Non-invasive punctal plug delivery system offers a host of positive performance characteristics
System delivers predetermined drug dosage directly to tear film, improving retention rates
In phase II testing, the latanoprost-loaded punctal plug provided 5 mm Hg to 5.5 mm Hg IOP-lowering over the study’s 12-week duration. The decision for transitioning to development of a travoprost-loaded system was based on the fact that travoprost is more potent than latanoprost and so has the potential to provide even greater IOP-lowering.
“Relative potency is an important consideration when delivering a very low concentration of medication,” Muller said. “In animal models of glaucoma, we found that compared with latanoprost, a travoprost plug was associated with an additional 1.5 mm Hg to 2 mm Hg of IOP lowering.”
Safe and high satisfaction
Data from clinical trials also show that the device was safe and met with high patient satisfaction.
Patients were asked to rate comfort on a visual analogue scale of 0 (best) to 100 (worst). Mean scores at baseline were typically 18 or 19, increased a few points in the first week after device insertion, and then returned to baseline.
“Even though the device sits in the punctum, epiphora was not a problem,” Butchofsky explained. “If anything, patients may feel their eyes are more comfortable after the plug is placed because of improved tear retention.
“In the associated patient demographic, the majority of patients are likely to have mild-to-moderate dry eye and feel the benefit of the improved tear retention. When the study was completed, patients stated they preferred the device over conventional drops and were disappointed to have to return to using their previous therapy,” he added.
Butchofsky pointed out that he has worn the plug for one year.
“Other than experiencing a mild foreign body sensation transiently after insertion, I have no real awareness that the plug is present, and it seems to be virtually impossible to dislodge despite eye rubbing,” he said.