Abstract
Purpose :
To investigate the progression rate of retinal nerve fiber layer (RNFL) defects of young eyes in comparison with those of old eyes with myopic normal tension glaucoma (NTG).
Methods :
We retrospectively reviewed the serial changes of RNFL defect width in patients with myopic NTG. We included young group as patients under age of 30 and patients over age of 40 as old group, by the age at first examination. We measured the serial circumferential widths of RNFL defect by superimposing the peripapillary scan circle of Cirrus HD-OCT and the serial red-free fundus photographs. We calculated the rate of RNFL defect width progression using the generalized linear model and compared them between the groups.
Results :
The young group had 39 eyes and the old group had 44 eyes, mean age at first examination was 25.5 ± 3.5 and 50.5 ± 6.9 years for the young and old groups, respectively. The spherical equivalent, axial length, tilt ratio, tilt axis, and central corneal thickness between the two groups were comparable (-6.41 ± 2.99 vs -5.37 ± 2.18 D, 26.68 ± 1.24 vs 26.17 ± 0.91 mm, 1.31 ± 0.22 vs 1.38 ± 0.28, 7.3 ± 14.4 vs 11.1 ± 8.3, and 536.2 ± 44.7 vs 534.9 ± 28.2 µm, respectively, all p > 0.05). The young group had higher untreated baseline intraocular pressure (IOP) (16.6 ± 1.9 vs 14.7 ± 2.5 mmHg, p<0.001) but average follow-up IOP with medical treatment (15.0 ± 1.7 vs 14.6 ± 2.2 mmHg, p=0.343) were comparable compared to the old group. Baseline RNFL defect width had no significant difference (33.3 ± 20.3 vs 28.6 ± 23.2, p=0.331), but the change in RNFL defect width was wider (18.5 ± 14.3 vs 5.2 ± 6.4°, p=0.004), and the rate of RNFL defect progression was significantly faster (3.602 ± 3.122 vs 1.095 ± 1.356°/yr, p<0.001) in the young than in the old group.
Conclusions :
Young eyes with myopic NTG showed significantly faster progression rate of RNFL defect width compared to that of old eyes, under comparable follow-up IOP. The pathogenesis of RNFL defect in two groups may be different, regarding myopia-related and age-related glaucomatous damage.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.