Polymeric Materials for Eye Surface and Intraocular Applications

Abstract

Ocular applications of polymeric materials have been widely investigated for medical diagnostics, treatment, and vision improvement. The human eye is a vital organ that connects us to the outside world so when the eye is injured, infected, or impaired, it needs immediate medical treatment to maintain clear vision and quality of life. Moreover, several essential parts of the eye lose their functions upon aging, causing diminished vision. Modern polymer science and polymeric materials offer various alternatives, such as corneal and scleral implants, artificial ocular lenses, and vitreous substitutes, to replace the damaged parts of the eye. In addition to the use of polymers for medical treatment, polymeric contact lenses can provide not only vision correction, but they can also be used as wearable electronics. In this Review, we highlight the evolution of polymeric materials for specific ocular applications such as intraocular lenses and current state-of-the-art polymeric systems with unique properties for contact lens, corneal, scleral, and vitreous body applications. We organize this Review paper by following the path of light as it travels through the eye. Starting from the outside of the eye (contact lenses), we move onto the eye’s surface (cornea and sclera) and conclude with intraocular applications (intraocular lens and vitreous body) of mostly synthetic polymers and several biopolymers. Initially, we briefly describe the anatomy and physiology of the eye as a reminder of the eye parts and their functions. The rest of the Review provides an overview of recent advancements in next-generation contact lenses and contact lens sensors, corneal and scleral implants, solid and injectable intraocular lenses, and artificial vitreous body. Current limitations for future improvements are also briefly discussed.

Recent Advances of Intraocular Lens Materials and Surface Modification in Cataract Surgery

“…The ideal injectable IOL is in a liquid state during the implantation procedure and subsequently forms a stable solid or remains in liquid form. Liquid materials for injectable IOL need to meet the basic conditions: good biocompatibility, non-toxicity, ability to maintain a transparent state, and sufficient refractive power ( Karayilan et al, 2021 ). The process of turning liquid materials into solids in vivo may involve some external stimulation, which is preferably non-invasive.…”

“…Biomaterials are used extensively in medicine nowadays, such as artificial organs, regenerative medicine, wound repair and bioimaging fields ( Karayilan et al, 2021 ). Ophthalmology is also an important application area of biomaterials ( Han H. et al, 2020 ; Wang K. et al, 2021 ).…”

“…They usually focused on innovations in structural design, in which case there are more commercialized IOL ( Čanović et al, 2019 ; Dick and Gerste, 2021 ; Werner, 2021 ). There were also some reviews on the application of polymer materials in ophthalmology ( Kirchhof et al, 2015 ; Karayilan et al, 2021 ). They introduced the applications of polymeric materials not only in IOL but also in other ophthalmic fields, such as contact lenses and vitreous replacement.…”

Clustering and Hierarchical Organization of 3D Printed Poly(propylene fumarate)-block-PEG-block-poly(propylene fumarate) ABA Triblock Copolymer Hydrogels

“…[1][2][3][4] To mimic these assemblies and complex structures, biomaterials, including synthetic hydrogels, able to organize at the nanoscale via microphase separation in water, bringing specific macroscopic properties, have shown significant interest and potential. [5][6][7][8] Hydrogels are able to display a broad range of properties making them applicable to many unmet medical needs including depots for therapeutic delivery, [9][10][11] contact lenses, 12,13 coatings and cell scaffolds for tissue engineering. 14,15 In particular, mechanical properties of hydrogels have been reported as a factor for modifying the differentiation and proliferation behavior of human mesenchymal stem cells (hMSCs).…”

“…Spontaneous self- and hierarchical assembly underpins most biological systems, including tissues. − To mimic these assemblies and complex structures, biomaterials, including synthetic hydrogels, able to organize at the nanoscale via microphase separation in water, bringing specific macroscopic properties, have shown significant interest and potential. − Hydrogels are able to display a broad range of properties, making them applicable to many unmet medical needs including depots for therapeutic delivery, − contact lenses, , and coatings and cell scaffolds for tissue engineering. , In particular, mechanical properties of hydrogels have been reported as a factor for modifying the differentiation and proliferation behavior of human mesenchymal stem cells (hMSCs). − In this context, the design of simple hydrogels and the thorough understanding of their formation process throughout self-assembly phenomena is a critical point toward the development of future materials for tissue engineering. Simultaneously, elaboration of materials adapted to be used in state-of-the-art technologies such as additive manufacturing, also known as three-dimensional (3D) printing, turns out to be a necessity. , Thanks to 3D printing, objects can be generated without the need for molds, enabling a high degree of flexibility in design, contributing to the development of patient-specific products.…”