Interocular difference in progression of glaucoma correlates with interocular differences in retrobulbar circulation.

PURPOSE: To evaluate the correlation between interocular difference in progression of glaucomatous damage and interocular differences in retrobulbar blood flow.

METHODS

On the basis of a retrospective analysis of visual fields, progressive damage was identified in 20 patients with primary open-angle glaucoma. As a parameter of interocular difference in progression of visual field damage, the angle (gamma) between the regression lines of the visual field index mean defect over time per eye was calculated for each subject. The relationship between the angle gamma and interocular differences in intraocular pressure and retrobulbar color Doppler imaging parameters was analyzed by a multiple linear regression analysis in a stepwise forward approach.

RESULTS

With larger interocular differences in progression of glaucomatous damage, lower mean blood flow velocities in the ophthalmic artery (partial r = -.69; P <. 0016), higher resistivity indices in the central retinal artery (partial r =.48; P <.0456), and higher peak systolic velocities in the ophthalmic artery (partial r =.52; P <.0285) were noted in the eyes with more marked progression of damage (multiple r =.71; P <. 0099). Interocular differences in progression of visual field damage were not related to intraocular pressure or extent of visual field damage.

CONCLUSION

Independent of the extent of the interocular difference in glaucomatous damage and intraocular pressure, interocular difference in progression of glaucomatous visual field damage correlates with interocular difference in retrobulbar hemodynamic parameters.