Search

To analyze potential alterations in corneal nerve morphology and function in different stages of Fuchs’ endothelial corneal dystrophy (FECD). Thirty eyes with FECD underwent in vivo confocal microscopy using the Heidelberg Retina Tomograph II (HRT II; Heidelberg Engineering, Heidelberg, Germany) and the Rostock Cornea Module (RCM) to quantify the morphology of the central subbasal corneal nerve plexus (total nerve length, total nerve number, number of main nerve trunks, number of nerve branches) as well as esthesiometry (using the Cochet-Bonnet esthesiometer) of the central cornea to determine central corneal sensation as a measure of nerve function. Findings were correlated with an age-matched control group of 30 healthy individuals. Comparisons to biomicroscopical stage of FECD, visual acuity and central corneal thickness were performed using Spearman correlation. Depending on slit-lamp examination, all 30 eyes were classified into FECD stage 1–4 (stage 1: six eyes; stage 2: 15 eyes; stage 3: six eyes; stage 4: three eyes). Total nerve length (ρ = −0.8, p

The VEGF-A family plays a crucial role in the induction of pathological corneal neovascularization. The role of the different VEGF-A isoforms during lymphangiogenesis is only little-known. Current anti-angiogenic therapies in the eye and other organs inhibit all VEGF-A isoforms, and have effects on both blood and lymphatic vessels. Here we investigate whether selective targeting of the isoform VEGF 165 is able to inhibit corneal lymphangiogenesis under inflammatory conditions.The mouse model of suture-induced corneal neovascularization was used to assess the antihem- and antilymphangiogenic effect of topically applied pegaptanib. Corneal blood and lymph vascularized areas were analyzed morphometrically. Furthermore, we analyzed the proliferative effects of VEGF A 121, 165, and 189 on blood and lymphatic endothelial cells (BEC/LEC) via a cell-proliferation assay.Pegaptanib significantly inhibited inflammatory corneal hemangiogenesis (p 0.01), but not lymphangiogenesis in vivo (p 0.05), both topically as well as systemically, in the inflamed cornea. In vitro, BECs were more susceptible to pegaptanib than LECs.Targeting VEGF-A 165 significantly inhibits hem- but not lymphangiogenesis, suggesting VEGF-A 165 to be critical for hem-, but dispensable for lymphangiogenesis, at least in the inflamed cornea.

Dear Editor, Graft preparation is a challenging step during posterior lamellar keratoplasty in Descemet membrane endothelial keratoplasty (DMEK) [1–4]. Here, the 15-μm-thick endotheliumDescemet membrane layer (EDM) is manually stripped off the donor cornea before it is inserted into the host’s anterior chamber. For better visualization, the EDM is usually stained with trypan blue 0.06 % (VisionBlue, DORC [Dutch Ophthalmic Research Center] International BV, Zuidland, The Netherlands) [5]. However, the intraocular use of dyes such as trypan blue carries the risk of undesirable side effects, as these dyes may have cytotoxic properties [6, 7]. Indeed, various studies have shown cytotoxic effects of trypan blue on corneal endothelial cells [6–8]. Therefore, there is a need for less toxic dyes for use during lamellar transplant surgery. Phacodyne is a newly available dye for ophthalmic surgery that contains 1 % soluble lutein and only 0.04 % trypan blue (Peschke Medizintechnik GmbH, Waldshut-Tiengen, Germany) [9]. The purpose of this study was to analyze differences in staining properties of Phacodyne compared with VisionBlue, and to investigate potential cytotoxic effects of trypan blue and lutein on corneal endothelial cells. This experimental study was carried out at the Department of Ophthalmology, University of Cologne, Germany. The study adhered to the tenets of the Declaration of Helsinki, and was approved by the institutional review board. In order to compare staining properties of the analyzed dyes, four corneal donor buttons were placed endothelial side up into a Hanna punch block (MORIA Inc., Doylestown, PA, USA) and covered with either Phacodyne (n=2) or VisionBlue (n= 2) for staining of the EDM for 1 min. The dyes were subsequently removed, and pictures of the stained EDMwere taken using a surgical microscope (OPNI LUMERA 700; Carl Zeiss Meditec, Inc., Oberkochen, Germany). For analysis of endothelial cell toxicity, seven corneal rims, after stripping of the central Descemet membrane for standard DMEK surgery using VisionBlue, were quartered into four equal pieces, placed into a 12-well plate, and then incubated with either VisionBlue (n=14) or Phacodyne (n=14) to ensure that the same location was measured. Endothelial cells on the quartered rims (after the central Descemet was stripped off) were counted prior to staining and after 15 and 30 min of incubation, using light microscopy (Zeiss Axio Vert 25, AxioVision 2.05; Carl ZeissMeditec, Inc., Oberkochen, Germany). Statistical analysis was performed using the Mann–Whitney U test, and a p value