Long-Term Outcomes Of Two First-Generation Trabecular Micro-Bypass Stents (Istent) With Phacoemulsification In Primary Open-Angle Glaucoma: Eight-Year Results

The short- and medium-term outcomes of two first-generation trabecular micro-bypass stents (iStent) have been extensively studied; however, only few studies have investigated its long-term outcomes. Here, we assessed the long-term efficacy and safety of two iStents with concomitant cataract surgery in eyes with primary open-angle glaucoma (POAG) while also evaluating measures of disease stability using visual field and optical coherence tomography (OCT) of the optic nerve and the macula throughout 8 years of follow-up.

 

A longitudinal, single-center consecutive case series.

 

Glaucomatous eyes that underwent implantation of two first-generation trabecular micro-bypass stents (iStent) with concomitant cataract surgery were included. Eight-year efficacy outcomes included mean intraocular pressure (IOP) and medications, as well as surgical success. Safety outcomes included best-corrected visual acuity (BCVA), visual field mean deviation (VF-MD), cup-to-disc ratio (CDR), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness, and adverse events.

 

A total of 62 POAG eyes were included. At 8 years postoperative, IOP reduced by 26% from 19.2±3.9 mmHg preoperatively to 14.2±2.4 mmHg (P < 0.001), 91.1% of eyes achieved IOP ≤ 18 mmHg (vs. 51.6% preoperatively), 69.6% of eyes achieved IOP ≤ 15 mmHg (vs. 14.5% preoperatively), and 25% of eyes achieved IOP ≤ 12 mmHg (vs. 1.6% preoperatively). Medication use decreased by 17.9% from 2.8 ± 1.1 preoperatively to 2.3±1.2 (P = 0.018). Surgical success was 90%, as 6 eyes underwent subsequent glaucoma surgeries. Safety measures of BCVA, CDR, RNFL thickness and GC-IPL thickness remained stable through 8 years. VF-MD remained stable until postoperative year 5 and subsequently progressed according to the natural history of glaucomatous disease.