Purpose: To conduct a ≥15-year follow-up assessment of the visual field (VF) in normal-tension glaucoma (NTG) patients receiving medical therapy and to identify risk factors for VF progression.
Design: A retrospective clinical study.
Methods: Medical records of 78 eyes of 78 NTG patients monitored for ≥15 years were reviewed. VF progression was defined by a mean deviation (MD) deteriorated twice by 3.00 dB from baseline (MD criterion) and an annual decrease in the MD slope exceeding -0.5 dB/year (MD slope criterion). Logistic regression analysis was employed to identify risk factors for VF progression.
Results: The mean follow-up period was 18.3 years. The average intraocular pressure (IOP) before treatment was 15.1 ±1.9 mmHg and the average treated IOP was 13.5 ±1.5 mmHg with 2.0 medications. Forty-two eyes (53.8%) showed VF progression using the MD criterion and 15 eyes (19.2%) showed a negative MD slope less than -0.5 dB/year. Disc hemorrhage (DH) was observed in 30 eyes (38.5%). The mean VF progression rate was -0.38 ±0.30 dB/year in the DH group and -0.24 ±0.28 dB/year in the non-DH group (P = 0.012). Multiple logistic regression analysis identified DH [relative risk (RR) 4.28; P = 0.028] as a risk factor for VF progression using the MD criterion. DH (RR 8.77; P = 0.007) and IOP fluctuation during follow-up (RR 5.03; P = 0.048) were detected as risk factors using the MD slope criterion.
Conclusions: DH and IOP fluctuation were associated with VF progression in NTG during long-term therapy.