The relationship between structure and function as measured by OCT and Octopus perimetry.

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma is a progressive optic neuropathy characterized by visual field loss.
• Assessing the structure-function relationship is crucial for understanding glaucoma progression.
• Retinal nerve fiber layer (RNFL) thickness and visual field sensitivity are key metrics.

Purpose of the Study:

• To investigate the structure-function relationship between Octopus perimeter (OP) visual field areas and peripapillary RNFL thickness.
• To compare these metrics in healthy individuals and glaucoma patients.
• To determine the correlation between visual field sensitivity and RNFL thickness.

Main Methods:

• Prospective recruitment of 88 normal subjects and 150 open-angle glaucoma patients.
• Automated perimetry using Octopus perimeter (OP) and optic nerve head imaging with Cirrus spectral-domain optical coherence tomography (OCT).
• Principal component analysis and Pearson correlations were used to analyze visual field regions and RNFL thickness sectors.

Main Results:

• Mild to moderate correlations were found between visual field regions and peripapillary RNFL thickness.
• Each visual field region correlated with multiple RNFL sectors, and vice versa.
• The strongest correlation (r=0.63) was between RNFL thickness at 5 and 7 o'clock positions and the superonasal OP region.

Conclusions:

• Retinal sensitivity assessed by OP correlates moderately with RNFL thickness measured by OCT.
• The study identified an overlap in visual field regions within the optic disc.
• These findings contribute to understanding the relationship between structural damage and functional deficits in glaucoma.