[Chemokines in ophthalmology]. / Chemokine in der Augenheilkunde.

Chemokines are chemotactically active cytokines, which coordinate the distribution of immune cells within the body and also regulate the migration of leukocytes in malignant and inflammatory processes. Chemokines are a heterogeneous group of short-chain proteins that are divided into different subgroups on the basis of their structure. In addition to the chemokines (ligands) various chemokine receptors also exist. The chemokine system is given its complexity by the high redundancy of ligand-receptor interactions: one single ligand can bind to different receptors and a single receptor can interact with different ligands. In terms of receptors, distinct immune cell types have characteristic receptor expression patterns, which can be used for the immunological characterization of leukocytes. Important basic research is currently leading to a better understanding of the chemokine system. The essential importance of the chemokine system in various diseases of the anterior and posterior eye segments is becoming increasingly apparent. The following synopsis explains the individual clinical aspects as well as the underlying scientific work in the context of "chemokines in ophthalmology".

Peripheral hypertrophic subepithelial corneal degeneration presenting with bilateral nasal and temporal corneal changes.

PURPOSE: To characterise the history, clinical and histopathological features of patients with bilateral nasal and temporal peripheral hypertrophic subepithelial corneal degeneration in a German population. METHODS: A detailed ophthalmological and dermatological history and clinical findings were recorded of nine patients with bilateral simultaneous nasal and temporal peripheral corneal degeneration from two centers in Germany. Excised tissues were studied by histopathology, immunohistochemistry, and transmission electron microscopy. RESULTS: Foreign body sensation and need of artificial tear substitutes were the only symptoms reported regularly. Schirmer's and Jones-test were normal in all, but fluorescein break-up time of >10 s was found in five eyes of four patients. Best corrected visual acuity was reduced only under glare conditions. Corneal topography revealed irregular astigmatism in 13 of 14 eyes. Follow-up median time was 35 months. Most cases were stable within the follow-up period. Light and electron microscopy revealed the findings of superficial vascularised corneal hypertrophic scars, oxytatlan fibers, and discontinued Bowmans layer. CONCLUSION: In this series of German patients with peripheral hypertrophic subepithelial corneal degeneration, the changes were predominantly located in the palpebral aperture and often present in both eyes. No associated surface disease could be established in this study. Light and transmission electron microscopy showed histological features that are similar to Salzmann's corneal changes without any inflammation. We hypothesise that light exposure and a localised limbal insufficiency could be involved in the pathogenesis.

[Immunosuppressives to prevent rejection reactions after allogeneic corneal transplantation]. / Immunsuppressiva zur Verhinderung von Abstoßungsreaktionen nach allogenen Hornhauttransplantationen.

In order to prevent rejection of an allogeneic corneal transplant after perforating (high risk) keratoplasty, active agents from different classes of pharmacological substances are used, as with solid organ transplantation. In addition to glucocorticoids, antiproliferative agents, small molecule inhibitors and antibodies, those belonging to the group of macrolides with their many derivatives represent an interesting class of substances in this context. As a supplement to cyclosporin A (CSA) the most successful macrolide in transplantation medicine, animal experiments are currently being carried out to test newer macrolide derivatives, such as sanglifehrin A (SFA). This overview describes the classes of drugs and modes of action of currently administered standard medications in the clinical routine and new developments are presented.

Cathepsin proteases promote angiogenic sprouting and laser-induced choroidal neovascularisation in mice.

Cysteine cathepsins are a family of proteases involved in intracellular protein turnover and extracellular matrix degradation. Cathepsin B (Ctsb) and cathepsin Z (Ctsz) promote tumorigenesis and Ctsb is a known modulator of tumor angiogenesis. We therefore investigated the angiomodulatory function of these cathepsins in vitro as well as in a mouse model of laser-induced choroidal neovascularization (laser-CNV). Ctsb(-/-), Ctsz(-/-), Ctsb/Ctsz double-knockout (Ctsb/z DKO), and wild type (WT) mice underwent argon laser treatment to induce choroidal neovascularization (CNV). The neovascularized area was quantified individually for each lesion at 14 days after laser coagulation. In vitro the effects of cathepsin inhibitors on angiogenesis were analysed by endothelial cell (EC) spheroid sprouting and EC invadosome assays. Retinas from cathepsin KO mice did not show gross morphological abnormalities. In the laser CNV model, however, Ctsb/z DKO mice displayed a significantly reduced neovascularized area compared to WT (0.027 mm(2) vs. 0.052 mm(2); p = 0.012), while single knockouts did not differ significantly from WT. In line, VEGF-induced EC spheroid sprouting and invadosome formation were not significantly altered by a specific cathepsin B inhibitor alone, but significantly suppressed when more than one cathepsin was inhibited. Our results demonstrate that laser-CNV formation is significantly reduced in Ctsb/z DKO mice. In line, EC sprouting and invadosome formation are blunted when more than one cathepsin is inhibited in vitro. These results reveal an angiomodulatory potential of cathepsins with partial functional redundancies between different cathepsin family members.

[Beyond TGF-beta: wound healing modulation in filtering glaucoma surgery]. / Wundheilungsmodulation nach filtrierenden Glaukomoperationen: Was kommt nach TGF-beta?

Conjunctival scarring remains the major problem in filtering glaucoma surgery. Antimetabolites afford a reduction of scar formation, but considerable side effects limit their application. Here, we review the mechanisms and peculiarities of wound healing following glaucoma surgery and report on new developments in the field of wound healing modulation. The growth factor TGF-beta has a central role in wound healing and scarring. Therefore, novel concepts of wound healing modulation comprise scavenging of TGF-beta and specific inhibition of disinct downstream intracellular signalling pathways. Several compounds have entered preclinical evaluation and offer new potential to modulate scarring in future combination therapies.

Long-term results of Erbium YAG-laser-assisted deep sclerectomy.

PURPOSE: To evaluate the long-term results of Erbium YAG-laser-assisted deep sclerectomy (DS). In this procedure, the delicate dissection of a deep corneoscleral lamella is greatly simplified by using the Erbium YAG-laser. METHODS: Data of 14 consecutive patients (10 male, four female, age 67.7+/-10.4 years), who underwent surgery from 1999 to 2000 were analysed retrospectively. The procedure was begun as a standard DS. The deep corneoscleral lamella was dissected with a pulsed Erbium YAG-laser (energy: 40-100 mJ, frequency: 5-10 Hz). Schlemm's canal was unroofed and the lamella thinned until aqueous percolated continuously through the membrane. RESULTS: The mean follow-up time was 50.4+/-6.8 months. The mean preoperative intraocular pressure (IOP) was 37.7+/-10.5 mmHg. The mean postoperative IOP was 16.1+/-3.9 mmHg at 1 month, 15.1+/-4.3 mmHg at 3 months, 16.4+/-4.5 mmHg at 12 months, and 17.6+/-8.7 mmHg at 50.5 months. The complete success rates (IOP< or =21 mmHg+IOP reduction > or =20% without glaucoma medication) were 83.3% at 3 months and 50% at 12 and 50.5 months. Rates for qualified success (IOP< or =21 mmHg+IOP reduction > or =20% with glaucoma medication) were 91.7% at 3 months, 92.9% at 12 months, and 78.6% at 50.5 months. The number of glaucoma medications was reduced from 3.07+/-0.92 preoperatively to 1.14+/-1.41 at 50.5 months. A single case of anterior-chamber penetration, requiring iridectomy, was the only intraoperative complication. CONCLUSIONS: Erbium YAG-laser-assisted DS has the advantage of a greatly simplified dissection, while offering a successful long-term IOP control comparable to conventional DS.

[Postoperative care after glaucoma filtration surgery]. / Nachsorge nach filtrierenden Glaukomoperationen.

Scarring of the filtering bleb is the main complication after glaucoma filtration surgery. Postoperative care most importantly determines success or failure of the operation. Both, preoperative antiinflammatory treatment and reduction or discontinuation of topical medication have a positive effect on postoperative conjunctival wound healing. After conventional postoperative care only about 40% of patients reach target pressures in the long-term without topical medication. Intensified postoperative care (IPC) increases the success rate by 25% after 5 years. Central to the concept of IPC is a wound modulating therapy which is adapted to the phases of wound healing of the filtering bleb. Evaluation of filtering bleb morphology is a prerequisite for the application of topical steroids and 5-fluorouracil. In addition, dedicated counseling of the patient and close follow-up are mandatory. In order to further increase the success rate of penetrating glaucoma surgery and decrease the side effects of the current antimetabolite therapy more research on wound healing as well as specific therapy to prevent scarring are necessary.

[Primary iris stromal cyst with unusual symptoms in an adult]. / Primäre Vorderkammerzyste mit ungewöhnlicher Symptomatik bei einem Erwachsenen.

BACKGROUND: Most epithelial cysts of the anterior chamber ("iris stromal cysts") occur after penetrating ocular injuries and represent secondary epithelial ingrowth. Primary iris stromal cysts are less common and mostly congenital. Acquired primary iris stromal cysts in adults are extremely rare and cause less often symptoms than congenital cysts. PATIENT: A 41-year old patient presented with sudden loss of visual acuity, epiphora and photophobia of his right eye. A large iris cyst was found in the nasal lower quadrant of the anterior chamber. It had not been present 3 years before when the patient was last seen by an ophthalmologist. There was no history of trauma and no signs of preceding ocular injury at slit-lamp examination. The cyst was surgically removed by iridocyclectomy. Postoperatively the patient developed cataract and macular edema. A phacoemulsification with posterior chamber lens implantation as well as a systemic treatment with steroids and acetazolamide were necessary. Until now, two years after surgery, the cyst did not recur. CONCLUSIONS: Primary iris stromal cysts also occur in adults. In contrast to previous reports the cyst of our patient has caused acute symptoms.

[Endoscopically controlled erbium YAG laser goniotomy. Initial preclinical trials]. / Endoskopisch kontrollierte Erbium-YAG-Laser-Goniotomie. Erste präklinische Versuche.

INTRODUCTION: Endoscopic erbium-YAG laser treatment is a new approach in glaucoma surgery. In contrast to conventional laser systems, the photoablative erbium-YAG laser allows microperforations of the trabecular meshwork without thermal side effects. We report our first preclinical trials using this new system. METHOD: We used the Endognost system (Schwind Co.). The device combines an endoscope and illumination fiber (0.5 mm diameter), laser fiber (0.5 mm) and a irrigation tube in one probe with a 1.1 mm external diameter. The Endognost system was tested in porcine and enucleated human eyes. All eyes were examined histologically. RESULTS: The endoscopic view into the anterior chamber allows for precise allocation of the laser pulses. Using a single pulse mode with 10 mJ a micropuncture of the trabecular meshwork can be achieved without damaging the adjacent tissue. Using multiple pulses or higher energy levels leads to damage of the posterior wall of Schlemm's canal and to thermal side effects. CONCLUSIONS: Endoscope guided erbium-YAG laser effects on trabecular tissue are comparable to those produced by a 308 nm excimer laser. Therefore, a similar reduction in intraocular pressure can be expected.

Efficacy trial of topically administered interferon gamma-1 beta gel in comparison to laser treatment in cervical intraepithelial neoplasia.

OBJECTIVE: Dose dependent response of cervical intraepithelial neoplasia (CIN) to topically administered interferon (IFN) gamma was assessed and compared with conventional laser therapy. PATIENT AND METHODS: 33 women were included in a randomized phase II trial which was double blinded for IFN dosages. Twenty-four patients received IFN gamma-1 beta gel and a control group of nine patients was treated with laser surgery. 18 patients had smears suggesting CIN II and 15 patients had smears suggesting CIN III. The response was assessed 6 months after starting of IFN gamma-1 beta treatment or having laser surgery. RESULTS: Topical IFN gamma-1 beta treatment gave a cure rate of 42% independent of IFN dosage as compared to an 89% cure rate with laser therapy (P = 0.02). Patients with CIN II responded better compared with patients with CIN III. Current smokers showed a significantly lower cure rate whereas use of oral contraceptives (OC) did not influence response. High viral load with high risk types of human papillomaviruses (HPV) was associated with a better response.

Effects of histamine on inositol phosphates and intracellular Ca2+ in human glomerular epithelial cells.

The effect of histamine on the phosphoinositide turnover and intracellular free calcium activity [Ca2+]i was examined in human glomerular epithelial cells in culture. Addition of histamine to glomerular epithelial cells resulted in formation of inositol phosphates in a time- and dose-dependent manner. A transient maximum of inositol trisphosphate (InsP3) was observed within 10 s. Stimulation of protein kinase C by short-term pretreatment (15 min) of glomerular epithelial cells with phorbol 12-myristate 13-acetate caused a dose-dependent inhibition of the histamine-induced inositol phosphate accumulation. The baseline of [Ca2+]i in the cells was 115 +/- 2.7 nmol/l (n = 103). Histamine (ED50: approx. 2 x 10(-7) mol/l) caused a rapid and transient increase in [Ca2+]i as detected by fura-2 microfluorimetry studies. In a calcium-free extracellular solution the rapid increase of [Ca2+]i was still present. The H1 receptor antagonist mepyramine (IC50: approx. 8 x 10(-9) mol/l) inhibited the histamine (10(-6) mol/l) response on [Ca2+]i. Cimetidine, a potent H2 receptor antagonist, showed no effect. This data indicates that H1 receptor activation causes hydrolysis of phosphatidylinositol 4, 5-bisphosphate by phospholipase C activation, and consecutive mobilization of intracellular calcium. Since histamine is a mediator of inflammation, antigen response and cellular injury, these findings could be of importance for the understanding of glomerular epithelial cell pathology.

Effect of bradykinin on the cytosolic free calcium activity and phosphoinositol turnover in human glomerular epithelial cells.

The effect of bradykinin (BK) on the intracellular free calcium activity [Ca2+]i and phosphoinositide (PI) turnover was investigated in human glomerular epithelial cells (GEC) in culture. Human GEC exhibited a baseline [Ca2+]i of 114 +/- 3 nmol (n = 81). BK (ED50 10(-9) mol/l) caused a rapid and transient increase in [Ca2+]i, which could also be observed in the absence of extracellular calcium. The effect of BK (10(-8) mol/l) on the [Ca2+]i was inhibited by the BK2 antagonist Hoe 140 (IC50 10(-8) mol/l). BK also induced PI turnover in a time- and dose-dependent manner. A transient increase in (1,4,5)-inositol-triphosphate (InsP3) formation from 1,445 +/- 119 to 4,629 +/- 323 cpm occurred after 5 s. Stimulation of protein kinase C (PKC) by short-term preincubation (15 min) of human GEC with phorbol-12-myristate-13-acetate (PMA) induced a dose-dependent inhibition of the BK-stimulated (10(-7) mol/l) inositol-phosphate formation. Downregulation of PKC by preincubation of human GEC with PMA (24 h, 10(-6) mol/l) or inhibition of PKC by pretreatment with staurosporin (1 h, 10(-6) mol/l) resulted in a slight but significant augmentation of the BK-induced InsP3 stimulation. The data indicate that BK induces stimulation of [Ca2+]i and PI turnover via a BK2 receptor in human GEC. PKC might exert a negative feedback function for the BK-induced PI turnover.

Effect of nucleotides on the cytosolic free calcium activity and inositol phosphate formation in human glomerular epithelial cells.

1. Glomerular epithelial cells (GEC) were cultured from human kidneys and immunologically characterized. 2. The effect of extracellular nucleotides on the cytosolic free calcium activity [Ca2+]i was investigated with the fura-2 microfluorescence method. Extracellular UTP, UDP, UMP, ATP, adenosine 5'-O-(3-thio)-trisphosphate (ATP-gamma-S), inosine-triphosphate (ITP), guanyltriphosphate (GTP), 2-methylthio-ATP, AMP, alpha,beta-methylene-ATP and adenosine led to a rapid, transient, concentration-dependent increase of [Ca2+]i, followed by a plateau above the baseline level. 3. In a calcium-free extracellular solution, the rapid increase of [Ca2+]i was still present, whereas the plateau level was abolished. 4. ATP and UTP (ED50 both: 10(-5) M) stimulated inositol trisphosphate (InsP3) formation in GEC. 5. The order of potency for the purine nucleotides in stimulating InsP3 formation was ATP = ATP-gamma-S greater than ADP greater than 2-methylthio-ATP greater than AMP = a,beta methylene-ATP = adenosine. 6. The increase of InsP3 induced by ATP (10(-5) M) could be inhibited by the P2 receptor blocker suramin (greater than 10(-4) M). Reactive blue 2 exhibited a weak stimulating effect on the InsP3 formation and only a weak inhibitory effect at a concentration of 10(-3) M was observed. 7. Protein kinase C activation by preincubation of GEC with phorbol 12-myristate 13-acetate (PMA, 100 ng ml-1, 15 min) abolished the effect of ATP (10(-5) M) on InsP3 formation. Downregulation of protein kinase C by long term incubation (18 h) with PMA had no significant effect on the phosphoinositol turnover induced by ATP.8. The results indicate that an increase of [Ca2+]i and inositol phosphate breakdown can be mediated via activation of a P2 receptor in human GEC.