Inner and Outer Retinal Contributions to Pupillary Light Response: Correlation to Functional and Morphologic...

Area of Science:

• Ophthalmology
• Neuroscience
• Vision Science

Background:

• Primary open-angle glaucoma (POAG) is a progressive optic neuropathy.
• Retinal structure and function are compromised in POAG, affecting visual perception.
• Pupillary light responses (PLRs) reflect the integrated function of various retinal cell types.

Purpose of the Study:

• To investigate the contribution of inner and outer retinal photoreceptors to PLRs in POAG patients.
• To correlate PLRs with functional (color vision, visual field) and morphologic (OCT) parameters in POAG.
• To assess the impact of POAG severity on PLR components.

Main Methods:

• Evaluated 45 POAG patients and 25 controls.
• Measured PLR using an eye tracker with blue (470 nm) and red (640 nm) light stimuli at varying intensities.
• Assessed color vision (Cambridge Color Test), visual field (standard automatic perimetry), and retinal nerve fiber layer thickness (OCT).

Main Results:

• Moderate and severe POAG showed significantly decreased PLRs for both blue and red stimuli.
• PLR reduction correlated with POAG severity, indicating impaired rod, cone, and ipRGC function.
• All POAG stages exhibited blue-yellow axis color vision deficits, with correlations found between visual field, OCT, color vision, and PLR.

Conclusions:

• Both inner and outer retinal pathways contribute to PLRs, and are affected in moderate to severe POAG.
• Worsening color vision in POAG correlates with reduced high-intensity PLR.
• These findings may improve clinical management strategies for POAG.