An attempt to optimize the outcome of penetrating keratoplasty in congenital aniridia-associated keratopathy (AAK).

PURPOSE: To propose an optimized microsurgical and medical approach to reduce the risk of complications after penetrating keratoplasty (PKP) in patients with aniridia-associated keratopathy (AAK). METHODS: Retrospective observational case series of 25 PKP performed in 16 patients with AAK. Preoperative indications were endothelial decompensation and vascularized scars (68%) or graft failure (32%) due to limbal stem cell deficiency. The optimized approach included a combination of a small corneal graft size (around 7.0 mm), interrupted 10-0nylon sutures, simultaneous AMT as a patch, large bandage contact lens, temporary lateral tarsorrhaphy, postoperative autologous serum eye drops, and systemic immunosuppression. Main outcome measures included: visual acuity, transplant survival, and complications encountered during follow-up of 107 weeks on average. RESULTS: A complete modified keratoplasty scheme was used in 10 of 25 PKP (group 1), while at least one of the modifications was missing in the other 15 PKP (group 2). After 8 weeks of follow-up, the epithelium was closed in 23 eyes. Visual acuity improved in 19 eyes at 6 months of follow-up, and remained stable in six eyes. None of the eyes showed a decrease in visual acuity. At the last post-operative follow-up, this visual improvement persisted in 14 eyes and graft survival rate after 156 weeks (3 years) was 69% in group 1 versus 44% in group 2 (p = 0.39, log-rank test). Secondary corneal neovascularization (8%), scarring (4%), ulcer (4%), or graft rejection (8%) happened mostly in the second group which was missing at least one of the suggested modifications. CONCLUSIONS: PKP in congenital aniridia must be considered as a high-risk keratoplasty. An optimized therapeutic approach seems to be promising in order to reduce the postoperative complication rate in these most difficult eyes.

[The cornea as an indicator for systemic diseases]. / Die Hornhaut als Indikator für Systemerkrankungen.

Numerous systemic diseases can be manifested at the cornea. Sometimes the corneal involvement is the first sign of the systemic process. It may be manifested in many different forms, such as an ulcer in the corneal periphery or a crystalline keratopathy. Therapy is interdisciplinary and primarily directed against the underlying disease.

Electrochemotherapy with bleomycin and cisplatin enhances cytotoxicity in primary and metastatic uveal melanoma cell lines in vitro.

Electrochemotherapy (ECT) enhances responsiveness to cytotoxic drugs in numerous cell lines in vitro. Clinically ECT is widely applied for skin tumor ablation and has shown efficacy in treating non-resectable colorectal liver metastases. There is limited experience of ECT for ocular tumor therapy. We investigated the cytotoxic effect of bleomycin and cisplatin in combination with electroporation on chemoresistant human uveal melanoma (UM) cell lines in vitro. Four UM cell lines (Mel 270, 92-1, OMM-1, OMM-2.5) were treated with electroporation (pulse amplitude 300-1000 V/cm, 8-80 pulses, 100 µs, 5 Hz) and increasing concentrations of bleomycin and cisplatin (0-7.5 µg/ml). Cell survival was analyzed by MTT viability assay after 36 hours. UM cell lines were resistant to both bleomycin and cisplatin. In combination with electro- poration, the effects of bleomycin and cisplatin were increased 8-70 fold and 3-15 fold, respectively, in all UM cell lines. At the lowest concentration of bleomycin tested (1 µg/ml), viability was maximally reduced in all UM cell lines by ≥69% with electroporation conditions of 750 V/cm and 20 pulses. All UM cell lines were more resistant to cisplatin; however, electro- poration of 1000 V/cm and 8 pulses resulted in similar reductions in cell viability of 92-1, Mel270 with 2.5 µg/ml cisplatin, OMM2-5 cells with 5 µg/ml cisplatin and OMM1 cells with 1 µg/ml cisplatin. In vitro ECT with bleomycin or cisplatin is more effective than the highest concentration of the antineoplastic drug or electroporation alone, opening new perspectives in primary and metastatic UM treatment.

Anatomy-based DMEK Wetlab in Homburg/Saar: Novel aspects of donor preparation and host maneuvers to teach descemet membrane endothelial keratoplasty.

Use of Descemet Membrane Endothelial Keratoplasty (DMEK) has been limited because of problems with donor preparation, i.e. tearing of the Descemet membrane and difficulties in unfolding the Endothelium-Descemet-Membrane-Layer (EDML) in the anterior chamber (AC). The purpose of this work was to describe a novel approach to teaching anatomy-based donor and recipient preparation in a DMEK-Wetlab. We teach successful mono-manual donor preparation of human corneas in organ culture not suitable for transplantation, including peripheral markers for orientation. We also teach safe recipient preparation in a freshly-enucleated pig eye in organ culture preservation medium for atraumatic introduction of the EDML roll into the AC, reliable orientation of the EDML during surgery, and stepwise unfolding within the AC. Twenty-two candidates in the 1. Homburg Cornea Curriculum HCC 2015 who practiced both preparations using three human donor corneas and three pig eyes assessed the procedure as follows: (1) overall grade of the Wetlab 1.4 (median 1, range 1 to 2 - on a scale from 1 (excellent) to 6 (terrible); (2) most participants and tutors stated that the Wetlab is most effective for colleagues who have some previous experience with corneal microsurgery. Our novel anatomy-based approach to simulating donor preparation and graft implantation for DMEK seems to meet the expectations and requirements of colleagues with previous experience in corneal microsurgery and will help to reduce the rate of complications for incipient DMEK surgeons in the future. Clin. Anat. 31:16-27, 2018. © 2017 Wiley Periodicals, Inc.

[Safety of Hyaluronic Acid in Postoperative Treatment after Penetrating Keratoplasty]. / Verträglichkeit von Hyaluronsäure zur Oberflächenpflege nach perforierender Keratoplastik.

BACKGROUND: The objective of this clinical trial was to confirm the safety of phosphate-free high molecular weight hyaluronate (HYLO®-GEL) as lubricant for postoperative care after penetrating keratoplasty. PATIENTS AND METHODS: 51 eyes were followed up 6 weeks after penetrating keratoplasty under therapy with phosphate-free high molecular weight hyaluronate. Visual acuity, intraocular pressure, conjunctival hyperaemia, conjunctival chemosis, corneal fluorescein staining, corneal infiltrates, corneal endothelial-epithelial decompensation, Descemet's folds, Tyndall effect, cells in the anterior chamber and subjective assessment of lacrimation, foreign body sensation, pressure sensation, burning, mucus and itching were recorded on the first, third and fifth postoperative days and six weeks postoperatively. Tolerance was rated by the patient and the attending ophthalmologist. RESULTS: The following objective parameters improved significantly from day 1 to week 6 in patients treated with phosphate-free high molecular weight hyaluronate: visual acuity, conjunctival hyperaemia, conjunctival chemosis, corneal fluorescein-staining, corneal endothelial-epithelial decompensation, Descemet's folds, the maximum diameter of corneal erosion, Tyndall effect and cells in the anterior chamber. In addition, there was significant improvement in the course of the following subjective complaints: lacrimation, foreign body sensation, pressure sensation and itching. In total 63 % (32/47) of the study patients reported excellent local tolerance of phosphate-free high molecular weight hyaluronate on day one postoperatively. This proportion rose to 86 % (37/43) 6 weeks postoperatively. The safety of phosphate-free high molecular weight hyaluronate was rated by the ophthalmologists as "perfect" in 92 %, as "acceptable" in 6 % and as "unacceptable" in 2 % of eyes. CONCLUSION: Therapy with phosphate-free high molecular weight hyaluronate results in significant improvements in objective findings and subjective symptoms after penetrating keratoplasty. Tolerance was rated as "excellent" by the ophthalmologist in 92 % of patients in the early postoperative follow-up.

[Development of Endothelial Cell Density after Penetrating Keratoplasty in Patients with Fuchs Dystrophy or Keratoconus - Comparison of Excimer Laser and Mechanical Trephination]. / Entwicklung der Endothelzelldichte nach perforierender Keratoplastik bei Patienten mit Fuchs-Dystrophie oder Keratokonus ­ Vergleich von Excimer-Laser- und mechanischer Trepanation.

Purpose The aim of this retrospective study was to compare the development of endothelial cell density (ECD) after penetrating keratoplasty (PKP) in patients with Fuchs dystrophy (FD), keratoconus (KC) or "other diagnoses" (OD), depending on the type of trephination. Patients and Methods In 104 eyes with Fuchs dystrophy, keratoconus or "other diagnoses", the ECD after PKP using either excimer laser (EXC) or mechanical trephination (MECH) was registered after 1.5, 6, 12, 18 and 24 months. With linear and exponential regression models, the endothelial cell loss (ECL) was determined as absolute and percentage cell loss per year. Results For the entire group of patients, ECD was significantly higher after EXC-PKP during the full range of follow-up (except 6 months). With a linear regression model, there was no significant difference in the absolute ECL per year (p = 0.084), but with an exponential regression model, there was a significant difference in the percentage ECL per year (p = 0.021) in favour of EXC trephination. For keratoconus (n = 33), except for the 24-month-follow-up (p = 0.035), ECD was not significantly different on the basis of EXC vs. MECH. With a linear regression model, there was a significant difference in the absolute ECL per year (p = 0.015) in favour of EXC-trephination, but with an exponential regression model there was no significant difference in the percentage ECL per year (p = 0.088) between the two types of threphination. In patients with FUCHS (n = 35) - except for the 6-week-follow-up (p = 0.024) - ECD was not significantly different for EXC vs. MECH. With linear/exponential regression model, the ECL per year was not significantly different in favour of any type of trephination (p = 0.287/p = 0.121). In patients with OD (n = 36), ECD was not significantly different for EXC vs. MECH. With a linear/exponential regression model, the ECL per year was not significantly different in favour of any type of trephination (p = 0.494/p = 0.787). Conclusion During the first 24 months after PKP, a significantly higher ECD and a significantly lower percentage of ECL per year was observed after EXC trephination for the entire group of patients. For the different diagnostic groups KC, FD and OD, no significant difference in ECD or ECL loss was noticed over a range of follow-up intervals. This may most likely be attributed to the small number of patients in the three subgroups.

[Functional Results and Graft Failure after Repeat Keratoplasty]. / Funktionelle Ergebnisse und Transplantatversagen nach Re-Keratoplastik.

Background and Purpose Keratoplasty is the oldest and most successful transplantation method in man. Despite the immunological privilege of the cornea, the graft fails in up to 10 % of patients, depending on corneal disease, quality of donor tissue and patient compliance, and repeat keratoplasty may then be necessary. The aim of this study was to verify factors which affect the functional result and graft survival after repeat keratoplasty. Patients and Methods In this single centre, consecutive retrospective case series, patients were included who were treated at Department of Ophthalmology, Saarland University Medical Centre with repeat keratoplasty between January 1st 2001 and December 31st 2010. Data were recorded with an Access Database from the medical records and statistically analysed with SPSS 19.0. The surgical reports and the results from the follow-up examinations concentrated on visual acuity, intraocular pressure, endothelial cell density, corneal topography and tomography and corneal graft reactions. Results The results of the study showed that trephination with the excimer laser was significantly superior (p = 0.009) to mechanical trephination with a motor trephine with respect to corrected visual acuity. Corrected visual acuity after 2 years was 0.39 in the laser group, compared to 0.16 in the group with mechanical trephination. A graft diameter under 7.5 mm showed a significant negative impact on postkeratoplasty astigmatism (p = 0.004). After a follow-up period of 120 months, the rate of immunological graft rejection was 20/60 % (p = 0.259) in the patient group with graft diameters ≤ 7.5 mm/> 7.5 mm, respectively. Conclusion The present study shows that repeat keratoplasty using excimer laser gives better functional rehabilitation, if corneal morphology permits this (for example, the vascularisation). However, the trephination method has no significant impact on graft survival. The basic principle for repeat keratoplasties is that the diameter of the graft should be as great as possible but as small as necessary.

[Effect of Morphological and Functional Parameters on Ocular Pulse Amplitudes: An Analysis in Ocular Hypertension and Different Types of Glaucoma]. / Der Einfluss von morphologischen und funktionellen Parametern auf die okuläre Pulsamplitude: eine Analyse bei verschiedenen Glaukomformen und okulärer Hypertension.

Background and Purpose: Ocular blood flow imbalance and the loss of autoregulation are widely believed to be important factors in the pathogenesis of glaucoma. The purpose of this study was to investigate the impact of morphometric and functional changes on ocular pulse amplitude (OPA) in normal tension glaucoma (NTG), primary open-angle glaucoma (POAG), pseudoexfoliation-glaucoma (PEX) and ocular hypertension (OHT). Patients and Methods: This prospective study included 172 patients with manifest glaucoma and OHT. All patients were examined with dynamic contour tonometry (DCT), Goldmann applanation tonometry (GAT), Heidelberg retina tomography II (HRT), and Octopus visual field analysis (program 30II). In order to identify potential determinants of OPA, a generalised linear model (GLM) analysis was defined. As effect sizes, we included gender as a factor and intraocular pressure (measured by DCT [IOP]), optic disc area, cup area, mean deviation (MD), central corneal thickness (CCT), cup-disc ratio (CDR), and patient age as covariates. Results: Mean OPA was lower in patients with NTG than in other groups. In the generalised linear model in the entire population, a larger OPA was associated with a larger IOP and female gender. In the NTG group, we did not identify effect sizes, whereas, in the OHT group, IOP (measured with DCT) and MD, in the POAG group IOP (measured with DCT) and gender and in the PEX group MD and gender showed a positive effect on OPA. Conclusions: In this study, we showed that in the NTG group neither demographic nor morphological or functional factors affected OPA. However, in the OHT and POAG groups, OPA was influenced by IOP (measured with DCT), in the OHT and PEX group by MD and in the POAG and PEX groups by gender.

[Amniotic Membrane Suspension and Autologous Serum - Are they Important for Wound Healing?] / Amnionmembransuspension und autologes Serum ­ spielt der Inhalt eine Rolle für die Wundheilung?

Autologous serum (AS) and amniotic membrane transplantation (AMT) are used in the treatment of several ocular surface diseases. AMT is associated with a surgical intervention. Surgery could be avoided by using eye drops prepared from an amniotic membrane homogenate (AMH) or amniotic membrane suspension (AMS). EGF, bFGF, IL-6 and IL-8 were detected in AMS. However, EGF and bFGF concentrations in AMS were about 1.7-17× lower than in AMH, and IL-6 and IL-8 could not be detected in AMH. 100 % AMS, 15 and 30 % AMH significantly decreased proliferation of human corneal epithelial cells (HCECs) compared to controls (p = <0.002 for all), but 15 and 30 % AMS did not affect proliferation. Migration increased significantly compared to controls with 15 and 30 % AMS (p < 0.001), but did not change significantly with 15 or 30 % AMH (p = 0.153 and p = 0.083). Proliferation of HCECs was significantly greater with 15 % AS than with 30 % AS (p < 0.001). HCEC migration was significantly greater with 30 % AS than with 5 % AS (p < 0.01). In summary, 15 and 30 % AMS and 15 and 30 % AS exhibit the best supportive effect on human corneal epithelial cells. Nevertheless, we always have to keep in mind that individual growth factor concentrations exhibit high inter-individual fluctuations in AS or AMS eye drops.

Crosslinking and corneal cryotherapy in acanthamoeba keratitis -- a histological study.

PURPOSE: Acanthamoeba keratitis is rare, but difficult to treat. Penetrating keratoplasty is performed in therapy-resistant cases. Nevertheless, subsequent recurrences occur in 40 % of the cases. In addition to triple-topical therapy (polyhexamid, propamidinisoethionat, neomycin), treatment alternatives are corneal cryotherapy and/or crosslinking (CXL). The aim of our present histological study was to analyze the persistence of acanthamoebatrophozoites and cysts, the persistence of bacteria, and activation of keratocytes in corneas of acanthamoeba keratitis patients following corneal cryotherapy and/or CXL. PATIENTS AND METHODS: We analyzed histologically corneal buttons (from penetrating keratoplasties) of nine patients with acanthamoeba keratitis, following corneal cryotherapy (two patients) or a combination of crosslinking and corneal cryotherapy (seven patients), using haematoxilin­eosin, periodic acid Schiff (PAS), Gram and alpha-smooth muscle actin (alpha-SMA) stainings. RESULTS: Acanthamoeba trophozoites persisted in three corneas after cryotherapy and CXL. Cysts persisted in one of two corneas following corneal cryotherapy and in six of seven corneas after a combination of CXL and cryotherapy. One cornea showed positive Gram staining, but there were no alpha-SMA positive keratocytes in any of the corneas. CONCLUSIONS: Crosslinking and corneal cryotherapy have only limited impact on killing of acanthamoeba trophozoites, cysts, or bacteria. Corneal cryotherapy and CXL did not stimulate myofibroblastic transformation of keratocytes.

[Intracorneal Ring Segments to Treat Keratectasia - Interim Results and Potential Complications]. / Intrakorneale Ringsegmente bei Keratektasien - Zwischenergebnisse und potenzielle Komplikationen.

BACKGROUND AND PURPOSE: Implantation of intracorneal ring segments (ICRS) using a femtosecond laser is a minimally invasive procedure which represents a reliable option to widen the spectrum of the stage-related therapy of keratoconus in patients with contact lens intolerance, or with post-LASIK-keratectasia or pellucide marginale degeneration (PMD). METHODS: From August 2011 to September 2015, 84 eyes of 69 patients were implanted with ICRS. 74 eyes were implanted with INTACS-SK (Intacs, Addition Technology, Inc.), and 10 eyes were implanted with KeraRing SI6 (Mediaphacos Ltda.). The indication is taken in the presence of a clear central cornea and the patients had to fulfill the corneal diagnostic tests required for implantation. Tunnel creation should nowadays only be carried out by femtosecond laser, in order to avoid intra- and postoperative complications. RESULTS: Three months after surgery, the INTACS-SK group showed an increase in uncorrected distance visual acuity (logMAR) from 0.99 ± 0.35 to 0.29 ± 0.17. The KeraRing SI6 group showed an increase in uncorrected distance visual acuity (logMAR) from 0.93 ± 0.4 to 0.41 ± 0.34. The keratometric values were reduced in both groups. CONCLUSION: Uncorrected and corrected distance visual acuity can be improved by implantation of the ICRS. Progression of ectasia seems to be retarded. Consistent follow-up visits at close intervals are necessary to identify complications at an early stage. However, larger case series and a longer postoperative observation period are required. Complications after ICRS implantation are rare, due to strict patient selection and modern surgical techniques.

[PKP for Keratoconus - From Hand/Motor Trephine to Excimer Laser and Back to Femtosecond Laser]. / Perforierende Keratoplastik bei fortgeschrittenem Keratokonus - vom Hand-/Motortrepan hinauf zum Excimerlaser und zurück zum Femtosekundenlaser.

For patients with keratoconus, rigid gas-permeable contact lenses are the first line correction method and allow good visual acuity for quite some time. In severe stages of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no longer tolerated. If there are contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis. In patients with advanced keratoconus - especially after corneal hydrops due to rupture of Descemet's membrane - penetrating keratoplasty (PKP) is still the first line surgical method. Non-contact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and for patients with repeat grafts due to "keratoconus recurrences" due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually, depending on corneal size ("as large as possible - as small as necessary"). Limbal centration is preferred intraoperatively, due to optical displacement of the pupil. During the last 10 years, femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces "vertical tilt" and "horizontal torsion" of the graft in the recipient bed, and thus results in significantly less "all-sutures-out" keratometric astigmatism (2.8 vs. 5.7 D), more regular topography (surface regularity index [SRI] 0.80 vs. 1.0) and better visual acuity (0.80 vs. 0.60), in comparison to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. However, the refractive outcome of femtosecond laser keratoplasty resembles that with motor trephine. In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination, with intraoperative disadvantages and high postoperative astigmatism.

[The Chameleon of Herpetic Keratitis - Diagnosis and Therapy]. / Das Chamäleon der Keratitis herpetischer Genese - Diagnose und Therapie.

In Europe, herpes simplex virus type I (HSV) is a common cause of keratitis. The disease may be well treated if the ophthalmologtist is aware of the various types of clinical expressions of this typical unilateral chameleon, and treatment is adjusted accordingly. Types of expression include: (i) epithelial keratitis (dendritica/geographica), (ii) stromal keratitis (necrotising vs. non-necrotising = "interstitial keratitis"), (iii) endotheliitis (= "disciform keratitis"), (iv) so-called "metaherpetic keratitis" (= neurotrophic keratopathy), (v) (vascularised) corneal scars. In the acute phase, concomitant ocular hypertension should be treated predominantly without surgery (no prostaglandin analoga!). After keratoplasty and in cases of severe recurrences of herpetic keratitis, systemic aciclovir administration (2 × 400 mg/day) for at least one year is indispensable!

[The revised newest IC³D classification of corneal dystrophies]. / Die revidierte neueste IC³D-Klassifikation der Hornhautdystrophien.

PURPOSE: This report suggests how corneal dystrophies (CDs) should be diagnosed at the slit lamp and specifies the new IC(3)D classification of CDs in 2015 which incorporates new information. METHODS: IC(3)D reviewed all peer-reviewed articles on CDs 2008 to 6/2014. Corneal dystrophy templates and anatomic classifications were updated. RESULTS: To detect landmarks for correct classification of CDs, opacity patterns and opacity units are determined at the slit lamp. Opacity patterns are described as (1) horizontal extension, (2) vertical extension ("depth") and clarity of the (3) cornea in between. Horizontal extension is assessed using a broad beam, vertical extension using a bright, thin slit lamp beam in high magnification. For assessment of opacity units, examination using retroillumination with dilated pupil is indispensable! This is especially true for epithelial and endothelial CDs. With a better review of the cellular origin of CDs, a new anatomic classification is proposed: 1. epithelial and subepithelial; 2. epithelial-stromal transforming growth factor beta-induced (TGFBI); 3. stromal; 4. endothelial dystrophies. Epithelial recurrent erosion dystrophies include three epithelial dystrophies (Franceschetti CD, dystrophia Smolandiensis, and dystrophia Helsinglandica) and are differentiated against TGFBI dystrophies, also associated with recurrent epithelial erosion. The chromosome locus of Thiel-Behnke CD is only located on 5q31. The entity previously called Thiel-Behnke on chromosome 10q24 may be a unique corneal dystrophy. Congenital hereditary endothelial dystrophy (CHED, formerly CHED2) is an autosomal recessive disorder. The autosomal dominant inherited CHED (formerly CHED1) is insufficiently distinct to be a unique entity and most cases appear to be similar to other reported dystrophies, particularly posterior polymorphous corneal dystrophy (PPCD). CONCLUSIONS: The 2015 revision of IC(3)D classification includes an updated anatomic classification more accurately describing TGFBI dystrophies to affect multiple layers. Some entities, e.g., Grayson Wilbrandt, Meretoja syndrome, and CHED2 are removed. All authors and reviewers should adhere to this classification of CDs!

[Reproducibility of Scheimpflug Tomography Measurements Regarding Corneal Front and Back Surface Power]. / Reproduzierbarkeit der Messungen der Scheimpflug-Tomografie für die Brechwerte der vorderen und hinteren Hornhautgrenzfläche.

BACKGROUND AND PURPOSE: The Oculus Pentacam® is one of the most commonly used devices in ophthalmology for assessment of the anterior eye segment. The purpose of this study was to determine the reproducibility of the corneal power as measured by the Pentacam® in a normal population. METHODS: We enrolled 25 eyes of 25 subjects aged between 13 and 68 (46.7 ± 21.7) years, within a spherical equivalent from - 4 D to + 4 D and refractive cylinder up to 5 D and without notable pathologies or history of surgery. A sequence of 5 measurements was performed using the Pentacam®, the Zeiss IOLMaster® as well as an autorefractometer after (re-)positioning the patient's head and the measurement device. From the Pentacam® we collected power data for the corneal front and back surfaces, apical corneal thickness at apex and internal anterior chamber depth. From the IOLMaster®, we extracted corneal power data, and from the autorefractometer we obtained refractive power data of both cardinal meridians. For statistical analysis, we used Cronbach's α as a measure of reproducibility and Spearman's rank correlation test for correlation of data. RESULTS: Pentacam® yields highly reproducible power data for both corneal surfaces, with Cronbach's α of greater than 0.97 for primary parameters (e.g. radii of curvature) and 0.9 for secondary parameters (e.g. vector components of astigmatism). Central corneal thickness and eccentricities of both surfaces as well as anterior chamber depth yielded highly reproducible values, with α of ≥ 0.97. Corneal power derived from IOLMaster® and objective refraction extracted from the autorefractometer yielded α values of around 0.9. Mean corneal power of Pentacam® and IOLMaster® correlated well, but there was no correlation to spherical equivalent. Astigmatism values from Pentacam® and IOLMaster® correlated well with each other and with refractive cylinder. CONCLUSION: Our results indicate that measurements of anterior segment using the Pentacam® yield highly reproducible results in a normal population without major pathologies of the anterior eye segment.

[Surgeon's Impact on Graft Endothelial Cell Density and Corneal Thickness after Penetrating Keratoplasty for Keratoconus and Fuchs' Dystrophy]. / Einfluss der individuellen mikrochirurgischen Technik auf Endothelzelldichte und Pachymetrie nach perforierender Keratoplastik bei Patienten mit Fuchs-Dystrophie oder Keratokonus.

PURPOSE: The aim of this study was to examine the short- and long-term variability of graft endothelial cell density (ECD) and central corneal thickness (CCT) after penetrating keratoplasty (PKP) between different surgeons. PATIENTS AND METHODS: 370 eyes with keratoconus (KC) or Fuchs' dystrophy (FUCHS) after standardised primary excimer laser PKP (four experienced surgeons) were analysed. ECD and CCT were determined at 12 months after PKP before suture removal, and at two years after final suture removal. RESULTS: 12 months after PKP, ECD was significantly higher for surgeon 1 in FUCHS as compared to surgeons 3 (p = 0.05) and 4 (p = 0.04), in KC it was significantly higher for surgeon 1 as compared to surgeon 2 (p = 0.001) and for surgeon 1 as compared to surgeon 4 (p = 0.006). However, in FUCHS this difference was no longer significant two years after suture removal (p > 0.5), and in KK only in comparison of surgeons 1 and 2 (p = 0.04). RESULTS concerning CCT were inhomogeneous. CONCLUSIONS: The surgeon's individual handwriting seems to have an impact on the ECD in the short-term after PKP. However, differences between surgeons tend to become insignificant in the long run after suture removal.

[Growth Factors and Interleukins in Amniotic Membrane Tissue Homogenate]. / Wachstumsfaktoren und Interleukine in Amniongewebehomogenat.

PURPOSE: Application of amniotic membrane homogenate eye drops may be a potential treatment alternative for therapy resistant corneal epithelial defects. The purpose of this study was to determine the concentrations of epidermal growth factor (EGF), fibroblast growth factor basic (bFGF), hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), interleukin-6 (IL-6) and interleukin-8 (IL-8) in amniotic membrane homogenates. METHODS: Amniotic membranes of 8 placentas were prepared and thereafter stored at - 80 °C using the standard methods of the LIONS Cornea Bank Saar-Lor-Lux, Trier/Westpfalz. Following defreezing, amniotic membranes were cut in two pieces and homogenized in liquid nitrogen. One part of the homogenate was prepared in cell-lysis buffer, the other part was prepared in PBS. The tissue homogenates were stored at - 20 °C until enzyme-linked immunosorbent assay (ELISA) analysis for EGF, bFGF, HGF, KGF, IL-6 and IL-8 concentrations. RESULTS: Concentrations of KGF, IL-6 and IL-8 were below the detection limit using both preparation techniques. The EGF concentration in tissue homogenates treated with cell-lysis buffer (2412 pg/g tissue) was not significantly different compared to that of tissue homogenates treated with PBS (1586 pg/g tissue, p = 0.72). bFGF release was also not significantly different using cell-lysis buffer (3606 pg/g tissue) or PBS treated tissue homogenates (4649 pg/g tissue, p = 0.35). HGF release was significantly lower using cell-lysis buffer (23,555 pg/g tissue), compared to PBS treated tissue (47,766 pg/g tissue, p = 0.007). CONCLUSION: Containing EGF, bFGF and HGF, and lacking IL-6 and IL-8, the application of amniotic membrane homogenate eye drops may be a potential treatment alternative for therapy-resistant corneal epithelial defects.

[Effect of Photodynamic Inactivation (PDI) using Riboflavin-Conjugated Antibody against Staphylococcus aureus]. / Effekt photodynamischer Inaktivierung (PDI) mit Riboflavin oder riboflavinkonjugierten Antikörpern gegen Staphylococcus aureus.

PURPOSE: Crosslinking/riboflavin-UVA photodynamic therapy is a potential treatment alternative in antibiotic resistant infectious keratitis. For photodynamic therapy a specific (against bacteria) conjugated antibody may be used in order to increase the effect of the treatment. In our present study we analysed the impact of photodynamic inactivation using riboflavin-conjugated antibody or riboflavin alone on Staphylococcus aureus, in vitro. METHODS: Staphylococcus aureus (S. aureus) was incubated in 1 : 100 diluted riboflavin-conjugated antibody (R-AB) for 30 minutes in darkness. Following UVA-light illumination (375 nm) with an energy dose of 2, 3, 4 and 8 J/cm(2), bacteria were brought to blood agar Plates for 24 hours before colony-forming unit (CFU) counting. In an additional group, we incubated bacteria to 0, 0.05 or 0.1 % riboflavin 5-phosphate as described above followed by illumination using UVA light (375 nm) with an energy dose of 2 J/cm(2), before CFU counting. RESULTS: The number of CFU decreased significantly (inactivation of 36 %, p = 0.022) using 1 : 100 diluted riboflavin-conjugated antibody and 2 J/cm(2) UVA-light illumination, compared to untreated controls. The use of 3, 4 und 8 J/cm(2) energy dose and R-AB in 1 : 100 dilution did not further change the decrease of CFU (inactivation of 39, 39 and 40 %; p = 0.016; p = 0.016; p = 0.015). The use of 0.05 % or 0.1 % riboflavin 5-phosphate alone and UVA-light illumination reduced the CFU count significantly (inactivation of 73 and 55 %; p = 0.002; p = 0.005), compared to untreated controls. CONCLUSIONS: The use of riboflavin-conjugated antibody or 0.05 % or 0.1 % riboflavin 5-phosphate and UVA-light illumination reduces the number of CFU of S. aureus. However, none of these photodynamic therapies reached the necessary 99 % killing rate of these bacteria. Further work is needed to increase the efficacy of riboflavin-conjugated antibodies against antibiotic resistant bacteria.

[The Effect of Non-Depolarising Muscle Relaxants on Ocular Pulse Amplitude and Intraocular Pressure]. / Beeinflussung der okulären Pulsamplitude und des Intraokulardrucks durch nicht depolarisierende Muskelrelaxanzien.

AIM: In general anaesthesia (GA) for ocular surgery the chosen non-depolarising muscle relaxant has a high influence on the fluctuations of intraocular pressure (IOP) and ocular pulse amplitude (OPA). PATIENTS AND METHODS: In 229 patients, who needed GA for their ophthalmic surgery, OPA and IOP were measured with the dynamic contour tonometer (DCT) before and 5 minutes after intubation. For GA, three groups of non-depolarising muscle relaxants, namely, mivacurium (n = 71), atracurium (n = 91) and rocuronium (n = 67) were used. RESULTS: The IOP decreased by about 4.0 ± 2.3 mmHg using mivacurium in GA, by about 6.1 ± 2.2 mmHg using atracurium and by about 7.4 ± 1.7 mmHg using rocuronium (p < 0.001). The relative decrease of the IOP was 20% for mivacurium, 31% for atracurium and 37% for rocuronium. For mivacurium the OPA decreased from 3.4 ± 1.5 mmHg to 2.2 ± 1.1 mmHg (p < 0.001) in contrast to atracurium (decrease from 3.6 ± 1.5 mmHg to 1.8 ± 0.8 mmHg; p < 0.001) and rocuronium (decrease from 3.1 ± 1.6 mmHg to 1.7 ± 0.9 mmHg; p < 0.001). Mean OPA reduction was lowest with mivacurium (1.3 mmHg) and the highest with atracurium (1.7 mmHg). The mean relative decrease of the OPA was 34% with mivacurium, 46% with atracurium and 43% with rocuronium (p < 0.001). There was no linear correlation between the relative OPA decrease and the relative IOP decrease. CONCLUSION: Risks for ophthalmic surgery may be minimised by avoiding mivacurium in general anaesthesia. Due to its negative effects on IOP and OPA mivacurium does not seem to be suitable for operations with a large opening in the eye such as penetrating keratoplasty and block excision. Rocuronium can be used because it induces a favourised intraoperative decrease of the IOP.