Outflow facility studies in the perfused human ocular anterior segment

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Tissue Engineering

Background:

• The human aqueous outflow pathway is crucial for maintaining intraocular pressure.
• Existing models for studying this pathway often rely on animal testing or lack physiological relevance.
• Understanding the trabecular meshwork's (TM) function is key to treating glaucoma.

Purpose of the Study:

• To develop and validate a novel in vitro tissue model of the human aqueous outflow pathway.
• To assess the physiological relevance and long-term viability of the model.
• To establish an alternative to animal testing for studying aqueous humor dynamics.

Main Methods:

• Utilized an eviscerated anterior corneoscleral shell with intact trabecular meshwork (TM).
• Perfusion of the TM with culture medium at physiological pressure (37°C, 5% CO2).
• Morphological and functional assessments of outflow tissues over several days.

Main Results:

• The model maintained tissue morphology and function comparable to in vivo human/primate outflow systems.
• Measured outflow facility (0.271 ± 0.018 µL/min/mmHg) aligns with in vivo tonography values.
• Outflow facility decreased linearly with increased perfusion pressure, and TM removal increased resistance by 41%.

Conclusions:

• The developed tissue model provides a physiologically relevant platform for studying the human aqueous outflow pathway.
• This model demonstrates long-term viability, enabling detailed investigation of TM biology.
• It serves as a promising alternative to animal testing in ophthalmology research.