Relationship between 24-hour mean ocular perfusion pressure fluctuation and rate of paracentral visual field progression in normal-tension glaucoma.

PURPOSE

To investigate the relationship between unstable mean ocular perfusion pressure (MOPP) and the rate of paracentral visual field (PVF) progression in patients with medically treated normal-tension glaucoma (NTG).

METHODS

The data of 157 eyes of 122 patients with NTG who were followed for more than 6 years (mean follow-up, 8.7 years ± 12.6 months) and had more than 5 reliable standard visual field (VF) tests were analyzed retrospectively. Groups in the highest, middle, and lowest tertiles of 24-hour MOPP fluctuation (HMF, MMF, and LMF, respectively) were compared in terms of rates of change of mean thresholds in the central 10° (PVF), 10° to 24°, and global areas by using a linear mixed model. Clinical factors associated with rapid PVF progression were also investigated.

RESULTS

The LMF and HMF groups did not differ significantly in the mean global rate of VF changes (-0.52 vs. -0.71 dB/y; P = 0.07). The HMF group had a significantly faster progression of VF defects in the central 10° area than the LMF group (-1.02 vs. -0.54 dB/y; P < 0.001) but did not differ in terms of progression of VF defects in the peripheral 10° to 24° area (-0.39 vs. -0.495 dB/y; P = 0.425). PVF progression was significantly associated with 24-hour MOPP fluctuation (β = -0.31, P < 0.001) and VF damage severity at initial presentation (β = 0.134, P = 0.011).

CONCLUSIONS

Medically treated NTG eyes with greater 24-hour MOPP fluctuations (HMF) had faster PVF defect progression than eyes with stable 24-hour MOPP (LMF). Twenty-four hour MOPP fluctuation associated significantly with PVF progression velocity.