A new strategy to replace the natural vitreous by a novel capsular artificial vitreous body with pressure-control valve

Abstract

Purpose The current vitreous substitutes such as silicone oil, heavy silicone oil, and polymeric gels that are directly injected into vitreous cavity frequently cause severe intraocular complications. There is a very urgent need to find a more suitable artificial vitreous substitute for pars plana vitrectomy (PPV) surgery. Methods We have devised a novel capsular artificial vitreous using tailor-made silicone rubber elastomer. The novel device was implanted into the vitreous cavity of rabbit after PPV and the eye was examined by ophthalmoscopy, fundus photography, and tonometry during an 8-week treatment period. B-scan ultrasonography, electroretinogram (ERG), and histological studies by light microscopy were also performed at the end of 8 weeks.Results The novel artificial vitreous body consists of a thin vitreous-like capsule with a silicone tube-valve system. The capsule can be folded and implanted into vitreous cavity through 1.5 mm incision on sclera. Physiological balanced solution (PBS) was then injected into the capsule and inflated to support retina and control intraocular pressure (IOP) through the tube-valve system subsequently fixed under the conjunctiva. Experiments using rabbits showed that the novel vitreous body could effectively support the retina and apparently induced no significant pathological changes in the eye over 8 weeks. Conclusion This approach may provide a new research strategy in the vitreous replacement technology. The novel artificial vitreous body device can effectively support retina, control IOP, and has good biocompatibility. It may be a good alternative to injecting artificial vitreous although its tamponade properties and usefulness still have to be proven in complex vitreoretinal diseases.

Evaluation of supporting role of a foldable capsular vitreous body with magnetic resonance imaging in the treatment of severe retinal detachment in human eyes

“…After foldable installation into the eye, a balanced salt solution (BSS) could be injected into the capsule and inflated to support the retina and control the intraocular pressure through the tube-valve system. 18 In the rabbit model of PVR, we found that the FCVB very closely mimicked the morphology and restored physiological functions, such as support, refraction, and cellular barriers during a 3-month observation period, without the obvious complications commonly induced with traditional silicone oil (see Supplemental Text 1). In addition, the FCVB changes the refraction very little when compared with silicone oil and heavy silicone oil, based on the Gullstrand-Emsley and Liou-Brennan schematic eyes.…”

“…In previous studies, we used a new strategy and rationale to fabricate the artificial vitreous substitute using FCVB [18][19][20] and first demonstrated that the FCVB can restore the structure and partial functions of a detached retina that are not easily reattached with silicone oil. 21 Patients in this predicament cannot obtain an intact eyeball and are forced to live with the outcomes of atrophy.…”

“…16,17 In previous studies, we proposed a new strategy to replace the natural vitreous body using a novel foldable capsular vitreous body (FCVB). [18][19][20][21] The FCVB consisted of a thin, vitreous-shaped capsule with a tube-valve system created using computer and industrial technology. After foldable installation into the eye, a balanced salt solution (BSS) could be injected into the capsule and inflated to support the retina and control the intraocular pressure through the tube-valve system.…”

Safety of Medium-Chain Triglycerides Used as an Intraocular Tamponading Agent in an Experimental Vitrectomy Model Rabbit

“…Various substances and approaches have been explored, but to date, clinically available alternatives to conventional tamponades (gas and silicone oil) are still very limited. [12][13][14][15][16][17][18] Identifying and developing a novel intraocular tamponading agent is a challenging task, albeit with a large therapeutical potential. The first step of this approach is to determine if the agent would be toxic to the retina or other ocular tissues.…”

Vitreous Substitutes

“…It is a thin, vitreous-shaped capsule made of a silicone rubber elastomer with a silicone tube valve system filled with a physiologically balanced solution or silicone oil. 41 The silicone rubber capsule has shown good biocompatibility and is easily implanted and removed experimentally in rabbit eyes. Over an 8-week treatment period, there was no corneal opacity, intraocular inflammation, or vitreal opacity but there was a high incidence of cataracts in the rabbit eyes, whether they were caused by the material of the FCVB or the lens structure of their eyes should be further evaluated.…”