scholarly journals Preliminary Study on Retinal Vascular and Oxygen-related Changes after Long-term Silicone Oil and Foldable Capsular Vitreous Body Tamponade

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Wei Yang ◽  
Yongguang Yuan ◽  
Yao Zong ◽  
Zhen Huang ◽  
Shuyi Mai ◽  
...  
Keyword(s):  
Silicone Oil ◽  
Vitreous Body ◽  
Preliminary Study

Biomedical Materials to Repair Retinal Detachments

1985 ◽  
Vol 55 ◽  
Author(s):  
Miguel F. Refojo
Keyword(s):  
Retinal Detachment ◽  
Silicone Rubber ◽  
Methyl Acrylate ◽  
Silicone Oil ◽  
Vitreous Body ◽  
Light Sensitivity ◽  
Scleral Buckling ◽  
Intraocular Injection ◽  
Other Substances

ABSTRACTImplants are essential for the repair of retinal detachments. The implant buckles the wall of the eye and apposes the detached retina with the choroid, thus restoring light sensitivity to the retina. The scleral buckling also relieves traction on the retina from a shrinking vitreous body. The implant materials most commonly used are solid silicone rubber and silicone sponges, but both types have some disadvantages. A poly(hydroxyethyl acrylate-co-methyl acrylate) hydrogel implant with improved properties of softness and antibiotic absorption is also available for retinal detachment surgery. Proliferative vitreoretinopathy involves various conditions of retinal detachment complicated by vitreous fibrosis, which, after vitrectomy, may be treated with intraocular injection of fluids that support the retina against the choroid. For conditions requiring a long-term implant, silicone oil although controversial is the material of choice. Many other substances have been investigated but none better has yet been found.

scholarly journals Substitutes and Colloidal System for Vitreous Replacement and Drug Delivery: Recent Progress and Future Prospective

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 121
Author(s):  
Minal Thacker ◽  
Ching-Li Tseng ◽  
Feng-Huei Lin
Keyword(s):  
Recent Progress ◽  
Silicone Oil ◽  
Vitreous Body ◽  
Colloidal System ◽  
Experimental Phase ◽  
Short Term ◽  
Vitreous Substitute ◽  
Pathological Conditions ◽  
Macular Holes

Vitreoretinal surgeries for ocular diseases such as complicated retinal detachment, diabetic retinopathy, macular holes and ocular trauma has led to the development of various tamponades over the years in search for an ideal vitreous substitute. Current clinically used tamponade agents such as air, perfluorocarbons, silicone oil and expansile gases serve only as a short-term solution and harbors various disadvantages. However, an ideal long-term substitute is yet to be discovered and recent research emphasizes on the potential of polymeric hydrogels as an ideal vitreous substitute. This review highlights the recent progress in the field of vitreous substitution. Suitability and adverse effects of various tamponade agents in present day clinical use and biomaterials in the experimental phase have been outlined and discussed. In addition, we introduced the anatomy and functions of the native vitreous body and the pathological conditions which require vitreous replacement.

scholarly journals AN EXPERIMENTAL STUDY OF A NOVEL DOMESTIC VITREOUS SUBSTITUTE “VITREOLON” IN COMPARISON WITH SILICONE OIL IN SIMULATED RETINAL DETACHMENT IN RABBITS

Biomeditsina ◽  
2019 ◽  
pp. 78-89
Author(s):  
I. B. Alekseyev ◽  
A. R. Korigodskiy ◽  
E. N. Iomdina ◽  
A. A. Fedorov ◽  
V. E. Belkin ◽  
...  
Keyword(s):  
Experimental Study ◽  
Retinal Detachment ◽  
Silicone Oil ◽  
Physiological State ◽  
Vitreous Body ◽  
Ophthalmic Surgery ◽  
Experimental Animals ◽  
Clinical Conditions ◽  
Observation Period

This article presents the results of an experimental study of a new domestic preparation “Vitreolon”, an artifi cial vitreous body based on a weakly cross-linked hydrogel. The safety and effi cacy of this product for the treatment of retinal detachment in experimental animals was evaluated in comparison with silicone oil. The tamponade properties of each drug, their effect on the internal structure of the animal’s eye, convenience and safety of use in ophthalmic surgery were investigated. A base for conducting detailed preclinical and clinical trials was prepared.Rabbits of the gray chinchilla breed were chosen for the study, largely because the size of their eye is close to that of the human eye. This fact allowed us to study the effect of “Vitreolon” in an amount approximately equal to that used in clinical conditions. During the experiment, the indicators of ophthalmological examinations of experimental animals were recorded. The physiological state of the animals was controlled daily. The observation period ranged from 3 months (for rabbits with a silicone tamponade) to 6 months (for rabbits with a tamponade using the new hydrogel artificial vitreous body).It is found that “Vitreolon” is not inferior to silicone oil in terms of tamponade properties. Moreover, it boasts a number of signifi cant advantages, such as a lack of emulsifi cation, absence of migration to the anterior chamber of the eye, no effect on the exchange of intraocular fl uid, no effect on the intraocular pressure (IOP), long-term retention of the shape and transparency. The characteristics of the new hydrogel artifi cial vitreous body are close to those of the native vitreous body. The application of “Vitreolon” in ophthalmic surgery will increase the effi cacy of retinal detachment treatment by reducing the recovery time.

scholarly journals Foldable capsular vitreous body implantation for treatment of traumatic retinal detachment: two case reports

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052199025
Author(s):  
Baihui Zeng ◽  
Qian Wang ◽  
Guiqin Sui ◽  
Mingxuan Wang ◽  
Wei Xie ◽  
...  
Keyword(s):  
Retinal Detachment ◽  
Large Scale ◽  
Silicone Oil ◽  
Case Reports ◽  
Vitreous Body ◽  
Clinical Applications ◽  
Current Evidence ◽  
Vitreoretinal Disease ◽  
Silicone Oil Tamponade

Retinal detachment caused by severe ocular trauma is a type of refractory vitreoretinal disease. Current treatment methods include vitrectomy combined with silicone oil tamponade. However, long-term use of silicone oil tamponade has various complications, including a risk of silicone oil dependence that eventually leads to eyeball atrophy and enucleation. Foldable capsular vitreous bodies (FCVBs) offer a good solution for these problems. However, FCVBs have not been used in large-scale clinical applications and few cases have been reported in the published literature. The main use of FCVBs, based on current evidence, is in the treatment of the relatively few (but important) patients whose eyes have no visual potential; the aim of treatment in these patients is globe preservation, rather than restoration of vision. Here, we describe two patients who underwent FCVB implantation. The findings in these patients indicated that FCVBs can effectively support the vitreous cavity and detached retina. FCVB implantation may thus offer a safe and effective method for treatment of severe retinal detachment, avoiding the inconvenience caused by silicone oil dependence and enucleation. To confirm its long-term usefulness in clinical applications, many additional case reports are needed.

Ultrastructural observations of the aorta of calves implanted with a mechanical left ventricular assist device

1990 ◽  
Vol 48 (3) ◽  
pp. 834-835
Author(s):  
J P Cassella ◽  
V Salih ◽  
T R Graham
Keyword(s):  
Left Ventricular Assist Device ◽  
Ventricular Assist Device ◽  
Left Ventricular ◽  
Aortic Tissue ◽  
Assist Device ◽  
Ventricular Assist ◽  
Transmission Electron ◽  
Left Ventricular Assist ◽  
Preliminary Study

Left ventricular assist systems are being developed for eventual long term or permanent implantation as an alternative to heart transplantation in patients unsuitable for or denied the transplant option. Evaluation of the effects of these devices upon normal physiology is required. A preliminary study was conducted to evaluate the morphology of aortic tissue from calves implanted with a pneumatic Left Ventricular Assist device-LVAD. Two 3 month old heifer calves (calf 1 and calf 2) were electively explanted after 128 days and 47 days respectively. Descending thoracic aortic tissue from both animals was removed immediately post mortem and placed into karnovsky’s fixative. The tissue was subsequently processed for transmission electron microscopy (TEM). Some aortic tissue was fixed in neutral buffered formalin and processed for routine light microscopy.

scholarly journals Partial Decellularization for Segmental Tracheal Scaffold Tissue Engineering: A Preliminary Study in Rabbits

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 866
Author(s):  
Luong Huu Dang ◽  
Yuan Tseng ◽  
How Tseng ◽  
Shih-Han Hung
Keyword(s):  
Mechanical Stability ◽  
Vital Staining ◽  
Potential Method ◽  
Term Survival ◽  
Long Term Survival ◽  
Cartilage Cells ◽  
Preliminary Study ◽  
Epithelial Layers

In this study, we developed a new procedure for the rapid partial decellularization of the harvested trachea. Partial decellularization was performed using a combination of detergent and sonication to completely remove the epithelial layers outside of the cartilage ring. The post-decellularized tracheal segments were assessed with vital staining, which showed that the core cartilage cells remarkably remained intact while the cells outside of the cartilage were no longer viable. The ability of the decellularized tracheal segments to evade immune rejection was evaluated through heterotopic implantation of the segments into the chest muscle of rabbits without any immunosuppressive therapy, which demonstrated no evidence of severe rejection or tissue necrosis under H&E staining, as well as the mechanical stability under stress-pressure testing. Finally, orthotopic transplantation of partially decellularized trachea with no immunosuppression treatment resulted in 2 months of survival in two rabbits and one long-term survival (2 years) in one rabbit. Through evaluations of posttransplantation histology and endoscopy, we confirmed that our partial decellularization method could be a potential method of producing low-immunogenic cartilage scaffolds with viable, functional core cartilage cells that can achieve long-term survival after in vivo transplantation.

Mathematical modeling of fluid movement inside the eyeball during intravitreal injection

2021 ◽  
pp. 106-109
Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Residence Time ◽  
Complex Structure ◽  
Posterior Vitreous Detachment ◽  
Vitreous Body ◽  
Complete Removal ◽  
Intravitreal Injections ◽  
The World

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.

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