iStent plus cataract surgery

Favourable glaucoma outcomes with micro-bypass stent with cataract surgery

Dermot McGrath

Posted: Saturday, June 6, 2020

Colin I Clement PhD, FRANZCO

Implantation of the iStent inject (Glaukos) in combination with cataract surgery significantly and safely reduced intraocular pressure (IOP) and the medication burden in eyes with various types and severities of glaucoma, according to a study presented at the 37th Congress of the ESCRS in Paris.

“This real-world experience from a number of different Australian surgeons augments the existing evidence for iStent inject as a promising and safe treatment option for glaucoma and is the largest multicentre cohort of patients treated with iStent inject to date from the Asia-Pacific region,” said Colin I Clement PhD, FRANZCO, of Sydney Eye Hospital, Australia.

Describing the properties of the iStent inject, Dr Clement said it was a trabecular micro-bypass system made up of two titanium stents for ab interno implantation. The stents, which are just 230 microns in diameter and 360 microns in height, are designed to increase access to collector channels with multiple lateral lumens facilitating aqueous outflow from the anterior chamber.

“The minimal tissue disruption of the stent leaves the natural anatomy intact and preserves the potential for future treatment options,” he said.

Dr Clement presented data from a retrospective case series of 165 eyes of iStent inject procedures combined with phacoemulsification carried out by five different Australian surgeons. The vast majority of patients were primary open angle glaucoma (70%), but other indications included appositional angle-closure, pseudoexfoliative glaucoma and ocular hypertension. Key outcome parameters were IOP reduction, medication use, visual acuity and adverse events.

The mean patient age at baseline was 71.4 years, mean IOP was 18.3 mmHg (± 5.4) and mean medications were 1.7. The severity of the glaucoma was recorded as mild in 70%, moderate in 18% and severe in 12%.

The results showed a statistically significant reduction of 23.2% in mean IOP and a 71.5% reduction in mean medication use from 1.7 to 0.47 after 12 months.

“Overall around 85% of patients had an improvement in their IOP control and a similar majority had a reduction in medications required to reduce their IOP,” said Dr Clement.

There were very few complications overall, with 2 of 165 eyes with incorrectly positioned stents, 2 with corneal oedema, 2 with prolonged anterior chamber inflammation, 1 stent which came in contact with the iris, and 1 case of hyphaema which resolved without treatment.

Overall the visual acuity was 20/40 or better in 97% of patients after surgery at 12 months compared to 93% before surgery. Three eyes went on to have additional glaucoma procedures to reduce their IOP down to target levels.

“The real-world evidence demonstrated significant IOP and medication reduction achieved in various types of glaucoma and the safety profile of the stent was favourable with a low complication rate similar to that following cataract surgery alone,” he concluded.