Study shows no correlation between IOP reduction and blood flow disturbance

Eur J Ophthalmol. 2012;22(1):77-82.

IOP reduction did not appear to correlate with ocular blood flow changes in patients with open-angle glaucoma, a study found.

"The results of our study suggested that the blood flow disturbances found in patients with glaucoma seem to be independent of the IOP," the study authors said. "The findings of the present study illustrate that although ocular hemodynamics may be influenced by elevated IOP, dramatic chronic decreases in IOP do not lead to change in ocular blood flow as measured by the technique utilized in this study."

The prospective study included 46 eyes of 46 patients with open-angle glaucoma. Mean patient age was 57.6 years.

Mean baseline IOP was 33 mm Hg measured with Goldmann applanation tonometry and 29.3 mm Hg measured with dynamic contour tonometry. Ocular pulse amplitude was also measured.

Patients underwent surgical or pharmacologic treatment for glaucoma after baseline examination and underwent another examination 1 month after treatment.

Investigators used color Doppler imaging to assess peak systolic velocity and end-diastolic velocity in the ophthalmic artery, central retinal artery and short posterior ciliary arteries.

Study results showed no correlation between IOP reduction and changes to blood flow parameters.

Reductions in Goldmann applanation tonometry, dynamic contour tonometry and ocular pulse amplitude measurements were statistically significant (P < .0001). Changes in blood flow parameters were statistically insignificant.

Limitations of the study included a small patient group, use of a single ocular imaging modality and a lack of data on the retina or other vascular beds, the authors said.