Relation between macular retinal ganglion cell/inner plexiform layer thickness and multifocal electroretinogram...

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma is a progressive optic neuropathy characterized by retinal ganglion cell (RGC) loss.
• Assessing RGC structure and function is crucial for early glaucoma detection and management.
• Nonhuman primate models offer valuable insights into glaucoma pathogenesis and potential therapeutic targets.

Purpose of the Study:

• To investigate the relationship between macular RGC+IPL thickness and macular RGC function using multifocal electroretinography (mfERG).
• To evaluate the utility of these measures in a nonhuman primate model of experimental glaucoma.
• To determine if structural and functional assessments can be complementary in diagnosing glaucomatous neuropathy.

Main Methods:

• Used spectral-domain optical coherence tomography (SD-OCT) for RGC+IPL thickness measurements.
• Employed multifocal electroretinography (mfERG) to assess RGC function, including mfPhNR, mfOP, and mfLFC.
• Analyzed correlations between structural (RGC+IPL, RNFL thickness) and functional (mfERG) parameters in control and experimental glaucoma eyes using linear regression and ANOVA.

Main Results:

• Strong correlation found between average macular RGC+IPL thickness and temporal RNFL thickness (r² = 0.90, P < 0.001).
• All mfERG measures significantly correlated with RGC+IPL thickness in both control and experimental eyes (P < 0.001).
• Functional deficits (mfERG amplitude reduction) were proportionally greater than structural thinning in mild to moderate glaucoma, particularly in the inferior temporal quadrant.

Conclusions:

• Macular RGC+IPL thickness and mfERG measures are strongly correlated, indicating their complementary roles.
• These combined structural and functional assessments can enhance the diagnosis of glaucomatous neuropathy.
• The findings support the use of both SD-OCT and mfERG for comprehensive glaucoma evaluation.