Drug Eluting Contact Lenses For The Treatment Of Glaucoma

Abstract

Purpose: : To report the in vivo and in vitro testing of a latanoprost-eluting contact lens designed for the treatment of glaucoma.

Methods: : Drug-eluting therapeutic contact lenses (TCL) were created by encapsulating latanoprost-Poly(lactic-co-glycolic acid) films in methafilcon A by ultraviolet light polymerization. TCLs (n=4) were placed in 5 mL of phosphate buffered saline at 37°C with continuous rotation (64 RPM). The release media was sampled and changed daily. Drug concentrations were measured with an enzyme-linked immunosorbent assay (ELISA). TCLs were inserted on the left eye of New Zealand white rabbits (n=3) for 10 days. The eyes were examined under an operating microscope and the anterior chamber (AC) fluid was collected during 1, 3, 5, 7, 10, and 14 days of continuous wear. Latanoprost 0.005% solution (drops) was topically applied to rabbit eyes and the AC fluid was sampled at the following times after drop administration (1, 3, 6, 12, and 24 hrs). Each sample was collected on a different day and the AC drug concentration was measured by ELISA. The 24-hr area under the curve (AUC) for latanoprost drops was calculated and compared to the AC concentration measured during 14 days of TCL wear.

Results: : In vitro, TCLs demonstrated an initial burst and then eluted a sustained and therapeutic daily amount of latanoprost for 4 weeks. In vivo, the TCLs demonstrated no signs of toxicity. Through 14 days of continuous wear, TCLs delivered more drug to the anterior chamber each day than latanoprost drops.

Conclusions: : This contact lens design can potentially be used as a treatment for glaucoma and as a platform for ocular drug delivery with widespread applications.

Keywords: contact lens • clinical laboratory testing • intraocular pressure