The Effect of Phacoemulsification on Intraocular Pressure in Eyes with Hyperfiltration Following Trabeculectomy: A Prospective Study.

INTRODUCTION: The aim of this study was to evaluate the effect of visually non-significant cataract extraction in patients with hypotony maculopathy and reduced visual acuity due to over-filtering blebs after trabeculectomy.

METHODS: Patients with intraocular pressure (IOP) < 6 mmHg and documented hypotony maculopathy due to over-filtering blebs after trabeculectomy were prospectively recruited. Eligible patients underwent visually non-significant cataract phacoemulsification, no earlier than 12 weeks from the diagnosis of hypotony maculopathy. IOP and visual acuity before and after phacoemulsification were compared at 1 and 3 months from surgery. Correlations between age, time interval between surgeries, baseline IOP, bleb type and IOP and visual acuity changes at 3 months after phacoemulsification were investigated.

RESULTS: From January 2010 to September 2014, 20 consecutive adult patients met the inclusion criteria. Before phacoemulsification, mean IOP was 3.1 ± 1.6 mmHg. Following phacoemulsification, mean IOP increased to 8.6 ± 4.1 mmHg at 1 month (p < 0.01) and to 9.1 ± 4.3 mmHg at 3 months (p < 0.01). IOP elevation following phacoemulsification was observed in 16 of 20 eyes (80%). Mean visual acuity improved from Snellen 0.5 ± 0.1 to 0.6 ± 0.1 at 1 month (p < 0.01) to 0.7 ± 0.2 at 3 months (p < 0.01) after phacoemulsification. In 4 eyes in which the IOP was not elevated, surgical revision of the previous trabeculectomy was performed. No significant correlations between investigated variables, visual acuity and IOP changes at 3 months after phacoemulsification were found.

CONCLUSION: Phacoemulsification of visually non-significant cataract appears to be a safe and effective technique for managing chronic ocular hypotony with deep anterior chamber due to over-filtering blebs.