Characteristics of visual field progression in medically treated normal-tension glaucoma patients with unstable ocular perfusion pressure.

PURPOSE To investigate the characteristics of visual field (VF) progression in medically treated normal-tension glaucoma (NTG) patients (Koreans) with unstable ocular perfusion pressure (OPP). METHODS One hundred one eyes of 101 NTG patients followed up for more than 4 years (mean follow-up, 6.2 years ± 12.1 months) were included. Modified Anderson criteria (MC) and linear regression analysis (LA) of VF mean deviation (MD) within the central 10° and 10° to 24° area were assessed for determining VF progression in groups with lowest (LMF) and highest (HMF) 24-hour mean OPP [MOPP = 2/3;(mean arterial pressure - IOP)] fluctuation. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios (HRs) for the association between clinical risk factors including 24-hour MOPP and central VF progression were obtained by using Cox proportional hazards models. RESULTS Three of 33 eyes in the LMF progressed, whereas 12 of 34 eyes in the HMF progressed within the central 10° according to the MC; the between-group difference was significant (P = 0.010). By LA within the central 10°, two eyes from the LMF and nine from the HMF groups showed progression (P = 0.025). The HMF showed a greater cumulative probability of central VF progression than the LMF, by both LA and MC (Kaplan-Meier analysis, P = 0.003, 0.015, log-rank test). In multivariate analysis, only 24-hour MOPP fluctuation was significantly associated with central VF progression (P = 0.014). CONCLUSIONS The 24-hour MOPP fluctuation was the most consistent prognostic factor among various IOP, blood pressure, and clinical factors for central VF glaucomatous progression in our series of NTG eyes.