Abstract
Purpose: :
To investigate the effects of ethyl alcohol on retrobulbar perfusion in normal subjects.
Methods: :
In 12 healthy subjects (age range: 27–43 yr; 4 male, 8 female), color Doppler imaging (CDI, Siemens Sonoline Sienna) was performed before and 45 min after oral intake of 80 ml 40 vol% ethyl alcohol. Enddiastolic (EDV) and peak systolic velocities (PSV) were measured in the central retinal artery (CRA) and the ophthalmic artery (OA). Additionally, systemic blood pressure, heart frequency, intraocular pressure (IOP), and blood alcohol concentration were monitored.
Results: :
Mean IOP decreased significantly from 12 ± 2 mmHg to 11 ± 2 mmHg after alcohol intake (p= 0.01). Neither arterial systolic nor diastolic blood pressure showed significant change (p=0.2 and 0.7, respectively). Mean blood alcohol concentration was 0.38 ± 0.16 g/l. Mean PSV in the CRA showed a significant increase from 10.8 ± 1.6 cm/s before to 11.6 ± 1.2 cm/s after ethyl alcohol intake (p= 0.03). Accordingly, mean EDV in the CRA increased from 3.9 ± 0.7 cm/s to 4.4 ± 0.7 cm/s. Similarly, we found statistical significant acceleration of flow velocities in the OA (p= 0.02 for PSV and p=0.04 for EDV).
Conclusions: :
Ethyl alcohol is known to induce peripheral vasodilation. In this study we found significant acceleration of flow velocities in the retrobulbar vessels although systemic arterial blood pressure remained stable. Moreover, our results indicate that low levels of blood alcohol might lead to an IOP reduction. Further studies will be needed to test the relationship of increased blood flow velocities, ethanol concentration, IOP and retinal function.
Keywords: drug toxicity/drug effects • perimetry • blood supply