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Lacritin and Heparanase Levels in Human Tears After Laser Refractive Surgery

21 Years
55 Years
Open (Enrolling)

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Trial Information

Lacritin and Heparanase Levels in Human Tears After Laser Refractive Surgery

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. A recently developed immunoassay for lacritin may help
characterize the lacritin response following refractive surgery with the possible
development of recombinant lacritin as a novel therapeutic agent for wound healing.
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) at the
Walter Reed Center for Refractive Surgery.

Inclusion Criteria:

- Active duty US Army Soldiers eligible for care at WRAMC

- Undergoing PRK or LASIK

- Male or female, of any race, and at least 21 years old and not older than 55 years
old at the time of the tear collection. The lower age limit of 21 years is intended
to ensure documentation of refractive stability.

- Appropriately aged individuals who report that their eyes are "normal" and who have
no active eye illness as determined by the principal investigator or

- Ability and willingness to understand and provide informed consent to participate in
this study.

- Up to -10.00 diopters of myopia.

- Subject must expect to be located in the greater Washington DC area for a 12 month
period post-operatively.

- Consent of the subject's command (active duty) to participate in the study.

- Access to transportation to meet follow-up requirements.

Exclusion Criteria:

- Any reason to be excluded for PRK or LASIK

- Female subjects who are pregnant, breast-feeding or intend to become pregnant during
the study. Female subjects will be given a urine pregnancy test prior to
participating in the study to rule out pregnancy. [Pregnancy and breastfeeding are
contraindications to refractive surgery in general, including PRK, whether
participating in this study or not]

- Patients with known sensitivity or inappropriate responsiveness to any of the
medications used in the post-operative course.

- Any physical or mental impairment that would preclude participation in any of the

- Anterior basement membrane dystrophy

- History of recurrent epithelial erosion

- Significant dry eye (symptomatic with Schirmer <5mm at 5 minutes)

- Other corneal epithelial disorder or healing abnormality

- Individuals with any infectious or inflammatory ocular conditions (e.g. have "pink
eye" or uveitis).

- Individuals diagnosed with dry eye or other ocular surface condition, including but
not restricted to neurotropic keratitis, anterior basement membrane dystrophy, and
recurrent corneal erosions.

Type of Study:


Study Design:

Observational Model: Cohort, Time Perspective: Prospective

Outcome Measure:

The primary outcome measure is tear lacritin levels pre- and post-surgery.

Outcome Time Frame:

pre and standard visits up to 6 months post-surgery

Safety Issue:


Principal Investigator

Kraig S. Bower, MD

Investigator Role:

Principal Investigator

Investigator Affiliation:

Walter Reed Army Medical Center


United States: Federal Government

Study ID:




Start Date:

January 2010

Completion Date:

December 2013

Related Keywords:

  • Myopia
  • Myopia
  • refractive surgery
  • PRK
  • Lacritin
  • Heparanase
  • Myopia



Walter Reed National Military Medical CenterBethesda, Maryland  20889
Fort Belvoir Community HospitalFort Belvoir, Virginia  22060