Relationship between glycosylated hemoglobin A1c and ocular circulation by laser speckle flowgraphy in patients with/without diabetes mellitus.

PURPOSE: To determine whether there are significant correlations between the hemodynamics of the optic nerve head (ONH) and choroid as shown by laser speckle flowgraphy (LSFG) and the fasting blood sugar (FBS) and HbA1c level in patients with/without diabetes mellitus (DM).

METHODS

We analyzed 196 consecutive patients (151 men, 45 women). The pulse waveform analysis parameters of the mean blur rate (MBR), blowout score (BOS) and blowout time (BOT) in the ONH and choroid were evaluated. We used a multiple regression analysis to determine the independent factors for the LSFG parameters that are significantly correlated with FBS or HbA1c. We evaluated the relationship between the LSFG parameters FBS and HbA1c obtained from the 147 non-DM patients.

RESULTS

The multiple regression analysis revealed that hematocrit and HbA1c were factors contributing independently to the choroid MBR. The age, gender, pulse pressure, heart rate, spherical refraction and HbA1c were identified as factors contributing independently to the BOS in the ONH. The multiple regression analysis indicated that age, height, pulse pressure, heart rate and HbA1c were factors contributing independently to the BOS in the choroid. A Pearson's correlation analysis showed that the BOT values in the ONH and choroid were significantly correlated with the HbA1c in the non-DM patients.

CONCLUSION

Our results confirmed that HbA1c, even within the normal range, affected the blood flow in the ONH and choroid. LSFG may be a useful method to detect abnormalities of asymptomatic ocular circulation.