A new use for Intraocular Lenses - antibiotic and other drug-delivery
Posted on 12/06/2006
The results of a study conducted at Prof. David J. Apple’s Salt Lake City laboratory and published this month*, suggest that in future intraocular lenses (IOLs) may be used to do more than simply restore vision: they could be used to deliver doses of antibiotic and anti-inflammatory drugs inside the eye.
The lead researcher Guy Kleinmann MD of the David J Apple, MD Laboratories for Ophthalmic Devices Research at the University of Utah John A. Moran Eye Center evaluated the ability of Rayner lenses to release the antibiotics. Dr Kleinmann pre-soaked C-flex® prior to implantation, using commercially available solutions of gatifloxacin (Zymar) or moxifloxacin (Vigamox). Aqueous humor samples were taken at regular intervals after implantation. A control group had C-flex® implanted which had not been pre-soaked but where at the end of the operation, one drop of Vigamox was applied to the right eye and 1 drop of Zymar to the left eye. The results showed high concentrations of both antibiotics in all eyes implanted with the pre-soaked IOLs. Dr Kleinmann said, “as expected, these antibiotic concentrations decreased over time, but even the 6-hour sample concentrations were markedly higher than the concentrations found in the control after 4 hours. This shows the Rayner C-flex® IOL can be effective as a drug-delivery system for fourth-generation fluoroquinolones, in the early hours post-operation – that is just the time when the eye is at its most vulnerable to infection”.
Speaking at this year’s APAO in Singapore, Professor Apple observed that, “the incidence of endophthalmitis (eye infections) has increased in recent years in patients following routine cataract eye surgery. It is significant that the pre-soaked IOL is producing a more sustained drug effect than conventional drug delivery. The alternative of topical application of antibiotics does not have such a long-lasting effect as getting the drug in via the lens to the eye. These Rayner hydrophilic IOLs are uniquely able to release the antibiotic into the surrounding intraocular environment and so prevent infection. The results suggest a new and important use for hydrophilic lenses which the hydrophobic acrylic, silicone and PMMA IOLs can not match. In the future we will restore vision and simultaneously prevent the intraocular infection, via the IOL.”
*Kleinmann G, Apple DJ, Chew J, Stevens S, Hunter B, Larson S, Mamalis N, Olson RJ. “Hydrophilic acrylic intraocular lens as a drug-delivery system: Pilot study.” J Cataract Refract Surg. 2006 Apr; 32 (4):652-4.