scholarly journals Microstructured collagen films for 3D corneal stroma modelling

2021 ◽  
pp. 1-10
Author(s):  
Juha Prittinen ◽  
Xin Zhou ◽  
Fouzia Bano ◽  
Ludvig Backman ◽  
Patrik Danielson
Keyword(s):  
Corneal Stroma

Collagen fibrillogenesis in vitro: interaction of types I and V collagen

1986 ◽  
Vol 44 ◽  
pp. 210-211
Author(s):  
Arthur J. Wasserman ◽  
Kathy C. Kloos ◽  
David E. Birk
Keyword(s):  
Type I Collagen ◽  
Corneal Stroma ◽  
Minor Component ◽  
Homogeneous Distribution ◽  
Type I ◽  
Type V Collagen ◽  
Fibril Morphology ◽  
Type V ◽  
In Vitro Interaction

Type I collagen is the predominant collagen in the cornea with type V collagen being a quantitatively minor component. However, the content of type V collagen (10-20%) in the cornea is high when compared to other tissues containing predominantly type I collagen. The corneal stroma has a homogeneous distribution of these two collagens, however, immunochemical localization of type V collagen requires the disruption of type I collagen structure. This indicates that these collagens may be arranged as heterpolymeric fibrils. This arrangement may be responsible for the control of fibril diameter necessary for corneal transparency. The purpose of this work is to study the in vitro assembly of collagen type V and to determine whether the interactions of these collagens influence fibril morphology.

scholarly journals Collagen analogs with phosphorylcholine are inflammation-suppressing scaffolds for corneal regeneration from alkali burns in mini-pigs

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Fiona C. Simpson ◽  
Christopher D. McTiernan ◽  
Mohammad Mirazul Islam ◽  
Oleksiy Buznyk ◽  
Philip N. Lewis ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Nerve Regeneration ◽  
Graft Failure ◽  
Corneal Stroma ◽  
Advanced Stage ◽  
Term Survival ◽  
Corneal Regeneration ◽  
Type V ◽  
Mini Pigs

AbstractThe long-term survival of biomaterial implants is often hampered by surgery-induced inflammation that can lead to graft failure. Considering that most corneas receiving grafts are either pathological or inflamed before implantation, the risk of rejection is heightened. Here, we show that bioengineered, fully synthetic, and robust corneal implants can be manufactured from a collagen analog (collagen-like peptide-polyethylene glycol hybrid, CLP-PEG) and inflammation-suppressing polymeric 2-methacryloyloxyethyl phosphorylcholine (MPC) when stabilized with the triazine-based crosslinker 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The resulting CLP-PEG-MPC implants led to reduced corneal swelling, haze, and neovascularization in comparison to CLP-PEG only implants when grafted into a mini-pig cornea alkali burn model of inflammation over 12 months. Implants incorporating MPC allowed for faster nerve regeneration and recovery of corneal sensation. CLP-PEG-MPC implants appear to be at a more advanced stage of regeneration than the CLP-PEG only implants, as evidenced by the presence of higher amounts of cornea-specific type V collagen, and a corresponding decrease in the presence of extracellular vesicles and exosomes in the corneal stroma, in keeping with the amounts present in healthy, unoperated corneas.

scholarly journals Relative rates of biosynthesis of collagen type I, type V and type VI in calf cornea

1991 ◽  
Vol 274 (2) ◽  
pp. 615-617 ◽  
Author(s):  
P Kern ◽  
M Menasche ◽  
L Robert
Keyword(s):  
Type I Collagen ◽  
Collagen Type ◽  
Corneal Stroma ◽  
Collagen Type I ◽  
Type I ◽  
Type Vi Collagen ◽  
Sds Page ◽  
Proline Incorporation ◽  
Type V

The biosynthesis of type I, type V and type VI collagens was studied by incubation of calf corneas in vitro with [3H]proline as a marker. Pepsin-solubilized collagen types were isolated by salt fractionation and quantified by SDS/PAGE. Expressed as proportions of the total hydroxyproline solubilized, corneal stroma comprised 75% type I, 8% type V and 17% type VI collagen. The rates of [3H]proline incorporation, linear up to 24 h for each collagen type, were highest for type VI collagen and lowest for type I collagen. From pulse-chase experiments, the calculated apparent half-lives for types I, V and VI collagens were 36 h, 10 h and 6 h respectively.

scholarly journals Stem Cells in the Path of Light, from Corneal to Retinal Reconstruction

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 873
Author(s):  
Ovidiu Samoila ◽  
Lacramioara Samoila
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Clinical Success ◽  
Corneal Stroma ◽  
Cell Transplant ◽  
Inclusion Criteria ◽  
Epithelial Stem Cells ◽  
Corneal Epithelial ◽  
Stem Cells Transplantation ◽  
Limbal Epithelial Stem Cells

The future of eye reconstruction invariably includes stem cells transplantation. Corneal limbus, corneal stroma, trabeculum, retinal cells, optic nerve, and all structures that are irreversibly damaged and have no means to be repaired or replaced, through conventional treatment or surgery, represent targets for stem cell reconstruction. This review tries to answer the question if there is any clinical validation for stem therapies, so far, starting from the cornea and, on the path of light, arriving to the retina. The investigation covers the last 10 years of publications. From 2385 published sources, we found 56 clinical studies matching inclusion criteria, 39 involving cornea, and 17 involving retina. So far, corneal epithelial reconstruction seems well validated clinically. Enough clinical data are collected to allow some form of standardization for the stem cell transplant procedures. Cultivated limbal epithelial stem cells (CLET), simple limbal epithelial transplant (SLET), and oral mucosa transplantation are implemented worldwide. In comparison, far less patients are investigated in retinal stem reconstructions, with lower anatomical and clinical success, so far. Intravitreal, subretinal, and suprachoroidal approach for retinal stem therapies face specific challenges.

scholarly journals Accidental Corneal Intrastromal Intraocular Lens Implantation with the Wound-Assisted Technique and Clinical Course with Anterior Segment Optical Coherence Tomography

2021 ◽  
pp. 283-287
Author(s):  
Jo Moriya ◽  
Shinichi Sakamoto ◽  
Satoru Inoda ◽  
Hidenori Takahashi ◽  
Hidetoshi Kawashima
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Lens ◽  
Anterior Segment ◽  
Corneal Stroma ◽  
Age Related Macular Degeneration ◽  
Optical Coherence ◽  
Corrected Visual Acuity ◽  
Age Related ◽  
Intracameral Injection ◽  
Air Tamponade

Accidental intraocular lens (IOL) implantation into the corneal stroma is a rare clinical entity that can occur during the wound-assisted technique. In this report, we describe a case of an 81-year-old man who underwent cataract surgery in which the IOL was implanted into the corneal stroma with the wound-assisted technique, and we present changes in anterior segment optical coherence tomography. The IOL was removed and reinserted after widening the incision. Air tamponade was created by intracameral injection. An anterior chamber tap was performed 10 h later to reduce increased intraocular pressure. Interlayer separation of the corneal stroma was confirmed 30 min postoperatively but was corrected 4 days later. The patient’s best-corrected visual acuity (BCVA) was logMAR 0.30, and he had been diagnosed with age-related macular degeneration before surgery. Although the opacity of the corneal stroma persisted, BCVA improved to logMAR 0. When using the wound-assisted technique for IOL insertion, surgeons should take care not to implant the IOL into the corneal stroma.

Flow conductivity of human corneal stroma

1970 ◽  
Vol 10 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Irving Fatt ◽  
Bengt O. Hedbys
Keyword(s):  
Corneal Stroma

scholarly journals Mechanical Properties of Bioengineered Corneal Stroma

2021 ◽  
pp. 2100972
Author(s):  
Nello Formisano ◽  
Cas Putten ◽  
Rhiannon Grant ◽  
Gozde Sahin ◽  
Roman K. Truckenmüller ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corneal Stroma

scholarly journals Severe Corneal Morphological Alterations after Excimer Laser Surface Ablation for a High Astigmatism

2021 ◽  
pp. 492-496
Author(s):  
Anna M. Roszkowska ◽  
Giovanni W. Oliverio ◽  
Giuseppe A. Signorino ◽  
Mario Urso ◽  
Pasquale Aragona
Keyword(s):  
Excimer Laser ◽  
Corneal Stroma ◽  
Corneal Topography ◽  
Laser Surface ◽  
Slit Lamp ◽  
Slit Lamp Examination ◽  
Morphological Alterations ◽  
Surface Ablation ◽  
Confocal Images

We report long-term alterations of anterior corneal stroma after excimer laser surface ablation for a high astigmatism. The patient claimed progressive visual loss in his right eye (RE) during the last 3 years after bilateral laser-assisted subepithelial keratectomy (LASEK) surgery. His examination comprised visual acuity (UDVA and CDVA), slit-lamp examination, corneal topography and tomography, AS-OCT, and confocal microscopy. The UDVA was 0.1 in his RE and 1.0 in the left eye. The CDVA in the RE was 0.8. The slit-lamp examination showed a stromal lesion in the inferior paracentral corneal zone, with multiple vertical tissue bridges and severe thinning. Corneal topography and tomography showed central flattening with inferior steepening and severe alteration in elevation maps. AS-OCT showed void areas in the anterior stroma with thinning of the underlying tissue, and confocal images were not specific. In this case, progressive corneal steepening and thinning that manifest topographically as inferior ectasia occurred in correspondence to the singular stromal alterations after LASEK.

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