Importantly, we found that overexpression of BDNF reduced vision loss following sustained IOP elevation (
Figs. 3B,
3C). Before OHT was induced in the right eyes, the baseline acuity of BDNF_OE mice was 0.42 ± 0.02 cyc/deg (
n = 35), comparable to that of their left eyes (0.43 ± 0.02 cyc/deg,
n = 35). At 1 month post IOP elevation, the mean acuity of right eyes was 0.39 ± 0.04 cyc/deg (
n = 13), significantly higher than in the OHT eyes from the control group (0.31 ± 0.09 cyc/deg,
P < 0.001, 2-way ANOVA, Tukey's posttest,
Fig. 3B). At 2 months post IOP elevation, the acuity of right OHT eyes from BDNF_OE mice was reduced 17% (0.35 ± 0.08 cyc/deg of right eyes versus 0.42 ± 0.02 cyc/deg of left eyes,
n = 39), while the mean acuity of OHT eyes in control mice fell by 35% (
n = 25,
Figs. 3B,
3C). More than 50% of the OHT eyes of control mice (17 out of 25 mice) had acuities below 0.30 cyc/deg, while only 15% of the OHT eyes from BDNF_OE mice (6 out of 39 mice) showed similarly low acuities (
Fig. 3C). By 6 months following chronic IOP elevation, the mean acuity of OHT eyes of control mice had decreased from 0.43 ± 0.01 to 0.19 ± 0.03 cyc/deg (
n = 11), whereas the mean acuity of OHT eyes of BDNF_OE mice decreased only from 0.42 ± 0.01 to 0.33 ± 0.02 cyc/deg (
n = 10,
P < 0.001, 2-way ANOVA, Tukey's posttest,
Fig. 3B). In other words, even though overexpression of BDNF did not eliminate a reduction in visual acuity, it helped to preserve acuity in mice with OHT.