Long-term visual field progression after Ex-PRESS implantation versus trabeculectomy in refractory glaucoma

To compare the long-term visual field progression between Ex-PRESS® filtration surgery and trabeculectomy in patients with medically uncontrolled glaucoma, focusing on functional outcomes rather than intraocular pressure (IOP) alone.

We retrospectively analyzed the cases of 109 eyes (Ex-PRESS: 51; trabeculectomy: 58) followed for ≥ 3 years at a single tertiary center. Eyes requiring additional glaucoma surgery within 36 months were excluded. Visual fields were assessed using Humphrey 24-2/30-2 or AP-7700 equivalent programs. Progression was quantified using the mean deviation (MD) slope (dB/year). We used a linear mixed-effects model with random intercepts for patients and eyes to compare visual field progression, adjusting for baseline factors (age, sex, BMI, SBP, baseline IOP, baseline MD, visual field program) and postoperative parameters (mean IOP, IOP fluctuation).

Baseline age and pseudophakia were higher in the Ex-PRESS group, but postoperative IOP was comparable between groups (Ex-PRESS: 11.8 ± 2.6 mmHg; trabeculectomy: 11.4 ± 3.0 mmHg). Adjusted MD slopes were - 0.20 dB/year (95% CI - 0.35 to - 0.06) for Ex-PRESS and - 0.15 dB/year (95% CI - 0.28 to - 0.02) for trabeculectomy (p = 0.59). Subgroup analyses of 24-2/30-2 and 10-2 fields yielded consistent results. Diastolic blood pressure showed a weak correlation with the MD slope, but this was nonsignificant in a multivariable analysis.

Among eyes that remained free from reoperation during the first 36 postoperative months, no significant difference in long-term visual field progression was detected between Ex-PRESS implantation and trabeculectomy after statistical adjustment. Under well-controlled postoperative IOP conditions, non-IOP vascular factors may contribute to residual visual field progression. These findings contribute to the limited evidence regarding long-term visual field outcomes after Ex-PRESS implantation.