Retinal neural dysfunction in diabetes revealed with handheld chromatic pupillometry

Area of Science:

• Ophthalmology
• Neuroscience
• Diabetology

Background:

• Diabetic retinopathy (DR) is a leading cause of vision loss.
• Early detection of neural dysfunction is crucial for managing diabetic eye disease.
• Handheld chromatic pupillometry offers a potential non-invasive method for assessing retinal function.

Purpose of the Study:

• To evaluate handheld chromatic pupillometry for detecting and localizing retinal neural dysfunction in diabetic patients.
• To compare pupillometric responses in diabetic patients with and without DR against healthy controls.

Main Methods:

• A cross-sectional study involving 82 diabetic patients (with and without DR) and 93 controls.
• Assessed pupil radius changes in response to blue and red light stimuli using a handheld pupillometer.
• Analyzed pupillometric parameters including constriction amplitudes and post-illumination pupillary responses (PIPRs).

Main Results:

• Diabetic retinopathy (DR) patients showed decreased phasic constriction amplitudes compared to controls.
• Maximal constriction amplitudes were reduced in DR patients and those without DR compared to controls.
• Net PIPR was decreased in both diabetic groups, indicating wavelength-dependent pupillometric dysfunction.

Conclusions:

• Handheld chromatic pupillometry effectively reveals retinal neural dysfunction in diabetes, even in the absence of DR.
• Diabetic patients without DR showed primarily inner retinal dysfunction.
• Diabetic patients with DR exhibited dysfunction in both inner and outer retinal layers.