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

ABSTRACT

Purpose: 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.

KEYWORDS:

• End stage
• intraocular pressure
• normal tension glaucoma
• progression
• visual field

Funding

This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), which is funded by the Ministry of Education, Science, and Technology (no. NRF-2014R1A1A3A04051089).

Declaration of interest

The authors report no conflicts of interest. The authors have no proprietary interests in or financial support for the development or marketing of instruments or equipment mentioned in this article or any competing instruments or equipment.

Additional information

Funding

This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), which is funded by the Ministry of Education, Science, and Technology (no. NRF-2014R1A1A3A04051089).