Clinical and Anterior Segment OCT Predictors of Intraocular Pressure After Phacoemulsification in Eyes With Prior Trabeculectomy.

PRCIS: Lower preoperative IOP, greater bleb height, and a shorter trabeculectomy-to-phacoemulsification interval are associated with greater postoperative IOP elevation in eyes with prior trabeculectomy.

PURPOSE: To identify clinical factors and filtering bleb morphologic features associated with intraocular pressure (IOP) changes after phacoemulsification in eyes with prior trabeculectomy.

PATIENTS AND

METHODS

This retrospective, consecutive case series included 76 eyes of 71 Japanese patients who underwent phacoemulsification following primary trabeculectomy. Bleb morphology was evaluated preoperatively using 3-dimensional anterior segment optical coherence tomography (AS-OCT). The primary outcome was the change in IOP from baseline to 1 year after phacoemulsification. Associations between IOP change and prephacoemulsification AS-OCT parameters and clinical variables were assessed. For categorical analyses, eyes exhibiting both an IOP increase of >2 mm Hg and a percentage IOP increase of >20% at 1 year were classified into the IOP increase group; the remaining eyes constituted the no IOP increase group.

RESULTS

Fifty-one eyes were assigned to the no IOP increase group and 25 eyes to the IOP increase group. Prephacoemulsification IOP differed significantly between the groups ( P =0.037). A shorter interval from trabeculectomy to phacoemulsification ( rs =-0.320, P =0.005), lower prephacoemulsification IOP ( rs =-0.424, P <0.001), and greater maximum bleb height ( rs =0.284, P =0.013) were significantly associated with a larger IOP increase. Multivariable linear regression confirmed independent associations of IOP change with the interval ( P =0.005), prephacoemulsification IOP ( P =0.003), and maximum bleb height ( P =0.022).

CONCLUSIONS

IOP elevation after phacoemulsification in post-trabeculectomy eyes was associated with lower IOP and greater bleb height before phacoemulsification, and with a shorter trabeculectomy-phacoemulsification interval.