[Critical endothelial procedures during posterior lamellar graft preparation and transplantation]. / Endothelkritische Prozeduren während der Herstellung und Transplantation posteriorer lamellärer Hornhauttransplantate.

BACKGROUND: In view of the very low proliferation rate and functional importance of the corneal endothelium in maintaining corneal transparency, safeguarding the integrity of this monolayer plays a central role in posterior lamellar corneal transplantation. Several critical endothelial procedural stages are necessary to carry out such a transplantation. OBJECTIVE: This article presents various preparatory and operative approaches for carrying out the necessary and critical stages within the framework of posterior lamellar corneal transplantation and concentrates on the question of optimization. METHODS: A review of our own studies and studies of other groups is presented. RESULTS: For the performance of critical endothelial procedural steps, a variety of approaches are available. These range from preparation and insertion of the transplant, through the manipulation during centralization up to the effects of postoperative air or gas bubble tamponade. CONCLUSION: Because endothelial damage can permanently impair the integrity of lamellar transplants, a minimal handling and no touch policy should be strived for in all critical procedures. Long-term data on the follow-up course will show which of the procedures favored by various authors lead to the best postoperative results.

[The emerging technology of tissue engineering : Focus on stem cell niche]. / Zukunftstechnologie Tissue-Engineering : Fokus auf die Stammzellnische.

Limbal stem cells reside in a highly specialized complex microenvironment that is known as the stem cell niche, an anatomically protected region at the bottom of the Palisades of Vogt, where the stem cells are located and where their quiescence, proliferation and differentiation are maintained in balance. Besides the epithelial stem and progenitor cell clusters, the limbal niche comprises several types of supporting niche cells and a specific extracellular matrix mediating biochemical and biophysical signals. Stem cell-based tissue engineering aims to mimic the native stem cell niche and to present appropriate microenvironmental cues in a controlled and reproducible fashion in order to maintain stem cell function within the graft. Current therapeutic approaches for ex vivo expansion of limbal stem cells only take advantage of surrogate niches. However, new insights into the molecular composition of the limbal niche and innovative biosynthetic scaffolds have stimulated novel strategies for niche-driven stem cell cultivation. Promising experimental approaches include collagen-based organotypic coculture systems of limbal epithelial stem cells with their niche cells and biomimetic hydrogel platforms prefunctionalized with appropriate biomolecular and biophysical signals. Future translation of these novel regenerative strategies into clinical application is expected to improve long-term outcomes of limbal stem cell transplantation for ocular surface reconstruction.

[Therapy options for malignant eyelid tumors]. / Therapie bei malignen Lidtumoren.

Basal cell carcinomas are the most common malignant tumors of the eyelids. Patient history, clinical symptoms and signs, inspection, palpation and slit-lamp examination usually allow a working diagnosis; however, the clinical diagnosis requires histopathological confirmation and determination of the histopathological type. Squamous cell carcinomas, sebaceous gland carcinomas, melanomas and Merkel cell carcinomas can metastasize usually via the lymph vessels into the regional lymph nodes. Microscopically controlled excision of the primary tumor into healthy tissue is most commonly the first goal. Palpation and ultrasonography of the regional lymph nodes and also computed tomography (CT) with contrast enhancement and magnetic resonance imaging (MRI) for tumors with perineural sheath cell invasion are necessary to define the TNM stage. Non-surgical treatment options are becoming more popular in the further management of malignant eyelid tumors.

Blockade of CCR7 leads to decreased dendritic cell migration to draining lymph nodes and promotes graft survival in low-risk corneal transplantation.

The chemokine receptor CCR7 is essential for migration of mature dendritic cells (DCs) to the regional lymph nodes, and it has been shown that blocking of CCR7 improves graft survival after high-risk corneal transplantation in vascularized recipient corneas. However, it is so far unknown whether blocking of CCR7 reduces migration of DCs from the avascular cornea to the draining lymph nodes and whether this leads to improved graft survival also in the low-risk setting of corneal transplantation, which accounts for the majority of perforating transplantations performed. Therefore, in this study, pellets containing Freund's adjuvant and bovine serum albumin (BSA) conjugated to Alexa488 fluorescent dye were implanted into the corneal stroma of BALB/c mice to analyze antigen uptake by corneal DCs and their migration to the regional lymph nodes. After pellet implantation, mice were either treated by local administration of a CCR7 blocking fusion protein that consisted of CCL19 fused to the Fc part of human IgG1 or a control-IgG. In vivo fluorescence microscopy showed uptake of Alexa488-conjugated BSA by corneal DCs within 8 h. Furthermore, analysis of single cell suspensions of draining lymph nodes prepared after 48 h revealed that 2.1 ± 0.3% of CD11c(+) cells were also Alexa488(+). Importantly, DC migration was significantly reduced after topical administration of CCL19-IgG (1.2 ± 0.2%; p < 0.05). To test the effect of CCR7 blockade on graft rejection after allogeneic low-risk keratoplasty, corneal transplantations were performed using C57BL/6-mice as donors and BALB/c-mice as recipients. Treatment mice received two intraperitoneal loading doses of CCL19-IgG prior to transplantation, followed by local treatment with CCL19-IgG containing eye drops for the first two weeks after transplantation. Control mice received same amounts of control-IgG. Kaplan-Meier survival analysis showed that in the CCL19-IgG treated group, 76% of the grafts survived through the end of the 8 week observation period, whereas 38% of the grafts survived in the control group (p < 0.05). Taken together, our study shows that blockade of CCR7 reduces the migration of mature corneal DCs to the draining lymph nodes and leads to improved graft survival in low-risk corneal transplantation.

[Pathology and prognostic factors of conjunctival melanoma]. / Pathologie und Prognosefaktoren konjunktivaler Melanome.

BACKGROUND: Conjunctival melanoma is a rare but potentially fatal disease. The 10-year melanoma mortality can be up to 30 %, recurrence rates after treatment up to 50 % and the overall incidence of metastasis is 26 %. Improved treatment options are needed to increase the tumor-free survival of affected patients. OBJECTIVES: The aim of the study was to perform clinical and pathological staging using the TNM classification and to correlate the results with treatment modalities and recurrence rates. MATERIAL AND METHODS: The study included a case series of 80 eyes from 80 patients (42 females and 38 males, age 28-90 years) with histopathologically proven conjunctival melanoma studied by reviewing medical records, pathology reports and color photographs. The main evaluated characteristics were demographic information, tumor size, thickness, pathological diagnosis, BRAF mutation testing, clinical and pathological staging, recurrence, metastasis and duration of follow-up (mean 48 months). RESULTS: The lesions predominantly involved the bulbar conjunctiva (60 %) and other sites that were less often involved were the palpebral conjunctiva (23 %), conjunctival fornix (22 %) and lacrimal caruncle (15 %). Of the tumors 36 % were TNM classified as pTis, 34 % as pT1, 20 % as pT2 (palpebral, fornix and caruncle) and 10 % as pT3. Local recurrences were noted in 36 % of the patients (18 % Tis, 26 % T1, 32 % T2 and 70 % T3) and regional and distant metastasis in 20 % of the patients (0 % Tis, 10 % T1, 15 % T2 and 60 % T3). DISCUSSION: In this study increasing T stages were more often associated with recurrences and metastasis. Future studies correlating the TNM staging with histopathological and genetic predictors may help to improve the management of patients with conjunctival melanoma.

[Treatment of severe recurrent symblepharopterygium: combined ipsilateral autologous limbus and homologous amniotic membrane transplantation]. / Behandlung des schweren rezidivierenden Pterygiums mit Symblepharonbildung: Kombinierte ipsilaterale autologe Limbus- und homologe Amnionmembrantransplantation.

BACKGROUND: This retrospective study reports on four patients with severe recurrent symblepharopterygium formation and extensive subconjunctival scarring who were treated with a novel surgical technique combining free limbal autografting and amniotic membrane transplantation. PATIENTS AND METHODS: The surgical technique included symblepharolysis, meticulous removal of subconjunctival scar tissue, ipsilateral free limbal autograft and homologous amniotic membrane transplantation. RESULTS: There were no intraoperative or postoperative adverse events and three patients had no manifestation of recurrence of pterygium, symblepharon or diplopia during a mean follow-up period of 172 ± 18 weeks (39 ± 4 months) postoperatively. Only one patient had persistent symblepharon and experienced a recurrence of pterygium approximately 40 weeks (9 months) after surgery. CONCLUSION: The results suggest that ipsilateral autologous limbal and homologous amniotic membrane transplantation can be an effective therapeutic approach in the treatment of recurrent pterygium with symblepharon formation.

[Pigment dispersion syndrome and pigmentary glaucoma. Morphometric analysis of the anterior chamber segment with SL-OCT]. / Melanindispersionssyndrom und -glaukom. Morphometrische Analyse des vorderen Augenabschnittes mittels SL-OCT.

BACKGROUND: The purpose of this study was to analyze if anterior chamber parameters are risk factors for the development of pigment dispersion syndrome (PDS) and/or for the conversion to pigmentary glaucoma (PG). PATIENTS AND METHODS: This study included a total of 63 eyes from 35 patients with PDS and PG and 65 eyes from 49 unaffected volunteers as the control group. The following parameters were measured by slit lamp optical coherence tomography (SL-OCT): anterior chamber volume (ACV) and depth (ACD), angle opening distance (AOD) and the trabecular iris space area (TISA) at 500 µm and 750 µm from the scleral spur. Comparisons between the following groups were performed: between the PDS/PG and the control group, between PDS and PG and between male and female patients. RESULTS: The results of ACV, ACD, AOD and TISA were significantly higher in PDS/PG patients when compared to the control group. There were no significant differences between PDS and PG. The gender-specific comparison also showed no significant differences. CONCLUSIONS: Significantly higher anterior chamber parameters are a possible risk factor for development of PDS; however, a higher risk of conversion to PG does not seem to correlate with increased anterior chamber parameters. The parameters of the anterior chamber are apparently not associated with the male predominance of PDS and PG.

[Cross-linking in an artificial human cornea via induction of tissue transglutaminases]. / Vernetzung einer humanen künstlichen Hornhaut durch Induktion von Tissue-Transglutaminasen.

PURPOSE: In recent years many three-dimensional cornea models have been developed. However, they show poor collagen stability in the stroma. Transglutaminases (Tgases) are calcium-dependent proteins which play an important role in cross-linking of the corneal stroma. The purpose of this study was to find out whether it is possible to induce in vitro cross-linking of the stroma in an artificial hemicornea model with the help of Tgases. MATERIALS AND METHODS: For the construction of the hemicornea, human SV40 adenovector corneal epithelial cells (HCE) and human SV40 adenovector corneal keratocytes (HCK) were cultivated. Confluent HCK cells were treated for 24 h with transforming growth factor beta (TGFb) 1, 2 and 3 at different concentrations as well as with other growth factors and the treated cells were compared to untreated cultivated cells. The quantification of the expression of the Tgases by HCKs was examined with the use of real time PCR, Western blot imaging and immunochemistry. RESULTS: All concentrations of TGFbs used resulted in a significant increase of Tgase-mRNA, Tgase protein level and Tgase activity. The Tgases remained unaffected after treatment with other growth factors in comparison to untreated control cells. Treatment of the hemicornea with TGFb2 showed a very strong contraction and haze in comparison to the untreated hemicornea. CONCLUSION: It has been shown for the first time that TGFb induces a strong expression of Tgases in HCK cells. This effect caused an undesired contraction and haze of the human hemicornea model. Further research is necessary in order to find out whether the induction of Tgases in the HCK cells can be regulated without losing stability of the constructed hemicornea.

Influence of atypical retardation pattern on the peripapillary retinal nerve fibre distribution assessed by scanning laser polarimetry and optical coherence tomography.

AIM: To investigate the influence of atypical retardation pattern (ARP) on the distribution of peripapillary retinal nerve fibre layer (RNFL) thickness measured with scanning laser polarimetry in healthy individuals and to compare these results with RNFL thickness from spectral domain optical coherence tomography (OCT) in the same subjects. METHODS: 120 healthy subjects were investigated in this study. All volunteers received detailed ophthalmological examination, GDx variable corneal compensation (VCC) and Spectralis-OCT. The subjects were divided into four subgroups according to their typical scan score (TSS): very typical with TSS=100, typical with 99 ≥ TSS ≥ 91, less typical with 90 ≥ TSS ≥ 81 and atypical with TSS ≤ 80. Deviations from very typical normal values were calculated for 32 sectors for each group. RESULTS: There was a systematic variation of the RNFL thickness deviation around the optic nerve head in the atypical group for the GDxVCC results. The highest percentage deviation of about 96% appeared temporal with decreasing deviation towards the superior and inferior sectors, and nasal sectors exhibited a deviation of 30%. Percentage deviations from very typical RNFL values decreased with increasing TSS. No systematic variation could be found if the RNFL thickness deviation between different TSS-groups was compared with the OCT results. CONCLUSIONS: The ARP has a major impact on the peripapillary RNFL distribution assessed by GDx VCC; thus, the TSS should be included in the standard printout.

[Selective lacrimal sac biopsy for external dacryocystorhinostomy: a clinical pathological study]. / Selektive Tränensackbiopsie bei externer Dakryozystorhinostomie: Eine klinisch-pathologische Studie.

BACKGROUND: Tumors of the lacrimal drainage system are rare but potentially life-threatening. The purpose of this study was to investigate the applicability of selective lacrimal sac biopsy in 500 cases of external dacryocystorhinostomy for acquired dacryostenosis. PATIENTS AND METHODS: Lacrimal sac biopsy was obtained selectively for atypical clinical and/or intraoperative findings. The frequency and spectrum of biopsies were recorded and correlated with the follow-up results. RESULTS: Lacrimal sac biopsy was performed in 19 external dacryocystorhinostomies (3.8%) including non-Hodgkin B-cell lymphoma (3), squamous carcinoma (2), mucoepidermoid carcinoma (1), malignant melanoma (1), oncocytoma (1), pyogenic granuloma (4), Wegener's granulomatosis (4) and sarcoidosis (3). Within 5 years none of the patients without biopsy developed systemic inflammatory diseases or lacrimal neoplasms. The 5-year survival was 87% in patients with significant lacrimal sac pathology and 96% in patients without significant pathology. CONCLUSION: External dacryocystorhinostomy with selective biopsy for atypical clinical and intraoperative findings allows safe diagnosis and management of potentially life-threatening lacrimal lesions.

[Complications after posterior lamellar keratoplasty (DSAEK): prevention, detection and treatment]. / Komplikationen nach posteriorer lamellärer Keratoplastik (DSAEK): Vermeiden, Erkennen und Behandeln.

PURPOSE: The aim of this study was to outline typical complications after Descemet's stripping automated endothelial keratoplasty (DSAEK) and to discuss their prevention and management. METHODS: Our own clinical results and PUBMED literature search were evaluated. RESULTS: Postoperative flap dislocation, which can be effectively treated by re-bubbling the graft, is the most common and typical complication after DSAEK. CONCLUSIONS: Careful preoperative indication, surgery and postoperative care make DSAEK a safe and effective new therapeutic option for patients with endothelial corneal disease.

[DMEK: Descemet membrane endothelial keratoplasty]. / DMEK: posteriore lamelläre Keratoplastiktechnik.

BACKGROUND: Penetrating keratoplasty is at present the gold standard for surgical treatment of corneal endothelial pathologies but tremendous progress has been made in recent years in improving the technology of (posterior) lamellar keratoplasty techniques, such as Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: A review of the literature was carried out using PUBMED and own clinical and experimental data. RESULTS: Isolated transplantation of Descemet's membrane with endothelial cells after stripping the host Descemet's membrane is a new surgical technique for Fuchs endothelial dystrophy and pseudophakic bullous keratopathy. Visual rehabilitation seems to be faster and better with DMEK compared to penetrating keratoplasty. CONCLUSION: Posterior lamellar keratoplasty techniques such as DMEK will replace penetrating keratoplasty as the gold standard for treatment of a large segment of corneal endothelial pathologies.

[Descemet's stripping automated endothelial keratoplasty (DSAEK)]. / Posteriore lamelläre Keratoplastik (DSAEK).

Penetrating keratoplasty has been the gold standard for the surgical treatment of corneal endothelial pathologies, but tremendous progress has been made in recent years in improving the technology of posterior lamellar keratoplasty techniques such as Descemet's stripping automated endothelial keratoplasty (DSAEK). This progress is shown by a literature review using PubMed sources and our own clinical and experimental data. Posterior lamellar keratoplasty using a microkeratome is a reliable surgical technique for Fuchs' endothelial dystrophy and pseudophakic bullous keratopathy. Visual rehabilitation is faster with lamellar compared with penetrating keratoplasty, but final visual acuity seems to be a bit reduced. Posterior lamellar keratoplasty techniques such as DSAEK may replace penetrating keratoplasty as the gold standard for treating a large proportion of corneal endothelial pathologies.

Tumour-associated lymphangiogenesis in conjunctival malignant melanoma.

BACKGROUND: To evaluate whether tumour-associated lymphangiogenesis, that is the formation of new lymphatic vessels (LVs) induced by a tumour, occurs in and around conjunctival malignant melanoma (MM). METHODS: Clinical files and conjunctival specimens of 20 patients with histologically diagnosed conjunctival MM were analysed. Sections were stained with LYVE-1 and podoplanin antibodies as specific lymphatic endothelial markers and Ki67 as proliferation marker. The tumour area and the area covered by LV (LVA), LV number (LVN) and LV density (LVD) were measured within the tumour and in the peritumoural area in digital images of the specimen. The LV results were correlated with the histopathological characteristics, tumour location, recurrence rate, mitomycin C therapy and presence of metastases. RESULTS: LVs were detected in all specimens within the tumour and peritumourally. Significantly more Ki67(+) proliferating lymphatic endothelial cells were detected in the tumour and in the peritumoural tissue up to 300 microm compared with the surrounding normal conjunctiva (>300 microm distance). There was a slightly positive correlation between the tumour size and the LVN and LVA in the 50 microm zone adjacent to the tumour. We did not find any significant correlations between LVs and histopathological and clinical characteristics (location, shape, relapses, metastases), possibly due to the small sample sizes. Non-limbal tumours with involvement of tarsus or fornix showed a tendency towards a higher LVD compared with limbal tumours. CONCLUSION: Conjunctival MMs display tumour-associated LV within and around the tumour. The MM seems to induce lymphangiogenesis not only in the tumour, but also in its proximity.

[Web-based electronic patient record as an instrument for quality assurance within an integrated care concept]. / Webbasierte elektronische Krankenakte im Rahmen eines integrierten Versorgungskonzepts als Instrument der Qualitätssicherung.

OBJECTIVE: A prerequisite for integrated care programmes is the implementation of a communication network meeting quality assurance standards. Against this background the main objective of the integrated care project between the University Eye Hospital Erlangen and the health insurance company AOK Bayern was to evaluate the potential and the acceptance of a web-based electronic patient record in the context of cataract and retinal surgery. METHODS: Standardised modules for capturing pre-, intra- and post-operative data on the basis of clinical pathway guidelines for cataract- and retinal surgery have been developed. There are 6 data sets recorded per patient (1 pre-operative, 1 operative, 4-6 post-operative). For data collection, a web-based communication system (Soarian Integrated Care) has been chosen which meets the high requirements in data security, as well as being easy to handle. This teleconsultation system and the embedded electronic patient record are independent of the software used by respective offices and hospitals. Data transmission and storage were carried out in real-time. RESULTS: At present, 101 private ophthalmologists are taking part in the IGV contract with the University Eye Hospital Erlangen. This corresponds to 52% of all private ophthalmologists in the region. During the period from January 1st 2006 to December 31st 2006, 1844 patients were entered. Complete documentation was achieved in 1390 (75%) of all surgical procedures. For evaluation of this data, a multidimensional report and analysis tool (Cognos) was used. The deviation from target refraction as one quality indicator was in the mean 0.09 diopter. CONCLUSIONS: The web-based patient record used in this project was highly accepted by the private ophthalmologists. However there are still general concerns against the exchange of medical data via the internet. Nevertheless, the web-based patient record is an essential tool for a functional integration between the ambulatory and stationary health-care units. In addition to the telemedicine functions of the system, we achieved the export of the data to a data warehouse system in order to provide a flexible and powerful tool for quality assurance analysis and reporting.

Transient postoperative vascular endothelial growth factor (VEGF)-neutralisation improves graft survival in corneas with partly regressed inflammatory neovascularisation.

BACKGROUND: High-risk keratoplasties are usually performed after an uninflamed and quiescent interval in corneas with partly regressed blood and lymphatic vessels. We analysed whether the inhibition of post-keratoplasty revascularisation in mice with partly regressed corneal vessels ("intermediate-risk") improves graft survival. METHODS: Three interrupted stromal sutures (11-0) in corneas of Balb/c mice (6-8 weeks old) were placed for 6 weeks. Six months after suture removal, penetrating keratoplasty was performed with C57BL/6 donors. The treatment group received a vascular endothelial growth factor-A specific cytokine trap (VEGF Trap) intraperitoneally at days 0, 4, 7 and 14 after keratoplasty (25 mg/kg per mouse; controls received equal amounts of Fc protein). Pathological haemangiogenesis and lymphangiogenesis prior to as well as 3 days or 8 weeks after keratoplasty and graft survival were analysed. RESULTS: Three days after keratoplasty corneal revascularisation was sufficiently reduced by VEGF Trap (haem-vascularised areas 42.7% reduction; lymph-vascularised areas 54.7% reduction). Survival proportions 8 weeks after keratoplasty were 36% in the treatment group compared with 9% in the control group (n = 11; p<0.05). At that time no differences in haemangiogenesis or lymphangiogenesis were observed between the two groups. CONCLUSION: Early transient postoperative induction of haemangiogenesis and lymphangiogenesis and reformation of regressed corneal blood and lymphatic vessels are important for transplant rejections after "intermediate-risk" corneal transplantation.

Changes in donor corneal lenticule thickness after Descemet's stripping automated endothelial keratoplasty (DSAEK) with organ-cultured corneas.

AIMS: The aim of the study was to quantify changes in donor and host corneal tissue after Descemet's stripping automated endothelial keratoplasty (DSAEK) using organ-cultured corneas and to correlate these findings with the visual acuity during intermediate-term follow-up. METHODS: Fifteen eyes of 15 consecutive patients, with Fuchs' endothelial dystrophy treated with DSAEK using organ-cultured corneas, underwent ophthalmological examination, including slit lamp-adapted optical coherence tomography, at 1, 3 and 7 days, and 4 weeks, 8 weeks and 6 months after the surgery. RESULTS: The mean best spectacle-corrected visual acuity (BSCVA) improved from 20/100 pre-operatively to 20/40 at 6-months post-operatively (p<0.0001). A continuous decrease of thickness of the grafted lenticule was observed during the follow-up (mean thickness immediately after surgery 191(SD 56) mum, compared with 100 (SD 38) mum 6 months after surgery, p<0.001). The central corneal thickness decreased from 1057 (SD 86) mum at the first post-operative day to 661 (SD 74) mum after 6 months. Both central corneal thickness and the thickness of the posterior donor lamella correlated with the 6-month BSCVA (Pearson correlations -0.745 and -0.589, respectively, p<0.05). CONCLUSIONS: Organ-cultured corneas can be used successfully for DSAEK. The thickness of the grafted corneal lenticule correlated with the BSCVA 6 months after the surgery. It decreased continuously during the follow-up period.

[Nodular fasciitis of the eyelid and anterior orbit in children: case report and review of the literature]. / Noduläre Fasziitis im Kindesalter im Bereich des Lids und der vorderen Orbita: Kasuistik und Literaturübersicht.

An 8-year-old boy presented with a 6-week history of a rapidly progressive erythematous swelling of the right upper eyelid. Ultrasonography and magnetic resonance imaging revealed a subcutaneous nodular mass of the right upper eyelid medially with extension into the anterior orbit. The clinical differential diagnosis included rhabdomyosarcoma. A transcutaneous excisional biopsy was performed, and histopathologic examination confirmed the diagnosis of nodular fasciitis. Five years after surgery, there is no evidence of local recurrence, and the result is aesthetically satisfactory.