal decline. Over the past decades evidences obtained from experimental studies supported the role of auto-antibodies in glaucoma which cause retinal ganglion cell (RGC) loss and glia activation. The aim was to examine if glia activity changes in retina after immunization with S100 calcium-binding protein and optic nerve homogenate (ONA). MethodsRats were immunized with S100 and ONA in Freund's Adjuvant and Pertussis Toxin (n=6). Both groups were compared with NaCl as a control group (n=6). After 28 days astrocytes and RGC density was quantified in retinal cross-sections using glia fibrillary acidic protein (GFAP, Millipore) and brain specific homeobox (Brn-3a, Santa Cruz) in double staining to investigate gliosis and loss of RGC at once. Photos were taken in two central and two peripheral areas of four sections per eye. GFAP intensity was scored ranging from 0 (no signal) to 3 (severe signal) and a group comparison was performed using student t-test. Additionally, immunostaining with anti-Iba1 and anti-ED1 was performed to gain further knowledge about the role of activated microglia in retina. ResultsA significant lower number of RGCs was detectable in ONA and S100 group after 28 days (S100: p=0.005; ONA: p=0.0005). Findings of glia cells in ONA immunized rats revealed a massive invasion of glia compared to control group. A significant difference regarding GFAP staining intensity could be observed between the ONA (mean score 2.3{+/-}0.70) and the control group (1.8{+/-}0.67, p=0.000001). The mean GFAP score in the S100 group was not significantly higher than in control group and stayed within the normal range (p=0.7). ConclusionsTherefore, we conclude that the immunization with certain ocular antigens such as ONA causes gliosis which is engaged in eliciting RGC death in this model. Other antigens like S100 lead to RGC loss without significant gliosis. The severity of gliosis seems to be highly antigen-dependent. These findings indicate that the immunization with ONA causes a lower RGC density which is linked to proliferation and invasion of glia in this model.
    Invest. Ophthalmol. Vis. Sci.; 01/2012
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    ABSTRACT: The aim of the study was to investigate the presence and distribution of PE-11, a peptide derived from chromogranin B, in the rat eye. For this purpose, newborn rats were injected with a single dosage of 50mg/kg capsaicin subcutaneously under the neck fold and after three months, particular eye tissues were dissected and the concentration of PE-11-like immunoreactivity was determined by radioimmunoassay. Furthermore, PE-11-like immunoreactivities were characterized in an extract of the rat eye by reversed phase HPLC. Then, the distribution pattern of PE-11 was investigated in the rat eye and rat trigeminal ganglion by immunofluorescence. As a result, PE-11 was present in each tissue of the rat eye and capsaicin pretreatment led to a 88.05% (±7.07) and a 64.26% (±14.17) decrease of the levels of PE-11 in the cornea and choroid/sclera, respectively, and to a complete loss in the iris/ciliary body complex. Approximately 70% of immunoreactivities detected by the PE-11 antiserum have been found to represent authentic PE-11. Sparse nerve fibers were visualized in the corneal and uveal stroma, surrounding blood vessels at the limbus, ciliary body and choroid and in association with the dilator and sphincter muscle. Furthermore, immunoreactivity was present in the corneal endothelium. In the retina and optic nerve, glia was labeled. In the rat trigeminal ganglion, PE-11-immunoreactivity was visualized in small and medium sized ganglion cells with a diameter of up to 30μm. In conclusion, there is unequivocal evidence that PE-11 is a constituent of capsaicin-sensitive sensory neurons innervating the rat eye and the distribution pattern is typically peptidergic in the peripheral innervation but in the retina completely atypical for neuropeptides and unique.
    Peptides 03/2011; 32(6):1201-6. · 2.52 Impact Factor
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    ABSTRACT: Multiple studies indicate that T-cells play a major role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, but recently an involvement of antibodies has also been discussed. The aim of our study was to examine the effects of myelin basic protein (MBP) immunization on survival of neurons, alteration of antibody reactivity, and microglia in the retinal ganglion cell layer. EAE was induced in rats by immunization with MBP. Intraocular pressure (IOP) measurements and funduscopies were performed regularly. Neuron cell density was evaluated on cresyl-stained retinal flatmounts. IgG antibody deposition and activated microglia were detected in retina and optic nerve sections via immunohistology. The intensity of autoreactive IgG antibodies was quantified in successive serum samples via tissue arrays. Significant loss of neurons was detected 6 weeks after immunization (p < 0.05). At the same time, IgG antibody deposits accumulated in the retina and the optic nerve of EAE animals and a significant microglia turn-over to activation was observed. The level of IgG antibody reactivity against retina and optic nerve tissue continuously increased (p < 0.05). While clinical parameters indicated typical EAE progression, we observed no changes in IOP (p > 0.9) or abnormalities in fundi. Immunization with MBP not only causes neuron loss in the retinal ganglion cell layer, but also triggers antibody reactivity against ocular tissue. Possibly some of these antibodies are involved in the induction of neuronal apoptosis. This study suggests that, apart from T-cell mediation, alteration of antibody reactivity and activated microglia do also influence the ocular pathomechanisms in the EAE model.
    Albrecht von Graæes Archiv für Ophthalmologie 02/2011; 249(7):1009-20. · 1.93 Impact Factor
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    ABSTRACT: The aim of this study was to characterize the serum antibody reactivities occurring after ocular ischemia reperfusion. The time course of serum antibody responses was examined. Wistar rats were exposed to transient ocular ischemia by elevating intraocular pressure to 130 mm Hg for 60 minutes. Axonal damage was evaluated on optic-nerve sections 2 and 4 weeks later. Blood samples collected before and several times after ischemia were used for antibody detection via customized protein microarrays. Different tissue antigens, including heat shock proteins (HSPs) and crystallins, were selected based on previous identification of antibody reactivities in studies on ischemic events or ophthalmic diseases associated with ischemia. Antibody reactivity was compared using multivariate statistical techniques. Significant axonal damage was observed 2 and 4 weeks after ocular ischemia (P < 0.05). Animals showed certain immunoreactivities against antigens even before ischemia, whereas many reactivities increased afterward. Significantly different responses were detected 2, 3, and 4 weeks after ischemia (P < 0.05). Antibody reactivity against actin, glial fibrillary acidic protein, HSP 27, vimentin, or spectrin continually increased. Ischemia induced by acute intraocular pressure elevation led to complex changes in antibody reactivities in sera of treated animals. Upregulation of serum autoantibodies, especially against heat shock and structural proteins, progressively increased throughout the 4-week follow-up period, whereas others such as ubiquitin decreased. The upregulation of anti-HSP 27 antibodies might be an attempt to protect the tissue from ischemic damage.
    Investigative ophthalmology & visual science 02/2011; 52(6):3468-74. · 3.43 Impact Factor
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    ABSTRACT: PurposeAntibodies against retinal antigens occur in patients with glaucoma. Previous studies using a model of experimental autoimmune glaucoma demonstrated that immunization with certain ocular antigens causes an immune-mediated retinal ganglion cell (RGC) loss in rodents. MethodsLewis rats were immunized with a retinal ganglion cell layer homogenate (RGA, n=10) and compared to controls (CO, n=10). RGC density was quantified using cresyl stained retinal flatmounts after six weeks. Retina and optic nerve cross-sections were used for detection of autoreactive antibodies, antibody depositions, and microglia cells (via anti-Iba 1 antibody). Depositions and microglia were counted on all cross-sections. A scoring system, ranging from 0=no DAB staining to 3=strong staining, was applied for the intensity of the autoreactive antibody stain. A possible retinal gliosis was also analyzed, using anti-GFAP antibody. Severity of gliosis was scored by three examiners, scores ranging from 0=no staining, to 3=strong GFAP positive staining. The two groups were compared via t-test. Additionally, brain sections were analyzed for possible pathological findings. ResultsImmunization with RGA did only lead to a reduced retinal ganglion cell density (p=0.007) but also to antibody deposits in the retina (RGA: 3.0{+/-}0.5/mm; CO=1.3{+/-}0.3/mm). An increase in autoreactive antibodies occurred in retinas after immunization, at six weeks a mean score of 4{+/-}0.3 was observed for the RGA group compared to 0.3{+/-}0.1 for controls (p=0.004). Additionally, we detected a reactive Muller cell gliosis (scores: RGA=2.03{+/-}0.1, CO=1.3{+/-}0.2; p=0.001) as well as the invasion of activated microglia cells (RGA: 6.3{+/-}0.9 cells/mm, CO: 2.2{+/-}0.2 cells/mm; p=0.005). Observations of the CNS revealed no pathological aberrations, such as inflammatory infiltrates, demyeliniation or hemorrhages. ConclusionsOur findings suggest that autoreactive antibodies play a substantial role in mechanisms leading to retinal ganglion cell death, possibly through binding to RGCs and therefore triggering apoptosis. RGC loss seems to lead to Muller cell activation as well as the invasion of activated microglia, which might be associated with debris clearance.
    Invest. Ophthalmol. Vis. Sci.; 01/2011
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    ABSTRACT: PurposeOptic neuritis and experimental autoimmune encephalomyelitis (EAE) are mainly characterized by autoimmune inflammatory demyelination. Beside T-cell mediation, recently an involvement of antibodies has also been discussed. Aim of our study was to examine the effects of myelin basic protein (MBP) immunization on retinal ganglion cell (RGC) survival, optic nerve alteration, changes of antibody reactivity, and microglia. MethodsOptic neuritis was induced in rats by immunization with MBP (MBP, n=10), pertussis toxin (PTX) and incomplete Freund's adjuvant (IFA). A control group (CO, n=10) received only PTX and IFA in NaCl. EAE scoring, intraocular pressure (IOP) measurements, and funduscopies were performed regularly. Ganglion cell density was evaluated on cresyl stained retinal flatmounts after six weeks. Optic nerve demyelination was graded by 0-3 scoring (demyelination score=ds) after Luxol Fast Blue staining. IgG antibody deposition and activated microglia were investigated in retina and optic nerve sections via immunohistology. The intensity of autoreactive IgG antibodies was quantified in successive serum samples via tissue arrays. Data was analyzed using ANOVA, Tukey's post hoc or t-test. ResultsSignificant RGC loss was detected in EAE animals six weeks after immunization (CO=3805 cells/mm2, MBP=3544 cells/mm2; p<0.05). Optic nerve demyelination was observed (MBP:ds=1.77, CO:ds=0.62; p<0.01) and IgG antibody deposits accumulated in the retina and axons of EAE animals. Activated microglia cells were significantly increased in retina of EAE animals (CO=2.15 cells/mm, MBP=6.15 cells/mm; p<0.05). A twofold higher amount of activated microglia was noticed in optic nerves of the MBP group (CO=3.16 cells/ROI, MBP=6.46 cells/ROI; p=0.03), while the number of ramified microglia was slightly decreased (CO=12.90, MBP=7.80; p=0.13). The level of IgG antibody reactivity against retina and optic nerve components continuously increased (p<0.05). We observed typical EAE progression but no changes in IOP (p=0.9) or abnormalities in fundi. ConclusionsImmunization with MBP triggers antibody reactivity against ocular tissue and causes RGC loss and demyelination. This suggests that antibody reactivity and their deposition in retina and optic nerve are possibly involved in the induction of RGC apoptosis. Induced by this stimuli, microglia were activated and do also influence the ocular pathomechanisms in EAE optic neuropathy.
    Invest. Ophthalmol. Vis. Sci.; 01/2011
  • ARVO Meeting Abstracts; 01/2011
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    ABSTRACT: In an experimental autoimmune animal model, retinal ganglion cell (RGC) loss was induced through immunization with glaucoma-related antigens. The target of this study was to investigate the pathomechanism behind this decline and the serum antibody reactivity against ocular and neuronal tissues after immunization with glaucoma- and non-glaucoma-associated antigens. Rats immunized with optic nerve antigen homogenate (ONA) or keratin (KER) were compared to control rats (CO). Intraocular pressure (IOP) was measured, and the fundi were examined regularly. Four weeks afterward, cells were counted in retinal flat mounts. Retina, optic nerve, and brain sections from healthy animals and optic nerve sections from immunized animals were incubated with serum collected at different time points. The occurrence of autoreactive antibodies was examined. Signs of antibody deposits, microglia activation, and demyelination were sought in optic nerves of immunized animals. Brain sections were examined for abnormalities. No IOP or fundus changes were observed. Animals immunized with ONA showed a significant cell loss compared with the CO group. Elevated autoreactive antibodies against retina, optic nerve, and brain were observed. Animals immunized with KER, despite their immunologic response against KER, demonstrated neither RGC loss, nor increased development of autoreactive antibodies. Optic nerve from animals immunized with ONA demonstrated antibody accumulation, glia activation, and demyelination. No such observations were made in the KER or CO groups. Brain sections were without pathologic findings. Systemic autoimmunity against ocular and neuronal epitopes, mediated by accordant autoreactive antibodies, is involved in the inflammatory processes that cause RGC degeneration in this experimental animal model.
    Investigative ophthalmology & visual science 01/2011; 52(12):8835-48. · 3.43 Impact Factor

Publication Stats

344 Citations
73.54 Total Impact Points

Institutions

  • 2013
    • Universitätsklinikum Knappschaftskrankenhaus Bochum
      Bochum, North Rhine-Westphalia, Germany
  • 2011–2013
    • Ruhr-Universität Bochum
      Bochum, North Rhine-Westphalia, Germany
  • 2003–2011
    • Johannes Gutenberg-Universität Mainz
      • Department of Medical and Pharmaceutical Chemistry
      Mayence, Rheinland-Pfalz, Germany
  • 2009
    • Universitätsmedizin der Johannes Gutenberg-Universität Mainz
      • Department of Ophthalmology
      Mainz, Rhineland-Palatinate, Germany