Elevation of the antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline: a blood pressure-independent beneficial effect of angiotensin I-converting enzyme inhibitors

Blockade of the renin-angiotensin system (RAS) is well recognized as an essential therapy in hypertensive, heart, and kidney diseases. There are several classes of drugs that block the RAS; these drugs are known to exhibit antifibrotic action. An analysis of the molecular mechanisms of action for these drugs can reveal potential differences in their antifibrotic roles. In this review, we discuss the antifibrotic action of RAS blockade with an emphasis on the potential importance of angiotensin I-converting enzyme (ACE) inhibition associated with the antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP)

Complications of deep anterior lamellar keratoplasty. Avoid, recognize and treat

Deep anterior lamellar keratoplasty (DALK) offers tremendous advantages over penetrating keratoplasty (PK). Intraoperative safety is increased due to reduced opening of the eye interoperatively and the fact that no endothelial graft rejection can take place as the patient's own corneal endothelium is retained. Despite these advantages the number of DALK procedures performed each year in Germany remains constant at a low level. One reason could be that the DALK technique offers some complexity and at the same time intraoperative conversion to PK has to be performed in some cases due to rupture of Descemet's membrane. Moreover, interface-related and DALK-specific complications exist which can contribute to an unfavorable visual outcome. Most of these complications, such as incomplete attachment of Descemet's membrane or opacification within the interface between Descemet's membrane and the posterior corneal stoma can be resolved by adequate measures making PK for revision barely necessary. As visual acuity does not differ between PK and DALK, the benefits of DALK - lack of endothelial immune reaction and increased ocular stability during surgery - outweigh the risk of additional complications and DALK should therefore be performed whenever appropriate

Intraoperative Optical Coherence Tomography In Deep Anterior Lamellar Keratoplasty

Background: Like penetrating keratoplasty (pKPL), deep anterior lamellar keratoplasty (DALK) is a standard treatment for keratoconus and stromal corneal dystrophies. Intraoperative optical coherence tomography permits live or real-time monitoring during surgery, especially if it is necessary to estimate distances or if the anterior chamber view is limited. Methods: Review of literature from PUBMED and our own clinical and experimental data. Key words were intraoperative Optical Coherence Tomograph, DALK, Deep anterior lamellar keratoplasty and iOCT. The time frame was set from 2005 to 2016. Results: All surgical steps were visualisable by intraoperative OCT during DALK surgery. Intraoperative OCT permits depth estimation during deep needle insertion and allows the visualisation of intraoperative interface fluid. Conclusion: Intraoperative OCT facilitates standardisation during several steps of DALK. Future prospective studies should concentrate on the safety profile of intraoperative OCT-guided DALK compared to DALK without intraoperative monitoring

Pediatric corneal surgery and corneal transplantation

The surgical treatment of congenital corneal diseases or corneal diseases occurring during infancy is demanding even for experienced corneal surgeons. Besides the need for frequent examinations under anesthesia during the postoperative follow-up in young children and infants (e.g. after corneal transplantation), the surgeon frequently encounters intraoperative and postoperative problems, such as low scleral rigidity, positive vitreous pressure and a narrow anterior chamber. Other problems include increased fibrin reaction, an increased risk of rejection in cases of allogenic corneal transplantation and frequent loosening of sutures necessitating replacement or early removal. Lamellar corneal transplantation reduces the risk of graft rejection and the risk of wound leakage. Moreover, posterior lamellar keratoplasty in children offers a faster visual recovery compared to penetrating keratoplasty and thus reduces the risk of amblyopia

Descemet membrane endothelial keratoplasty in complex eyes

BackgroundDescemet membrane endothelial keratoplasty (DMEK) has become the standard surgical treatment for Fuchs' endothelial corneal dystrophy (FECD) in Germany. In addition to classical FECD, there are endothelial disorders amenable to DMEK associated with complex changes in the anterior segment of the eye, such as anterior synechia of the iris, larger iris defects, after glaucoma surgery, after vitrectomy and after trauma.ObjectiveThis article provides an overview of the possibilities to treat patients with complex anterior segment situations in the presence of corneal endothelial decompensation with DMEK.Material and methodsDescription of problems and current surgical techniques when performing DMEK in complex situations.ResultsReconstruction of the iris or the iris/lens diaphragm often needs to be performed either simultaneously or in aprevious operation to treat patients with complex anterior segment alterations with DMEK. Both very shallow and very deep anterior chambers pose amajor problem. A DMEK graft from older donors (above 70years) is prone to less rolling and should be preferred in patients with adeep anterior chamber (e.g. after vitrectomy). The graft size should also be adapted to the available space, e.g. asmaller graft diameter should be selected for eyes with anterior synechia.ConclusionThere are only afew evaluations of DMEK under complex conditions; however, it appears that the rate of secondary graft failure, endothelial cell loss and the rebubbling rate are increased in this very heterogeneous group of diseases. Further studies are needed to identify risk factors for anegative progression after DMEK in complex eyes