Objective:

To investigate the association between glycemic variability and early neuroretinal changes in pediatric patients with type 1 diabetes without microvascular complications.

Approach:

• Study Design: A 3-year longitudinal study involving 25 pediatric patients aged 10 to 20 years with type 1 diabetes and 18 age-matched healthy controls.
• Measurement Techniques: Spectral-domain optical coherence tomography (OCT) was used to measure neuroretinal layer thickness.
• Evaluation Metrics: Changes in retinal structure were evaluated alongside continuous glucose monitoring (CGM)-derived measures of glycemic variability, HbA1c, and neuropathic measures.

Key Findings:

• At baseline, inner retinal nerve fiber layer thickness was lower in patients with type 1 diabetes compared to controls (20 μm vs. 21 μm).
• Significant thinning of the inner ganglion cell layer and outer plexiform layer was observed during follow-up.
• Greater glycemic variability was associated with thinner retinal layers, particularly the inner nuclear and outer plexiform layers.
• Greater time in range correlated with thicker retinal layers.
• No significant correlations were found between HbA1c levels and macular layer thickness.

Interpretation:

Higher glycemic variability and lower time in range were linked to inner retinal thinning and less stable retinal structure over the 3-year period.

Limitations:

• Small sample size and highly selected population with good glycemic control and no microvascular complications.
• Lack of corneal confocal microscopy in the study.

Conclusion:

Further longitudinal evaluation is required to determine if neuroretinal nerve damage can serve as a non-invasive predictive marker of diabetic neuropathy.

Sources:

• Scientific Reports