Abstract
Purpose: :
Current treatment options for dry eye syndrome include multiple doses of topical anti-inflammatory drugs. To evaluate the effectiveness of a single iontophoretic dose of a corticosteroid for treating Concanavalin A (Con A) induced dry eye in rabbits.
Methods: :
300 µg of Con A or saline were injected into the lacrimal glands of white New Zealand rabbits to induce inflammation, which is a well-established model of dry eye syndrome. 48 hours after Con A injection, the rabbits received a single iontophoretic dose of dexamethasone phosphate or saline using the EyeGate II device; a 3 mA current was applied for 5 minutes. The tear flow was measured with Schrimer strips and ocular surface damage was assessed by fluorescein staining followed by slit lamp microscopy. As indicators of inflammation, interleukin-1-beta (IL-1β) and transforming growth factor beta-1 (TGF-β1) in the lacrimal gland and cornea of rabbits were measured by ELISA.
Results: :
Injection of Con A into the lacrimal gland of rabbit eyes significantly decreased tear volumes, substantially increased ocular surface damage for up to 8 days when compared to animals injected with saline, and significantly increased IL-1β and TGF-β1 production in the lacrimal glands at the two measured time points (days 4 and 8) post Con A injection. A single iontophoretic dose of dexamethasone phosphate 48 hours after Con A injection significantly increased tear volume and reduced ocular surface damage when compared to control animals that received Con A injection and iontophoretic treatment with saline. In addition, the single iontophoretic dose of dexamethasone phosphate decreased IL-1β 2.5-fold and TGF-β1 1.5-fold in the lacrimal glands 48 hours post treatment when compared to rabbits treated with an iontophoretic dose of saline.
Conclusions: :
These data indicate that a single iontophoretic administration of dexamethasone phosphate significantly reduces lacrimal gland inflammation and the symptoms associated with Con A induced dry eye in rabbits.
Keywords: cornea: tears/tear film/dry eye • corticosteroids • lacrimal gland