Corneal health sustained 3 years after iStent inject implantation
Researchers observed no additional risk to corneal endothelial safety beyond that of cataract surgery alone in 3-year data after iStent inject implantation.
This is “particularly relevant in light of concerning ECD outcomes seen with other MIGS devices,” according to a presentation at the virtual American Society of Cataract and Refractive Surgery meeting.
Using data from patients enrolled in the pivotal trial for the iStent inject (Glaukos), Thomas W. Samuelson, MD, and colleagues looked at endothelial eye health after 3 years, as well as patient-reported outcomes (PROs) over the 2-year period of the trial. The iStent inject is a trabecular micro-bypass device consisting of two 0.23 mm diameter titanium stents placed ab interno into Schlemm’s canal.
In the pivotal trial, 505 glaucomatous eyes were randomly assigned 3:1 to a phacoemulsification plus iStent inject arm or a phacoemulsification-only arm. In the current study looking at endothelial cell density (ECD) and endothelial cell loss (ECL), 135 eyes in the inject group and 40 eyes in the cataract surgery group were included.
Mean change in ECD between the two groups at 3 years was neither clinically meaningful nor statistically significant: –12% in the inject group and –14% in the phacoemulsification-only group.
Likewise, when looking at ECL greater than 30%, results favored the inject group at 6.7% of eyes vs. 10% of eyes in the cataract surgery group, again not a clinically meaningful or statistically significant difference, Samuelson said.
In the PRO portion of the study, visual parameters measured by VFQ-25 statistically significantly favored the inject group at 1 month, 6 months and 12 months (P < .05), and although not statistically significant, results favored the inject group at 24 months. Non-visual parameters measured by Ocular Surface Disease Index showed no meaningful difference between the two groups at 1 month, 6 months, 12 months or 24 months.
“But pooling the data over 24 months, it was statistically favorable for the inject group compared to cataract surgery alone,” Samuelson said.
- Samuelson TW. Long-term safety and patient reported outcomes on 2nd generation trabecular micro-bypass stent system. Presented at: American Society of Cataract and Refractive Surgery meeting; May 16-17, 2020 (virtual meeting).