Interdigitation Zone Change According to Glaucoma-Stage Advancement.

Area of Science:

• Ophthalmology
• Glaucoma Research
• Retinal Imaging

Background:

• Normal-tension glaucoma (NTG) is a progressive optic neuropathy.
• The macular interdigitation zone (IZ) is a key anatomical feature of the outer retina.
• Understanding IZ changes may provide insights into glaucoma pathogenesis.

Purpose of the Study:

• To compare the macular interdigitation zone (IZ) area in normal eyes versus eyes with varying stages of normal-tension glaucoma (NTG).
• To investigate the relationship between IZ area and glaucoma severity.

Main Methods:

• High-resolution spectral-domain optical coherence tomography (SD-OCT) was used to image the macula in 42 normal eyes and 146 NTG eyes.
• Macular B-scans were analyzed to quantify the IZ area by counting marked image boxes.
• Subjects included normal, pre-perimetric, mild-to-moderate, and severe NTG groups.

Main Results:

• A significant reduction in IZ area was observed across NTG stages compared to normal eyes (P < 0.001).
• IZ area decreased progressively from normal to pre-perimetric, mild-to-moderate, and severe NTG.
• A strong positive correlation was found between IZ area and mean deviation (MD) in NTG eyes (r = 0.64; P < 0.001).

Conclusions:

• Spectral-domain optical coherence tomography (SD-OCT) demonstrates reduced macular interdigitation zone (IZ) area in normal-tension glaucoma (NTG).
• The degree of IZ reduction is associated with glaucoma severity.
• These findings suggest potential outer retinal layer alterations during glaucoma progression.