Evaluating the trabecular micro-bypass stent combined with phacoemulsification compared to phacoemulsification alone

The aim of this study was to assess the effect of iStent (trabecular micro-bypass stent) implantation in combination with phacoemulsification on IOP and glaucoma medications and to compare this to the outcome of phacoemulsification alone.

A retrospective consecutive comparative review was undertaken. 131 eyes with ocular hypertension and medically controlled glaucoma underwent phacoemulsification alone (n=78 group I) or combined with gonioscopic-guided implantation of one iStent (n=31, group II) or two iStents (n=22, group III). Patients were assessed at postoperative weeks 1, 3 and 6, and months 3 and 6. Pre- and post-operative measures included visual acuity, IOP and glaucoma medications.

Post-operatively at 6 months, mean IOP decreased from 16.3 mmHg to 14.2 mmHg in group I (p<0.01), from 16.7 mmHg to 15.1 mmHg in group II (p<0.16) and from 17.0 to 13.8 in group III (p=0.05). Mean glaucoma medication decreased from 1.9 to 1.6 in group I (8%, p=0.12), from 2.5 to 0.8 in group II (27%, p=0.04), and from 2.1 to 1.0 in group III (45%, p<0.01).

iStent implantation resulted in similar IOP reduction to phacoemulsification alone but achieved a significantly greater reduction in glaucoma medications. This may improve compliance and quality of life, and reduce health care costs in patients with early to moderate glaucoma.