Steroid-Eluting Contacts Show Promise

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Patients who have difficulty complying with dosing schedules for their corticosteroid eyedrops might one day have an easier time of it, thanks to a steroid-eluting contact lens that is showing promise during preclinical testing.¹

Sandwiched inside a hydrogel contact lens (DexaLens, TherOptix; formerly known as Dex-Lens), a polymer ring containing dexamethasone delivered the medication continuously and effectively onto rabbit corneas for up to seven days.

If these early results are borne out in human stud­ies, the steroid-eluting contact lens “might be able to address any ocular inflammatory condition that you would typically treat with steroids. That includes uve­itis, post-traumatic corneal injury, postcorneal trans­plant inflammation, and postcataract surgery,” said Joseph B. Ciolino, MD, at Massachusetts Eye and Ear/Harvard Medical School in Boston.

Design. The contact lenses that the researchers used are made from methafilcon, a biocompatible hydrogel that is commonly used in bandage contact lenses. Encapsulated in the periphery of the lenses is a ring-shaped dexamethasone-polymer film. The central lens is clear, to allow light into the eye.

Results in rabbits. In a previous animal study, Dr. Ciolino and his colleagues found that the medication released by the contact lens onto the cornea diffused into the posterior segment and was able to inhibit VEGF-induced retinal vascular leakage.²

In this study,¹ the treatment inhibited suture-induced corneal neovascularization and inflammation for seven days and, in a five-day lipopolysaccharide-induced uveitis model, anterior uveitis. These outcomes were “similar to that of hourly-administered dexamethasone eyedrops,” the researchers noted.¹

In a secondary ocular irritation analysis, samples of drug concentration in the test animals’ retinas showed that it peaked two days after lens insertion and aver­aged 4,353 ng/g. That finding compared to an average of 21 ng/g in the retina after administration of eight hourly doses of commercial 1.0% dexamethasone eye­drops.

Cautious optimism. “The steroid-eluting contact lens is a technology that ophthalmologists should consider as a promising potential therapeutic because it can de­liver steroid to the eye in a sustained manner. In doing so, it eliminates patient adherence as part of the treat­ment equation. It may be able to eliminate the need for steroid injections,” Dr. Ciolino said.

However, as he pointed out, “We will have to per­form human studies to better understand whether [the contacts] can be more effective than steroid eyedrops.”

—Linda Roach

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1 Bengani LC et al. Acta Biomater. 2020;116:149-161.

2 Ross AE et al. Biomaterials. 2019;217:119285.

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Relevant financial disclosures—Dr. Ciolino: TherOptix: C,O,P.

For full disclosures and the disclosure key, see below.

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