Central retinal vascular trunk deviation in unilateral normal-tension glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Retinal Imaging Analysis

Background:

• Glaucoma diagnosis and progression are influenced by optic nerve head biomechanics.
• The lamina cribrosa (LC) offset, often assessed using the central retinal vascular trunk (CRVT) position, is a potential indicator of susceptibility.
• Understanding the relationship between LC/BMO offset and normal-tension glaucoma (NTG) is crucial for early detection.

Purpose of the Study:

• To determine if the position of the CRVT, as a surrogate for LC offset, is associated with glaucoma in NTG patients.
• To evaluate the CRVT's deviation from the Bruch's membrane opening (BMO) center as a diagnostic marker.

Main Methods:

• Spectral-domain optical coherence tomography (SD-OCT) was used to image the optic nerve head.
• The offset index (CRVT deviation from BMO center relative to BMO margin) and angular deviation were calculated.
• Comparison of offset index and angular deviation between NTG eyes and fellow control eyes within individuals.

Main Results:

• NTG eyes exhibited a significantly larger offset index compared to control eyes (P<0.001).
• A larger offset index was identified as the sole significant risk factor for NTG diagnosis (OR=31.625, P<0.001).
• The offset index remained larger in NTG eyes across all axial lengths, with the smallest values observed at 23.4 mm axial length.

Conclusions:

• The increased offset index in NTG eyes suggests a potential role for LC/BMO offset as a loco-regional susceptibility factor in glaucoma development.
• CRVT position relative to BMO is a valuable indicator in the assessment of NTG.