Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Area of Science:

• Ophthalmology and Biomedical Engineering
• Microfluidics in medical devices
• Glaucoma treatment strategies

Background:

• Glaucoma is a leading cause of irreversible blindness affecting over 70 million people globally.
• Elevated intraocular pressure (IOP) is the primary target for halting glaucoma progression.
• Current treatments involve microfluidic devices like glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) to manage aqueous humor (AH) outflow.

Purpose of the Study:

• To analyze natural and artificial microfluidic pathways for AH in glaucoma.
• To provide insights into IOP abnormalities and improve current glaucoma implant designs.
• To critically review glaucoma implants from a microfluidics perspective.

Main Methods:

• Detailed modeling and analysis of AH microfluidic pathways (natural and artificial).
• Categorization of current glaucoma implants into four groups based on AH drainage targets.
• Review of implant mechanisms and classification into three technological waves: microtube, microvalve, and microsystem.

Main Results:

• Current implants are categorized by drainage site: Schlemm's canal, suprachoroidal space, subconjunctival space, and ocular surface.
• Glaucoma implant designs are classified into three evolutionary waves: microtube, microvalve, and microsystem.
• Microfluidic principles offer a framework for understanding and improving glaucoma implant efficacy.

Conclusions:

• Future glaucoma treatment microsystems will integrate AI for active, wireless IOP control and real-time monitoring.
• Enhanced microfluidic designs can improve safety, reduce complications, and increase IOP-lowering efficacy.
• Further research into microfluidic structures and functions is crucial for advancing glaucoma implant technology.