Rate of Progression Among Different Age Groups in Glaucoma With High Myopia: A 10-Year Follow-Up Cohort Study.

PURPOSE

To investigate the rate of structural and functional progression in different age groups of highly myopic glaucoma patients and identify risk factors associated with rate of change in functional parameters.

DESIGN

Retrospective clinical cohort study.

METHODS

This study included open-angle, normal-tension glaucoma (NTG) patients with high myopia who had been followed-up for at least 8 years. Patients were divided into two age groups, "younger (under age 40)" and "older (age 40 or over)," according to their age at presentation, and progression rates for visual field index (VFI), mean deviation (MD) and peripapillary retinal nerve fiber layer (RNFL) thickness were evaluated. Intergroup comparison was performed, and associations between age and progression rates for structural and functional parameters were assessed by scatter plots with linear regression and locally weighted scatterplot smoothing. Cox proportional hazards modeling was performed to identify factors for progression rate of functional parameters.

RESULTS

A total of 320 eyes of 320 highly myopic NTG patients (mean age at presentation, 38.7 ± 10.4 years) were included in this study with a mean follow-up duration of 13.1 ± 6.2 years. The rate of VFI, MD, and RNFL thickness change showed a positive correlation with the age at presentation (P = .013, .002, and .003, respectively). The mean rate of MD change was -0.36 ± 0.39 dB/year in younger age group and -0.22 ± 0.27 dB/year in older age group (P < .01). In the locally weighted scatterplot, the rate of change in VFI, MD, and RNFL thickness showed a fast-progressing pattern in those aged 19 to 29 years and 40 to 49 years, and a slow-progressing pattern in those aged 30 to 39 years and 50 years or older. Baseline IOP (β= -0.041; 95% CIs, -0.139-0.413; P = .047) and baseline VFI (β= 0.364; 95% CIs, 0.247-0.461; P < .01) was significantly related to the VF MD change rate.

CONCLUSIONS

The glaucoma progression rate in highly myopic NTG showed a bimodal pattern based on the age at presentation, younger patients exhibiting faster progression compared to older patients. Baseline IOP and VFI were significantly related to functional progression rate. The findings of this study may assist in deciding the treatment strategy for highly myopic NTG patients.