[The effect of hyperbaric oxygen on ophthalmic artery blood velocity in patients with diabetic neuropathy]

We investigated changes in the blood velocity of the ophthalmic artery to observe its relationship to the complication of diabetes mellitus before and after hyperbaric oxygen therapy (HBO). Color Doppler imaging (Toshiba, SSA-260A) was used. In this study, there were 7 diabetic neuropathy patients, 3 diabetes patients without neuropathy, and 7 normal subjects for control. These patients were examined before and after HBO. The patients were made to breathe 100% oxygen at 2.0 atmosphere absolute (ATA) for one hour. HBO is sometimes used for treatment of diabetic neuropathy. HBO produced an average decrease in blood velocity of 15.0 +/- 9.0 (mean +/- standard deviation) % in normal subjects, 10.7 +/- 8.6% in diabetes patients without neuropathy, and returned to the baseline level 4 hours after the conclusion of HBO. On the other hand, the blood velocity increased by about 20.6 +/- 9.5% in diabetic neuropathy patients regardless the degree of severity of diabetic retinopathy. These results suggest that the increase in the blood velocity of the ophthalmic artery after HBO in diabetic neuropathy patients could be attributed to an imbalance in autonomic nervous function.