Thirty-Six-Month Multicentre Outcomes of Combined Phacoemulsification and Hydrus Microstent Implantation in Eyes With Normal Tension Glaucoma.

PRECIS: This retrospective multicentre study of 77 NTG eyes undergoing phacoemulsification and Hydrus implantation showed a sustained reduction in medication burden, while maintaining IOP levels. Complications were rare and nonsight-threatening.

PURPOSE: To evaluate 36-month outcomes of combined phacoemulsification and Hydrus Microstent implantation (Phaco-Hydrus) in eyes with normal tension glaucoma (NTG).

METHODS

This multicentre retrospective study included 77 NTG eyes from Singapore and Canada that underwent Phaco-Hydrus between 2014 and 2023. Primary outcomes were changes in intraocular pressure (IOP) and medication burden, and cumulative success probabilities from Kaplan-Meier (KM) analyses. Longitudinal changes were analysed using generalized estimating equations.

RESULTS

Of 77 eyes, 31 completed 36 months of follow-up. Mean baseline IOP and medications was 13.5±2.5 mm Hg and 1.7±0.9, respectively. No significant reductions in IOP were observed. A sustained reduction in medication use was observed at all follow-up timepoints ( P ≤0.001). At 36 months, medication use decreased by -0.7±0.2 [adjusted mean difference±SE of the mean [SEM]]. Proportion of medication-free eyes increased from 7.8% (n=6/77) at baseline to 45.2% (n=14/31) at 36 months. Cumulative success probabilities varied widely based on definitions. When defined as a decrease in ≥1 medication from baseline without an increase in IOP, or IOP ≤15 mm Hg and reduced ≥20% from baseline while medication-free, and no additional laser or incisional glaucoma surgery, this was 40.7% at 36 months. No visual field mean deviation progression was detected. Adverse events were infrequent and nonsight-threatening.

CONCLUSION

In eyes with NTG, Phaco-Hydrus may offer a greater role in medication reduction or achieving a medication-free status over 36 months, rather than absolute IOP reduction.