[Diagnostics, clinical aspects and genetics of congenital corneal opacities]. / Diagnostik, Klinik und Genetik kongenitaler Hornhauttrübungen.

BACKGROUND: Congenital corneal opacities are comparatively rare diseases with high amblyogenic potential. PURPOSE: The present work provides an overview of the diagnostics, clinical aspects and genetics of congenital corneal opacities. METHODS: A literature search was carried out to compile an overview and illustration with own clinical case examples. RESULTS: Differentiated diagnostics are of high importance in the treatment of patients with congenital corneal opacities. A close cooperation between the medical departments involved and also the parents is absolutely essential. The structured classification of congenital corneal opacities provides the basis for a targeted treatment. DISCUSSION: The causes and the clinical symptoms of congenital corneal opacities are manifold. The correct diagnosis should be made early and in an interdisciplinary manner. Based on this, conservative and surgical treatment measures can be planned and an impending development of amblyopia can be specifically counteracted.

[Preconditioning of vascularized high-risk eyes using fine-needle diathermy and cross-linking]. / Präkonditionierung von vaskularisierten Hochrisikoaugen mittels Feinnadeldiathermie und Crosslinking.

BACKGROUND: The risk of allograft rejection following high-risk keratoplasty increases with the area of corneal neovascularization. Pharmaceutical and physical regression of corneal neovascularization before keratoplasty may offer the potential to reduce the risk of graft rejection after high-risk keratoplasty. OBJECTIVE: This article provides a review of the literature on the preconditioning of vascularized high-risk eyes using fine-needle diathermy and corneal cross-linking (preoperative preconditioning by lymphangioregression). METHODS: A literature search was carried out in PubMed and a summary of own data is presented. RESULTS: Animal experimental studies showed that both fine-needle diathermy and corneal cross-linking lead to a regression of corneal neovascularization and prolong graft survival after high-risk keratoplasty. Furthermore, studies from our institute provide first evidence that both procedures also lead to a reduction of corneal neovascularization in the clinical practice and thus potentially reduce the risk of allograft rejection after subsequent high-risk keratoplasty. DISCUSSION: Fine-needle diathermy and corneal cross-linking provide effective therapeutic approaches for angioregressive treatment and seem to prolong graft survival following high-risk keratoplasty. Larger prospective and controlled clinical trials are needed to further investigate these promising therapeutic approaches.

[10 years of Descemet membrane endothelial keratoplasty in Fuchs endothelial corneal dystrophy : What have we learned?] / Zehn Jahre "Descemet membrane endothelial keratoplasty" bei Fuchs-Dystrophie : Was haben wir gelernt?

BACKGROUND AND OBJECTIVE: Descemet membrane endothelial keratoplasty (DMEK) has increased in popularity since its introduction over 10 years ago. This article presents a summary of the experiences of the past years collected at the Department of Ophthalmology at the University of Cologne. METHODS: A literature review of DMEK studies primarily from the Department of Ophthalmology at the University of Cologne, Germany was carried out. Own experiences in the fields of donor selection and graft preparation, DMEK surgery, complication management and postoperative treatment are summarized. RESULTS: Since the introduction of DMEK experience has been gained and ongoing improvements have occurred ranging from donor-recipient allocation to postoperative follow-up. These led to a better reproducibility of the intervention for the surgeon, to a better postoperative result and to a reduction of the complication rate. DISCUSSION: The DMEK represents a safe and individualized procedure for endothelial transplantation for corneal endothelial dysfunction. Continuing development of the method leads to optimization and safer results.

[Deep Anterior Lamellar Keratoplasty : Experiences and results of the first 100 consecutive DALK from the University Eye Hospital of Cologne]. / Tiefe anteriore lamelläre Keratoplastik : Erfahrungen und Ergebnisse der ersten 100 konsekutiven DALK aus der Kölner Universitätsaugenklinik.

BACKGROUND: Deep anterior lamellar keratoplasty (DALK) is a treatment option for patients with diseases of the corneal stroma without endothelial involvement and has been used at the Department of Ophthalmology of the University of Cologne since July 2011. Experiences and results of the first 100 consecutive cases from Cologne with a minimum follow-up of 1 year are summarized. MATERIALS AND METHODS: We included the first 100 consecutive DALKs. Indications for anterior lamellar keratoplasty, the feasibility of the surgery, the postoperative course, in addition to the complications and clinical outcome 3 months after complete suture removal, were examined. The rate of conversion to penetrating keratoplasty in all planned DALKs during the observation period was also recorded. Mean follow-up was 25.6 ± 13 months. RESULTS: In 99 eyes of 97 patients (72 men, 25 women; aged 43.5 ± 16.9 years), the first 100 DALKs were performed in the period between 26 July 2011 and 27 January 2015 (87 cases electively, 13 cases as DALK à chaud, 1 of which was a second DALK). The most common indications were keratoconus (68%), corneal ulcers (13%), and corneal scarring (13%). On average, visual acuity increased from 0.83 ± 0.4 to 0.09 ± 0.1 logMAR. In 6 eyes (6%) grafts could not be preserved because of a corneal ulcer (n = 5, n = 3 of which were recurrent episodes), and in 1 case because of postoperative bulbus trauma. Rate of conversion to penetrating keratoplasty during the observation period was 11.5%. In eyes with keratoconus, visual acuity increased from 0.89 ± 0.4 before DALK to 0.06 ± 0.1 logMAR (best-corrected with contact lens) and the conversion rate was 17.6%. CONCLUSION: DALK represents a reliable technique for corneal transplantation in different pathological conditions of the cornea and the risk of endothelial immune responses can be avoided completely. In keratoconus and corneal scarring in particular, DALK can be used as a safe treatment option with very good results.

[Intraoperative optical coherence tomography in corneal and glaucoma surgical procedures]. / Intraoperative optische Kohärenztomographie bei hornhaut- und glaukomchirurgischen Eingriffen.

BACKGROUND: Optical coherence tomography (OCT) is the clinical gold standard for anterior and posterior segment imaging. Since OCT devices have been integrated into surgical microscopes, this technique is also available intraoperatively in anterior segment surgery. OCT is well established in imaging very thin or transparent structures as they appear in corneal or glaucoma surgery. Therefore, intraoperative OCT can deliver important information for the surgeon which is superior to the normal surgical microscope. OBJECTIVES: In the present work, an overview about the opportunities of intraoperative OCT in cornea and glaucoma surgery are presented. MATERIAL AND METHODS: The recent literature (PubMed) and our own experience at the Center for Ophthalmology, University Hospital of Cologne are analysed. RESULTS: Intraoperative OCT enables real-time imaging during corneal and glaucoma surgery. Several clinical studies exist, indicating its benefit, e. g. in DMEK, DALK, DSAEK, Boston Keratoprosthesis, canaloplasty or trabectome surgery. Several structures, not visible in the surgical microscope, can be visualized using intraoperative OCT. CONCLUSIONS: As a real-time and high-resolution imaging device, intraoperative online OCT delivers additional information in glaucoma and corneal surgery, compared to the normal operating microscope. Nonetheless one of the main problems is the shadowing produced by surgical instruments. Today the main limitation is the lack of randomized-controlled clinical trials, evaluating the benefit of microscope-integrated intraoperative OCT, compared to the microscope.

[Corneal donation : Dilemma between growing demand and declining donor rate]. / Hornhautspende : Ein Dilemma zwischen wachsender Nachfrage und sinkender Spenderrate.

BACKGROUND: One of the most important requirements for successful corneal transplantation is the availability of donor tissue and thus the approval for postmortem corneal tissue donation. The aim of this study was to investigate donor willingness compared to the continuously increasing demand in recent years. MATERIAL AND METHODS: Archives of the local eye bank at the Department of Ophthalmology, University of Cologne, Germany in the time period between 1 July 2011 and 31 December 2015 were examined regarding the willingness for corneal donations in deceased patients from the University Hospital of Cologne. Absolute numbers of deceased, exclusion criteria for donation as well as the rate of negative and affirmative decisions were evaluated. RESULTS: In 235 (5.1 %) out of 4593 deceased at the University Hospital of Cologne, corneal donation was accomplished during the observation period. Of the patients 2923 (63.6 %) were excluded because of absolute contraindications for corneal donation and the rate of absolute contraindications increased from 46.6 % in 2011 to 68.9 % in 2015. Willingness for corneal donation in potentially suitable deceased patients diminished from 34.9 % in 2011, to 34.3 % in 2012, 35.5 % in 2013, 28.4 % in 2014 and to 24.1 % in 2015. In relation to the total number of deceased, the number of corneal tissue donations decreased from 11.5 % in 2011 to 3.5 % in 2015. CONCLUSION: Despite a rising demand, data from Cologne seem to indicate that the number of corneal donations has declined to some extent. In order to increase the number of corneal donors in the future, further educational work as well as standardization and optimization of the tissue donation process seem to be urgently needed.

[Influence of 20 % sulfur hexafluoride (SF6) on human corneal endothelial cells : An in vitro study]. / Einfluss von 20 % Schwefelhexafluorid (SF6) auf humane korneale Endothelzellen : Eine In-vitro-Studie.

BACKGROUND: In posterior lamellar keratoplasties, such as Descemet membrane endothelial keratoplasty (DMEK) and Descemet's stripping automated endothelial keratoplasty (DSAEK) an air bubble is left inside the anterior chamber to promote graft attachment during the early postoperative period. In the case of insufficient graft adhesion a renewed intracameral air injection is often necessary. The use of sulfur hexafluoride diluted with air (SF6 20 %) as an alternative to pure air may further enhance graft attachment and reduce the rebubbling rate. The effect of SF6 20 % on corneal endothelium is currently unclear and was therefore examined in vitro. MATERIAL AND METHODS: For this study 12 human corneoscleral discs were mounted in artificial anterior chambers, the systems were continuously filled with culture medium and the anterior chambers with air (n = 5) or SF6 20 % (n = 7) as tamponade. After 6 days of storage in the incubator endothelial cell density, toxicity on endothelial cells and corneal thickness were evaluated. RESULTS: There were no significant differences in endothelial cell loss (p = 1.000), endothelial cell count (p = 0.648), toxicity on endothelial cells (p = 0.048) and central corneal thickness (p = 0.905) between the two groups after 1 week. The level of significance was defined as p ≤ 0.05 and adjusted to p ≤ 0.0056 according to the Bonferroni correction for multiple testing. CONCLUSION: The use of SF6 20 % as tamponade in the anterior chamber for posterior lamellar keratoplasty can be proposed as a safe alternative to pure air filling related to endothelial cell loss. Increased toxic effects on the corneal endothelium by SF6 20 % were not detected in this study; however, further prospective clinical trials are needed to examine the long-term effects in humans.

[The German Acanthamoeba keratitis register: Initial results of a multicenter study]. / Das Deutsche Akanthamöbenkeratitis-Register : Erste Ergebnisse einer multizentrischen Erhebung.

BACKGROUND AND PURPOSE: In September 2011 the cornea section of the German Ophthalmological Society (DOG) established the first German Acanthamoeba keratitis registry. The data of this multicenter survey are being collected, compiled and evaluated at the Department of Ophthalmology at the Saarland University. The aim of this article is to present an intermediate report. PATIENTS AND METHODS: Data from 172 eyes with Acanthamoeba keratitis were collected during the last 10 years. For this interim report we actually evaluated 121 eyes (60.2 % female patients, average age 41.3 years) and collected the following data: date of onset of symptoms, date and method of diagnosis, initial diagnosis, anamnestic data, clinical symptoms and signs at diagnosis and during follow-up, conservative and surgical therapy. Criteria for inclusion in the Acanthamoeba registry was the established diagnosis of an Acanthamoeba keratitis with at least one of the methods described in this article. RESULTS: Acanthamoeba keratitis could be histologically proven in 55.3 % of the cases, via PCR in 25.6 %, with confocal microscopy in 20.4 % and using in vitro cultivation in 15.5 %. Clinical symptoms and signs in Acanthamoeba keratitis were pain in 67.0 %, ring infiltrates in 53.4 %, pseudodendritiform epitheliopathy in 11.7 % and keratoneuritis in 5.8 %. In 47.6 % of the cases the initial diagnosis was herpes simplex virus keratitis followed by bacterial keratitis in 25.2 % and fungal keratitis in 3.9 %. Acanthamoeba keratitis was the correct initial diagnosis in only 23.2 % of cases. The average time period between first symptoms and diagnosis was 2.8 ± 4.0 months (range 0-23 months). A triple therapy with Brolene® Lavasept® and antibiotic eye drops at least 5 ×/day was used in 54.5 % of eyes (n = 66). Penetrating keratoplasty was performed in 40.4 %, in 18 cases in combination with cryotherapy of the cornea. The mean graft diameter was 7.9 ± 1.1 mm (range 3.5-11.0 mm). The final visual acuity (Snellen visual acuity chart at 5 m) was comparable in the two groups of eyes with (5/40 ± 5/25) and without (5/32 ± 5/25) keratoplasty. CONCLUSION: Acanthamoeba keratitis is a rare and often very late diagnosed disease and two thirds of the cases were initially misdiagnosed. The early recognition of the typical symptoms is crucial for the prognosis of the disease. All ophthalmological departments in Germany are invited to submit further data of all confirmed cases (berthold.seitz@uks.eu), whether retrospectively or prospectively in order to generate an adequate standardized diagnostic and therapeutic approach for this potentially devastating disease.

"OSMO-UT-DSAEK" using THIN-C medium.

BACKGROUND: When performing ultra-thin Descemet's stripping automated endothelial keratoplasty (UT-DSAEK), the quality of the stromal interface and stromal thickness seem to be critical for visual outcome. The aim of this study was to investigate whether additional osmotic deswelling prior to UT-DSAEK improves the quality of the cut surface and leads to a more reliable and deeper cut in UT-DSAEK ("OSMO-UT-DSAEK"). METHODS: Seventeen human donor corneas not usable for transplantation were used in this experiment. After standard deswelling with culture Medium II, ten corneas were randomly assigned to be additionally deswollen within THIN-C medium. The other remaining seven corneas were put back into culture Medium II. All corneas were placed in an artificial anterior chamber system (Moria); a double path cutting procedure using a microkeratome (Moria) was then performed. Corneal thickness was measured by ultrasound biomicroscopy and in paraffin-embedded slides, followed by histological grading of the cut surface. RESULTS: Stromal interface smoothness significantly improved after preconditioning in THIN-C medium (Pearson P = 0.019). The correlation of the corneal thickness obtained by UBM (mean 706 ± SD 208 µm) and histology (mean 530 ± SD 159 µm) was not significant (Pearson r = 0.11, P > 0.05, mean difference 247, 95 % CI [+50;+304]). We found no significant correlation between the microkeratome setting and the actual thickness of the lenticule measured in histological analysis in both media as well as for the first and second cut (first cut: Pearson r = 0.9, P = 0.1, 95 % CI [-10;+96], second cut: Pearson r = 0.9, P = 0.4, 95 % CI [-10;+22]). CONCLUSION: Preconditioning of corneas with THIN-C medium significantly improved the quality of the graft interface in UT-DSAEK, but did not significantly improve the cut precision of the microkeratome.

[Prevention and management of complications in Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK)]. / Komplikationsvermeidung und -management bei "Descemet membrane endothelial keratoplasty" (DMEK) und "Descemet stripping automated endothelial keratoplasty" (DSAEK).

BACKGROUND: Posterior lamellar keratoplasty, in the form of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK), has become a standard procedure for therapy of endothelial diseases of the cornea. The aim of this article is to describe strategies to prevent and manage complications in DMEK and DSAEK surgery. METHODS: The article is based on a PubMed literature search and own clinical data. Key words used were "DMEK", "DSAEK", "Descemet membrane endothelial keratoplasty" and "Descemet stripping automated endothelial keratoplasty". RESULTS: The DMEK and DSAEK procedures are safe surgical strategies for treating endothelial corneal diseases if the indications are made correctly. CONCLUSIONS: The DMEK procedure is the standard procedure for improvement of visual acuity especially for younger patients with Fuchs' dystrophy and DSAEK is particularly suitable for eyes with complicated anterior chamber situations.

[Implant exposure after viscocanalostomy with reticulated hyaluronic acid (SK-GEL)]. / Implantatexposition nach Viskokanalostomie mit hochvernetzter Hyaluronsäure (SK-GEL).

BACKGROUND: Lately, the application of intrascleral implants has been increasingly discussed to improve success rates of nonpenetrating surgery for the treatment of open-angle glaucoma. PATIENTS AND METHODS: A 36-year-old male patient with medically uncontrolled pigmentary glaucoma underwent viscocanalostomy with intrascleral implantation of reticulated hyaluronic acid (SK-GEL) in his right eye. RESULTS: The immediate postoperative course was unremarkable with control of intraocular pressure without additional glaucoma medications. At first follow-up, 2 weeks post surgery, conjunctival dehiscence with partial extrusion and exposure of the reticulated hyaluronic acid implant was observed. Under topical tobramycin ointment a gradual limbal readaptation of the conjunctiva over the surface of the exposed parts of the implant with formation of a filtration bleb was noted. Therefore, surgical revision remained unnecessary. CONCLUSIONS: Implant exposure following nonpenetrating antiglaucomatous surgery is a specific complication, which can appear whenever intrascleral implants are used. Depending on the local situation nonsurgical treatment may be successful.

Ultrasound biomicroscopy and its value in predicting the long term outcome of viscocanalostomy.

AIMS: To examine whether the early postoperative morphology at the site of sclerectomy, as visualised by ultrasound biomicroscopy (UBM), is an indicator of the mechanisms that lower intraocular pressure (IOP) and/or predictors of the long term outcome of viscocanalostomy. METHODS: 15 eyes of 14 patients with medically uncontrolled open angle glaucoma and no history of surgery underwent viscocanalostomy according to Stegmann's technique. Ultrasound biomicroscopy was performed during the first month after surgery. The following parameters were assessed: dimensions of the intrascleral "lake," presence of a filtering bleb, presence of a subconjunctival cavity or a suprachoroidal hypoechoic area, and the thickness of the residual trabeculocorneal membrane. A complete ophthalmological examination was performed the day before and the day after surgery. Follow up visits were scheduled 1 week, 4 weeks, 6 months, and 12 months after surgery. RESULTS: At 1 year successful control of IOP (<20 mm Hg) was achieved without further manipulation or medication in six of 15 eyes. The size of the intrascleral "lake" (average 0.62 mm(3)) did not correlate with later IOP; however, a visible route under the scleral flap and accidental perforation of the trabeculocorneal membrane were associated with long term lowering of IOP. Normal thickness of the trabeculocorneal membrane (0.10-0.15 mm) was indicative of IOP control with and without medication. When UBM showed an early collapse of the intrascleral cavity, control of IOP was not achieved. Other UBM findings did not predict long term function. CONCLUSION: In accordance with previous studies, the authors found that UBM examination is a useful method to evaluate outflow mechanisms after glaucoma surgery. This study shows that UBM imaging of external filtration during the early postoperative period can be used to predict the success of viscocanalostomy. However, to establish conclusively what parameters of UBM predict successful viscocanalostomy a larger number of patients must be studied.

[Painless acanthamoeba keratitis]. / Akanthamöbenkeratitis ohne Schmerzen12.

BACKGROUND: Acanthamoeba keratitis is a severe, painful corneal infection found in contact lens wearers. The entity can easily be confused with herpetic or fungal keratitis, especially if no ocular pain is reported. HISTORY AND SIGNS: A 32-year old myopic female presented a unilateral keratitis of unknown etiology since 3 weeks. Administration of topical antiviral substances and corticosteroids led only to temporary improvement of the condition. The patient complained of photophobia but not of ocular pain. The affected eye showed corneal edema, central stromal thickening, descemet's striae as well as fibrin deposits on the corneal endothelium and in the anterior chamber. DIAGNOSIS: An aqueous specimen was negative for a viral infection. A culture for bacteria was negative. Staphylococci were cultured from corneal scrapings and Enterococci from the contact lens solution. Another corneal scraping revealed Acanthamoeba class II (6 weeks after the onset of symptoms). CLINICAL COURSE: Under treatment with propamidine, polymyxin b, neomycin, gramicidin and polyhexidine (topical) as well as fluconazole/ketoconazole (systemic) the diameter of the annular infiltrate, which had developed decreased, but the infiltrate persisted. In the further course, the infiltrate persisted while the amount of fibrin in the anterior chamber increased. Penetrating keratoplasty was performed. Histologic examination of the host corneal tissue revealed massive infiltration with Acanthamoeba. CONCLUSIONS: Severe pain and history of wearing contact lenses are features suggestive of Acanthamoeba keratitis. The patient presented here had a history of contact lens wear, but no ocular pain was reported. The characteristic annular infiltrate had a late onset. Bacterial superinfection could not be ruled out. Therapeutic penetrating keratoplasty had to be performed as the condition deteriorated inspite of intensive chemotherapy. With penetrating keratoplasty a good visual acuity could be regained.