Aqueous Flow Measured by Fluorophotometry in the Mouse

Area of Science:

• Ophthalmology
• Pharmacology
• Physiology

Background:

• Aqueous humor dynamics are crucial for intraocular pressure regulation.
• Accurate measurement of aqueous flow is essential for understanding ocular physiology and testing therapeutics.
• Existing methods for measuring aqueous flow in mice can be invasive or lack precision.

Purpose of the Study:

• To evaluate a novel fluorophotometer for measuring aqueous humor flow in murine eyes.
• To assess the impact of different anesthesia regimens on aqueous flow measurements.
• To determine the efficacy of aqueous flow suppressants using the fluorophotometer.

Main Methods:

• A fluorophotometer was used to measure fluorescein concentration in murine eyes.
• Mice were anesthetized with ketamine/xylazine, tribromoethanol, or ketamine alone.
• Aqueous flow was calculated based on corneal and anterior chamber fluorescein levels.
• Comparisons were made with anterior chamber cannulation and drug treatments (timolol, dorzolamide).

Main Results:

• Ketamine/xylazine anesthesia resulted in significantly lower aqueous flow compared to other regimens.
• Timolol and dorzolamide effectively reduced aqueous flow under specific anesthesia conditions.
• Fluorophotometry yielded lower aqueous flow values than anterior chamber cannulation but with less variability.

Conclusions:

• The noninvasive fluorophotometer reliably detects effects of anesthesia and suppressants on murine aqueous flow.
• This method offers a technically simpler and more consistent alternative to cannulation for aqueous flow assessment.
• The mouse fluorophotometer is suitable for longitudinal and crossover studies in ocular research.