HbA1c and retinal sensitivity in diabetics using microperimetry

Area of Science:

• Ophthalmology
• Diabetology
• Retinal Imaging

Background:

• Diabetic retinopathy (DR) is a leading cause of vision loss.
• Early detection of retinal changes is crucial for managing diabetes.
• HbA1c is a key indicator of long-term glycemic control.

Purpose of the Study:

• To investigate the relationship between HbA1c levels and retinal sensitivity.
• To assess retinal sensitivity in the central macula using MP-1 microperimeter.
• To determine if HbA1c impacts visual function in diabetic patients.

Main Methods:

• Prospective study involving 32 healthy subjects and 60 diabetic patients (30 without DR, 30 with mild non-proliferative DR).
• Full-threshold microperimetry performed on the central 10° retina using the MP-1 device.
• Linear regression analysis to correlate HbA1c values with retinal sensitivity.

Main Results:

• Significant differences in mean retinal sensitivity were observed across the three groups (p=0.001).
• A significant regression equation showed HbA1c predicts retinal sensitivity (R²=0.545, p=0.0001).
• A 0.64dB decrease in retinal sensitivity occurred for every 1mmHg increase in HbA1c.

Conclusions:

• Retinal sensitivity in the central macula is demonstrably affected by HbA1c levels.
• Elevated HbA1c is associated with reduced retinal sensitivity, even in early stages of DR.
• Microperimetry can detect functional vision changes related to glycemic control.