Factors Associated with Loss of Visual Function in Medically Treated Advanced Normal Tension Glaucoma

Abstract

ABSTRACTPurpose: To investigate the risk factors associated with a progressive loss of visual function (LV) in medically treated advanced normal tension glaucoma (NTG).Methods: In this retrospective observational study, a total of 87 eyes of the 87 NTG patients with a baseline visual field (VF) mean deviation (MD) of worse than –10 decibel (dB) (average follow-up period: 5.3 years) were included. All the participants were categorized into two groups according to the baseline VF MD [group 1 (≥−16 dB) and group 2 (<−16 dB), respectively]. The participants were also divided into older (≥64 years) and younger (<64 years) groups according to the median split of baseline age. Hazard ratios (HRs) for the association between potential risk factors and LV were obtained using the Cox proportional hazards models.Results: Fifty-one eyes were classified as group 1 (VF MD; −13.5 ± 1.8 dB), and 36 eyes as group 2 (−21.0 ± 4.1 dB). LV occurred in 33 eyes (64.7%) in group 1 and in 29 eyes (80.6%) in group 2 during the follow-up period. In total participants, younger age (HR; 0.971, p = 0.008) and lower initial best-corrected visual acuity (BCVA) (HR; 18.4, p = 0.007) were found to be significant risk factors for LV. In group 1, younger age and lower baseline BCVA were associated with LV; whereas, no significant risk factor was found in group 2. In the younger group, myopia and disc hemorrhage were found to be the risk factors.Conclusion: The risk factors associated with progressive LV differed according to the baseline VF stages or the age among advanced medically treated NTG patients.