Ellipsoid Zone Change According to Glaucoma Stage Advancement

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Glaucoma is a progressive optic neuropathy characterized by visual field loss.
• Retinal structural changes, particularly in photoreceptors, may precede or accompany functional deficits.
• Spectral-domain optical coherence tomography (SD-OCT) allows high-resolution imaging of retinal layers.

Purpose of the Study:

• To compare the intensity of the retinal photoreceptor ellipsoid zone (EZ) between normal eyes and eyes with varying stages of glaucoma.
• To investigate the relationship between EZ intensity and glaucoma severity.

Main Methods:

• A retrospective cross-sectional study involving normal eyes and eyes with preperimetric, mild-to-moderate, and severe glaucoma.
• High-resolution SD-OCT scans were used to quantify relative EZ intensity (EZ/ELM ratio).
• Statistical analysis compared EZ intensity across glaucoma stages and correlated it with visual field mean deviation (MD).

Main Results:

• Relative EZ intensity was significantly lower in severe glaucoma compared to mild-to-moderate glaucoma (P < .001).
• Mild-to-moderate glaucoma eyes showed significantly lower relative EZ intensity than preperimetric glaucoma eyes (P < .001).
• No significant difference in relative EZ intensity was found between preperimetric glaucoma and normal eyes (P = .751).
• A strong positive correlation was observed between relative EZ intensity and visual field MD in glaucomatous eyes (r = 0.83, P < .001).

Conclusions:

• Relative EZ intensity reduction is evident in mild-to-moderate and severe glaucoma stages.
• These findings suggest potential mitochondrial dysfunction in photoreceptor inner segments during glaucoma progression.
• Further research is needed to determine the clinical utility of EZ intensity as a biomarker in glaucoma.