Enhancing the structure-function relationship in glaucoma using anatomical compensation of retinal nerve fibre layer

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma diagnosis relies on correlating structural measures like retinal nerve fibre layer (RNFL) thickness with functional visual field (VF) tests.
• Existing structure-function relationships may be weakened by demographic and anatomical variations.
• Improving this correlation is crucial for accurate glaucoma assessment and management.

Purpose of the Study:

• To determine if compensating RNFL thickness measurements for demographic and anatomical factors enhances the structure-function relationship in glaucoma patients.
• To evaluate the impact of compensation on the correlation between RNFL thickness and mean deviation of the visual field (MD VF).

Main Methods:

• A cross-sectional study included 600 eyes from 412 glaucoma patients with varying visual field loss.
• Standard automated perimetry and spectral-domain optical coherence tomography were performed.
• Retinal nerve fibre layer (RNFL) thickness was compensated for age, refractive error, optic disc parameters, and retinal vessel density.

Main Results:

• Compensated RNFL data significantly increased the correlation between RNFL thickness and MD VF from 0.49 to 0.62.
• The proportion of visual field locations showing a significant structure-function relationship rose from 61% to 78% with compensated data.
• Compensated RNFL thickness showed a more robust correlation in specific visual field regions compared to uncompensated measurements.

Conclusions:

• Compensated RNFL data provide a stronger correlation with visual field parameters in glaucoma.
• Structure-to-function maps incorporating anatomical variances can improve the identification of localized structural and functional loss.
• This approach offers potential for more precise glaucoma diagnosis and monitoring.