Association of Cognitive Function and Retinal Neural and Vascular Structure in Type 1 Diabetes

Area of Science:

• Ophthalmology
• Neurology
• Endocrinology

Background:

• Cognitive dysfunction is a significant public health concern in aging individuals with type 1 diabetes.
• Diagnosing cognitive dysfunction in this population is challenging and time-consuming.
• Previous studies suggest a link between proliferative diabetic retinopathy and cognitive impairment.

Purpose of the Study:

• To investigate the association between retinal structural and vascular abnormalities and cognitive impairment in individuals with long-duration type 1 diabetes.
• To determine if retinal imaging can serve as a noninvasive method to assess cognitive function in type 1 diabetes.

Main Methods:

• An observational cross-sectional study involving 129 participants from the Joslin Medalist Study (≥50 years with type 1 diabetes).
• Cognitive function assessed using validated tests for psychomotor speed, immediate, and delayed memory.
• Retinal imaging performed using Optical Coherence Tomography (OCT) and OCT Angiography (OCTA) to measure neural retinal layer thicknesses and vascular density (superficial and deep capillary plexuses).

Main Results:

• Reduced vascular density in both superficial (SCP) and deep (DCP) capillary plexuses was associated with poorer delayed memory and psychomotor speed.
• Thinning of the retinal outer nuclear layer correlated with decreased psychomotor speed in both dominant and nondominant hands.
• Outer plexiform layer thickness was associated with impaired delayed memory.

Conclusions:

• Noninvasive retinal imaging techniques like OCT and OCTA show potential for estimating the risk of cognitive dysfunction in people with type 1 diabetes.
• Retinal structural and vascular changes may serve as biomarkers for cognitive impairment in this population.