Levels of the Novel Glycoprotein Lacritin in Human Tears After Laser Refractive Surgery
Annual rept. 28 Sep 2012-27 Sep 2013
HENRY M JACKSON FOUNDATION FOR THE ADVANCEMENT OF MILITARY MEDICINE BETHESDA MD
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Lacritin is a naturally occurring tear protein with antimicrobial activity that is capable of stimulating mitogenesis in human corneal epithelial cells and promoting production of tears in lacrimal gland acinar cells. Heparanase HPSE acts as a regulator for lacritin by cleaving heparan sulfate chains and allowing lacritin to bind. We aim to measure both tear lacritin and HPSE pre- and post-operatively to elucidate lacritin and HPSE s response in patients undergoing PRK photorefractive keratectomy and LASIK Laser-assisted in situ keratomileusis with the possibility of the development of recombinant lacritin as a novel therapeutic agent for wound healing. Up to 196 patients eligible to undergo PRK or LASIK at the Warfighter Refractive Surgery and Research Center at Fort Belvoir will be consecutively recruited 98 PRK 49male49female and 98 LASIK 49male49 female. Tears will be collected using a safe and established method at the pre-operative visit and at 1 day, 1 week, 1, 3 and 6 months post-operatively to quantify tear lacritin and HPSE. Study design will allow for within subject comparison of lacritin and HPSE before and after surgery as well as comparison of responses between procedures PRK vs. LASIK. The primary outcome measure is tear lacritin levels pre- and post-surgery. The secondary outcome is tear HPSE levels pre-and post-surgery. Preliminary data in PRK participants shows there is a significant difference in lacritin levels within in the early postoperative period and between surgical procedures. It is unknown whether such differences would have a meaningful impact on visual outcomes or optical quality. Based on the PRK study results to date, there is no correlation. Ongoing testing in this study will help determine if there is a difference in lacritin levels in participants undergoing LASIK as well as if lacritin concentrations affect early and long-term optical quality and visual outcomes in PRK and LASIK participants.
- Medicine and Medical Research