Effects of trabeculectomy on the postoperative central visual field as revealed by refraction values.

PURPOSE: To evaluate the effects of trabeculectomy on the rate of deterioration of the central visual field (VF) in patients with normal-tension glaucoma (NTG), as revealed by refraction values.

STUDY

DESIGN

Retrospective case series.

METHODS

We retrospectively analyzed 28 eyes, including 12 high myopic (spherical equivalent [SE] < - 6 diopters without pathological myopia) and 16 non-high myopic (SE ≥ - 6 diopters) eyes. The rate of VF deterioration (dB/year) was determined using linear regression analysis of 30 -2 and 10 -2 VF tests. The Wilcoxon signed-rank test was used to compare deterioration rates between groups. To assess the influence of initial post-surgery effects, statistical analyses were conducted with and without data from the initial postoperative VF exam.

RESULTS

Trabeculectomy significantly reduced intraocular pressure (IOP) in myopic (14.1 to 9.0 mmHg, P ≤ 0.01) and non-myopic (13.4 to 9.5 mmHg, P ≤ 0.01) eyes. Postoperatively, the 10-2 VF deterioration rate significantly decreased in myopic (- 1.31 to - 0.55 dB/year, P = 0.01) and non-myopic (- 0.80 to - 0.30 dB/year, P = 0.03) eyes. Excluding the first postoperative VF exam, the deterioration rates were - 0.51 ± 0.24 dB/year and - 0.54 ± 0.89 dB/year, respectively, indicating a minor impact on progression assessment.

CONCLUSIONS

Trabeculectomy may mitigate central VF deterioration in myopic NTG patients, emphasizing the potential benefits of timely surgical intervention. Further studies are needed to determine the optimal timing for surgery.