gms | German Medical Science

Multiple pharmacological studies claim that there are no vascular changes due to intraocular pressure (IOP) reduction alone. In our study we induced a decrease of the IOP by oculopression. Its effect on the retrobulbar haemodynamic was studied by means of colour Doppler imaging.

17 patients (age 72±8; 7f, 10m), prepared for cataract surgery, were included in a prospective study. Before and after 5 minutes of oculopression the IOP was measured by Tonopen (Technomed). Colour Doppler imaging (Siemens Sonoline Sienna) was used to determine the peak systolic (PSV) and end-diastolic velocities (EDV) as well as resistive Index (RI) before and after oculopression in the ophthalmic artery (OA), the central retinal artery (CRA), the central retinal vein (CRV), the temporal short ciliar arteries (TPCA) and the nasal short ciliar arteries (NPCA).

After oculopression there was a significant reduction of the IOP of 4.5 mmHg (p<0,0001). Colour Doppler imaging showed a significant increase of the PSV after oculopression in all studied vessels (OA by 8%, p<0.02; CRA by 15%, p<0.0001; CRV by 22%, p<0.0001; TPCA by 12%, p<0.0001; NPCA by 18%, p<0.0001). After oculopression EDV had also a significant increase (CRA by 17%, p<0.0015; CRV by 13%, p<0.0017; NPCA by 14%, p<0.049). The RI of the studied vessels showed no significant changes before and after oculopression.

Oculopression induced a significant IOP reduction. Furthermore, there is an increase of the flow velocities of the retrobulbar vessels, this may be due to an increase of perfusion pressure. This aspect is important for pharmacological studies with topical antiglaucoma medication, concerning their vascular effects on retrobulbar vessels.