Background This study was performed to reinvestigate the detailed anatomy of the connective tissues related to the levator palpebrae superioris (LPS). Materials and Methods One hundred and twenty human orbits were prepared macroscopically or with the help of an operational microscope. Connective tissues related to the LPS were measured, removed, and prepared for histology. Different staining procedures including immunohistochemistry for α‐smooth muscle actin were applied to analyze the quality of these tissues. Results Preparation consistently revealed two definite fibromuscular transverse ligaments related to the LPS, i.e., Whitnall's ligament (WL) and a definite intermuscular transverse ligament (ITL) underlying the LPS. The ITL exhibited a greater anterio‐posterior extension than WL. In sagittal section, the ITL was observed slightly more posterior in the orbit than WL. Histologically, both ligaments consisted of collagenous fibers, elastic fibers, and smooth muscle fibers. WL was connected with the LPS by sagittal fibroelastic connecting strands. Conclusions Two transverse ligaments of fibromuscular tissue, WL and the ITL, form a sleeve superior and inferior to the LPS. This sling is supposed to assist the LPS in its action and should be preserved at ptosis surgery. © Wiley‐Liss, Inc.

Identification of interactors is a major goal in cell biology. Not only protein-protein but also protein-carbohydrate interactions are of high relevance for signal transduction in biological systems. Here, we aim to identify novel interacting binding partners for the β-galactoside-binding proteins galectin-1 (Gal-1) and galectin-3 (Gal-3) relevant in the context of the eye disease proliferative vitreoretinopathy (PVR). PVR is one of the most common failures after retinal detachment surgeries and is characterized by the migration, adhesion, and epithelial-to-mesenchymal transition of retinal pigment epithelial cells (RPE) and the subsequent formation of sub- and epiretinal fibrocellular membranes. Gal-1 and Gal-3 bind in a dose- and carbohydrate-dependent manner to mesenchymal RPE cells and inhibit cellular processes like attachment and spreading. Yet knowledge about glycan-dependent interactors of Gal-1 and Gal-3 on RPE cells is very limited, although this is a prerequisite for unraveling the influence of galectins on distinct cellular processes in RPE cells. We identify here 131 Gal-3 and 15 Gal-1 interactors by galectin pulldown experiments combined with quantitative proteomics. They mainly play a role in multiple binding processes and are mostly membrane proteins. We focused on two novel identified interactors of Gal-1 and Gal-3 in the context of PVR: the low-density lipoprotein receptor LRP1 and the platelet-derived growth factor receptor β PDGFRB. Addition of exogenous Gal-1 and Gal-3 induced cross-linking with LRP1/PDGFRB and integrin-β1 (ITGB1) on the cell surface of human RPE cells and induced ERK/MAPK and Akt signaling. Treatment with kifunensine, an inhibitor of complex-type -glycosylation, weakened the binding of Gal-1 and Gal-3 to these interactors and prevented lattice formation. In conclusion, the identified specific glycoprotein ligands shed light into the highly specific binding of galectins to dedifferentiated RPE cells and the resulting prevention of PVR-associated cellular events.

Background: This study was performed to reinvestigate the detailed anatomy of the connective tissues related to the levator palpebrae superioris (LPS).Muterials and Methods: One hundred and twenty human orbits were prepared macroscopically or with the help of an operational microscope. Connective tissues related to the LPS were measured, removed, and prepared for histology. Different staining procedures including immunohistochemistry for a-smooth muscle actin were applied to analyze the quality of these tissues.Results: Preparation consistently revealed two definite fibromuscular transverse ligaments related to the LPS, i.e., Whitnall's ligament (WL) and a definite intermuscular transverse ligament (ITL) underlying the LPS. The ITL exhibited a greater anterio-posterior extension than WL. In sagittal section, the ITL was observed slightly more posterior in the orbit than WL. Histologically, both ligaments consisted of collagenous fibers, elastic fibers, and smooth muscle fibers. WL was connected with the LPS by sagittal fibroelastic connecting strands.Conclzlsions: T w o transverse ligaments of fibromuscular tissue, W L and the ITL, form a sleeve superior and inferior to the LPS. This sling is supposed to assist the LPS in its action and should be preserved at ptosis surgery. 0 1996 Wiley-Lisa, Inc.

The first three days seem to represent a relatively safe period during which surgery for macula-off retinal detachment may be postponed without compromising the patient's visual prognosis.

Proliferative vitreoretinopathy (PVR) is the major cause of persistent loss of vision after retinal detachment surgery and is characterized by the formation of scar-like fibrocellular membranes on the neuroretina giving rise to tractional retinal (re-)detachment. Epithelial-mesenchymal transition, adhesion, migration and proliferation of retinal pigment epithelial (RPE) cells disseminated from the normal site at Bruch's membrane in concert with an activation of glial cells, hyalocytes and immune cells are key cellular events in the onset of the disease. The interplay between the cellular events and various growth factors, cytokines and matrix proteins thereby drives the undesirable formation of PVR membranes. Blocking these pathological events would greatly enhance the overall prognosis of surgical treatment. Clinical trials assessing the efficacy of antiproliferative and anti-inflammatory substances have yielded mixed results. Thus no safe or sufficiently effective pharmacological agent has so far been established in the clinical routine. Recent advances in the fundamental understanding of the pathogenesis of PVR aided in the identification of several new therapeutic targets to block the cellular events intrinsic to the disease. This article gives an overview of the results for adjunct therapies already tested in clinical studies and highlights experimental concepts for novel treatment strategies.