Structure-Function Relationship between Flicker-Defined Form Perimetry and Spectral-Domain Optical Coherence...

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma suspects with normal standard automated perimetry (SAP) require sensitive methods to detect early glaucomatous changes.
• Flicker-defined form (FDF) perimetry offers a functional assessment of the visual field.
• Spectral-domain optical coherence tomography (SD-OCT) provides structural information of the optic nerve head, specifically the peripapillary retinal nerve fiber layer (RNFL) thickness.

Purpose of the Study:

• To evaluate the relationship between functional parameters obtained from repeated FDF perimetry and structural parameters from SD-OCT.
• To determine if RNFL thickness correlates with visual field sensitivities in glaucoma suspects with normal SAP findings.

Main Methods:

• Prospective study including glaucoma suspects with normal SAP.
• Visual field testing using FDF perimetry (Heidelberg Edge Perimeter) at two visits.
• Peripapillary RNFL thickness measurement using SD-OCT (Spectralis).
• Correlation and regression analyses between global and sectoral RNFL thickness and visual field sensitivities.

Main Results:

• Significant correlations were found between global RNFL thickness and global mean deviation (MD) and pattern standard deviation (PSD) from FDF perimetry.
• The strongest correlations between structure and function were observed in the temporal superior and temporal inferior sectors.
• Cluster-point based suspicious visual field defects were identified in 52% of the eyes.

Conclusions:

• Global and sectoral peripapillary RNFL thickness is correlated with visual field sensitivity and defects in FDF perimetry among glaucoma suspects with normal SAP.
• These findings suggest that combining FDF perimetry and SD-OCT can aid in the early detection of glaucoma.