Phakic or Pseudophakic OAG Subjects Implanted With 2 Trabecular Bypass Stents: 18-Month Findings
Narrative Responses:
Purpose
Evaluate long-term outcomes in subjects with open angle glaucoma (OAG) not controlled on one ocular hypotensive medication after micro-invasive glaucoma surgery (MIGS) involving implantation of two trabecular micro-bypass stents in a single procedure by the MIGS Study Group.
Methods
This study enrolled phakic or pseudophakic OAG subjects not controlled on one medication, with CD ratio ≤ 0.95 and IOP ≥ 18 mmHg and ≤ 30 mmHg. Thirty-nine qualified subjects with IOP ≥ 22 mmHg and ≤ 38 mmHg after medication washout were implanted with two trabecular bypass stents (iStent®). Ocular hypotensive medication was prescribed if postoperative IOP exceeded 21 mmHg. Safety assessment included fundus /optic nerve evaluation, slit-lamp findings, BCVA, and complications/adverse events. Efficacy endpoints at Month 12 included unmedicated IOP reduction ≥ 20% vs. baseline and unmedicated IOP ≤ 18 mmHg. Postop follow-up through 5 years is ongoing.
Results
To date, 34 subjects have been followed through 18 months. Mean preoperative medicated IOP was 20.6 mmHg (SD 2.0); unmedicated (baseline) IOP was 24.1 mmHg (SD 1.4). Postop mean IOP was 14.2 mmHg (SD 3.4) at 1 month, 13.2 mmHg (SD 1.5) at 6 months, 13.5 mmHg (SD 1.8) at 12 months and 13.7 mmHg (SD 2.0) at 18 months. At Month 12, 36 of 39 subjects had IOP reduction ≥ 20% and IOP ≤ 18 mmHg without medication; 3 of 39 subjects were on medications. One subject experienced a small hyphema at week postoperative that resolved by one month.
Conclusion
Micro-invasive glaucoma surgery (MIGS) to implant two trabecular stents in this series of phakic or pseudophakic OAG subjects not controlled on medication resulted in significant reduction in mean postoperative IOP to ≤ 14 mmHg through 18 months, significant reduction in medication burden, and a favorable safety profile.