[Pattern electroretinogram and macular perfusion in glaucoma]

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Primary Open-Angle Glaucoma (POAG) is a leading cause of irreversible blindness.
• Early detection and understanding of POAG pathophysiology are crucial for effective management.
• Microcirculatory and functional changes in the macula may precede overt optic nerve damage.

Purpose of the Study:

• To investigate microcirculatory and functional alterations within the macula of patients diagnosed with POAG.
• To explore the relationship between macular microcirculation, retinal nerve fiber layer thickness, and electrophysiological responses in POAG.

Main Methods:

• Employed Optical Coherence Tomography Angiography (OCT-A) to measure vessel density (wiVDRetina) in the foveal and parafoveal regions.
• Assessed macular thickness and ganglion cell complex (GCC) parameters using SD-OCT.
• Evaluated retrobulbar blood flow via Color Doppler Imaging (CDI) and retinal function using pattern electroretinogram (PERG).

Main Results:

• A significant decrease in t-PERG P50 amplitude was observed in early (2.8±1.6 µV) and advanced (2.3±1.5 µV) POAG compared to healthy controls (6.1±1.3 µV).
• Relative vessel density in the macular capillary bed was reduced in early (45.9±5.0%) and advanced (41.8±5.0%) POAG versus controls (51.3±3.0%).
• Correlations were found between OCT-A, CDI parameters, and morphological/functional measures in normal and early glaucomatous eyes.

Conclusions:

• Early-stage POAG is characterized by diminished macular microcirculation and impaired PERG function.
• Circulatory and functional deficits show significant correlations in the early stages of POAG, suggesting a common pathophysiological pathway.
• These findings underscore the potential of OCT-A and PERG as sensitive biomarkers for early POAG detection and monitoring.