Evaluation of iris functional capillary density in experimental local and systemic inflammation

Area of Science:

• Ophthalmology
• Microcirculation Research
• Inflammatory Disease Models

Background:

• Ocular microcirculation impairment is critical in inflammatory eye diseases like anterior uveitis.
• Effective tools are needed to study the eye's microvasculature for developing new treatments.
• Intravital microscopy (IVM) is a key experimental method for evaluating microcirculation in small animals.

Purpose of the Study:

• To investigate the iridial microcirculation (IMIC) in endotoxin-induced uveitis in rats and mice using IVM.
• To introduce novel parameters for quantifying changes in IMIC during inflammation.
• To establish IVM as a reliable tool for assessing experimental eye inflammation.

Main Methods:

• Induction of systemic inflammation in rats via intravenous endotoxin.
• Induction of local inflammation in mice via intravitreal endotoxin.
• Real-time IVM of IMIC at specific time points post-endotoxin administration.
• Off-line analysis of video recordings to quantify functional capillary density (FCD) and dysfunctional capillary density (DCD).

Main Results:

• Systemic inflammation significantly decreased FCD compared to controls.
• Local inflammation led to a significant reduction in functional capillaries within the IMIC.
• Intravitreal endotoxin increased DCD and shifted the FCD/DCD ratio, indicating impaired perfusion.
• IVM successfully detected and quantified microcirculatory changes in experimental ocular inflammation.

Conclusions:

• IVM is a feasible and valuable method for studying IMIC in experimental ocular inflammation.
• Quantification of FCD and DCD provides insights into microvascular dysfunction during uveitis.
• This approach aids in evaluating therapeutic interventions targeting ocular microcirculation.