Background Goniosynechialysis (GSL) to remove peripheral anterior synechiae (PAS) alongside standard cataract surgery has potential theoretical advantages, Published randomised trials, however, have not shown conclusive functional benefits and aqueous outflow changes following GSL are unknown. This study aimed to compare electronic Shiøtz tonographic aqueous outflow facility (TOF) following phacoemulsification with or without GSL in patients with primary angle closure (PAC) and PAC glaucoma. Secondary outcomes were changes in intraocular pressure (IOP) and use of glaucoma medications.

Methods Prospective randomised pilot study of 26 patients on glaucoma medication, with ≥90° PAS and significant lens opacity. Patients were randomised 1:1 to receive phacoemulsification with intraocular lens (IOL) implantation only (phaco) or phacoemulsification with IOL plus GSL (phaco-GSL).

Results Fourteen patients were randomised to phaco-GSL and 12 to phaco alone. TOF increased with phaco-GSL from 0.099±0.07 μL/min/mm Hg to 0.194±0.07, μL/min/mm Hg, p=0.0006, while the phaco group showed no significant change. IOP reduced in both groups, but reduced significantly more following phaco-GSL (46.0%) compared with phaco alone (27.6%, p=0.04). Medication use and extent of PAS only reduced with phaco-GSL, from 0.923±0.86 to 0.384±0.18 medications, p=0.0279, and from 249.2±83.4 to 110.8±53.9° PAS, 6 months postoperatively. No serious adverse events occurred in either group.

Conclusions Eyes randomised to both surgical groups had similar and good outcomes at 6 months in this pilot study. However, only eyes undergoing GSL combined with standard phacoemulsification had significantly increased TOF, reduced glaucoma medication dependence and PAS postoperatively. GSL should therefore be considered in such patients.

Trial registration number: NCT00719290, Results.