Optic nerve head circulation after intraocular pressure reduction achieved by trabeculectomy.

OBJECTIVE

To study the effects of trabeculectomy and needling revision of poorly functioning blebs on the optic nerve head (ONH) circulation in patients with primary open-angle glaucoma (POAG).

DESIGN

Prospective, nonrandomized, self-controlled trial.

PARTICIPANTS

Nineteen POAG patients (age range, 52 +/- 12 years; mean +/- standard deviation) undergoing trabeculectomy and six POAG patients (age range, 62 +/- 14 years) undergoing needling revision of the bleb.

METHODS

Using the laser speckle method, the normalized blur (NB) value, a quantitative index of blood velocity, was determined every 0.125 seconds and averaged more than three cardiac pulses in the optic nerve head (NB(ONH)).

MAIN OUTCOME MEASURES: The NB(ONH) and intraocular pressure (IOP) in both eyes, and blood pressure (BP) and pulse rate (PR) were measured before and 2 days and 1, 4, and 8 weeks after trabeculectomy, and also before and 10 and 40 min after needling procedures.

RESULTS

Intraocular pressure in the operated eye was significantly decreased after trabeculectomy or needling procedures, and the ocular perfusion pressure was significantly increased by a maximum of 38%. The IOP in the unoperated eye, BP, and PR did not significantly change. The NB(ONH) did not significantly change in either the operated or unoperated eye.

CONCLUSIONS

Trabeculectomy and needling procedures induced little change in the ONH circulation.