Macular Blood Flow and Pattern Electroretinogram in Normal Tension Glaucoma.

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Normal tension glaucoma (NTG) is a progressive optic neuropathy.
• Assessing early functional changes in NTG is crucial for timely intervention.
• Optical coherence tomography angiography (OCTA) allows non-invasive visualization of retinal vasculature.

Purpose of the Study:

• To determine the association between macular vessel density (VD) and pattern electroretinogram (PERG) parameters in NTG patients.
• To explore if macular VD can serve as an early indicator of RGC dysfunction in NTG.

Main Methods:

• A cross-sectional study included 76 eyes of NTG patients.
• Macular VD was quantified from OCTA scans of the superficial retinal layers (RNFL and GCL).
• PERG (N95 amplitude), standard automated perimetry (SAP), and OCT-derived structural parameters (peripapillary RNFL, macular GCIPL thickness) were assessed.

Main Results:

• Higher macular VD was significantly associated with higher PERG N95 amplitude (p=0.048).
• Macular VD showed a significant correlation with N95 amplitude across all disease severities (r=0.352, p=0.002).
• Regression analyses revealed a bidirectional relationship between N95 amplitude and macular VD (p=0.035 and p=0.019, respectively).

Conclusions:

• Macular VD is significantly associated with PERG N95 amplitude in NTG.
• This correlation is particularly prominent in early glaucoma stages.
• Macular VD may reflect retinal ganglion cell (RGC) dysfunction preceding detectable changes on SAP.