Association of static and dynamic pupillary abnormalities with retinal microvasculopathy and neurodegeneration in...

To investigate the characteristics of pupillary statics and dynamics and explore the relationship between pupillary abnormalities and microvascular as well as neurodegenerative changes of retina in the early stages of diabetes.

This cross-sectional observational study included forty-eight diabetic subjects without diabetic retinopathy (NDR group), thirty-nine diabetic subjects with mild or moderate non proliferative diabetic retinopathy (DR group), and forty age- and sex-matched healthy adults (control group). Pupil size and pupillary light reflex were measured monocularly using a PLR-3000 dynamic pupillometer, and OCT/OCTA scans were acquired with a Van Gogh SS-OCTA device in all three groups.

Both static and dynamic pupillary parameters differed significantly among the three groups (p < 0.001). Pairwise comparisons showed that both basal and smallest pupil diameter were smaller in diabetes with or without retinopathy, compared to healthy control. Notably, pupillary dynamics didn't significantly reduce until retinopathy was present. Pupillary parameters showed a positive correlation with the thickness of the ganglion cell layer and inner plexiform layer in the parafovea, and the vessel density of the superficial vascular plexus and intermediate capillary plexus.

Static pupillary abnormalities appear before clinical diabetic retinopathy. Both static and dynamic pupillary abnormalities worsen alongside retinal microvascular and neurodegenerative damages in the early stages of diabetes. Evaluation for autonomic nervous dysfunction is recommended for all patients with diabetic retinopathy.