Posterior rat eye during acute intraocular pressure elevation studied using polarization sensitive optical coherence...

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Imaging

Background:

• Intraocular pressure (IOP) elevation is a critical factor in optic neuropathies.
• Accurate monitoring of IOP-related changes in ocular tissues is essential for early diagnosis and treatment.
• Polarization-sensitive optical coherence tomography (PS-OCT) offers advanced imaging capabilities for ocular structures.

Purpose of the Study:

• To investigate the posterior rat eye using PS-OCT during experimentally induced acute increases in IOP.
• To analyze the correlation between IOP levels and specific ocular parameters, including scleral birefringence and retinal nerve fiber layer (RNFL) characteristics.

Main Methods:

• Polarization-sensitive optical coherence tomography (PS-OCT) operating at 840 nm with 3.8 µm axial resolution was employed.
• Acute IOP elevation was induced in Sprague Dawley rats via anterior chamber cannulation.
• Three-dimensional PS-OCT datasets were acquired across a range of IOPs (14-105 mmHg), and quantitative analyses of scleral birefringence, RNFL retardation, and reflectivity were performed.

Main Results:

• All investigated parameters, including scleral birefringence, RNFL retardation, and reflectivity, demonstrated a substantial correlation with IOP.
• In the lower IOP range (14-45 mmHg), only scleral birefringence exhibited a statistically significant correlation with IOP.
• The study observed significant polarization changes in ocular tissues correlating with IOP variations.

Conclusions:

• Scleral birefringence emerges as a promising IOP-related parameter for investigation using PS-OCT.
• PS-OCT can effectively visualize and quantify changes in the posterior eye associated with elevated IOP.
• The findings suggest potential for PS-OCT in monitoring ocular health related to IOP fluctuations.