Investigators may have taken a vital step toward ditching eye drops, according to research published in Drug Delivery and Translational Research.1 In the hunt for prolonged, effective drug delivery alternatives, one team found success with an ocular insert for the controlled delivery of moxifloxacin in rabbit corneas. This insert could, hypothetically, be used to treat conditions such as corneal keratitis or bacterial endophthalmitis, the study suggests.

"We lose about 90% of the volume of an eye drop in the eye within minutes and in cases of bacterial keratitis we find we have to recommend q30 min or q1h dosing and patients are just not compliant,” explains Paul Karpecki, OD. “Any drug delivery system that increases concentration in the cornea and anterior chamber, or can penetrate further in the eye, will have greater utility and likely help with compliance."

The insert is made from a thin bio-adhesive polymeric material to allow moxifloxacin to permeate the cornea, sidestepping the nuisance of patient compliance issues. It “provided higher ocular diffusion than commercial formulations,” according to the study. It was tested on both fresh and frozen rabbit corneas.

“For patients with corneal infections who are not improving, I always question compliance,” says Mitch Ibach, OD, a Cornea, Glaucoma, Cataract, and Refractive Surgery Specialist at Vance Thompson Vision in Sioux Falls, SD. “This could be a big deal if it allows microbes to be taken down faster.”

Over the years, eye doctors and industry alike have tried countless methods to improve patient compliance with topical treatment—everything from sustained-release wafers to specially designed drop dispensers and smartphone reminder apps. Still, research shows that most patients admit to noncompliance.A majority of glaucoma patients simply cease using their medications within six months, according to the American Journal of Ophthalmology.3 In postoperative cataract care, compounded pharmaceuticals are allowing surgeons to reduce dependence on topical therapies, lessening the impact of patient compliance on outcomes.

1. Sebastián-Morelló M, Aracely Calatayud-Pascual M, Rodilla V, et al. Ex vivo rabbit cornea diffusion studies with a soluble insert of moxifloxacin. Drug Delivery and Transitional Research. 2018;8(1):132-9.
2. National Community Pharmacists Association Web site. Take As Directed: A Prescription Not Followed. December 15, 2006. Accessed April 17, 2018.
3. Nordstrom B, Friedman D, Mozaffari E, et al. Persistence and adherence with topical glaucoma therapy. Am J Ophthalmol. 2005;140(4):598-606.