A Novel Squid Glaucoma microShunt for Controlled Release of Aqueous Humor

BACKGROUND: Glaucoma is a progressive, multifactorial optic neurodegenerative disease and is the second leading cause of blindness, affecting 80 million patients globally. Elevated intraocular pressure (IOP) is the main modifiable risk factor. When medications and laser therapies fail, glaucoma drainage devices (GDDs) are implanted. Current GDDs have major drawbacks: 1) large sizes requiring extensive surgical dissection, 2) uncontrolled aqueous humor (AH) release risking vision loss, and 3) prolonged inflammation and fibrosis leading to a complication rate over 50% at 5 years. To address this clinical need, we developed a novel GDD, the Squid Glaucoma microShunt (SGS) which has been designed to release AH in a slow and controlled fashion. OBJECTIVE: The aims are to 1) review the chemical and physical properties of biocompatible polymers, 2) understand the properties of ultrananocrystalline diamond (UNCD) coating and its fabrication methods, 3) identify the top three optimal polymers for fabrication, 4) survey glaucoma specialists on the design of the SGS to stimulate further ideas for development, and 5) fabricate 3D-printed prototypes. METHODS: The characteristics of various polymers and UNCD were investigated through literature review and consultations with materials science experts. Top polymer candidates were assessed based on the following criteria: durability over time, flexibility/toughness, thermal capacity, ease of fabrication, biocompatibility, cost, physical form, U.S. Food and Drug Administration (FDA) approval, and prior use for ophthalmic applications. Glaucoma specialists were emailed a brief description of the SGS along with a 4-question survey: likelihood of using the SGS in their practice, advantages/disadvantages, and challenges experienced with current GDDs. 3D-printed prototypes of the SGS and twin microforceps were fabricated in collaboration with microfluidic device manufacturers. RESULTS: The three polymers that were selected for future laboratory testing include polytetrafluoroethylene (PTFE), polystyrene (PS), and polydimethylsiloxane (PDMS). Five responses from glaucoma specialists were received, and they provided an average 4.4/5 rating for the likelihood of using the SGS in their practice. 3D printed SGS prototypes with precise dimensions were fabricated using projection micro stereolithography along with metal microforceps prototypes. An alternative biofluid-based UNCD coating procedure that can be conducted at room temperature was developed in collaboration with Orlando Auciello, PhD.

Author dc:creator

• Mekala, Priya

Contributors dc:contributor

• Kooner, Karanjit
• Auciello, Orlando
• Gurney, N. Troy

• Glaucoma
• Glaucoma Drainage Implants
• Intraocular Pressure
• Polymers

Language dc:language

en

Identifier

1522122295

OAI identifier oai:identifier

oai:utswmed-ir.tdl.org:2152.5/10619