Abstract
Purpose :
To assess the ability of the contact lenses to lower the intraocular pressure (IOP) in the hypertensive eye of cynomolgus monkeys with unilateral laser induced glaucoma. IOP reduction with the contact lenses was also compared to that achieved with daily 0.005% latanoprost drops.
Methods :
Low dose (CLLO) and high dose (CLHI) latanoprost eluting contact lenses were produced by encapsulating a thin latanoprost-polymer film within the periphery of a methafilcon hydrogel, which was lathed into a contact lens. In this one-sample crossover study, we assessed the IOP lowering effect of CLLO, CLHI, or daily latanoprost drops in a single eye in the same four female monkeys. Each monkey consecutively received 1 week of continuous wear CLLO, 3 weeks without treatment, 5 days of latanoprost drops, 3 weeks without treatment, and 1 week of continuous wear CLHI. Prior to the initiation of each treatment, the IOP of the untreated eyes was measured hourly over the course of 7 hours (from 9:30 AM to 3:30 PM) to serve as the baseline IOP to which measurements obtained during the subsequent treatments were compared. Two-tailed paired t-tests were used for statistical analysis, and p<.05 was considered statistically significant.
Results :
Latanoprost drops resulted in IOP reduction (mean±SD) of 16±2% and 21±2 % on days 3 and 5. CLLO reduced IOP by 18±4%, 20±7%, and 18±10% on days 3, 5, and 8 respectively. CLHI lowered IOP by 32+1%, 35+1%, 37+2% on days 3, 5, and 8 respectively. In all three treatment groups, the IOP was significantly reduced compared to the untreated baseline at all time points measured. There was no difference in IOPs when comparing CLLO and drops (p>0.05) or CLHI and CLLO (p >0.05). On the last day of treatment for the CLhi and latanoprost drops, the CLhi lowered IOP more than the drops (p<0.05) at many time points.
Conclusions :
Sustained delivery of latanoprost by contact lenses is at least as effective, and possibly more so, than daily topical application of the FDA approved, clinically used, latanoprost eye drops. More research is needed to determine the optimal continuous release dose that would be well tolerated and maximally effective. Contact lens drug delivery may become an option for the treatment of glaucoma and a platform for ocular drug delivery.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.