retinal-pigment-epithelium-transplantation-non-human-primate-model

Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases

Retinal pigment epithelial (RPE) transplantation holds great promise for the treatment of inherited and acquired retinal degenerative diseases. These ...

National University of Singapore

National University Hospital, Singapore

Singapore Eye Research Institute (SERI)

Internal-tamponade agents are crucial surgical adjuncts in vitreoretinal surgery. Clinically used endotamponade agents act through buoyancy forces, yet can result in prolonged post-operative positioning, temporary loss of vision, raised intra-ocular pressure, cataract formation or the need for additional removal surgery. Here, we describe a thermogelling polymer that provides an internal tamponade effect through surface tension and swelling counter-forces. We tested the long-term biocompatibility of the polymer endotamponade in rabbit vitrectomy models, and its surgical efficacy and biocompatibility in a non-human primate retinal-detachment model. We also show that, while the thermogel biodegrades during the three months following surgery, it promotes the reformation of a vitreous-like body that mimics the biophysical properties of the natural vitreous. The thermogelling endotamponade might serve as a long-term vitreous substitute.

Retinal-detachment repair and vitreous-like-body reformation via a thermogelling polymer endotamponade.

Anti-vascular endothelial growth factors (anti-VEGF) have become the most common treatment modality for many retinal diseases. These include neovascular age-related macular degeneration (n-AMD), proliferative diabetic retinopathy (PDR) and retinal vein occlusions (RVO). However, these drugs are administered via intravitreal injections that are associated with sight-threatening complications. The most feared of these complications is endophthalmitis, a severe infection of the eye with extremely poor visual outcomes. Patients with retinal diseases typically have to undergo multiple injections before achieving the desired therapeutic effect. Each injection incurs the risk of the sight-threatening complications. As such, there has been great interest in developing sustained delivery platforms for anti-VEGF agents to the posterior segment of the eye. In recent years, there have been various strategies that have been conceptualised. These include non-biodegradable implants, nano-formulations and hydrogels. In this review, the barriers of drug delivery to the posterior segment of the eye will be explained. The characteristics of an ideal sustained delivery platform will then be discussed. Finally, the current available strategies will be analysed with the above-mentioned characteristics in mind to determine the advantages and disadvantages of each sustained drug delivery modality. Through the above, this review attempts to provide an overview of the sustained delivery platforms in their various phases of development.

Use of biomaterials for sustained delivery of anti-VEGF to treat retinal diseases.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Gopal Lingam

Department of Ophthalmology,
Yong Loo Lin School of Medicine,
Department of Ophthalmology, Yong Loo Lin School of Medicine

National University of Singapore

Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases

Gopal Lingam

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Ophthalmology,Yong Loo Lin School of Medicine,Department of Ophthalmology, Yong Loo Lin School of Medicine

National University of Singapore

Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases

Department of Ophthalmology,
Yong Loo Lin School of Medicine,
Department of Ophthalmology, Yong Loo Lin School of Medicine